I'm wanting to put an acoustic wall on the back wall of my dedicated home theatre. I've decided to allow 5.5 inches of framing, ie. 2x6 construction. I've heard of mixing insulations, available easily is Rockwool Safe N Sound and Comfortboard 80. Would it make sense to do a 3" Safe N Sound @ 2.5lb density and then go over top of it with the semi rigid Comfortboard 80 8lb density? Looking for some ideas.

Hi all,

I'm a newbie and need your help for rebuilding the PSU of my Counterpoint SA-5.1. This is what I'm talking about:



And this is the schematics for it. Remember, Counterpoint schematics are known to be different then what is really inside. That's the beauty of owning a Counterpoint



My starting point was to replace the first 100uf cap with a smaller value cap due to recommendations of Counterpoint experts here. As you see in the schematics, that cap is the first cap after the 6CA4 rectifier, and exceeds the datasheet values of 6CA4 tubes. Searching for a cap is slippery surface when you have little criterias. At some point I decided to use a film cap at due to the small PSU chassis of SA-5.1 I decided to built a new one from the beginning. This is the original PCB of the PSU. It had some works on it, left from the previous owners:



I'm lucky enough to have a new designed PSU board by our member Pars. He made some corrections to the original design. I'm planing to use this board on my rebuilt:



In my built I'll use a bigger chassis than this one, so I'll have plenty of place.

One of the changes I'm planning is the circuity at the main power switch. SA-5.1 is always on, to keep the heaters powered whenever the preamp is plugged in. The power switch controls the power to the heater on the rectifier tube only, which then powers up the HV section, and turns the preamp on. Our member VivaVee and Pars suggested a delay circuit which will turn on the heater immediately and HV section after a delay. VivaVee also suggested the Morgan Jones book but I'd be glad to hear any more help.

I'll change the electrolytic capacitors to film caps, add a IEC plug to the back. I may consider to omit the PCB and convert it to a point-to-point wiring, but I'm not experienced enough to do that.

Since there is a big transformer along with a 6AC4 tube in this case I want to add a thick enough case on the xfrmr to shield it. BTW, I'll use a Plitron toroidal xfrmr in the new PSU. I ordered Ott's book and looking for a bargain copy of Morrison's book.

Ok, let this be a start to the topic. I hope the helpful people on this forum join to this conversation.

Regards,

hi gang hope you can help me out,

just built an Ian Canada streamer set up with moode.

Using Mconnect to send Tidal and Qobuz and it is only seeing 44.1 on the display no matter what the sample rate is, this is confirmed on my ares2.

anyone else had this problem??

cheers

Dan

Hi guys,

Can anyone help me what type number both switches are? They are extremely rusted. They need a change unfortunately.
Looks like one is a single channel switch, the other is a dual channel switch.

Thanks!!

Basic question, can you safely remove the speaker foam protection around the basket? The one that allow you to safely rest the pa driver downside. It looks like some sort of cardboard underneath, maybe glue dried?
Thanks!

I wanted to share with you all my (mostly) completed pre-amp. I hope this is allowed and adds a unique implementation of the PGA2310 volume control to the forum. This project was inspired by Mark Hennessy’s great design (details here: https://www.markhennessy.co.uk/preamp/). I modified the design to better suit my much less ambitious needs. I also made a full embrace of surface mount technology and leveraged more advanced chips where convenient. This project started literally about 10 years ago (my last post was asking for some explanation of Mark's design) and I got it to 95% complete last year. Image are below. I have a video, but seems I can't upload it.

Volume Control
Like Mark, I based my design on the TI PGA2310 digital volume control with input and output buffers based on the OPA2134 and NE5332. The PGA2310 is the only IC in my design that utilizes a DIP package and that's because I was able to get free samples from TI and the DIP was somewhat better for my layout. On the buffers, I used SMD resistors and capacitors with impunity (except for the large coupling caps on the output). The SMD capacitors were all PPS capacitors as a very smart designer told me that these are appropriate for signal pathways. These are pretty fragile to solder manually, but I used reflow techniques and it was totally fine.

Source Selection
I didn't have crazy needs, just wanted to switch between my iPod, laptop, and desktop. I was originally planning on making one input a USB input for the iPod and using the MCU to do play/pause/etc. But, as the development phase outlived the iPod, that feature quickly got axed. In the end, I settled on two unbalanced RCA inputs and one balanced mini-XLR input (using the INA1650 as a balanced line receiver). The much reduced source number was also driven by a desire for a smaller PCB and a desire to have fewer than 7 push buttons (for programming reasons). On the output side, there is a line out and a variable out.

The sources are selected using Panasonic TQ2 SMD relays. These are small, SMD, and designed for telecom, so I hoped they would be okay for audio. I can't tell the difference! There's 3 for each input and 1 for the variable out.

If the SSM2404 were still around, you can bet I would have used those.

Power
Unlike Mark, I fully embraced modern voltage regulators and again, chased after those SMD packages. The digital side is powered at 5V by an ADM7150 LDO. The analog side is powered by the TPS7A39 bipolar LDO at +/-15V. The TPS7A39 was quite annoying to solder. I was lazy about fixing the footprint to ensure that it was in compliance with the board house design rules and had a shorting issue on an early design. This IC is also the one component that necessitated reflow (though I prefer reflow anyway as the board isn't full of flux residue after I'm done populating) because it has an exposed pad. During the pandemic, this IC was also hit hard by the supply chain issues. My suspicion was that it was initially designed for automotive applications and those suppliers were snatching up all the supply. I'm currently using a part that was salvaged from an earlier prototype. That's how desperate I was to get the part (I asked around a lot... even asked friends in China to help me find some off Alibaba). However, I couldn't find any alternate bipolar regulator that was this small and fit my needs, so I stuck with it.

In Mark's design, he had a separate supply just for the relays. I couldn't fathom a non-paranoid reason for that, so I just went with the 5V version of the TQ2 relays and powered them off the digital.

I also had another small LT1761 LDO at 5V to power my relay delay (more on that below). I could have used the digital 5V, but it would have led to a lot of segmentation of my power plane, so I decided against it.

In terms of grounding, I originally tried to follow the PGA2310 data sheet and have separate analog and digital grounds, but that became really annoying because I had to route a 5V return in the analog region for the un-mute relay. In the end, I decided just having a large continuous ground plane was good enough for me, no need to get hyper paranoid.

I also built un-regulated power supplies using Talema PCB mount toroidal transformers (these were Amveco when I started my project) to rectify and step-down the wall AC.

Relay delay/power supervisor
Mark uses a really complicated turn-on delay and voltage drop detection circuit based upon FETs and caps. I thought I figured it out enough to implement it in my different setting, but just couldn't get it working reliably. I ended up using a TPS3839 to monitor the input voltage to the LT1761. It also has a 200ms delayed turn on for the monitored voltage. When this voltage drops, it will open a TPS22860 switch that powers the un-mute relay. So, when the power droops, the output should be muted, protecting downstream components. I've not tested this, but hopefully it works. Get real. I'm lucky enough to live in an area with reliable enough power.

MCU
I settled on the PIC16F886. I didn't need all of the extra pins on the PIC16F887 that Mark uses in his design. I used a similar trick for the button detection where I used the ADC and a voltage ladder. I was all about hyper efficiency, so I designed the ladder to use the 3 MSB and those are added to the PCL to determine a destination. That was another reason I ended up with only 3 inputs (because I was also planning an un-mute, play-pause, and perhaps another button).

The "interface" is driven solely by an optical rotary with integrated pushbutton and the three source selection buttons. Currently, I only have source selection and volume control programmed. The push button is used to toggle the display on or off since it's so bright and I don't want burn in.

The SPI peripheral on the MCU is used to control the source selection relays, the input button indicator lights, and program the VFD. I had planned to use the UART peripheral to control the iPod, but we all know how relevant that is these days.

The firmware is in PIC assembly like on Mark's design. I had to download an old version of MPLAB to get the MPASM compiler. It was a fun learning experience.

Display
For the display, I chose the Noritake-Itron GU140x16G-7003B. I don't even know if this model has been officially released since. When I bought the VFD, the SPI version had been announced but not formally released. I emailed Noritake and inquired about it and was able to execute a transaction over email. I'm glad I was finally able to use that display because when I bought it, I was a poor student and it was an expensive purchase.

Layout
As you'll see from the images, I kept most of the design on a single PCB. There are separate PCBs for each of the unregulated power supplies and a glorified breakout board for the front panel. Other than the front panel PCB, they're all four layer boards.

Enclosure
I designed an enclosure around the extruded aluminum case used by the Mercury Helios 3S. I found a pair of discarded enclosures in the trash and knew these would be perfect. Currently, the case design makes liberal use of acrylic since that was cheap and easy to cut on a laser cutter. Eventually I would like to make some proper front and back panels using aluminum, but I'm too cheap and not motivated enough right now. It'd also be nice to have an actual window over the VFD.

Testing
No, I haven't bothered doing quantitative testing. I'm too lazy to make an adapter for BNC to RCA and find a function generator and spectrum analyzer or scope. And then if I wanted to test cross talk I'd need a second function generator? And if I wanted to check phase offsets between the L/R channel I'd need a network analyzer? No thanks. It sounds fine on my speakers. Good enough for me.

Next steps

• The firmware doesn't catch all of the rotations of the rotary encoder if it is rotated too fast. I would like to fix this eventually. The rotary encoder outputs are connected to the interrupt lines on the MCU. But my main loop that acts on these flags set by the interrupt service routine is probably too slow.
• I had plans for an IR remote, but I just needed to finish the project.
• I'd also like to make a DAC so that I actually have a balanced source to use for the balanced input. Maybe next decade.

Final words
Happy to answer questions if you have them. Hope my project can inspire all of you who have dormant projects to finally finish them.

Hello

I have 20 x BRAND NEW Eminence Alpha 15A Woofers

https://www.parts-express.com/Emine...H95WFHPbnNfu877k95R5Xg2HdD8EHh4YaAn4vEALw_wcB

I will sell these at $68 dollars each plus freight. These are brand new in the original cartons

This price is for 8 or more. Less than 8 - $75 dollars each

Thanks

Mark

Following previous posts on the “Ship of Theseus” thread around here https://www.diyaudio.com/community/...ngeable-amplifier-modules.383745/post-7437999 [stopping to avoid derailing the specific amp topic], here is a follow-up, in the Parts section, which might be more appropriate: heatsink = parts
The post shall serve as a reminder for myself, and maybe it would be usefull to others at some point.

After the original posts, here is what I learned

A. [from a discussion with a thermal engineer @work]
Outside heat exchange coefficient of h=20 w/(m²-C) was probably too optimistic. h=15w/(m²-C) might be better

B. [from the same discussion]
*Imposing temperature is like imposing a constraint for a mechanical calculation. It is better to impose a thermal power released by the transistor to calculate a state of equilibrium between power released by the transistor and power dissipated by the heatsink.
*He suggested Thermal Power = Electric Power as a starting point.

*Since M. Johnson indicated that each transistor of the Theseus should give about 30watts (approximation), I set a thermal flux of 93750 watt/m² for each roughly 20mm*16mm transistor surface. 93750*0.020*0.016=30.

C. [air temp measurement with an M2x 4U 400mm]
Different circuit & heatsinking, but it is what I have
Ambiant air temp: around 20/25degrees
Air temp inside the amp after 1h: 45degrees
Air temp between the fins after 1h: 35degrees.

This to put an approximation of temperature for the convection in the various calculation. (I was using much higher inner air temp: 65degrees before)



Using this with the “Ship of Theseus” reference, transistor located on the left side (6L6 here https://www.diyaudio.com/community/...ngeable-amplifier-modules.383745/post-6958070), leads to the following results (picture)
What is worth noting is the different in temperature between the 2 transistor surfaces, the one on the right being colder, most probably because he “sees” a bigger chunk of the heatsink.

Lower temperature of 42degrees indicates that the heatsink participate to cooling the inside (I guess)

I just came across a bunch of this chips from old stash.

Worth building these? It would be labor of love as it would need point to point wiring as I have no PCBs.

I am just getting started into building things after a long time and want to choose my projects carefully.

Regards,
Vinay

I have a thread over at Audiokarma, basically I was given a stack of ten Hafler Pro 5000 amplifiers that have been sitting outside in the elements for years, like over a decade. The guy took them to a couple of repair shops and was told they weren’t fixable as they couldn’t get parts for them, so they sat outside on the side of his house. In the PNW that means a lot of rain. With a lot of work I cleaned them up (first two only, working two at a time) made necessary repairs to the boards, recapped the boards, stripped the chassis and painted.



In one amp I had to replace a driver, a 2N5415 with a 2N5416. The other amp I only had to replace caps.

They both run pretty warm, but the one with the replaced driver idles hotter. The idle current after warm up of the amp having the new driver is 2.4a which seems kind of high. The other amp with no new silicon idles at 2.14 amp. I didn’t touch any of the trimmers within either amp. They are covered with paint so I know they are in the same position as they were when they left the factory. Even though the trimmers are sealed, maybe being in the elements have changed their values. I did check the resistances of the bias trimmer settings and they were all within their 1kohm range.

There is no service manual and no bias instruction. So I don’t know if the 2.4A idle draw is normal or the 2.14 is. I’d like to have the 4 channels I have working so far the same. I’m worried that maybe the one channel I changed the driver in might be way out.

Dan

This is a group buy for the purchase of the second generation Salas Shunt High Voltage Regulator.

It's a newer design that Salas did, with CRT brilliant layout work and a bunch of us prototyped over the holiday season. We had a zero percent failure rate of setups amongst us. (Which I consider great, as most of my work , well needs work)


Let's get to the point.
The board is $15 USD.

Mini-Kits will be available. The cost is higher than I wanted them to be - so I split them in two.




Again a disclaimer - this is the most dangerous product I have shipped yet. Failure to respect the high voltage of the product can have deadly consequences. This is not a beginners project!

The full specifications are in the PDF file. (attached as zip)



The google spreadsheet needs to be completed with your username and includes paypal payment details. Please don't post that address here.


Transistor Minikit 13 USD
1-Toshiba 2SK117's unmatched
3-Vishay 12V .5W Zener
2-20ma Red LED's
2-Supertex DN2540
1-IRF840
2-Fairchild KSA1381ETSU
2-TO-220 Mica Insulator
2-Keystone plastic washers

Resistor Minikit 9 USD
2- Dale CPF2 100ppm 68.1k
1-KOA M/F 1/4W 100ppm 1.82R
1-3296Y Bourns 1/2W 100ppm 200R
1-T93YA Bourns trimmer - 1/2W 100ppm 1K
3-Vishay Bayershlag 50ppm 100R
1-271 Series Xicon 1/4W 50ppm 10R
1-271 Series Xicon 1/4W 50ppm 1.8k
1-271 Series Xicon 1/4W 50ppm 470R
1-271 Series Xicon 1/4W 50ppm 220R


SSHV2 FULL KIT - Does not include board (And no BIG heatsink for IRF840)
$45

1-Toshiba 2SK117's unmatched
2-20ma Red LED's
2-Supertex DN2540
1-IRF840PBF
2-Fairchild KSA1381ETSU
2-TO-220 Mica Insulator
3-12v 1/2W Zener
2-Keystone plastic washers (above is transistor kit)
2- Dale CPF2 100ppm 68.1k
1-KOA M/F 1/4W 100ppm 1.82R
1-3296Y Bourns 1/2W 100ppm 200R
1-T93YA Bourns trimmer - 1/2W 100ppm 1K
3-Vishay Bayershlag 50ppm 100R
1-271 Series Xicon 1/4W 50ppm 10R
1-271 Series Xicon 1/4W 50ppm 1.8k
1-271 Series Xicon 1/4W 50ppm 470R
1-271 Series Xicon 1/4W 50ppm 220R (above to 68K resistor kit)
1-Molex 4P Fixed Terminal Block Black
1-TE Connectivity 2P Terminal Block
2-274-1AB Wakefield TO-220 Heatsink
1-647-10ABP Wakefield TO-220 Heatsink
1-Wima 10uf MKP4 1100v
1-Wima .33uf MKP10 630v

This is a thread to discuss the Aleph J PCB on the Universal Mounting Scheme from the DIYaudio store.

Link to UMS - http://www.diyaudio.com/forums/imag...sal/universal-mounting-specification-v2.1.pdf

6l6 said:

As for the board, I was envisioning the same basic layout as the F4, F5c, etc... The longer board with the outputs all on the lower edge.

Also, I would love to see R7 replaced with a trimmer pot, as that's where you will be able to dial out any DC offset on the outputs... Maybe put pads for a parallel resistor there as well...

J109's are basically impossible to get anymore, so most people will be using a matched pair of J74's... it would be handy if they were face to face so their cases can be zip-tied together for better thermal tracking.

Click to expand...

GKU said:

May I suggest some additional design proposals:

- Lead pitch for the use of 1/4W audiophil resistors as Dale or PRP
- Space for an - input foil capacitor as f.i. 1uF ClarityCaps PWA or ESA

Click to expand...

threads are here :

Babelfish M25 , AKA M2 on steroids , AKA M2-XA25 bstrd

SissySIT

reminder - read everything linked

last , hopefully most clear and informative schematics are here , take care to read all notes !!!!!

Edit on 02.11.2018. :

Populating pcbs :
- as always , mount first all resistors , take care to slightly elevate R8 - to ease measurements across it while setting current through input buffer JFets
-if you're eager to try Borbely White Cathode Follower thingy (input buffer iteration) , read note on left top of schematic ; if you're lazy to do that , just ignore 1-pin sockets you got and normally solder parts , according to mentioned note
-diodes - everything pretty straightforward , except ZD1 - for Babelfish M25 orientate it as silkscreen is showing , for SissySIT orientate it contrary/opposite to silkscreen
take care that Babelfish M25 is having differently connected protection diodes than SissySIT; for B. M25 populate on pcb just those positions shown on B. M25 schematic , for SissySIT populate on pcb just those positions shown on SissySIT schematic !! ...... but you already know that , because you studied both schematics in detail
- two tiny (isolated) wire bridges on right channel pcbs - mount it just for SissySIT , you don't need it for Babelfish M25
-solder trimpots in place , take care of notes in schematic about their initial setting value; it is absolutely essential!!!.... ignore left-right , use ohmmeter to check resistance
-solder all caps , be careful with polarity ..... I tried to ease life for all of us , putting + mark for each position , where it belongs
-solder BD transistors , take care of pinout - metal tab goes where thick stripe on silkscreen is - for both channels metal tabs are looking one at another ; slightly separate them , just to be sure that there is no possibility of contact between them
-solder 7805 regs ; again - metal tab goes where thick stripe is on silkscreen ; don't ask did I made a mistake of mounting at least one backwards
-solder optocouplers ; it's logical looking at silkscreen where corner dot goes ; if it isn't logical to you , see post #593 Babelfish M25, SissySIT - general building tips and tricks
-solder JP pins , leave it open for now , and close it (with that red plasticky thingie) only later when you set buffer DC output offset
-regarding signal xformers ....... as written in previous thread(s) , pcb is made that you can use either Edcor PC600:15K (same one as in M2) , or Jensen JT-123-FLPCH (same one as in M6) , or Cinemag CMOQ-4LPC (same one as in DEFiSIT and SIT-3) .
choose which you want , according to myths and legends , and expect to follow this procedure for Cinemags - locate pin 1 per datasheet , mark it with red dot , then cut pins 1 , 6 , 7 and 12 .......... (no fuss - they're unconnected anyway) ..... that solution was absolutely essential , to be able to squeeze pads for all 3 types .... then find proper orientation on pcb and solder them on pcbs
if you are not using Edcor , and you didn't read notes on schm and you already soldered R13 , just cut it's pins

some pics of necessary xformers trickery , post #62 , Babelfish M25, SissySIT - general building tips and tricks
More about xformer trickery - Cinemag pinout and orientation on pcb , post #652 , Babelfish M25, SissySIT - general building tips and tricks


Edit on 05.11.2018. :

-prepare mosfet(s) , bending their pins up ; in case of Babelfish M25 - because they're practically covered with pcb so you can't see type , it's impossible to see later did you put proper one in position , so maybe is clever to use white permanent marker and write "240" and "9140" on narrow top surface of mosfet case , so later you can check are they properly mounted ; again - don't ask did I tried functionality of Babelfish M25 with two IRFP240 , instead of 240+9140
-it's clever to use Keratherm - bought either from Store , or from conrad.de , for Greedy Boyz being on my side of Big Splash
-put mosfets on/under the pcb , in exact arrangement with mounting hardware as can be seen in posts #2 and #3 , just bellow this one ; to remind you , exact arrangement is :
heatsink-Keratherm-mosfet-pcb-big washer-smaller washer if needed-springie washer as absolutely necessary part-bolt
tighten with brain , not force , but not skimp on necessary force ; my solution is to always use stainless steel washers and especially Allen bolt , because nowadays that's only way to have certainly mechanically proper part ........ usual steel bolts are more often utter drek than not

-pcbs are made for UMS , so in case of Babelfish M25 - again see pictures - you have 3 mounting points - 2 are mosfet places , third one single bolt with plastic or metal distancer between pcb and heatsink, long as mosfet thickness ; in case of SissySIT - you have one mosfet place and 2 distancers ; that way pcb is dead spot on

-speaking of SissySIT , there you need some work regarding SIT mounting , but pretty much everything you can see from pictures in SissySIT thread , post #2 especially , but there are others ; SissySIT ; if you have doubt , ask here in thread ; better to use M4 hardware than M3 , but M3 is also OK if you strictly use SS and take care about proper support of isolating bushings etc.

mount both pcbs , and when you bolted everything as needed , then solder mosfet(s) and SIT (in case of Sissy)

Edit on 11.11.2018. :

now ...... few words about PSU ...... Papa's mono PSU drawing from F6 article is handy , few more words about - read in post #113 of this thread : Babelfish M25, SissySIT - general building tips and tricks

so , say that you populated pcbs , and mounted everything in case , along with PSU ; for SissySIT - be creative with SIT mounting - take care of proper isolation of everything and proper pinout (body drain , fat pin source , thin pin gate ) and having "flying'' gate resistor as close is possible to gate itself ; heatshrink flying one together with wire , it's stronger critter that way

you didn't forget to test PSU alone ?

best to work on one channel at a time only ; if you have dual mono (which this amp more than deserves) construction , mount mains fuse in one channel only and work on it (you can work on other one , but that's hard to do anything with dead one ) ; if you have (God Forbid!) shared PSU , then wire just one channel to PSU

IMPORTANT: insert 0R1, 3W minimum , resistor in-line with negative rail ; check one more time that all trimpots are where need to be ( read notes on schmtcs) and that JP1 is open ; if you have CRC PSU filter , you can use R in CRC instead mentioned 0R1 in neg. rail ; in that case ,when you set Iq and DC offset , you're done ; don't be alarmed seeing normal surge across that resistor while caps are pulling their juice during power up

mount one DVM across outputs , 2V range ; second one across 0R1 resistor , 200mV range

input shorted , no load on output

power it up , observe output - no more than 1V or so allowed ..... if more , something is fishy - power it off and cry here ; in same time - DVM across 0R1 must stay pretty much undecided ..... few mV or so are allowed

wait few mins , calming your breathing , then turn Iq trimpot 2 or 3 turns .......... wait few mins again to see is there any positive change in readout ; any change will be slow due to enormous RC constant of biasing circuit

turn 2 more turns and observe ........ wait 2 mins and repeat - in one moment there will be change - readout increasing as 3m3 Pana cap is getting juice , which means that gates of SIT and mosfet are going one from another , thus opening both of them for current

be patient - repeat procedure of 1-2 turns more untill you get steady 100 to 120mV across 0R1 , and in same time you can play a little with DC offset trimpot , to get it closer to 0mV

let it sit for some time , to allow heat in heatsink , then fiddle with pot to get more juice in , closer to (say) prescribed 180mV , which means 1A8 flowing through OS

if you're in ballpark of - say- 150-160mV and nice offset , put lid on and wait 10min , observing readouts all the time

coffee or tea are nice to have in proximity , and use it ........

if after 10 min everything is steady , pull lid off , power off and connect other channel ... repeating entire procedure

when you have both channels at 150-160mV across 0R1 , then you can play iteratively between them , to obtain 180mV at monitoring resistor (0R1) and 0mV at output

final fiddle with lid on , of course

when everything is steady , there must be also temp equilibrium of entire case ....... power off , remove both 0R1 and solder negative rail wires in their proper places

power up , re-set output offset , let it cook , re-check offset ;

now is proper time to set input buffers - pretty straightforward procedure , read notes in schematic ; it takes just a little time

in short - put your voltmeter (DC , 200mV range ) across R8 ; fiddle with R6 trimpot to get reading of 20mV , which means buffer Iq is 20mA

connect voltmeter (DC , 200mV range ) between GND and pin1 of JP ; fiddle with R7 to get as close to 0mV you can ; pin 1 is , well - forget orientation - this is one of two pins - showing a change in readout when you fiddle with R7

when you're done with that , close JP

put lid on , put screws in place

connect cheap dumbass speakers on outputs and your Ipod/pad/phone/CD/playstation/whatever on inputs , put some musak

if cheap dumbass spks are happy , and I'm good for that - connect your precious spks and sources and enjoy

did I forgot something ?

let me know .......

aha - always test isolation between output parts and heatsink ; proper torque is your friend ; use stainless steel screw/bolts/nuts/washers ; always use springie washers , also for Graetz bridges - they are going to die if nut goes loose and they're flapping on bottom of case ; speak friendly with your neighbors .... that way you'll enjoy your music in any time of day or night ; coffee and tea are ...... good outside of an amp ;

edit on 29.11.2018.

R4 and R5 - values changed from 27R to 39R , to cover broader range of input critters Idss ; will edit schmtcs later and bug Mods to change them in this post

edit on 20.12.2018.

I decided to change value of R3 , when used as Borbely WCF - instead of 1Meg , it is now 220K - calmer transient behavior during powering ON

edit on 13.09.2019.


SIT :

body is Drain
big pin is Source
small pin is Gate

Mosfet is , name to your face , pins down - from left to right - G, D, S

SissySIT parts placement, post #1048

I'll have more if needed, but for now - 42

edit on 17.09.2019. :

P1 pre-set help post #1092 , Babelfish M25, SissySIT - general building tips and tricks

edit on 01.10.2020.

Last iteratioon of schematic , with change to 6N139 optocoupler :

schematic post #1492

pcb sshot post #1529

edit on 31.12.2020. (damned year!) :

ERROR on SissySIT R2 pcb, left channel - post #1820, link : Babelfish M25, SissySIT - general building tips and tricks

ERROR No2. on SissySIT R2 pcb, both channels - post #1867, link: Babelfish M25, SissySIT - general building tips and tricks ; I'm pretty sure that's the last one
Remedy shown in post #1886: Babelfish M25, SissySIT - general building tips and tricks

Is there a concensus on what is currently "the best" class D amplifier boards? Specifically "best" for low noise. And availability from reputable sources would be a big plus for me!

I built some active speakers featuring pro audio coaxial drivers, and the horns are extremely sensitive, which means noisy. The horns are rated at 106dB, and they currently have a massive pad on them to cut the noise to a tolerable level. But it is still there.

So I would like to build a class D amp that is extremely quiet. At a minimum I'd like to build a 2 channel 30+ watt amp in a 1RU form factor with balanced inputs.

I would be interested in buying a ready made unit, but I haven't found one. I really do want the 1RU form factor and balanced inputs. And I want as much of a guarantee as possible that the amp will be genuinely quiet, suitable for high sensitivity drivers.

Depending on cost and availability, I may want to make it a 4 way amp, with 2x 30watt + 2x ~100 watts. (My mids are 98dB sensitivity, so they are also a bit noisy and require a pad to tame them...)

My current amp is a multichannel emptiva xpa gen 3 (class H).

service manual soundcraft ui24

Is it possible in a CRC to have a filter resistor with such low resistance that it has a negative effect on the power supply? I've a 0.1 Ohm 3W resistor with 630 mA running through it as an external single rail 5V PSU powering a DAC. So it's only dropping 0.06V and the power is way more than required. I find that with the mids and bass lack body and weight with the resistor in place, but are normal when the resistor is replaced by a straight wire. (Vishay RS02B)

I normally buy Bourns but recently stumbled across Tayda Electronics and couldn't resist the $0.28 Alpha cermet 25 turn knockoffs. Did I save money or do I have a pot- load of junk on the way? I'm all for saving a little where it makes sense but my dad's voice was ringing through my head as I shopped that site... "it only cost a little more to go the cheap route".
What's your experience?

Purchasing transistors from Flipelectronics was impossible.
Sorry guys.

I cloned the HECD-019A servo board for the tested and working Philips CDM12.1 mechanics.
Now I find myself with a problem.
I had to remove the P87C58 micro controller from the original board because the LQFP44 version is not for sale, I was able to find the PLCC44 version chip that I mounted on the new PCB but it does not work and therefore to make the prototype board work I had to remove it from the original board .
Now a doubt arises, does anyone know if this Philips controller, the P87C58 has a part of memory and therefore must be programmed?
Thanks for your help!

.. Europe preferred. I inherited a set of QUAD tube amps and want to restore these in memoriam to the owner.
PM please, thanks

"This design is a grommet washer to protect wires protruding through the bottom plate, typically done with mains wiring"

This is a very simple design to provide a 3D print grommet that "snaps" into a 12mm (or 1/2 inch for Version 2) hole drilled into the bottom perforated mounting plate for Modushop (or any metal plate for that matter) chassis. Instead of using the "lip up" approach to the bottom plate, which allows for mains wiring to sneak underneath from back to front, you can use the "lip down" approach (slightly less restrictive for mounting) and instead drill two large holes at the front and back of the plate. The grommets purpose is nothign more than to protect the mains wires from abraision damage which could potentially results in a mains-to-ground short if the insulation were to become damaged. There are two versions I've created. Version 1 for a 12mm hole (I used a 15/32 drill bit) whereas version 2 is for a slightly larger 1/2 inch hole (not yet confirmed it fits, but the dimensions implies it'll work fine).

I've included a zip file for each of the two versions that includes both STL and 3MF files. Happy to tweak the design for other hole diameters via a PM request with actual measurements, and post a new version. I've also included the current Fusion 360 file so anyone can modify the part to the hole size they desire (just know it may require tweaks to the design based on fillet dimensions used). Please post modifications here so others can benefit from your design tweaks/updates/remixes.

Printing Instructions

• No need for supports. No brim needed if you use a good "sticky approach" to bed adhesion (I use a glue stick).
• Ensure the print is solid by increasing wall count appropriately (aka, no "fill")

Install Instructions

• Drill the appropriate holes in your chassis where you want the mains wiring (or any wiring you want to run under the plate) to go (12mm or 1/2in based on available drill bit sizes and "version")
• You simply "snap" the grommet washer into place from the top down using a significant amount of pressure (a hammer may be required to snap it in depending on how accurate your drilled hole is). It's a very solid "lock" into the hole (zero adhesive of any type required).
  • Note that this design is DIRECTIONAL in how it's installed, and the crescent shaped cut out is where the wire bends at and turns toward the next protrusion, so pay close attention as you snap it into place. Once it's in, it's difficult to rotate orientation (not impossible, but not easy...requires a pliers)
• Now you can run your wires down through the perforated plate knowing they won't be damaged by the sharp metal edges on the hole.

Finished product...

Hi everyone, I write from Italy and I apologize if my English is not good, I am building an ACA version 1.8 and I do not find any information if the rear switch to choose the mono or stereo or xlr mode etc .... is it to be mounted in a specific direction or I can choose to do it as I want. I mean I have to respect a assembly direction with a specific pin up or down? Thank you very much.

Hi, I have a quad set from the store consisting if a pair of lsk170 and a pair of lsj74. I also have 12 extra j113s with bias resistors from the 6-24 crossover. Is there an SE to Balanced circuit that could utilize those devices that would be effective in driving a long 15-20' interconnect to a balanced pre? Or would it be more effective to use an edcor or cinemag transformer? I'm hoping to avoid having to get transformers. I have both +dc and +- dc supplies available.

I bought a set of mirrored 6550 push pull mono blocks yesterday.
The owner didn't have much info on them.
I paid a good price not knowing what the transformers are. Does anyone recognize the amplifiers or transformers?
They originally ran 4x 6550s with 5687 direct coupled cathode follower drivers, fixed bias, pentode mode, push pull parallel for something approaching 200w output power.
Any clues or info would be much appreciated.
Each amplifier weighs more than a 50 pound bag of chicken feed.
Chassis are 11" ×17" and the big caps are nearly the size of a can of beer.
What have I gotten myself into this time?
Thank you in advance.

Hi
I could use assistance determining the value of the fuse between my 24:v/10A SMPS and 4 channel Sure Class T ("100Wx4")) amplifier.
Note I only plan to use 3 channels in a triamplified stack ( i.e. one PS & amp board per channel driving midbass, midrange and tweet from an electronic Xover.I don't play very loud.
On the 24v rail, what amperage fuse would you recommend?
Thanks in advance,
-Charles

First time here sorry if something is off.
Few weeks ago I bought old Logitech x230 speaker set from flea market for 6euros. And now I got my self x530.
I'm asking if it would be good idea to make them into portable speaker(s)?
I know it's not that efficient but still it sounds like fun project and then i would have little version for bigger boombox that I've built before.
Or I could just keep it as pc speakers because my setup lacks speaker that's wired and usable at seconds notice.
My biggest problem with this is they input 230volt and I don't know if the amp accepts 12volt or something like it inside or is it purely 230volt amp

If you have experience turning old speakers into portable versions please write the experience pros and cons. Thanks

Title says it all. I'm shopping for subwoofer drivers, and I would like to have some idea how much harmonic distortion they will produce.
Is there any way to do this mathematically? Given the advanced state of speaker simulation software, I would hope there is.
Any thoughts and ideas would be appreciated!

good morning, I would just like to ask: does anyone know a good technician who repairs hi fi vintage speakers in and around Rome (ITALY) . If the topic is in the wrong forum I apologize and kindly ask the administrators if they can move it to the relevant forum, thanks! Greetings Ros

Hi all. After recapping this B & K Pro 10 Mc preamp I was aligning the knobs on the Input and Record controls when the aluminum split shaft rotary switch shaft finally gave up. B & K used dual set screws with these aluminum shafts probably knowing they would be destroyed after awhile.
It a CTS 1379038 2 pole 6 position. About as Hard to find as they come. I posted here hopefully thinking someone has been here before. I sold electronic parts over the counter for 15 years so I can normally find a part if it exists.
I have replaced controls like this doing a hardwired job, but I was hoping to avoid. Yes wishful thinking.

Hi,
I am trying to buildt a custom contact mic using https://www.richardmudhar.com/piezo-contact-microphone-hi-z-amplifier-low-noise-version/ (circuit picture below)


I want to record frequencies in range if 5-20 Hz. I simulated the circuit in ltspice and found better frequency response at the lower frequencies by replacing C1 by 100uF capacitor.
Frequency response:


I am looking for comments and suggestions for this change also can anyone suggest a suitable amplification circuit for amplifying mainly the lower frequencies (after the pre amplification).
My objective is to convert the microphone output into digital signal and process it further

1. when designing filters, how much should I worry about phase shift, is it that important eg can a 45deg shift be heard?
and if it is important how do you correct the phase in a passive filter?
2. when would you choose to use an active filter over a passive filter?
3. how do you choose between using a 1st order or 2nd order filter
4. What is the gain (I know it’s negative), of a 1st order and 2nd order passive filter?

thanks

Dear friends!
I'm designing a subwoofer amplifier using TDA7294. The summing amplifier and active LP filter is based on the NJM4580.
My questions:
1) I have 3 decoupling capacitors C1, C4, C5. Are they all needed or is it possible, for example, to remove C5? Or vice versa, remove C1 and C4, leaving C5?
2) I have the opportunity to use NJM4580, LM833DT, TL072CDT and LM358DT op amps. Which one is the best?
Thank you very much!

I have aligned all three drivers in my main speakers. In my case, there are lines on each of my drivers showing the point where sound emanates.

Is there any way to measure by sound if the drivers are aligned???

G'day everyone,

I am currently working on a Sanyo DCA 200 amp. I'm comfortable ordering replacement capacitors but have never worked on transistors before. I want to replace the 4 main output stage units but am a bit unsure how to go about getting suitable equivalents.

The transistors are marked:

1. SANYO B514D 91
2. SANYO B514D 91
3. SANYO D330D 60
4. SANYO D330D 60

From what I can figure out, 1&2 are PNP types and 3&4 are NPN types.

I usually use DigiKey to ship here in Australia so if they stock something that would be good.

If anyone can help me I'd appreciate it.
Cheers

Hi! It's my first time building purely from a schematic. I put a lot of thought into the layout and have it all assembled yet it's not passing sound. Unless I crank the power amp and then there's just an almost inaudible amount present. I guess I want to get some feedback on the layout... specifically if I've read the schematic right and translated it to a physical layout accurately. Second, do you have any thoughts on why it's not passing sound? Could be the layout and honestly the transistors are a bit confusing... Below I've attached the original schematic, the PS layout, and a single channel.

I should note I'm using a 24V volt power supply as the preamp documentation says it will accommodate 18V - 24V.

Thanks!
Jonah

Hey people,

someone gave me this amplifier, which has been lying around in a garden-shed for the recent 5 years. It's about 30 years old and, if one is into integrated stereo amps, it's a nice amp to keep ( look at the specs, it's massive, powerful and even stable at 2 Ohms).
First repair was an electrolytic which was responsible for the speaker-output relais, which didnt pull. That was a known issue with this amp and I had a fitting electrolytic (ELNA 3,3µF/100V instead of ELNA 3,3µF/50V) in my spare-parts box,
Now it plays music, but only in "direct"-mode. The tone controls aren't working. I think I could repair it, with some more internet-recherche and some trial & error. Cannot be so difficult.
But, what could I do with this machine? I'm into activ speakers, so I've got no use for such a dinosaur. First I thought about selling it, but this thing has 20kg. Sending it as a parcel will be difficult, not to say impossible.
Another thought is, taking it apart and using it as a subwoofer amplifier. It could run i.e. two 10", or bridged one bigger sub, as it is 2Ohm stable. But, somehow, it would be sad, to take apart such a fine old amp.
What would you do?

best regards
J.

Lots of people have used AC power toroids as output transformers because real output transformers are relatively scarce and expensive nowadays. Nothing new there. I'd guess that driver transformers are even more scarce since not every amplifier had one, even back when valve amplifiers were common. The transformer in the picture is a 120+120V to 28V 7.14A 200VA. Seeing it has two primary windings that can be used in series as a single centre tapped winding to drive the grids, we have a solution! I'd love to drive the low voltage side with a LM3875 or similar and feed the high voltage side to a pair of big triodes in zero bias class B2. Or even a pair of 807s in zero bias and driving the screens and beam forming plates plates directly and the control grid via 20K resistor. No problem supplying all the grid current needed. Anyone here tried this approach?

I'm currently recapping my arcam delta 290p (started on 1 of 3)
i am having an issues where once the small cap is out the hole get filled with solder that i cant get out or melt
i have used a desoldering tool
it just keeps getting worse the more i try.

has anyone get any tips i have thought to get a 0.3mm drill bit but i really dont want to go down that road.


thanks for any help

Also i use the hakko FX-888D and EDSYN DS017 DESOLDER TOOL

I have a pair of Wavecor WF152BD07 4ohm drivers. Really nice 5 1/2"ers with Balanced drive. Originally thinking a small bookshelf speaker for my TV room, but now I am using a sealed box with a SBAcoustics SB17CRC for that application.

So, What would you build with the Wavecor? Bookshelf? Use it as a mid in a 3way? I am open to suggestions.

I'm looking to build a few LFOs, just wondering if anyone has gerbers that they could share?

Hi all!
After exploring the magic of TDA1541 dac chip with this project:
https://jelabs.blogspot.com/2020/04/tda1541-nos-dac.html
...and needing another dac, I have the insane idea of applying a Papa's D1 stage to a 1521 board thanks to the PCBs made by His Mightyness ZM:
https://www.diyaudio.com/community/...0400a-who-have-heard-both.347298/post-6872371

Bad or good idea?
I do love that chip and there're lots of boards for it...

Thanks in advance.

There are many threads about SONY's laser heads (optical pick up's) from the KSS-Series. I have started also some threads in this case. The reasons are clear. First the no longer availability of most of them and second the big error rate sometimes after a short time of use. In general - from all laser units that I know, Sony's laser heads above KSS-120 by far the worst of all (life time, reliability), even the models for the ESPRIT series like KSS-272A. Two main reasons are therefore responsible:
1) the suspension of the collimator lens (plastic leaf spring instead spring wire)
2) the diode itself
Obviously it can happen sometimes (fortunately not often) that other laser head manufacturers than Sony also used such worse Sony diodes. If by such older CD players the RF level very low, you can assume, that a Sony diode is inside.

By JVC-, Pioneer- and Hitachi laser heads after more than 20 years in use there are still virgin light power (after lens cleaning) and thus good level by RF signal. Also the tracking behaviour isn't impaired due collimator lens suspension without plastic.Unfortunately for most brands SONY was the main supplier of optical pick up's.

After a certain time this threads are relatively hard to find. Therefore at bottom an URL overview of all threads from diyaudio about SONY's KSS series.
If one of you discover additional threads that I have overlooked, you can add here

Basic subjects regarded KSS Series from Sony
http://www.diyaudio.com/forums/digi...ter-laser-death-great-vintage-cd-players.html
http://www.diyaudio.com/forums/digi...ser-pickups-why-not-replacing-diode-only.html
http://www.diyaudio.com/forums/digital-source/25540-sony-cd-head-repairs.html
http://www.diyaudio.com/forums/digital-source/88928-electrical-adjustment-laser-pickup.html
http://www.diyaudio.com/forums/digi...uccessor-sld-104u-sony-esprit-kss-series.html
http://www.diyaudio.com/forums/digi...ick-up-cd-player-wholesaler-manufacturer.html
http://www.diyaudio.com/forums/digi...k-about-sonys-kss-optical-pick-up-series.html
http://www.diyaudio.com/forums/digital-source/38894-full-range-sony-cd-laser-pick-ups-photos.html
http://www.diyaudio.com/forums/vendors-bazaar/108098-new-optical-pickup-spare-parts-arrive.html
http://www.diyaudio.com/forums/digital-source/133261-whining-kss210a-after-replacement.html (adjustments)

Threads about KSS120C / KSS123A / KSS-152A
http://www.diyaudio.com/forums/digital-source/158651-kss-122a-kss-123a-they-interchabgeable.html
http://www.diyaudio.com/forums/digi...ns-magnetic-linear-rails-laser-transport.html (KSS-123A)
http://www.diyaudio.com/forums/digital-source/155077-revive-heavy-weight-denon-dcd3300.html (KSS-123A)
http://www.diyaudio.com/forums/digital-source/96953-disc-table-height-kss-laser-units.html (KSS-123A)
http://www.diyaudio.com/forums/digi...ichi-oms-5eii-7eii-weak-error-correction.html (KSS-123A)
http://www.diyaudio.com/forums/digital-source/67783-test-cd-cd-player-adjustment.html (KSS-123A-151A)
http://www.diyaudio.com/forums/digital-source/109082-trying-repair-old-onkyo-dx-1500-a.html (KSS-152A)
http://www.diyaudio.com/forums/digital-source/79903-luxman-d-105u-transport-identification.html (KSS-152A)
http://www.diyaudio.com/forums/digital-source/158453-sony-kss-152-replacement.html

Threads about KSS-151A
http://www.diyaudio.com/forums/parts/153347-laser-sony-kss-151-fore-denon-cd-s1.html
http://www.diyaudio.com/forums/digital-source/157687-kss151a-kss-151a-10-x-new.html
http://www.diyaudio.com/forums/digital-source/147776-laser-replacement-teac-vrds-10-a.html (KSS-151A)
http://www.diyaudio.com/forums/digital-source/27647-kss151a-laser-replacement.html
http://www.diyaudio.com/forums/digital-source/88594-how-evaluate-laser-pick-up-remaining-life.html (KSS-151A in CDP338ESD)
http://www.diyaudio.com/forums/digital-source/89000-laser-diode-current-kss-151a.html
http://www.diyaudio.com/forums/digital-source/91184-denon-dcd-1520-not-recognise-some-disc.html (KSS-151A)
http://www.diyaudio.com/forums/swap-meet/127868-fs-kss-151a-laser-pick-up.html
http://www.diyaudio.com/forums/swap-meet/119113-fs-sony-kss-151-laser-mechanism.html
http://www.diyaudio.com/forums/digital-source/67783-test-cd-cd-player-adjustment.html (KSS-123A-151A)
http://www.diyaudio.com/forums/digital-source/27376-laser-replacement.html (KSS-151A)
http://www.diyaudio.com/forums/digital-source/53874-kss-151a-pickup-wanted.html (KSS-151A needed)
http://www.diyaudio.com/forums/swap-meet/134760-fs-sony-kss-151a-laser-head.html
http://www.diyaudio.com/forums/digital-source/75337-wadia-drive-8-laser-unit.html (KSS-151A needed)
http://www.diyaudio.com/forums/digital-source/135202-sony-cdp-950-vs-m95-vs-222esd.html (KSS-150A-151A)
http://www.diyaudio.com/forums/digital-source/100420-teac-p10-transport-what-laser.html (KSS151 or KSS213 ?)

Threads about KSS-272A
http://www.diyaudio.com/forums/swap-meet/99773-wanted-laser-pick-up-kss-272-a-3.html
http://www.diyaudio.com/forums/digital-source/132147-kss272a-working-not.html
http://www.diyaudio.com/forums/digi...er-pickup-adjustment-accuphase-cd-player.html (KSS-272A)
http://www.diyaudio.com/forums/digital-source/89220-accuphase-dp-90-laser-head.html (KSS-272A needed)
http://www.diyaudio.com/forums/digital-source/43349-sony-cdp-x779es.html (KSS-272A needed)
http://www.diyaudio.com/forums/digital-source/97681-sony-cdp-x707es-diy.html (KSS-272A needed)
http://www.diyaudio.com/forums/swap-meet/122407-wtb-new-sony-khm-230aaa-kss-272a.html
http://www.diyaudio.com/forums/swap-meet/85287-wtb-sony-kss-272a-laser.html
http://www.diyaudio.com/forums/parts/99774-hard-find-laser-pick-up-kss-272-a.html
http://www.diyaudio.com/forums/digital-source/132147-kss272a-working-not.html
http://www.diyaudio.com/forums/digital-source/39405-sony-cd-laser-replacement-availability.html (KSS270A-KSS272A)

Threads about KSS-270A / KSS-271A / KSS-273A-B / KSS-281A
http://www.diyaudio.com/forums/digi...ble-use-kss240a-cdpx55es-instead-kss270a.html
http://www.diyaudio.com/forums/digital-source/154699-cdp-x333es-kss-271a-tracking-offset-probs.html
http://www.diyaudio.com/forums/digital-source/154669-cdp333es-skips.html (KSS-271A)
http://www.diyaudio.com/forums/digi...ter-laser-death-great-vintage-cd-players.html (KSS-273A)
http://www.diyaudio.com/forums/digital-source/82754-sony-optical-pick-up-kss-273-a.html
http://www.diyaudio.com/forums/digital-source/105295-laser-kss-273-b-hard-find.html
http://www.diyaudio.com/forums/parts/100577-need-help.html (KSS-273B)
http://www.diyaudio.com/forums/digital-source/30585-sony-cdp-x777es.html (KSS-281A needed)

Threads about KSS-240A / KSS-213A-V / KSS-210A / KSS-150A
http://www.diyaudio.com/forums/digital-source/81103-broken-arcam-alpha-8-trichord.html (Sony CDM-14/KSS-240A)
http://www.diyaudio.com/forums/digital-source/82612-troubleshooting-pick-up.html (KSS-240A)
http://www.diyaudio.com/forums/digital-source/101935-denon-dcds10-cd-player.html (KSS-240A)
http://www.diyaudio.com/forums/digital-source/32730-teac-vrds-t1-cd-transport.html (KSS-240A)
http://www.diyaudio.com/forums/parts/39473-sony-mhc1600-hcd-h1600.html (KSS-240A)
http://www.diyaudio.com/forums/digital-source/139605-kss-240a-based-transport-diy-player.html
http://www.diyaudio.com/forums/digital-source/100978-cdp-591-a.html (Solder bridge KSS-240)
http://www.diyaudio.com/forums/digital-source/108381-sony-laser-arcam-mcd.html (KSS-213-240)
http://www.diyaudio.com/forums/digital-source/26399-kss-213-laser-family.html
http://www.diyaudio.com/forums/digital-source/85363-taking-apart-rega-planet.html (Rega Planet 2000-KSS213B)
http://www.diyaudio.com/forums/digital-source/126608-sony-mhc-rv22-cd-section-problem.html (KSS-213B)
http://www.diyaudio.com/forums/digital-source/59654-tascam-cd-302-modifications.html (KSS-213B to C)
http://www.diyaudio.com/forums/digital-source/107257-cd-player.html (MHZS33-KSS213Q)
http://www.diyaudio.com/forums/digital-source/95276-sony-cd-player-optical-pickups.html (KSS-213A-V/KSS-210A-C)
http://www.diyaudio.com/forums/digital-source/96961-rotel-rcd930ax-help.html (KSS-210A-D)
http://www.diyaudio.com/forums/digital-source/94694-naming-conventions-sony-drives.html (KSS-210-KSM2101)
http://www.diyaudio.com/forums/digital-source/77734-sony-laser-alignment-kss-nad-cd.html (NAD502/512-KSS-210A)
http://www.diyaudio.com/forums/digi...8-based-sony-philips-need-service-manual.html (KSS-150A)
http://www.diyaudio.com/forums/digital-source/107757-comments-onkyo-dx-703-a-2.html (KSS-150A)

Threads about other KSS models
http://www.diyaudio.com/forums/digital-source/74910-sony-bu-1e-laser.html (Laser head without type No - BU = Base Unit = transport mechanism)
http://www.diyaudio.com/forums/digital-source/140856-heavyweight-sony-laser-loader.html (KSS-100A)
http://www.diyaudio.com/forums/digital-source/46796-laser-mechanism-sony-ex7esd.html (KSS-190A needed)
http://www.diyaudio.com/forums/car-audio/141649-kenwood-kdc-m9021se-laser-unit-problem.html (KSS 24430 Car Hifi)
http://www.diyaudio.com/forums/parts/21016-anyone-knows-where-can-i-buy-sony-cd-pick-up.html (KSS-331C needed)

It's been so long since my open baffle system was completed and honestly, due to famiy and living situation, I don't get to enjoy it as much as I used to. It's time for something scaled down and yet possibly MORE precise, MORE stunning and natural to listen to. Something I can fit comfortably into my bedroom and not disturb the wife and kids, but can't be headphones, as I can't last more than maybe an hour with headphones on, no matter how lightweight and comfortable they are. It's got the be real speakers with imaging.

I've got most of the design sorted out, but not sure what to do for the woofer/sub. Likely want it to be open baffle and as simple and light as possible, but open to options from y'all. Maybe a pair of something mounted totally naked, as the planar and midbass will be, but not 100% settled there. Looking for options with a QTS around .5-.7, low FS and 4 Ohms. Hit me with options regarding drivers or other novel designs for bass, either store bought or DIY. Could also just buy the dual Rhythmik 8" kit and mount that somehow. More concerned with clean, tight pitch definition than the last ounce of extension.

Photo of original system for comparison sake followed by photos of inspirations for this project.

Making room for new projects. LuDEF up for sale $150 plus shipping. Cinemags cmoq 4 hpc included. Tested and ready to get bolted down and started.

Looking to see if anyone can help steer me in a different direction than I’ve been going with a Sansui G-5500. It belongs to a friend of mine who asked me to diagnose a problem that I could not duplicate, and once we knew it was pretty solid we decided to do a restoration on it; change out the caps, trim pots, full cleaning etc.

So this worked out originally, and the unit was perfectly fine after the work. A month or so later he told me it was popping through the speakers even at low volume, so I have it back here again.

I have not been able to duplicate the issue he was having, but instead somehow introduced a new one which was that the unit was now going into protection when I was about halfway up on the volume level (sinewave test). In playing around with stuff I’m not sure how I did it but I managed to blow the outputs on the right channel. So I replaced them with the NJW equivalent subs and once I knew those were ok I also replaced all the sketchy driver transistors that I didn’t feel needed to be done the first time around. Now I am getting the relay to click into protection at about a quarter of the volume. Same input level, and also still no right channel.

I’m not sure if I’m concentrating in the right area right now because I’m getting flustered on this one. Anyone here familiar with the G-5500 by chance? I did check the stupid stuff like open emitter resistors, and I have pulled all my replacement parts and double checked. I’ve also replaced the HA12002 protection IC because I thought maybe I had damaged it when I was cleaning the corrosive glue away on the board. All the voltages look fine there, as well as on both channel outputs I’m getting my +/- 43v. I’m just a bit stumped at the moment…

Hi everyone, I'm starting a new project for the heresy big version (Klipsch Forte style), the components will be:
-B&C DE10 tweeter
-K53k medium with 15" horn.
As for the woofer, I don't know, I have selected some models that I can easily find, with a price around €150 and they are:
Eminence beta 12A (I already have this one)
B&C 12NDL76
RCF LF12X401
Dayton pa 310-8
LaVoce waf122.50
For each I attach the technical data sheets.
The dimensions will be approximately 100l like the FASTLANE AUDIO version with 4" port.
Which of these woofers might be best for you? I chose these because they are easy to find and affordable, but I could use others in that price range.

Thanks

Hello, I am looking for a rotary switch for a project I am working on. I just want to connect 3 things to it, an audio L R input and then two outputs, one that will select between three sets of speakers. Seems simple but I am not able to put together the right words to search and find it. Does anyone know how to find something like this?

Thank you!

Good afternoon. So I have had my Grado Labs Prestige’s Series SR-80 headphones for 28 years now. They have been sent back 1 time for the plastic part that holds the head band on and a wire finally broken in the middle. Well after sending them in to get repaired from 5 years ago it has happened again. I don’t want to send in my headphones for repairs I would like to fix it my self (if I can?). So where I began this repair is asking all of you what wire can I buy in bulk to repair the wire? I can buy, a wire pants boot Y splitter and the 3.5mm connector end. I can solder and I have a soldering station for that. So with all this out of the way now here’s a few final questions?
1. What kind of wire can I use? Balance or unbalanceed wire? Does it make a difference’s in the overall sound?
2.How does the plastic piece covering the driver come off to expose the wire so I can replace it?
3. Will the ohms change if I switch the wire and will it Be close to the ohms the head phones are now? I hope am not being too critical or going overboard?

Here are the wire Companies I am familiar with over the years that I have used in 1 way or another.

1. Gotham Audio.
2. Mogami Wire.
3. Canare Wire.
4. Supra Cables
5. Parts Express’s house brand now (Audtek).
6.Kimber Cable. (Diy stuff only).
7. Duelund Cables. (Given to me only 4 feet).
8. Wire World Cables.
9. Linn Speaker Cables.
10.Audio quest (years ago $5.00 bulk speaker cables).
11. Mono Prices 12 gauge wire (40 feet of it years ago).
12. I hate to say it last but, not least Monster cable ugh I said it. 🫢.

A lot of cables and info. I now it was a long post but, I wanted to put everything out on the table to see where I can go from here? Thanks for reading my post. Here are 2 pictures of the head phones with the wire showing and just my headphones model and series. Thanks Jeff

Hi,

I have one Altec 515B that needs a speaker cabinet, the woofer will be matched with a 288 driver and a 1005 multicell:

I am very eager about this project, but a DIY project that incorporates the original A5 cabinet is not the way I want to go..

I was wondering if anyone had inputs on which way to go: traditional bassreflex, do fancy the Altec 612 cabinet proportions, but is an Onken design also a way to consider with the 515B?, how big volumes are we talking about : question concerns both the traditional bassreflex ( Altec 612 ), but will a Onken design for a 515 be bigger the 360L Onken?

The whole system is rated 20 ohms... the 515 first needs a recone, guessing there is no point in measuring ( Dayton DATS ) the woofer before that time...

Hi all,

me and a friend are going to build ESL after building "normal" speakers for centuries.
So far we've read a lot about ESL's. The more we read, the more questions we have... I gues you know what I mean
Anyway, we are going to build hybrid speakers, me i'm going to use a Ripol (since i am a big Open-Baffle fan) for the bass section, my buddy will use a closed box.
We decided to cross them around 200-250 Hz. If passive or active is not sure at the moment...
The panel size will be 285x900mm divided in 20-12-6-6-6-12-20 segments.
And here the questions start...
If we use aluminium profiles for the frame and also for the cross-braces and use duoble-sided tape 0,2mm for bonding the membrane to the frame, will there be enough insulation against the membrane and also the wires?
In the picture you can see that we tried two different sizes of ds-tape, one is 0,2 mm, the other one is 1.5mm thick. This was to check wether the braces will stick strong enough to the frame, unfortunately they do not. Next step will be to check wether glueing the braces with Sikaflex221 to the frame.
If we use rivets to fix the braces it is ok, but we lose the insulating effect of the frame material, this is a sandwich of aluminium and some plastic (here in Germany it is called Alucobond).
Don't mind the stator wires on the pictures, this was only to check how fast the glue is drying.

Another question concerns the distance from stator to membrane. Since the material we want to use for the frame was only available in 4mm and we want to keep things simple, the distance/gap between stator wires (outside of the insulation) is only 2mm instead of 3mm like described on the website of Steen Frank Jensen.
To be honest, to keep things simple we are going to copy his model since it is not that big.
We also like all the other stuff we have seen here in this forum but most these ESL's are too big.
Anyway we include some ideas from here in our building process...

So we are looking forward to your answers.
We are sorry for the chaos with the pictures... We couldn't find a way to delete the needless ones...

Best regards, Juergen and Dani
from Germany

Hi

I have always been a fan of these mono block amplifiers via velleman .. both the el34 and kt88 version.
Velleman have long since stopped production of these years ago .. I purchased their last 27 boards they had in stock. I have now since decided to make my own new production boards (Velleman where ok) but the issue was that these boards where made before Gerber files.

So after some hard work I produced the artwork the old fashion way then painstakingly converted to a full Gerber file so I can get them made again.

My new boards are fully drilled with 2oz copper tracks. This is the 1st production board being populated, with the wire links 1st .. I will update more on the progress of the first board. This will be A 90w EL34 version. The new PCB boards are thicker as well so no flex ..

My 15 year old NAD C 545BEE is acting up. A slot loaded one would be nice.....

Can anyone help me identify this diode? They come from an Audiosonic ST-8000, about which no information can be found. It appears that the diode with 689mv is defective.
I want to replace them both and thought about 3x or 4x 1N4148, but when measuring I can't get an exact result/match. (By the way: Uf 2.59v on the tester gives Uf 2.21v on my multimeter with leads)
Does anyone have any good advice? Thank you!

Here is a YouTube video of waveforms and harmonics in a simple raw DC power supply. A good look at how waveforms are at different points in the supply.

Login to view embedded media

'Lil Stovey'



It's kind of an art project, but also a fully functional 5 gallon bucket shop sub with a chimney port.



8" driver from a Sony bookshelf system

Metal, wood, plastic, bedliner, acrylics





I have a few build photos but it seems pretty self-explanatory?

It was fun having an excuse to use an external port.

The holes in the chimney are so the port length is at the holes, but the chimney is visually as tall as it is. I think they might whistle a little at the very highest volume due to the relatively sharp edges, so I probably won't do that again. The straight part of the chimney is removable and usable at a higher tuning without it (the elbow alone is around 8 inches of port length, best as I could tell).

I learned that common buckets are HDPE, so nothing really sticks to them... I used PL 3x as a sealant but the end caps are mechanically fastened with (many) screws.

It's running full range in the video but will be crossed over to a matco 'bumpboxx' (which seems to have a nice volume-controlled line-out). And the video is just to show off the looks, not for the sound, fwiw

I have recently purchased a Matrix 805 from a friend. Have been using it since the past 3 months and it performed very well. Since last morning, I am only getting the tweeter to work on one speaker. The mid-woofer is not working. Tried swapping to the other amp and problem is definitely with the speaker. The tweeter is working well. Opened the back panel and everything seems connected perfectly well at the binding posts as well as the driver side in the front. Please guide me if this is a Crossover problem and how I can diagnose it. Thank you

Discontinued by miniDSP, but this processor still delivers the goods, especially on a channel-per-dollar basis.

In short:

• 2 channel input (1 stereo SPDIF coaxial in or 1 Toslink optical in, both stereo)
• 8 channel output (4 stereo SPDIF coaxial outputs)

Read the plugin spec here.

Works perfectly and will include the plugin software for both Mac and Windows for free.

Available for local pickup in the SF Bay Area

Asking $140 shipped in the US but open to reasonable offers. Global shipping available, message me.
Thanks!

Also selling 2 Soncoz DACs that I used with this miniDSP to create a killer budget active signal path.

Hello everyone

I’m thrilled to join the DIY Audio community. As an avid enthusiast of audio engineering and a DIYer at heart, I’ve been passionately involved in creating and tweaking my own audio equipment.

My latest project, a headphone amplifier that has CR-type phono equalizer and I have employed a circuit that applies the same amount of feedback to both the inverted and non-inverted outputs of the balanced output.

I look forward to exchanging ideas, learning from the community, and contributing to our shared passion for high-fidelity sound.😊

Best regards, Eri Hiromu

For repair of an old Focal Point Source Aria Five (from 1993, Manfred Zoller HiFi Design)
I want to know the difference between this two chassis models.
5K013L is to find here:
http://nedlab.com/wp/wp-content/uploads/2014/06/5k013l.pdf
http://www.diyaudio.com/forums/swap-meet/182448-4-focal-kevlar-5k013l-midbass.html
5K4211 is to find here:
http://www.diyparadiso.com/datasheets/speaker/focal/5K4211.jpg
Which of this both is the best choice?
Thanks for advices.

The I-Select board takes the selector functionality and volume control from the old mesmerize boards and implements in a standalone fashion.



This gives one a relay based selector control, relays perform reliably with great longevity and have superior electrical isolation characteristics.

This can also act as a standalone passive preamplifier, or be tied to the input of the DCB1, DCG3 or any other type of input for that matter.

The boards are $16.00



I am making a minikit available for this. It will come with no volume control, 4 inputs and a selector switch. However, read the guide, there are other ways to set this up to gather off a previous DC output voltage, and to power another unit if need be. So this is just a 'basic' type kit. More relays available on request.

4-EA2-12NJ-12V relays
8-1N4003G
1-EEU-FC1V222-Panasonic FC 35v 2200uf
1-Molex 2P Terminal Block Black
1-Headers & Wire Housings HSG 7P SINGLE ROW
1-Headers & Wire Housings 7P STRT 1 ROW GOLD 5.5MM MATING PIN
4-Headers & Wire Housings 3P STRT 1 ROW GOLD 6.8MM MATING PIN
4-Headers & Wire Housings HSG 3P SINGLE ROW NON-POLARIZED
25-Headers & Wire Housings 22-24 TERMINAL BULK
1-Wakefield 637-10ABPE heatsink
1-7812 voltage regulator
1-Rotary Switches ROTARY 2POL 6POS NS Alpha
1-Vishay MBB Through Hole .6w 10k 1% 50ppm
1-Kemet Film Capacitors .1uF 100volts 5%
1-20ma LED
$36.00

This thread is for a group buy for a new Salas board L-Adapter.

This regulated supply can do ~1.5 to ~20V higher current rates than previous shunt supplies offered by Salas. The board is 136mm x 63mm, 2oz copper, 2mm thick.

The amount of Digital Devices such as Raspberry Pi, wall-wart devices and DACs using lower voltage and increased current is growing and the desire for non Brick or USB power supplies has come knocking on our door for some time.

L-Adapter Technical and Build Thread:

https://www.diyaudio.com/forums/power-supplies/336685-adapter.html#post5761291

The Board L-Adapter USD$18 each




Built up pictures








LED orientation



The BOM for the board is really strait forward. The Transistors do not change regardless of voltage or current. All parts are available from Mouser for those who have easy access and shipping arrangements with them. Minkits will be offered and can shipped as flats internationally for a lower shipping price than full kits. Full kits are going to be offered as well, but will demand a significantly higher shipping costs as the heatsinks and caps require package shipping internationally. Minikits and full kits ship domestically at a lower rate. The full kit based around the expected needs to power a Raspberry Pi. Some lower current devices may not need the diode heatsinks, some higher current ones will need to mount the diodes and the TO-3P transistor directly to a chassis and or heatsink.

BOM below.
L-ADAPTER BOM DiyA - Google Sheets

Why these parts were chosen Diodes, Fuse, HS
The diodes are rated up to 200V and 30A, so these are higher than the regular MSRF860 that I ship with other kits. These can handle more current, have a low vF and are fast recovery. The Fuse is slow blow version chosen via Salas that will be able to handle transients above it's 8A rating. It's being used in the Power supply as part of a CRC Filter. The heatsinks are chosen for common dissipation needs.
Higher cap values can be used than 6800uf, but may need a In-rush current limiter to avoid problems. Caps should all be 105c rated, as this unit can produce heat when being run hard!

Sign up sheet is in my signature. GB Close date is not yet chosen. Please follow thread for updates and interest.

This is the official GB thread for the DCG-3 and DCSTB Power supply boards.

The DCG-3 is a JFET and MOSFET, 2 stage-single ended preamplifier/headphone amp
The preamplifier uses a DC Servo and three MOSFETs, hence the name DCG-3.



There is also simple series DC stabilizer designed to compliment the circuit. It is called the DCSTB board. It is of mirrored Configuration and is sized to fit in same width footprint as the preamplifier board. A BIB SSLV1.1 board or other regulator can be used as well, if you know how to set to 17.5V recommended voltage as well.



The main construction thread is located below. Most technical questions should be approached there.

Salas DCG3 preamp (line & headphone)

For selling and delivery purposes, this thread will do.

The costs for the DCG-3 board is 20.00, and 25.00 for the DCSTB Power supply.

Additionally, Transistor kits are available for components that need matching and can be seen in detail in the later part of the my kit blog

Salas Board Minikits and Full Kits - diyAudio

Here is a picture of my prototype running.


Board sizes are
DCG-3 -160x50mm
DCSTB- 160x106mm

The sign up sheet is in my signature for these boards, and are located on the right of the spreadsheet. Once enough boards are in demand, I will post the GB close date on this thread and in my signature. You should also receive a private message if you have signed up on the thread.

This is a GB for Salas Reflektor-D and Reflektor-Mini Power supply.
This is a Low Voltage supply designed specifically for digital.
3.3V to 7V at 600mA max output using board level sinks.
Schematic and build info in PDF attachment at the bottom of post.



In the words of Salas -

The Reflektor concept is a shunt voltage regulator made around a current mirror circuit. To keep equal current between its input and output legs, the mirror reacts to flow disturbances and drives a MOSFET in opposite direction. A current loop simple regulator is another way to describe it. Specifically Reflektor-D is a version focusing on the voltage region common for powering digital source projects. For convenient mounting and setting it utilizes board level sinks and simple ways to choose its current limit and voltage output levels


The board is offered in a Matte Black 2MM thick PCB with 2 OZ copper. The cost is $16.00 plus shipping.




It was a very easy build, it took me 45 minutes to complete and then start testing, and got near target voltages rather easily via the LED swaps.
Three different kits will be offered. A transistor kit, a resistor kit, and a full kit, which includes all parts for board except standoff parts and MOSFET bolts and nuts for the heatsink.




The Reflektor-Mini was created to be installed into some tight spots. It is a much smaller board that will require its MOSFETS to be chassis mounted and electrically isolated for sinking. It keeps a lower height profile too. It is DC input only, needs an incoming DC feed.
It uses a J2 2SK117GR to stabilize and tune output voltage. For keeping small size It has a conventional 2Pin output. It's a slightly more complicated build than the original in some aspects and simpler in some other, but will serve it purposes in being a potentially lower cost unit to construct, as well as a smaller footprint.





In conjunction with the Mini release, the DC Flexy board is introduced. It allows for use of industry standard Snap-in Elcos or 4 pin/pole Mundrorf M-Lytic AG+. These boards can be used as Raw DC units to front end the power supply for the Reflektor-D Mini. They come in a breakable pair so to be used in double mono or multi isolated configurations of more than one regulator to feed. if used in a system of one regulator only, the spare may be broken off and kept aside since it can be utilized in a variety of projects needing Raw DC. Even for the standard Reflektor-D when done in its DC input mode version.



The signup for the boards is in my signature.

Hey, has anyone tried Broskie Cathode Follower? What about sounds in comparison with discrete opamps? I am searching for tube output stage for AK4493. What type of tubes will be the best? I can buy ECC82 Valvo NOS for reasonable price

Hello All,
I have a 19-year-old Mark Levinson model 431 power amplifier. After sitting unused for about 2-years, I wanted to compare it to my current amplifier. I powered it up for a few days to let it warm up. While checking the input and output to adjust gains for the two amplifiers, I noted a -140mV DC at the input, the output was 0VDC. Both channels measured the same.

My question is, can that be considered normal? The manual says the input is a balanced topology, but I use it in single-ended mode. I noted that if I add a load (if that is the proper term here) of about 1K, the DC goes to zero.

Thanks for any help
Cheers,
ceulrich

I plan to recap this crossover and put new speaker cable binding posts on this ESS AMT bookshelf

I emailed ESS. They told me that they're looking for the manual and schematics of this ESS AMT Bookshelf.

here is the schematics I found:
https://audiokarma.org/forums/index.php?threads/ess-amt-1d-schematic-upgrade.306388/




On this particular crossover, which part should I replace? Thank you in advance!

I'm building the streamer using these instructions



However, all I need is a spdif out to the DAC.

I understand that I can use the TransportPiAES board instead of the HDMI board. But I'm trying to cut costs - can I use the TrasportPi MkII instead? The author mentioned it, but it looks like it's a different shape. Will it fit? Or what can I use for the spdif out with this configuration?

Thank you
Ken

Good day all. I ecently got a Velodyne CHT avtive subwoofer from a friend. Im needing some advice regarding this subwoofer....and Im hoping to get it here. When I initially plugged it in....it worked but as soons as I increased the volume...it would clip and the relay would kick in. It would only start playing again once I lowered the volume. I checked voltages going to both op amps and its spot on 14.8 volts. What i did find is.... on the attached schematic..... Q709 and Q708 which are the output transistors base-collector come up as a dead short when testing with a MM on continuity. On Q713 and Q716 the collector-emmitter comes up as dead shorts using the multimeter set to continuity. There are numerous other components in the circuits like resistors, diodes and even caps that do the exact same thing. Polarized caps do the exact same thing when testing with a multimeter set on continuity...but it only does it for a second and then no continuity. So far I have replaced all the smaller transistors...becasue I had them. Im hoping some of the more experianced techs could maybe have a look at the below schematic and maybe offer some advice on what to check...if at all possible. any help would be appreciated. Atatched schematic is from Velodyne support. Thanx in advance.....have a blessed and prosperous 2024.

Note: this curve tracer project has a come a long way, and is now called pypsucurvetrace. This thread is for documentation, development, and discussion PyPSUcurvetrace. The software is available as a Python 3 package at GitHub and documentation is available at ReadTheDocs.

-----------------------------------------------------------------------------------------------------------------

I recently was looking into curve tracers for power transistors. I want a setup that allows straight-forward and automatic interfacing of the curve tracer to a PC (for data acquisition and also for instrument control). While there are a few testers available for small-signal transistors, those devices don't seem very useful with power transistors.

So... I was sitting in my workshop, fiddling around with my Voltcraft PPS bench power supplies. I remembered that these PSUs have a USB computer interface, and it's actually not so difficult to talk to these PSUs via USB. I have used the PPSs at work with a little Python program that sets current or voltage limits, and reads the true voltages and currents from the PPS. The readings are surprisingly accurate (as confirmed with different DVMs). The different PPS models have different voltage and current limits, but most models will have no problem to torture a power transistor.

The idea would be to use two PPS PSUs with a computer to determine the voltage/current curves of a transistor as follows:

• The first PSU provides the voltage across the transistor and the current flowing through the transistor.
• The second PSU provide the voltage applied to the gate or base of the transistor.
• The computer sets the gate/base voltage (second PSU) and then traces the curve for this gate/base voltage by varying the voltage and current current limits at the transistor (first PSU).

I am pretty sure it would be straight forward to scan the U/I characteristics of a power transistor this way. However, the process would be rather slow (say 1 second per data point or longer), because the communication between the computer and the PPS is slow, and the PPSs are slow in setting the and reading the voltage and current values. I guess it might be tricky to keep the transistor at a sufficiently constant temperature during the test sequence. Do you think this might be an issue? Do you see any other issues with my idea?

Hello Everyone!

Recently ive been working on some amplifier project and im using the TDA1558Q. Im very confused with this chip, First of all ive copied the exact stereo circuit with the one in the datasheet and im facing problems. While pin 14 is low (Mute) everything is normal about a 100mA draw, but when the pin 14 goes high (Vp) it draws 1.2A with no external input and it measures 2.2V dc at the inputs and 6+V dc output. I thought it might be a faulty chip so i used a new one it does the same thing. Anyone that knows what is going on and what am i doing wrong with this because im very confused.

I sell PCB for MM preamplifier Actidamp MK3, designed by Mr. Dudek. It is a preamplifier with active damping. Another possible improvement of modern operational amplifiers.

I will supply all documents to the interested party.

Price: 30€ + shipping

Payment: Paypal, Wire transfer
Worldwide

Dear All,

My Nad C316BEE is broken : it does not turn on !
To fix it, I am looking for the schematics ( service manual ).
Of course there is service manual online, but for only the initial version.
Mine, version V2, has the Main VM3.0 card, with a different diagram.
Also totally different the POWER SWITCH board.
Without these diagrams, I do not know how to repair ( possible that it is problem with +5volts lost ? ).

If any of you had the diagrams ( sm will be the best ) for this V2 version...
And if he agrees to communicate them,
I will be eternally grateful to him !!!

Raymond
( pardon me for my poor English, I am French )

Let's create this thread with the same purpose as the tube photo gallery thread, but about transformers. We can show off pictures, measurements, explanations, etc, mostly for fun and potential sharing of knowledge.
I'm starting with my most recent project of freshly wound coils, that are specially made for SE high Rp output stages with Rp ranging from 10k to 24k in series primaries and 2,5k to 6k with paralleled primaries.

NOTE: This is still a work in progress, but the current design has proven to work rather well and has great fit and function at this point. Hardware needed is M3 bolts (8-20mm bolts work, ~12mm is ideal) and an associated M3 nut.

I'm giving these iterations away for free as a thank you to the diyaudio community. Interested parties just send me a prepaid shipping label so no money needs to be transferred. Reach out via PM to coordinate.

I created the wire post to help with wire separation and management in my F5m chassis (but works on all amps), and plan to share a final product as I go through iterations to optimize the design. There are now 4 different versions that are based on height (57mm, 100mm, 130mm, and 160mm). They all work well and create great zip tie points to hold wiring firmly in place and appropriately spaced (that part is up to you).

These mount to the bottom plate with a M3 bolt and nut (nut is technically optional). It will thread securely into the PLA print as the pocket/hole is 19mm deep and smaller than the thread outer diameter, however, there's also a slot if you want to add additional "rock solid" connection using an M3 nut (just slide the nut down the slot prior to bolting the post to the plate so the bolt threads into the nut).

The whole point is to create a structural point to connect to that guides and separates the various wire runs (filter board to amp board, amp board to speaker out, etc...). The goal is to make numerous versions for a variety of applications you can print at home (or use a buddies 3D printer, maker space, or fab house). The inspiration is from aerospace industry wire posts used to control and separate wire runs.

Although the material is "PLA" (Polyacitic acid), it's thermal properties seem to sill hold up inside the class A amps. I have not seen any deformation due to heat, even when the post is very close to the hot heat sink (heat sink is 60°C and PLA softens around 100°C) so as long as the loads are low (aka, just holding wires in place), the post does not deform under the heat loads.

I printed a bunch of these to give away to interested parties. Reach out via PM if you're interested.



M3 Nut just slides into the slot before bolting on.

TUBA completed as shown. Probably better for shipping not to have heat sinks mounted. Contact pins and bridges are included although they didn't come out in the pic.
100 +s&h.
Enjoy!

I was wondering if there is any support for establishing a “library” on DIYAudio consisting of different designs for custom punch/machining patters (in DWG format) for front and rear panels of various Modushop chassis?

For example patterns developed and actually used by members could be posted in an organized fashion, perhaps by chassis type, size, and application (e.g., generic preamplifier, ACP+, H2). Each design would be accompanied by a short description, e.g. 2 RCA input in 1/2” hole; 2 XLR D/size outputs, and so forth. One could then open files to see if configuration meets their needs and then submit them to Modushop rather than possibly incurring a drafting fee.

I’d be willing to work on this if there was interest and support from DIY Audio.

I’m asking if someone in Italy could help me contact the seller of some drivers I am interested in buying. They are listed on the subito.lt website. To be able to contact the seller I need to log in to the site, but I cannot do that as you need a Italian mobile number for the verification process. Would someone be kind enough to help me contact the seller?

Not many options for USB devices that can be used as a DSP/Xover for running 2 way active speakers? After lots of looking I've only found minidsp 2x4hd, sound blaster X3 and X4, and Asus Zonar U7.

So few options exist? There's like hundreds of single channel/headphone output USB DAC's.... but none have the ability to be used as active crossovers due to having only one output.
What are people using? I bought a used X3 and played some music (before trying it with apps to control 2 channels for the xover) and it doesn't sound clean enough to me to consider using it. I'm assuming the X4 is worse, as it's specs are worse. Then the minidsp 2x4hd has a rather poor review on audiosciencereview, and some people say the top end is missing some clarity. I'm coming from a pretty decent DAC I guess, or the X3 is this bad? So I'm worried the minidsp will sound worse too.. will it?

Any other decent performing mulitchannel output DAC I can buy without selling a kidney? It seems to be slim pickings. Also I prefer line-level output, or RCA.

SOLD!!

For Sale is one Sony VFet2 amplifier kit. You'll get ALL of the interesting/good/hard to find parts in closely matched pairs/quads. You just need to add the generic bits, a power supply, and a chassis to enjoy this beautiful and awesome amplifier.

This kit includes the following:

One pair of original DIYAudio VFet heatsink mounting brackets with predilled holes appropriately spaced for TO-3 cans
One pair of original DIYAudio VFet2 boards
Two complimentary pairs of original Sony Vfets: 2SJ28s measure 7.5v and 7.6v, 2SK82s measure 7.8v and 7.9v
One matched quad of original Toshiba jFets: 2SK170 measure 9.9mA and 9.8mA, 2SJ74 measure 9.9mA and 9.7mA
One matched quad of original Toshiba Fets: 2SK2013 measure 2.27v and 2SJ313 measure 2.27v
One pair ZTX450 transistors (unmatched)
One pair ZTX550 transistors (unmatched)
One pair of IRFP240 transistors (unmatched, but from same die)
One pair of IRFP9240 transistors, matched at 4.16v
Mica insulators for VFet TO-3 cans

Original Toshiba Front End Transistors:
2SK170/2SJ74 jFets were sourced from Spencer at FetAudio years ago. These are known/verfied original Toshiba jFets and a well-matched quad. 2SK2013/2SJ313 Fets were sourced from DIYA member NicMac long ago. They are known/verified original Toshiba parts and a well-matched quad.

Original Sony VFets sourced from Acronman at CircuitDIY years ago. These are known/verified original parts and a closely matched quad.

Here's a photo of everything that is included (oops, the ZTX450 transistors are not in the image, but still included):



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Hi folks,

I found a working Technics SA-303 and want to replace the stock R703 (470ohms - 5 Watts) due to heat damage on the board (circled in red). I don’t think there are any faults. I’ve measured 40 volts across the resistor. That is 3.5 Watts for a 5 Watt rated resistor! I found a thick film 10 Watt TO-220 package resistor and a heatsink that will fit in the volume (30mm x 30mm x 30mm). Wondering if there is a more common replacement for these power resistors. All of the other 10 watt rated resistors are too big. Thanks. Schematic and photo attached.