Hi all hope somebody can help ..... I am after a schematic layout for this built up board ...... the reason is I have 24v transformer and I want to connect it so that I have +30v and ground. Presently this board is designed to give +VE and -VE and ground. If I connect AC and ground it works but I am only getting something like 1/4 wave rectification. I want to cut the boards tracks and re connect the -VE bank so that it works as positive.......... the transformer would then connect to each AC input but not ground....

The problem I have is this is dual layer circuit board .... so has anybody built one of these and can they help regarding a general schematic...









https://oi1064.photobucket.com/albums/u367/D3savage/Top again_zpsnkkeg3kj.jpg?t=1594110071

https://oi1064.photobucket.com/albums/u367/D3savage/Top Left_zpsyh7bgqkz.jpg?t=1594110096

Hi there,

i have a SPL Dynamics S2000D, Powersupply was broken, few parts on the Driverboard from PWM was missing, but i got this fixed. PSU runs fine.

On the output section i have only on 4 of 8 Fets signal on the gates.



From the IRS21844 the LO-signal works. The HO don´t.

When i measure on VB-pin, i have only few milivolts. Could this be right?

Thanks

Hi.
I have a pair of B&W DM602s amplified with Marantz PM6006.
My interest is to add two subwoofer speakers, one for each stereo channel.
The idea came to me when I saw a design in which the stands of the speakers were made with the boxes of the subwoofers.
It was called RS BASS STANDS.
Dayton Audio RS 225-8 speakers were used in a 1.3 cubic foot cabinet.
The link is this:
http://projectgallery.parts-express....rs-bass-stand/
My question is this:
Can I connect an 80hz passive low pass filter between the amplifier and subwoofer and in turn connect an 80hz passive high pass filter between the same amplifier and the B&W dm602 boxes ?.
Would it be correct ?. Would the impedance of the set be affected?
Filters are these
Parts Express 80 Hz Low Pass 8 Ohm Crossover
80 Hz High Pass 8 Ohm Crossover.
Thank you and I await your opinions.
Jose.

Hi,

I am designing a two way speaker with a loaded tweeter on a waveguide and a 7" woofer.

Looking at using one of these two wave-guides, the Monacor W300 and the WG-148R by Vistason. The Vistason has USA distribution (low shipping available now) but the Monacor does not, and the shipping is kind of pricey at this point due to Covid. The driver can be attached directly to the Vistason but you need a 3d printed adapter for the Monacor

I am thinking about a XT19, SB19 or the XT 25.

It seems that the Vistason loads at 650Hz while the Monacor at about 450Hz (see attached graphs). Both are done by the same person under similar conditions but they are different tweeters, that is the best compassion I could get to determine the point of loading.

How can I calculate the minimal crossover frequency on the wave-guide ( I am shooting for the vicinity of 1500 Hz)?

Regarding the choice of waveguide, is the Monacor worth waiting for and the extra work of the adapter, or does the Vistason provide the desired frequency point and a good compromise?

Regarding the graph, Sound pressure at angles (15 °, 30 °, 45 °, 60 °)

Tks in advance

Hello everyone, does someone has a spare output coil for this amplifier Twisted Sounds 8.5k board if so please let me know. Thank you.

I’m looking for Neurochrome parallel 86 boards. These were designed for the L.M 4780 chip. If you have any spares please send me a PM.

Hello,

I have a hi-fi stereo system sound with separate pre-amplifier (with source selector, tone control, etc) and power amplifier. I find my pre-amp great but the problem is that all of its controls are sliding style (including the volume that have separate sliders for R and L channels - this is a real pain!).

I'd like to know how hard is to build a small box with a single rotating stereo signal attenuator to place between my pre-amp and power. So basically the idea is to leave the volume controls of my pre at the maximum position and use the rotation knob to control the volume.

PS: my electronic knowledge is limited to solder things and basic recognition/comprehension of parts.

Thanks!

Hi,

Please find below the way I managed to connect 2 devices on I2S output/input, using a simple cable.

The source is a USB>spdif interface, having a I2S output over a HDMI plug : Gustard U12
The « receiver » is a FDA (Full digital Amplifier), a QLS-Hifi QA100, having a I2S input over a RJ45 plug.

In my case, the downstream device is a FDA, it could be a DAC of course.

I do not have background in electronics, thus I just made a trial, just by connecting the right pins from each side.

The result is fairly simple : it works perfectly. No hum, no EMI that alters the sound etc.

In my case, the SQ is equal using this I2S cable connection, to a standart toslink link between the Gustar U12 & the QA100.
Thus, no gain in this exemple in using I2S.
But after discussion with others we ends up to the conclusion that it is due to the QA100 that have very good other inputs (toslink, aes, coax, bnc), this makes the difference between these standard inputs & I2S negligeable.
For instance, using I2S on another FDA like I.AM.D V200 makes the SQ much better than coax or toslink inputs.

***************************

These are photos & pics to see what I did :

Wires & color code & pin No in RJ45 & HDMI cable/connectors : basics
Basicaly, as I had no idea about pins in HDMI & RJ45 ports before that job, I just found these info thanks to our mate Google.

HDMI side :
HMDI plug => these are the pins numbers :
HDMI wires inside : 7 simples wires + 4 main foiled cables each made of 3 wires
=> drawing :
=> same info with pins No :
=> cross section cable view :

The digital data flow FROM the Gustard U12 HDMI input.
This is the info regarding the pins No & functions on its I2S/HDMI ouput.
It is available on the seller web page.
Of course you need that info to go forward ; I don’t know if these relation pins No vs function is commom to all manafacturers… I would say so. Ask for the manufacturer of your device to be sure.
=> layout :


RJ45 side :
The digital data flow TO the QA100 I2S input over RJ45 plug.
This is the info regarding the pins No & functions on its input :
=> simple photo on the QA100, you have all the info =>

RJ45 cables & pins :
1st, I noticed there are 3 types of RJ45 connectors, with the references : EIA-568-A or -B or -C.
These are the differences, it is about a change in the pins No (FYI)
=> 1st type => EIA-568-A & -C

=> 2 type : EIA-568-B

Photo of the RJ45 I used, it is a B type, and the color code you can see through is OK :
Tricky point : on the 2nd RJ45 cable I tested, it was written on its side it was a « C » type, but the wire colors you could see thru the connectors indicated that it was a « B » type, thus I connected it like a B type and it was OK. So, check this.


Which wire on HDMI side corresponds to which wire on RJ45 side ?
Basically, according to the photo of the QA100, the I2S on the RJ45 side requires only 5 wires (http://img15.hostingpics.net/pics/88250820151119154231.jpg ) :
pin1 = LRCK
pin3 = DATA
pin5 = BCK
pin7 = MCLK
all other pins = ground

On HDMI side, you have, according to this diagram http://img15.hostingpics.net/pics/644095GustardU12HDMIpinscode.jpg you have more « useful » pins.
For instance, you have a +5V pin, and 4 pairs => DATA+ & DATA -, BCLK+ & BCLK- etc…
So, to make it simple, I thought it is a good idea to let the RJ45 port to lead that connection !
Thus :
I don’t care about +5V pin on the HDMI side, I don’t care either about the DATA- BCLK- etc…
I found nice & straight forward to connect : DATA (on RJ45) to DATA+ (on HDMI) etc… and connect 1 ground pin on the RJ45 to 1 ground pin on the HDMI side.

This is it.
Then I just had to find & connect the wires like described above.


Inside RJ45 & HDMI cable/connectors : wires ID

Inside HDMI cable :
- take off the PVC => http://img15.hostingpics.net/pics/75532020151121231715.jpg
nice shield + foil
- open the foil => http://img15.hostingpics.net/pics/32240820151121232323textarrow.jpg
you have the 4 groups of 3 wires, as it was showed on this drawing (« + » pin, « -« pin, and ground> http://img15.hostingpics.net/pics/551890HDMIcablefrontviewPinsNofunctions.jpg
- please note that the color of foils & inside wires does not match the diagram I found, this one : http://img15.hostingpics.net/pics/740755HDMIcablecolorscode.jpg
thus, the game was to guess > trial > error > trial. 2 small mistakes, but no time lost on this.

Inside RJ45 :
let’s look at a SSTP cable. As said above regarding RJ45, you have 8 pins, corresponding to 4 pairs of 2 cables.
take off the PVC => you found a shield (it is cut on this photo) => inside the 4 pairs, foild => inside this tiny foil, you find a pair.
=> http://img15.hostingpics.net/pics/60183620151122164714.jpg
According to the pins used in the I2S connection written on the QA100, and the basic data regarding RJ45 plug B type, you realise you need only to deal with the white wires, the other ones will correpond to « ground ».

Usually, each pair is : full color on 1 wire, and color/white on the other wire ; easy to distinguish all these 8 wires.
In my case, in this exemple, no « color/white » wires… they are only white… no a big deal to distinguish & avoid a complete mess between all these full white wires, but really annoying that « color code » seems to be « optional » whatever the cable producer…

Look at the connection : http://img15.hostingpics.net/pics/42762820151122164803.jpg
the orange wire is on the pin2 => it is a B type cable (although it is written « C type » on the cable…). Thus you know which wire at the cable end correponds to the pin at connector side.


1st connection trial : wire to wire

The 1st test consisted in connecting the 2 cables like this :

Fairly basic & easier to test the right link between pin & cables. For instance, useful when pins No & ID given by the manafacturer of the interface or/and the downstream device are not correct.
I made a mistake and inverted on the HDMI side the wire from the green foil (LRCK in fact) & the silver foil (BCK in fact) : I had some sound, but full of EMI etc…After inversion => dead clear & nice sound.


2nd & final connection trial : RJ45 wires on HDMI connector

The 1st trial allowed to understand the pin/wire links & ID.
Then, to have a ready to use cable, with EMI as low as possoble, I needed to soldier it somehow.
The best way I found was to soldier the RJ45 wires on the HDMI connector.

HDMI connector : inside
this is the connector =>
you have some silicone aournd to take off…
then take off the pins you do not need using cutter & clamp.
As seen before, I chose to deal with the pins of the HDMI, only the DATA+, BCLK+, LRCK+ ; MCLK+ (seen here : http://img15.hostingpics.net/pics/644095GustardU12HDMIpinscode.jpg )

ATTENTION : I kept 1 pin links to the ground.
Because on this photo => http://img15.hostingpics.net/pics/52331920151122100016.jpg for fun, I cut the ground link => big hum => I wired back 2 ground wire (1 from each cable) => no hum => nice & clear sound

So finally, I have the super nice HDMI connector
side 1 => http://img15.hostingpics.net/pics/53591120151122153356.jpg
side 2 => http://img15.hostingpics.net/pics/68408520151122153414.jpg ; here the non-green wire is the ground.

RJ45 cable prepared for soldering.
the RJ45 is fully open, no sheild, foild etc…. Ready to be soldiered on the connector => http://img15.hostingpics.net/pics/97436520151122174440.jpg
The trickiest part of the job for a newbie in soldering is ahead…

Note that on this photo you have 2 RJ45 cables.
Why ? because I have 2 QA100 amp. 2 FDA used in passive BI-AMPLICATION for my floorstanding speakers.
The nice thing with this type of cable & I2S connection is that, as mentioned Globulegl on a other thread, there is NO ISSUE regarding impedance voltage etc… too tricky stuff for newbies…
With I2S, just soldier 2 RJ45 cable on 1 HDMI connector, and data will flow without any issue from the HDMI interface to the 2 device downstream on RJ45 port, in sync : perfect solution for spliiting digital audio. Much cheaper than optical splitter of course, & even more cheap than my Mutec MC1.1+ (but the Mutec MC1.1+ can handle inputs… with this cable, you split only the I2S)

RJ45 cable soldiered on the HDMI connector
side 1 =>
Side 2 =>
So, as you can see :
- the blue wire, alone on the ground pin
- and 2 wires soldiered on each pin, because 2 RJ45 cable for my biamp.
- dots on the white wires, it was to distinguish the color of each pair (given than in that bloody cable, the color/white wires were fully white…)


RJ45 wires & HDMI pins combination

Thus, the combination to link the Gustard U12 to the QA100 is the following :

HDMI connector.
As mentionned above, on RJ45 side we need 4 « active » pins (thus 4 wires) + 1 for the ground.
Thus on the HDMI connector, I kept the following pins : No 1 - 4 - 7 - 10, for the « active wires » ; and the pin 11 to connect the ground.
Reminder, see here the pins No & location on the connector =>

On the HDMI pin 1 (DATA+), you connect the RJ45 pin 3 ; white/green wire of the RJ45 cable type B; or the white one in the foill where you have the green wire.
On the HDMI pin 4 (BCLK+), you connect the RJ45 pin 5 ; white/blue wire of the RJ45 cable type B; or the white one in the foill where you have the blue wire.
On the HDMI pin 7 (LRCK+), you connect the RJ45 pin 1 ; white/orange wire of the RJ45 cable type B; or the white one in the foill where you have the orange wire.
On the HDMI pin 10, you connect the RJ45 pin 7 ; white/brown wire of the RJ45 cable type B; or the white one in the foill where you have the brown wire.
On the HDMI pin 11 (for instance, or another one linked to ground according the Gustard U12 info), you connect a full colored wire of the RJ45 cable, I chose blue…

As you can see on this photo for instance, my soldering is pretty awful, but it works… so why bother with I2S ?...

***********************************************

Sorry if this post is too long and/or not clear. Feel free to ask if you can’t catch a word about this tricky but simple connection.
Hope it helps
Rgds

I've just dug this old PSU out of a pile of junk.

Just out of interest I'm rebuilding it to see what it is like.

My question is. what modern MOS-FET would you use in this application ?

Originally it would have been a HPWR6501 but that is missing.

For sale 2 Antek AS-4458 power transformer 400VA 2x58v @ 3.4A, 12v @ 2A, 18v @ 2A
Never used. 1 has been opened.

$80 shipped in the US

I have for sale a VZAudio amplifier control system. A amplifier control board version 5.3 I believe, DC detect and amplifier temperature sensor.

I had the system installed in Tribute 3000 amplifier and it worked perfectly. I no longer use the amp and it has been disassemble. I have another set of control boards and will no longer need these.

$165

I have for sale a never used pair of BMS 12n630 neodymium 12" subwoofer drivers. I opened one box just to look, the other box is unopened. Neither have been connected.

I purchased these about 3 months ago from Assistance Audio thinking I was going to build 2 subwoofers but changed my mind.

$285 ea. plus shipping

SPECIFICATIONS
Application Subwo
ofer
Nominal impedance:
Ohm
4 or 8
Power handling AES noise:
W
600
Sensitivity (1 W / 1 m):
dB
96
Frequency response:
Hz
25 - 300
Voice coil diameter:
mm
77 (3”)
Voice coil material:
Cu
Voice coil winding depth:
mm 26
Magnet gap depth:
mm
10
Basket:
Cast Aluminum
Effect. diaphragm diameter D
mm
252
Frequency response measured 100 W (28.3 V) at 1 m in a closed enclosure of 50 liter incl. 2nd and 3rd harmonic d-is tortion raised 20 dB.
Impedance – 8 Ohm driver

THIELE-SMALL PARAMETERS
Resonance frequency:
Fs
Hz
28.6
DC resistance:
Re
Ohm
6.00
Mechanical Q factor:
Qms
6.24
Electrical Q factor:
Qes
0.35
Total quality factor:
Qts
0.33
Equivalent volume:
Vas
l
85.5
Moving mass:
Mms
kg
0.127
Mechanical compl.:
Cms
mm / N
0.24
BL factor:
BL
Tesla m
19.8
Effective piston area:
Sd
m2
0.0498
Max. linear excursion:
Xmax
mm
±8
Voice coil inductance:
Le1k
mH
0.68
Le10k
mH
0.44

I am fooling around with some Eagle parts. Just wonder if anyone happen to have an Eagle library for the CMC teflon 9-pin tube socket? 🙂

Thanks.
Rol

Any suggestions what to do with 4 of these:

Peerless TG9FD 10 08 (Vifa 9 BG 119/8 Fibre Glas) kaufen bei hifisound.de

There are some box plans on that site too, but for a pair. I got 4 to put in motion.

I am thinking of an opamp amplifier where I could change its gain by changing resistors.
Using large SMD resistors, is there fasteners like small fuse holders to hold such resistors.
Do you see solutions that would achieve reliable contacts.
I do not want a pot, because I need fixed gains that are extremely stable, looking for no gain drift.

So I need to build a "subwoofer" for a Pioneer AVR; the AVR has a built-in crossover and a high pass filter, so I'm aiming for 45 to 200 Hz as determined by these.

I like closed box sound and don't want to build too big; 25 liters is fine.

I am down to a choice of two drivers: Dayton Audio DC200-8 and HiVi M8N. They cost similar money where I am.

A WinISD simulation gives slightly better bass in a 25 L box for the M8N, but this depends on speakers fitting the advertised parameters; and some reviews say the M8N only really fits them after long burn-in. I play music very quietly most of the time, so I am not sure my usage would provide effective burn-in.

So which one should I pick, after all?

Hello. Housecleaning continues...

DIYSG products:
1 pair of new, unused EOS-6 waveguides for use with 1” exit compression drivers. See photos below, the tooling marks are from the manufacturer and will obviously not affect performance. Asking $20 for the pair (OBO)

1 pair of new, unused SEOS-15 waveguides (matte) for use with 1” exit compression drivers. SOLD

Dayton Audio products:
These were purchased to build an inexpensive, compact, full-range monitor

1 new, unused DC28FT 1-1/8” truncated silk dome tweeter. See group photo. $14
1 new, unused DC130AS-8 5-1/4” shielded woofer. See group photo. $14
1 pair of new, unused ND140-PR aluminum cone passive radiators. One box unopened, see group photo. $16 for the pair.

I will sell the Dayton lot for $35

CONUS ONLY, all prices plus shipping.

SEE POST #4 FOR PHOTOS

Hello,

Has anybody here used Welcome To Sound Audio Manufacturing for their PCBs?

What has been your experience?

Thanks;
Leo

Hi !!

I have a Nad 2600A that is burning its 10A fuses (and main one once). Other fuses are OK. I replaced them once but they burnt in the second in a stylish green spark 🙂

I have some knowledge of digital electronics, and kinda know my way around a soldering iron, but analog stuff is not my cup of tea unfortunately.

Could somebody point me in the right direction ? Is it worth the effort ?

Thanks a lot !

I have a pair of A7s: 416C 902A+811B plus a Fostex A90 supertweeter all going through the JE Labs passive XO (1k6 I think) and 1.33uF direct to the supertweeter. Driven by either 6V6 triode PP at ~3W or EL84 UL PP at ~10W.

I would like a bit more bass (of course!!) any suggestions as to a matching sub design? Not too clued up on LS design but do build all my own electronics so not afraid pf dirtying the hands. Are horn subs possible?

Having a bit of a clear out. UK based.

I know they are not necessarily DIY but thought someone on here may be interested.

1) Audio GD NFB3.1 DAC (upgraded)

Dual WM8741 dac chips and dual mono power supply design.

Good used condition minor scratches to case, Coax/USB/Toslink input, 2.5V (variable) and 2mA outputs, DIR9001 coax board, Audio GD supplied Amanero USB card, selectable filters, 10k ohm Log Dale Resistor ladder attenuator on outputs to make it variable, solid aluminium volume knob, Mogami cable. (comes with original Tenor USB card)

I use it directly with active monitors and it works really well, very clear and nothing but a resistor in the audio output. Could also be used with older amplifiers with lower voltage inputs.

£300 + Postage (in mainland UK) (or pickup see below)



2) Linn Axis turntable with Linn Basik Plus tonearm and Audio Technical VM95ML (micro linear) cartridge (stylus has 200 hours used out of 1000 hour life)

Very Good condition, lid has minor scratches but is clear and not cloudy, new hinges so they are not cracked and do work, wood surround very good, speed control works fine. Sounds wonderful, with the ML stylus on the AT VM95 body it digs out so much detail.

Comes with a Linn A2D phono stage in very good condition

£425 - prefer pick up in West Sussex or possibly drop off in Farnborough, Salisbury or occasionally Bristol.





More photos on my Flickr account - Items for Sale | Flickr

Also have videos of the volume control and turntable working if required.

Any questions please ask.

Im looking to buy a pair of this CCS boards if someone have this for sale.Send me email.

I replaced the driver transistors and diode and gate resistors on all 4 banks. When I check the drive signal 3 banks are at 4.04v and one of them is at 3.75v. The square waves look good and the drive signals coming off of the center leg of the fets of all 4 banks are identical in shape and voltage. When I check the voltage on the rails the +hv rail is at 162vdc but the -hv rail is at 4v. The board is in the heatsink will all screws for testing.

Reviewing some old Audio Express mags, I've been tempted to bypass the tweeters in my Klipsch Tangent 40Ws and replace them with the JBL2404H "baby butt" tweeters to remove some shoutiness I've experienced with these speakers. I've heard that the horn tweeters standard on these speakers aren't the best on the planet....

Though I've been part of these forums for many years at a low level of activity, I haven't introduced myself.

I'm in my early 30s living in Zurich, and have completed a couple of speaker projects (a small 2 way according to Tony Gee, as well as the 4-way dipole Nao Note II). I haven't designed any of my own speakers, and beyond wiring together some Class D boards into amps for the Nao Note IIs, haven't done much in the way of electronic components either.

I'm interested in optimizing room acoustics and listening to different DIY speakers and setups, so if anyone is in the Zurich area and interested in listening sessions and swapping ideas, PM me.

Musical interests lie most heavily in the classical tradition, everything from pre-baroque to modern composers, though there's plenty of electronic, traditional/folk/world, jazz, rock, etc. in the rotation.

John G.
I have a Technics SL-P990 cd player which will not play unless I manually spin the disc. Several people have reported a similar problem. The cure appears to be changing 2 smd capacitors associated with the motor drive. Can any body tell me the value and number of these capacitors on the circuit diagram and roughly where they are on the board. The SL-P990 does not appear to have a separate motor board, so they must be somewhere on the main board.
Thanks, John.

North Creek speaker kit CM-7. Includes 2 tower, 1 center and 2 monitors. Does not include cabinets. This is the kit as shipped from North Creek. No assembly has been attempted. Will ship for cost. Best offer.

Sorry but this is winding up being a difficult thing to find with Google... I'm getting every kind of sniffer/sensor probe coming up except for what I'm looking for.

Does anyone have a schematic for a device that can detect and amplify hum emitted by chokes, transformers, wires, etc. I've seen guys who made these. I suspect It's basically a coil pickup probe point, hooked up to a small op amp and small speaker, maybe a VU meter too. It is used to probe around the empty space of a chassis to find where hum is being emitted. It can be used to position chokes and transformers, detect what sides of a coil might be emitting the most or least hum field, etc. It would be a handy device for valve construction.

I would like to make one out of junk box parts on hand, if anyone has a good schematic for one of these. Could they share it?

Hi,

now my friend have a problem with Audio Note Conquest. One of the capacitor (marked red) blowed up second time. First one was 470uF 385V, second time was 470uF 500V. Do you have any ideas why this capacitor goes bad?

Best regards

hey all


so i snatched up a heck of a deal on a 5.1 system (def tech bp7006, clr2002, studio monitor 350, mirage s8) for $150


however the amps in the bp7006s are shot. they do work, but barely any output. this appears to be a very common problem for the 700x modules, so replacing them with the same troubled module for nearly 200/ea just isnt worth it



i attempted the 'hum fix' which entailed replacing a small capacitor bank on the amp, which did not address the issue. i measured the 5k pots which one measured 33-39k (nice) and the other goes from 8k-12k, so i bypassed the pot, to no measurable improvement. so i suspect the main 80v 6800uf caps might be at play here, but for the price of them (heck even finding them), i could just fit in a new board into the mix



inside these units, there are some nice toroidal transformers (49.5-24-0-24-49.5), so i didnt want these to go to waste. there is no markings for a VA rating, but there is a T 3.2A L 250V fuse on the unit. so perhaps someone could help maybe give a round about idea of the output


i dont mind clogging up any existing holes on the mounting plate, so trying to get something to fit the holes exactly is not really a requirement. and i'm not concerned with the fact that these can take either rca or speaker level input, sacrifices will have to be made there, plus the rca method imo is a better way for them to be hooked up anyway



so looking at some options, in the ease of 'plug and play' i was looking at the BTL tda8954th boards, they accept a simple ACV input, so one less thing to deal with, but i'd really only be using the 24v leads and i feel like there may be options to use the 49.5v leads instead? also, the drivers are 4ohm, not sure how the 8954th boards would do btl into 4ohm as i believe it's rated SE 4ohm BTL 8ohm according to the spec sheet. i thought i read 1.2v input for max output, and with an avr generally you'll only get 0.7v so perhaps thats enough to subdue the board into an acceptable range?



thoughts? i wanted to be able to share this fix/option with the deftech community who are stuck buying $200 replacements over and over again just to get another board due to fail. def tech used to be cool and just replace them at no charge, but since being bought, they have tightened the belt


anyway, here are some pics of the modules, i'll work up some wood/allumium mounting to get everything to fit once i find the board i'll be using as a drop in


thanks for anyone who has some ideas and ways to help!

Hello everyone,can anyone identify me this GZ34,the tube has no code.I am interested in who is the manufacturer of this tube,the factory,and if anyone knows year.Here are the pictures.Thanks

Maybe this is the correct forum (and not the Pass one).
I'm a very newby in electronics but I would like to try to build a Pass F5.
Only the F5 board and not the PSU, so I need a built PSU.
Best trafo than switching type...
Output should be +/-24 V plus the Ground with about 300W.

Please help me to choos the right one!!


Danilo

Good day.

I would like to build a good DAC.

I want to use the AK4493 DAC or 4495 even 4497 will do with LT3042.
Where can be find good layout for 4-layer PCB?

Thx.

Hi Guys,
I've built a set of Pensil cabinets out of Birch ply, not Baltic Birch alas. I need to mount the drivers on the wide side of the cabinet not the skinny as the instructions specify. Several years ago I recall one of the gurus (Scott or Dave or?) blessing this driver location. I've made the backs and bottoms removable so internal stuffing or lining will be easy. The Pensil specs call for some level of stuffing. I'm happy to use poly-fill or some other variant but am curious of the intent. Are we stuffing the cabinet to dampen cabinet vibrations to reduce unwanted coloration, slowing or speeding up the air flow to the terminus or something else? Also, should I still put the port on the same face as the driver? My plan is to have them painted by a car shop that painted my Fried subwoofers which have held up really well.
Thanks for any and all input.
Mark

Hello!

I've searched the last 2 weeks for Audio Players for my Raspberry Pi, but yet haven't found one that fits my purpose.
In theory its really simple:
My hardware includes a Pi (2 or 3) and a cheap amplifier plus speakers, there is no need for a good hifi experience.
I just want an offline player, that starts very quickly (because no special modules/services) and auto play all audio data on the USB stick I insert. Its headless and should work without any command, just like switching music CD's.

I tried PiCorePlayer because of its merit to poweroff without harm, but couldn't get it to work. Forum members said the player has to be online and can't autoplay.
MoOde, Volumio and RuneAudio should be similar and have way more features I don't want. MoOde ought to have many configurations, but the same problem as PiCorePlayer I estimate?

My next steps would be trying Archlinuxarm and then pygame, but I also don't know if it works there.
What would be the best solution for my task?

If it has to be online, I will accept that, but USB autoplay on boot and switching USB stick has to work!


Thanks in advance!

I have a dc audio 7k that pops when it shuts down. Any ideas what is causing this?

Also known as the "Death Of the Staircase". My previous design was called "The Staircase", so I thought of putting it to an end. 😀 This is the 3rd reconstruction of the amplifier with mostly the same parts, but a new chassis. The reason for rebuilding the old and not making a new is because it's cheaper - not having to buy entirely new parts. Afterwards it's my first and it will always be my amplifier for learning and practicing.

This version has improved chassis - rigid, very thick pine wood; coupling - interstage transformer 1:1; power supply - RIFA PEH169 high grade capacitors.

It is not completed yet. I have to build transformer housings, put black plate screws, tube top cap insulation and... I'm also winding hi-fi low Cp and low DCR psu chokes and maybe I'll do a higher grade power transformer. I'm very tempted to try regulation, maybe salas SSHV for the driver stage and "something else"for the output stage.

Every component is described in the schematic right here! It says it all.

I'm very happy with the result - smooth, liquid, live sound that makes you go into extasy right away 😀. The bass is a little slow and I guess the high PSU DCR is to blame, this is why I'm tempted for the regulation. Ideas never stop.

The power output is 11W. There are no power switches. The power cords are Neotech 3PS25 terminated with Valab rhodium IEC and plug. There is a separate power cord for the heaters.

Enjoy the pics. I'll shoot some more in a more thorough way these days.

Hi @all,

i work the last days on a broken amp. One fet in channel 4 was broken.

3 channels run fine. If i replace the broken, the new one gets in a few seconds really hot and the amp goes in protect.

I see that between gate and source was a difference of 6V DC. None of the other channel has it.

I replaced all the green marked fets, transistors, diodes, OP amp too.

but it will not work.

Anyone any idea?

Dropbox - IMG_20200630_211903.jpg - Simplify your life

Thanks

Hi,

I'm curious about the impedance curve of my new esl panels. I have REW installed on my laptop, but my laptop has only a mic out jack, no line inputs. I would like to use this scheme:

https://www.roomeqwizard.com/help/images/impedancesetup.jpg

I'm wondering what would be a good way to make a impedance plot with my laptop + REW: would an external USB soundcard with line input and mic output work? Something like this soundcard:

Product

Greetings, all. First post; retired lifelong police officer, turbine helicopter geek, as likely to go necrotic as quickly as this thread will.

I hope it helps somebody, somewhere, in whatever your future allows. The following is my way of giving back, to this group, especially.
Thank All Ya'll Very Much, DIYAudionerds. Your existence only enhances life quality.

A Gut, Hack, Mod and Polish Turd-Treat Especial*. A Moldie Oldie, but Goldie.
An Ambitiously Absurd Tale of Transforming Surplus into Slightly Better Surplus.
For Dummies, by a Dummy. *AvE

VICTIM
Anchor Audio Xtreme XTR6000CU1 Sound Reinforcement System, aka Anchor's obsolete, disowned millenial era bas_ard child, a Kitchen Sink Combo Cab, sans batterias.

SITREP:
-2016. Purely ignorant, infatuous impulse purchase. Lubbock TX pawn shop, $100. History unknown. "Very good knick", my Brit brothers might say.
-Clueless (Anchor Audio who?) but absolutely intrigued by its MILSPEC-like construction/design, etc; in a word, outstanding.
-Made in the State of Degeneration nee California in the late '90's, apparently. In spite of this, clearly built to be as indestructible as a Smyrna Glockenspiel.

-**Turns out, Anchor only markets to, essentially, "wedding rentals" alongside their corporate/conference/commercial venue et.al. demograph. Hidden secret in plain sight, hence my highly educated, yet total, ignorance of them.

NERDISTRY:
(representative internal pics will follow, precise photos upon forum request.)
The public marketing-wank brochure specs are readily available, but almost nothing else. Surprisingly scant info. Webwashed.

-The bi-amped thing is bi-bi-amped, QUAD-amped, essentially.
"Proprietary", through-hole mother-daughtercard mezzanine design, aviation-quality assembly. Every PCB crisply marked with pinouts & traces. Impressive and Unusual. HackNmod Freedom Bonus Points=Anchor, Inc.

-An apocryphal tale references a "passive companion speaker", its existence known by few, and seen by fewer....The 6001, allegedly born to suckle from a then-obscure oddity, 4-pole biamplified Speakon Socket. Professional Prescience Bonus Point=Anchor, Inc.
-properly and precisely shielded & separated ERFI noisy-bits.

-"DIVERSITY" UHF wireless RX module, 1-channel. For the tinker bits bin; unneeded, obsolete & unsupported, but a fascinating little RF device, and 12VDC...[more on that later.]
Conjoined to its plate-steel housing, (was) a then-high-end, Belgian Samsung DAC'd, 12VDC OEM CDR used in a few BMWs. Combined, they fill a single DIN or 1/2U space, with intriguing possibilities, as will follow.

GOAL:
Meh. Learning experience, heckuva lot of fun. Flying OClamps fitted, repurposed PDU PCB, etcetcetc. Maximum overdrive mods, because if worth doing, its worth overdoing. No rabbit hole too deep.

Anybody interested in specific details from here, I'll do my best to cover it with specificity. Otherwise, I'll gradually post the processes & pieces I used in coming days.

Eric

Found an old NAD T760 which needed a little TLC, clean it up, straighten the case etc. The only issue it had was a hum in the rear channels.

Initially using the optical input the noise was horrendous but calmed down after a few minutes but was still quite audible. If you just use the analog inputs things improve in all channels and if you use the pre-out RCA connectors the sound is again clean.

This led me to the belief the hum must be isolated to the surround board and changing the caps to newer ones would clean up the signal, so fitted some Elna Silmic II. I double checked the connections after I did each one and validated the caps were the same way round as before.

Put everything back together and while the rear channels sounds better the original hum is worse than before, not horrendous and when you watch a film it isn't very noticiable but I would like to resolve the issue if I can.

A visual inspection of the board looks fine and when I plugged it back in nothing I could reach got hot nor did the heatsink the transistors are attached to.

I do have some initial thoughts but would really appreciate any suggestions on what I could do to resolve this. I am no expert, not even at an intermediate level but I am trying to learn and happy to have a go.

A few thoughts I had:

Wondered it a shielded power supply would help.

The board has empty junction connectors marked A and B thought of connecting them with a separate wire

Could there be interference from the power supply which is right next to the board

Could there be interference from the AC3 board which has a random wire running to the surround board. NB. There are a few extra wires connecting boards together which I think is factory as I saw this in pictures of another T760 just a bit bizarre.

As I said, your suggestions would be appreciated

Happy Independence Day to all the USA members here! Have a good one and enjoy! 🙂

I had posed a question in the Aleph J thread a number of months ago to see if there was any reason I shouldn't try the following, and not receiving any negative feedback, I went ahead and made the changes this past week.

I had built an M2 and an Aleph J a while back. I've always loved the stereo imaging and sound-stage depth I get from mono-blocks, so I wanted to convert my amps to mono-blocks - but the expense for the extra chassis and power supplies kept me from doing so.

Since the Aleph J and the M2 use the same power supply, I decided to swap an Aleph J channel for an M2 channel between amps, so each amp has one Aleph J and one M2 board. I installed a heavy duty DPDT switch on the back of each amp, unhooked the V+ and V- from the power supply to the boards, and instead ran the V+ and V- to the center pole of the switch, and then ran lines from the switch to the V+ and V- of the audio boards. I didn't do anything with the ground lines.

The power supply in each amp now only powers one board depending on the position of the switch, and I change the RCA input, speaker outputs and switch position depending on whether I want to hear M2 mono-blocks or Aleph J mono-blocks.

How did it turn out? Really well. I always had a bit of a ground loop that I could hear in my Aleph J if my ears were close to the speakers. Beyond the increase in separation that mono-blocks bring, now both the M2 and the Aleph J are totally silent with my ears right next to the drivers.

Both amps were built with Antek 18V 300 VAC transformers. As a stereo amp with this transformer, the M2 sounded very pretty for jazz, and folk type music, but wouldn't really rock to satisfaction. Dedicating the power supply to a single audio board has given the M2 much more bass drive and punch. I was actually shocked at the difference, as I wasn't expecting it. Now the amp can rock as well.

Hear are a few not-so-great pictures that demonstrate the change.

P.S. Not that there would be any reason to, but as 6L6 pointed out when I asked about the idea earlier, you would never want to flip the switch while the amp is running.

I have 2 OPPO Sonica DAC's. In general, I really like the DAC and she plays beautifully w/DSF files from the hard drive.


Background: One of the Sonica's suddenly sound's slightly muddy or more like listening through a veil, lacking authority or punch. Frankly if I heard this DAC standalone for the first time, I would have assumed "meh, nice but not that impressed".


Performing an A-B swap out of one Sonica for the other, clearly demonstrates it's the DAC.


Question: Any idea what to check?

Thanks for any guidance.

HQ-Audio ESS9018 Reference DAC for sale, 500$ O.B.O.

Hi. Selling my great HQ-Audio (quanghao forum member). This is a great dac and it was my best dac before I upgraded to quanghao latest ESS9038/Tube I/V DAC. So Mine is for sale. It has the solid-state dula mono I/V converter and high current Class-A output stage. Full discrete low noise regulators for each DAC section, I/V section inspired by dCs apparently. Each I/V channel has +/- low noise shunt regulators. Excellent design and implementation, Sounds great!

Mine as these mods:
-Replaced the MELF stock I/V resistors with Nude Vishay resistors for best sound. A substancial upgrade!
-Installed a rear mounted 1/4'' headphone jack. The output section is powerfull enough to drive an headphone with ease.

It has the Amanero USB input that works great with my music server.
It has also coaxial, AES/EBU and optical SPDIF.
Everything is working perfectly.
Silver color, comes with remote. Accept up to 24bits/384Khz and DSD as well.

Asking 650U$ (O.B.O.) + Paypal fee + Shipping.

You won't find a better dac at this price...

Thanks for looking
SB

Hello Phreax !

I´m confused. I want to build my own High-End-CD-Player.
For the CD-Transport-Unit i want use an expensive Philips-VAU 1252 with the "I2S" Output. This is very good ,because i´m not use a Digital-Interface-receiver (like CS8412,CS8414..).
The Digital-Filter (DF17xx,..) i don´t use, too !
It´s very minimal: Only 2 piece ob Burr-Browns "PCM63" direct coupled to the Philips !
There is only one problem : The PCM63 is not "Stereo", I need
2 piece for a Stereo-DAC. But is there a way to "divide" or seperate the "I2S"-Signals for the "Left"- and the "Right"-Channel.

Then i thougt, i can take the "PCM69" because it´s a Monolithic-Chip "Stereo-DAC", but i cannot get this Type here in Germany.

Is there anybody there with a little Tip for me and my problem ...?

greetings from Obelix

I was wondering if anyone had done anything in the area of detecting shorts on power amp speaker outputs while the amp has its output muted by SSR.

What I mean is using some way to sense possible shorts on the speaker side while the speaker is disconnected from the amp by the SSR.

It's not difficult to do with electromechanical relays, using the other side of the switch that would normally not be used, to pickup the lead from the speaker while it's not physically linked to the amp's output, and when the relay is energized to unmute, the speaker is connected while the short sensing circuit no longer is...

The thing is, it's a bit different with SSRs, with no physical contacts being used, and there would be no way to disconnect the short sensing circuitry from the speaker once the amp is unmuted.

So far I haven't found any way to do this with SSRs, but perhaps some have given some thoughts and may have come up with something usable?

Do you think this is enough heatsink for two DLH amps? I think I pulled it off of a powered sub so not new and no spec's. ( No idea why it flipped the picts ).

Hey everyone.

So I've made my 3 way cabs and dicided to go active and my setup is 1x 2 channel amp for the 12" subs and 1x 4ch amp for the tweeters and mids and an active crossover unit to separate the frequencies.

I was in the studio the other night giving them a first test and managed to set everything up nicely and they sounded great but when it got to a live gig they really under performance in the sense of I could hardly get any volume out of them before feedback occurring!

My main question is do all amp channels need to clip at the same time as the mixer?

I ask this because all amps channels are just about registering a signal according to their displays while the mixer is at optimum levels. Obviously I haven't set the amps correctly but I just wanted to know if they all need to clip at the same time?

Hope this makes sense!
Sal

(delete)

Sorry, thought my post was gone and wrote it again.
How to delete this thread?

Dwm0608X_V20
any way to get these board somewhere,
its installed on a Ground zero gzua 1.1000dx.
Or if someone sits on scematic on this board. ?

I overheated the pads on the to ics so pretty much destroyed the copperlines around.
i reflowed the u2 an u3 too many times ,
i assume u2 was tl072 and u3 is lm311 or 211..

so it got this board messed up.

best regards
Niklas .

I am working on a OTL headphone amplifier where noise and hum is essential. I can't help being nervous about having AC on my heaters for the 6AS7 output tubes and 6SN7 small signal tubes.
I have done some reading about maybe applying DC to the heaters to eliminate the risk of 50hz noise. I can see that DC on the heaters is not something you do without side effects. My idea however is to mount the heaters in a MOSFET H-bridge so I can switch the current direction with 1Hz or so.
Would this idea give me the best or the worst of both worlds?
For the power supply itself I'm thinking of using a toroid transformer with the heaters in parallel if I go with the pure AC option. If I go for the switched DC I am planning on something like a Mean Well LRS-75-12 with the tubes in series of pairs.

Hello,


I have a Rotel RCD-971 CD player that I would like to modify so it can accept I2S signal from an external digital inputs receiver switch that has a I2S output.
In this way I will be able to connect external digital sources and use the Rotel's PCM63 DAC chip and have the anlalog output from the Rotel's analog outputs.
I need your help to understand where should I connect the DATA, BCK, LRCK, MCK outputs from my digital input selector to the PMD100 in the Rotel.


I'll appreciate any suggestions.


Thanks

what is a simple way to provide short citcuit protection ?
i have an sony amp that has and it works nicely as the music cuts out for like 20 secs of shorted

Hi just posted a new thread - a message popped up and before I could read it fully it disappeared ............ at a glance it mentioned thet the posting would not appear...........and I missed the rest. Are postings fully moderated then approved and then displayed............how long does this take??

Hello,

I got a good deal on 2 Mach5 IXL-18 with a Behringer NX6000D amp and I am keen to build my first DIY sub box (I have moderate wood working ability, and live in Canada, so buying flat packs will not be a great option).

But I am wondering what I should build.

For background info:
Use will be 75% music, 25% HT
Room is ~ 16ft x 10ft
The way the room is laid out, one sub will most likely go right behind the main listening position and one directly in front / center.

Priorities for me would be (in order):
#1 Accuracy and musicality, so I was looking into a sealed box. But then I was playing with WinISD and noted that I may not be able to get as deep as I would like without extreme DSP (which I am ok with) but also extreme cone excursion (which I don't want to blow these subs).

#2 Low extension, the lower the better (although this is my first proper sub, so we shall see how addicting that low end really is), so then I was maybe thinking about a large EBS build. Would a full or mini marty be a good fit?

Thankfully space will not be an issue, so really any box size I would make work.
Also, I typically listen below reference, so will not need them to hit crazy high levels.
I just want it clean and then deep.

Super keen for any recommendations.
Also, since this is my first build, if there are any recommended sites for designs (mostly if ported is the way to go) that would be great!

Sub specs if that helps:
Mach5 IXL-18
T/S Parameters
Fs = 17.7 Hz
Re = 3.4 Ohms
Qes = 0.39
Qms = 5.59
Qts = 0.37
Mms = 434.3 grams
Rms = 8.69 kg/s
Cms = 0.184 mm/N
VAS = 274.1 litres
Sd = 1029.2 cm2
Xmax = 22 mm
Cone Diameter = 36.2 cm
Le = 6.09 mH
Bl = 20.51 Tm
Power Handling: 800 Watts SPL (2.83v/1m): 89.2 db
Ported: 200 litres (7 cu.ft.) 19hz tuning
EBS: 365 litres (12.88 cu.ft.) 15hz tuning

Thanks!

Hi,

i am selling my tube amp TU-879S as i have recently changed the setup completely:

the amp is in very good condition, the circuit is modified with several audio grade Mundorf coupling capacitors, the tubes are new 1 x JJ ECC83, 2 x JJ 6L6 GC.

( currently it incl 230V Power supply, but i can also ship original 100V Transformer NOS Kitamura Kiden PT-877 ( K6C1SK )

let me know if anybody is interested
cheers
Michael

Hi all, I have on my bench work a Musical Fidelity xa2 with power transistor fault and I'm waiting for a new pair of SAP15PY and SAP15NY for replace.
The problem will be the setting of bias.
Anyone can help me to fix the bias point? I can't found the service manual.

Thanks very much

Sergio

Hi



Got the amp for £23 as spares or repair. Fancied a go as I had a spare SVI2004A chip which I did not need from China. Seller said it was working until it started going into protection from time to time but now full time.


Burned a cap C523 as soon as I plugged it in > replaced it > OK

Checked the pre drive transistors OK
Checked votages on SVI2004A Pin 1 and 16 at around 50v. Others not in spec either so I presume both channels affected.

Checked for cold solder joints > nothing yet
Replaced SVI2004A > no change (wanted to have a go at this - original probably ok and looks as if it is a genuine svi2004a)

Input selector does not work properly as it does not show red led selection. Only the yellow tape source selection.
Track on circuit board had been previously repaired. Cheked it



Any ideas / help would be appreciated ?


Thanks

I need some help with my minidsp. My old laptop bit the dust a few days ago and I bought a new one today, and I didn't get the chance to transfer a saved minidsp program from the old pc to the new one. The program is saved onto a a minidsp kit built into my speaker though. Is there an easy way to just plug my new pc into the minidsp and extract the program saved on there? Or do I have to get my old computer back online and export the program?

I checked the forum, and most of the hits were in the chip-amp forum and was dedicated to the "how to" of wiring existing chip-amps. That's nice, bit it doesn't help me understand how to set up the design parameters to get the desired output power from the partially designed mono-blocks. If this specific issue HAS been addressed and I missed it, a pointer to the thread would be greatly appreciated.

The situation :
I will have two mono-blocks per channel in an amp I'm working on (in simulation and a single rough prototype). They will be driving an 8 ohm speaker/crossover. I'm looking to get about 50W/ch, and rough math says I should have about half that power in each mono-block, but I'm getting confused with the math, and could use some help.

Rough math says to get 25w into an 8 ohm speaker, each mono-block will have to put in about 1.75A driven by 14Vrms, or roughly 40Vpp.

What I think the solution space looks like :
If I understand Bridged Mode correctly, while we get twice the voltage swing, each amp sees half the resistance, so we're now trying to drive 25w into 4 ohms, which results 2.5A at 10Vrms or roughly 28Vpp. Each mono-block provides that much voltage, at the same current, so that's 20v (total) swing at 2.5A, for 50w of power to the speaker.

If I understand Parallel Mode correctly, it is the opposite, each mono-block sees twice the resistance, but contributes to the total current, so you get twice the current you'd expect for the (doubled) resistance. In this case, 25w into 16 ohms results in 1.25A at 20Vrms, or roughly 56Vpp. But each mono-block provides that much current at the same voltage, so it's 20v at 2.5A (total), for 50w of power to the speaker.

The BIG question:
Is my math correct, and did I get the two circuit topologies right?

If so, bridged looks to be the way to go, from ease of setting up the power supply and modifying the circuit. Getting a clean 56Vpp signal sounds like a bit of a pain...

Next up will be to get to the output voltage of 10Vrms... from line level input. That will take a total of 30dB in gain (31x gain from 0.32v, consumer line-in levels, to the final output voltage of 10v).

Presently, the amp design gives about 12dB of gain, and I hope to get a fair bit more out of it, but I doubt I'll get all the way to 30dB gain out of such a simple amp design.

So, if I understand this part of the problem correctly, I'm looking at a pre-amp that can punch it up part way. The preamp will have to add (30dB-PowerAmpdB) worth of gain to get from consumer line-out level to 10v, and achieve 50w/ch, correct?

Hello!

I'm planning to build an amp with tha power of a 300b amp but with DHT 845 tubes.. I hope they are more economical and indistructible at this low voltages! Someone have build this amp?
I have some other low voltage schematics with845 to discuss...

Thanks in advance

Max ;o))

I've built a Subwoofer using TPA3118. It makes a big thump noise when I turn it on. Then this Thump Noise repeat after every 5 seconds. But when I turn my volume potentiometer at "0" and let it make a thump then slowly increase the pot meter, then the thumping noise disappears.

What's the problem here ??

[I'm completely new into DIY stuff]

I am trying to generate audio signals using LM386. But the problem is the impedance is not matching with the loud speaker.
I have given a supply voltage of 10 volts.

Got a message from steve about MEF

My Internet connection has gone down and it will take a service call with new equipment installation to get it going again. I don’t know yet how long that will take, but it’s looking like several days at least.


Thanks,
nosaj

Hello all,

I`m thinking of buying a new dac board. I have my music on a htpc(flac) and also use Spotify 😉

Today i use a Soekris 1021 v2 dac, but i need to try a new dac, mostly for fun and also to hear a new delta sigma (right?) dac.

What to buy?
This one and build a regulated dc supply will be cheaper...

ES9038 Q2M DAC DSD Decoder Support IIS DSD 384KHz Coaxial Fiber DOP | eBay

Or is it better to go for a eBay board with a 9038 pro chip? Cost alot more..

ES9038PRO Ulitmate DSD DAC OELD Display Successor of ES9028 DAC / XMOS XU208 USB | eBay

Maybe a stupied question 🙄 . But will i hear any diffrent when i play from Spotify?

BR //Daniel

Hi all !!

Is enough one 6S45P to drive (180vpp ) one 300B tube ?

Hi all. I am stuck with a thorny problem and I'm hoping someone out there can help.

I'm restoring a really early 1968 Silvertone 1422/Sears 40XL combo amp. I've got both channels of the amp up and running and sounding really good (just replaced all the electrolytics and several resistors that were out of spec). However, I was not surprised to find that the reverb was not working. I took the reverb unit apart hoping the problem was just a wire that had come loose. Instead I found a very primitive reverb using a couple of piezoelectric tabs. Apparently this was a common early reverb used on Danelectro amps made for Sears. I've attached a copy of a photo of the disassembled unit. Anyway a tab on one of the piezo units is disconnected at the base and not able to be fixed.

I would like to replace it with an Accutronics or other modern transducer reverb tank, but I don't know if the drive and recovery circuits are up to the task. One of the great frustrations of working on these amps is that there is no schematic available anywhere on the web. So, in order to begin the restoration process I made a detailed layout of the PCB, components and wiring to suss out the power circuit and other amp modules. I've attached a copy of the layout that I did. I don't have the ability to convert this to a schematic, bit I think I have figured out that the reverb drive is the output of one-half of the first 12AX7 (identified as V1 on the layout) coming off the plate (pinout 7) and traveling up to the reverb unit through a simple capacitor coupling. As best I can tell, the return is from the green wire on the center tab of the reverb pot which is connected to the right hand terminal strip and then back to the amp through the volume and tone networks via the red wire that connects to pin 7 of V3 (another 12AX7) through another simple capacitor coupling.

If anyone can help me figure whether a transducer replacement is possible it would be much appreciated.

For several reasons, I have selected the S5 Electronics preamp as my first valve project.
It's just about the simplest tube preamp schematic you can imagine. There's a cathode and plate resistor, cap on input and output.
Uses a 5670 twin triode. Tiny thing. Doesn't include a power supply.

So I'm looking to find anyone who's built this kit, like to know their experience and if there's any simple improvements without crazy modifications.
There could be others out there that have built similar simple preamps.
Like to hear their thoughts as well.

I don't know a lot about tubes, but I see many designs with a cathode resistor bypass cap.
I suppose I could just try it, but I'd rather ask than break the thing out of the gate. Are there any recommended values for the bypass cap?
The Cathode Bypass Capacitor Explained - DIY AUDIO BLOG, AUDIO WORKSHOP

For $25 more, I purchased slightly "better" resistors and caps: Clarity caps and PRR resistors as opposed to orange drops and carbon resistors.

Untitled

I repair the PS on this amp.Amp is producing audio but the high side FETs heating up more than the low side.Is that normal for this amp?

The output has been worked on befor.Drive signals looks good.

Hey guys, first time DIY here.

A small backstory and goals for my project..

I currently own a pair of B&W 705 s2 bookshelfs, they do sound good (very revealing and transparent) but I'd want something else and that something
is dynamics and midbass presence. I recognize that these bookshelvs do sound very good on reference material music, but older music, they just sound very tamed with little dynamics to it. Like if you hit up ACDC the bassdrum just sounds abit "lame", the guitars sounds quite abit meh aswell
(I can describe the guitar as the sound comes from a pair of audiophilespeakers rather than an actual guitar cabinet).
So I'd like something thats quite accurate but can deliver good punch in less bassheavy music like older mixed music without it being "bassy". (If thats even possible) Currently running the bookshelvs with a Hegel H90, also tried with h190 which is quiteabit beefier, however it's still lacks that presence.

The idea of the build was NOT to build myself a bass-monster, but rather get the definition in these critical mid bass area and midrange that makes music so much fun and engaging.
Like when you hear a cello you just get that presence of the full body of it, it pops the heck out delivering depth to the touch of the instrument.

Ive been messing with VituixCAD for quiteawhile now, however I have no previous experience at all building speakers. And with that lack of experience i do not know wether
I completely messed up anything very basic. I have never built a crossover but tought myself
the basics(from what I know in speaker-design and crossover design). Im more worried about the stuff that I don't currently know of which might be plenty.

My initial design goals:

• Good horizontal off axis.
• Fun engaging/dynamic and natural presence to instruments.
• Can play orchestral music and bigger pieces without sounding "flat".
• Reasonable easy to drive impedance and sensitivity wise.

My initial design:

• Timealligned woofers tweeter.
• 4way with a 6,5inch midbass coupler woofer.
• 70-85litre cab(empty)

Current elements in the design…

1. (TBD) Tweeter (1inch) Seas Excel E0011-06 T25CF002 Millenium -> https://www.hifikit.se/media/attachment/file/e/0/e0011_t25cf002_millennium_datasheet.pdf
2. High-mid (4,5inch) Scan-Speak Illuminator 12MU/8731T00 -> https://www.hifikit.se/media/attachment/file/1/2/12mu-8731t00.pdf
3. Mid-bass (6,5inch) Scan-Speak Revelator 18W/8531G00-> https://www.hifikit.se/media/attachment/file/1/8/18w-8531g00.pdf
4. (TBD) Bass (8inch) Scan-Speak Revelator 22W/8851T00 -> https://www.hifikit.se/media/attachment/file/2/2/22w-8851t00.pdf

Currently I have two setups one more classic:

Setup1:

• Tweeter 1inch
• Upper mid woof 4,5inch
• Midbass woof 6,5inch
• bass woof 8inch +

Setup2:

• Upper midwoof 4,5inch
• Tweeter 1inch
• Midbass woof 6,5inch
• bass woof 8inch +

Ill attatch a picture or two of the basic ideas..(not 100% to scale..)

These two depends quiteabit on the height of the speaker, my thought on the latter was that the tweeter and the midwoofers would "theoretically"
be more aligned given that the seating position is in a more narrow sweetspot vertically(aka ears by the tweeter).. (my logic is that both woofers shares the same distance to the listeners ears since tweeter is in the middle yielding more precise phase)

Extra:
The idea was scan-speak drivers using their revelator series and ive simumlated in this example a seas millenium tweeter. While the woofers im pretty sure i like the combination (except maybe the "sub woof" which depends on exactly how large i make my cabsize)
the tweeter is abit work in progress aswell (might checkout the satori berylium tweeter).

The "easiest/working" simulation of a crossiver ive found so far was using 2nd orders using VituixCAD.
It currently has not baffle-step compensation to it, nor any simulations towards baffle-diffraction(so keep that in-mind).
The elements are 8ohm , but the speaker seems to act more of a 6ohm rated using this specific crossover due to some overlap which i deem as worthy sacrifice.

Ported or passive rad is yet to be decided..
Questions:

1. Does anything of this make any sense?
2. I recognize that the crossover due to baffle-diffraction and time alignment have to be remoddeled and tweaked extensivly after the fact, do you guys use in-room measurments for that? Like do you start with the manufacturs given ZMA FRD or do you start with your own measurments in-cab?
3. The crossover i attatched is there anything wrong with it? or can i use that as a base?

Servicing a model 15 amplifier. Q113 and Q112 need replacements. Marantz part numbers DTM13 and DTM11 for these parts.

Any idea what these are in terms of industry standard part numbers?

Hi there,

any experience with the current Audax production?
Proraum does not offer the Z0 anymore, because
of being different to the older ones.
Anyway, I try to decide between HM170Z0 and HM170Z16
for an 3-way MTM project. It is active and DSP controlled.
The bass-mid drivers range would be about 90-1100 Hz.
For the purpose I am using Visaton W17E at the moment.
These are quite good for the money, but I would buy the
Audax drivers if there would be an improvement.
One reason for choosing them is that I don't need to build
new baffles. Also I am curious about them for a long time.
My goal is that they fit well to my Stage Accompany ribbon
tweeters.

I got these data from AARV:
Paramètres haut-parleur de THIELE et SMALL, sans filtre ni ampli
Paramètres haut-parleur de THIELE et SMALL, sans filtre ni ampli

It seems the parameters are the same. Confusing....

I would appreciate any help or insights 🙂

Kind regards,
Christian

The Accuphase E-305 was manufactured from 1987-1991. I have owned this amp for about 2 years, Years before the E-305 I owned an E-303. In between I owned several other amps, tube, SE tube, PP tube, several vintage Sansui solid state amps, vintage Marantz, Luxman and DIY solid state amps I built following threads on DIYAudio. To my ears nothing gives the balanced and detailed presentation like the Accuphase amplifiers.

The amp is nearly 30 years old So when I first received it I replaced all the electrolytic capacitors on all boards. The capacitors were replaced with the same values except in a few cases the voltage rating has been increased.

The E-305 has a phono section, 2 speaker outputs and tone controls.

The amplifier power transformer has a multi-voltage primary that can be wired for 100v, 117v, 220v, 240v. It is currently wire for 117v.

$1950 shipped

Thought this was a nice compilation, which came across my LinkedIn feed:

DIY – Scan-Speak A/S

Best,

E

Hi diyAudio,
I have a Musical Fidelity A3.2cr pre amp and amplifier separates. They are about 17 years old (2003 manufacture). They have never been serviced and I am currently not experiencing any issues (that I am aware of). They get a lot of use ~3 hours listening a day, and I leave them on all the time. They are class A/B and biased about 3watts in A and warm to the touch at idle.

A. is there any point in doing anything before there is a problem? No caps are bulging or leaking.

B. If recapping is suggested, how difficult is it for someone with limited electronics/soldiering experience. I own a Weller soldiering station for the occasional fixing of things

C. If recapping is suggested and I have someone else do it, can anyone recommend a shop in the Chicago area? I am in the NW suburbs but also can deliver downtown.

From my searching, I do not believe there are schematics available for the Musical Fidelity amplifiers. I only know of one shop in the UK that does rehabs of these units and the owner is a former Musical Fidelity technician that opened his own shop. I don't really want to ship 40lbs of amplifier to the UK and back.

Thanks for any suggestions.
Andy

I built two rev 1 LM3875 amps back in the day and was gifted a pair of rev 2 boards that I never built. I have most of the parts necessary to build these save for the transformer and I need an extra amp so I'm looking at building these.

Looking at chipamp.com on the Wayback Machine I came across the rev 3 / carlosfm unregulated PSU. I've come across a few variations of the schematic. Is this rev 3 PSU still the way to go?

My rev 1 builds are using 330VA 25+25V transformers. I don't currently have particularly difficult speakers to drive but would it make sense to use a lower voltage transformer for this build? With Avel Lindberg through parts-express, it seems my only other option would be 250VA 18+18V. Searching Digikey gives basically the same result.

Thanks.

Played around with the FIR Designer M beta

Nice new "Supplementary responses window" option

Fir Designer M beta : “Supplementary responses” window | Timo's World all around the globe

I built a Millett Hybrid Max headphone amp about a decade ago and used a bunch of Black Gate caps. It's been a great amp but I'm ready to move on to other things...I just built the Whammy, and may also build the NuTube headphone amp.

Is there any reason not to desolder the Black Gates from my old amp and use them in new projects? They still function fine, apparently, and regardless of the hype I think they sound great. I know electrolytics can dry up, but I also have a 40-year-old Yamaha receiver that still works great, so I take that with a grain of salt.

When it comes to wave guides on tweeters, I have very little knowledge. I would like to know more.

What is the typical profile of a wave guide? Parabolic? elliptical? exponential?

Do most people fabricate their own, or do they buy them?

Is there a thread on this site which covers the basics? or perhaps on another website?