Hi guys im fairly new to this subwoofer building scene thats why im on here for starters haha. I started a bit of research and found the Wbin to give off that big punchy chest feeling bass that i so desire and also has easy to access plans and drawings for a beginner builder like me.

I am open to suggestions if you guys would recommend something else but at the moment im thinking of an 18inch Wbin build for mainly outdoor uses like bush doofs etc(im a dj and and in need of a new subwoofer).
please any help would be much appreciated and I would also love to see any of your builds to give me some ideas for drivers and amps etc.

Thanks in advance.

Hi all,
please suggest me a cable for internal wiring of my diy loudspeakers.
....let me know your experience and comparison about different brands of cable, for example a comparison between....cardas, monster cable, audioquest.....
would be fine a timbre comparison.

t.i.a.

Hello,

I have a Divide down polyphonic organ that Ive modified by extracting the amplifier circuit, and taping in to the oscillator ICs directly. That signal is a strong line level, but I am wondering if it is better to install a coupling capacitor between the ICs and the the output.

Originally there was a .022uf capacitor before the extracted amplifier, and that cut out all the bass, so to be used with a small speaker inside the organ.

I tried a 2.2UF and that sounded full, but it seemed to cut out the very low frequency thump of the notes, which I really like. At the moment there is also a 1uf decoupling capacitor to ground, and a 1k resistor attenuating the audio signal.

It sounds better without the coupling capacitor but Id like to know if there is a better way about it. Without the coupling capacitor I can Measure DC voltage in the audio signal, but I can't hear any noise.

I could try a larger capacitor but I am concerned I could damage the now obsolete M082-AB1 ICs, so wanted to ask for some guidance before advancing.

I am using the organ connected to a DI box, but also sometimes with a VCF filter, with an estimated 100k input impedance, between the two.

Thanks

I'm selling the following set of XRKAudio PCBs:

2x Alpha Nirvana PCB (stereo set)
2x Smooth Like Butta (SLB) PSU PCB
2x SRR DC Protection boards. One of the SSR boards has faston connectors soldered on, I bought it this way as it was the board used for checkout from that production run.

Price is 230AUD + shipping.


Also selling one extra Smooth Like Butta PCB for 30AUD + shipping. Discount applies when taking everything.

Hi

A bit of a long shot, but I guess it's worth a try.

I'm a bit of a novice with regards to DIY audio, but coming from a background of very limited electrical knowledge and no soldering experience, I've managed to build Tom's modulus-86, RJM audios Emerald phono stage and a pair of Frugel-Horns.

I needed a preamp for the modulus-86 and decided to build Tom's Neurochrome Differential 8x2 preamp. However, I'm stuggling to get it to work possibly due to my lack of experience with SMD components. I don't think I'm a million miles away from getting it to work and Tom has been very helpful in trying to help me out. I can't help thinking though, that as I try to rectify one problem, I am unwittingly creating other prolems as I go along and feel like I'm going round in circles.

Is there anyone out there who would be prepared to take a look at the board and fix any errors? Any help would be very gratefully appreciated.

I'd like to try building a DIY PCM/DSD DAC with Amanero and DSD1794/2. I'd like to use Amanero DSD flag to drive the magic "X" circuit that will route the signals to DAC chip and set it in proper mode. Digital is not my thing, so I kindly ask if somebody can give me some pointers how to get it done.

I'm wondering if using DSD1792 with external uC won't be better in this case, as it can control inputs (via Amanero and eg. WM8805) and screen of some kind. I understand I need some digitally controlled switching grid to route signals?

What is the best way to make the routing circuit?

I'm not interested in using newest AK and ESS chips.

I want to learn more about electronics and the inner workings of audio equipment, so I've been modelling schematics I find online in KiCad.

I have need of a zero-gain buffer, so I've been reading up on preamps and buffer circuits, and have decided I want to build a opamp based buffer first. Something I can build on perfboard.
After that I'd like to move on to designing a PCB for a transistor based buffer like the Nelson Pass B1, but with regulated power supply and maybe some other features.

However I am an absolute noob when it comes to the theoretic side of electronics.

I was wondering if I could get some opinions on these schematics and if I'm heading in the right direction or not.
Is this power supply schematic somewhat overkill for a simple NE5532 buffer?
Any feedback would be greatly appreciated.

Good evening, I am a new member from Italy, my name is Emiliano, I wanted to make an Aleph 5 finale but I have problems finding mosfets, can you give me equivalents and articles where we talk about this realization?
Thanks in advance.

Heh, I logged in today to download some tube design info for LTSpice and I was shocked to see:

Last login: May 4 2004

So, uh, I forgot to login for a bit.

Anyway, current project: fixing up an Aussie Vadis 600R, it's working but needed a few things done to it. I've got the power transformer off for a rewind, replaced the ECC83 sockets, replaced all the electrolytics, a few faulty resistors, did some star grounding and put a clear protective layer over the controls panel. I had it working for a bit using a replacement transformer and it sounds nice, but I want to get the original back so I can have a crack at the bias.

So what's the difference other than the obvious visible shade difference? Is there an audible difference, or is it more of indicator of something like plant location, age, series, etc?

After reading about Merlin Blencowe's cathode coupled amp concept, I thought to give it a go.
Last week I built a nice little furball with parts I had laying around and wires running to several sockets so I could try not only ECC82 relatives, but octals and 7-pin mini's as well.
The cathode- and anode resistor are a starting point, so far from optimal for all tube types. Merely a start to get my head around the concept.
This is also my first adventure with the REW program to get an idea about the THD. I have no idea how accurate the absolute readings are, but it's good enough to compare types and settings in this experiment.

Last night I have made measurements on three Blackburn ECC82's, two RCA 5814A's, two Tesla ECC802S and an old unmarked Chinese tube I thought to be a 12AU7. After that a few UK and US 6SN7's, ECC32's, a computer tube with multiple markings (that are not equivalents according to the datasheets) and an E92CC.

Observations:
Tweaking the voltage on the grid of the second triode really works to bring THD to a minimum.
However, it's not easy to hit the absolute minimum with a regular pot. You'd need a multiturn pot for that.
Most tubes can be tweaked to similar THD levels at 1,00Vac output level: 0,03 - 0,04%. Exceptions are the Mullard that has a bit worn getter 0,08% (draws a little less current too), The NOS ECC802S's got to 0,04-0,05%, UK round-plate 6SN7 0,05%.
Pleasant surprises are the two computer types: E92CC (0,03%) and 6211/E180CC/whatever it is: 0,02%.
The Chinese tube draws a third of the current and amplifies a bit more, so this is no 12AU7. Still only 0,03% THD in this setup.
The ECC82 family has around 12V on the cathodes, or 8mA total. (except the worn Mullard).
The optimum voltage for the second grid is between 10,2 and 10,9V (leaving out the worn Mullard at 9,5V and one of the Tesla's at 11,5V).
6SN7's have between 9,7V and 10,8V (6,5-7,2mA) and 6,8-7,2V on the second grid.
Adjusting the gridvoltage/current through the second triode, changes the amplification factor.
Mind you, this is with a collection of tubes of different brands and unknown hours of use, so differences are to be expected.
It does (finally!) bring me to the question to the collective wisdom of this forum:
How to optimise this concept to make it usefull as a line amp?
Objectives:
- reduce the bias tweaking with changing/aging tubes.
- minimise THD
- minimise differences in amplification

Some options:
NFB from the output to the second grid. You could put a pot under R6 which would give both NFB and the positive voltage for the grid, but setting the pot, changes the NFB.
Replace the anode resistor with a CCS?
Replace the cathode resistor with a CCS (and feed the first triode with a resistor, turning it into an LTP)?
Insert a resistor between the cathode of the second triode and R2 and reference the grid to that? Combined with a CCS instead of R3?

I have a failed 2SK3850 Fet in the power switch on circuit of a Yamaha RX-497 stereo amplifier. It is a general switching Fet but it's going to take a few months to get one from China so I'm wondering if anyone knows of an easily available substitute that I can use in its place? I've tried to copy & paste the 2SK3850 datasheet but it wont work?

I just connected my SMPS300RE and it makes a high pitched sound. Is that normal? I can hear it from a couple feet away. Attached sample

20 years ago when my children were younger, i was constructing a tube amp. I was working long hours and was busy taking care of the kids with sports, school work etc. Point is only time I could work on my project was late at night when the kids we asleep. Well, this night I was finishing up the amp and testing the voltages when my young son called to me from his room. He could not get to sleep and I read him a story ("Tink Tock Takes a Trip"...pictures with 3 words per page) I read him this because I was impatient and wanted to get back to the project. He fell asleep and back to the project I went. I was on my knees and went back to it. Bam!😱 the circuit was energized with 600v dc.my whole body was paralyzed and I fell away and off the contact. Just something I think about often....and I still have "Tink Tock Tuck Takes a Trip", great book! Can't wait for the movie.

Be Careful

What 6SN7 tubes are liked and used around here?
I find some reviews here but here not enough information.
I am getting ready to buy some for me Golden Tube SE40 and would like some input on new ones and NOS ones as well.
Wait for recommendations!

Hi everyone, there are some threads about this but not with the answer I looking for. How much watt does a amplifier use with different frequencies. I know a 100 watt amp will give 100 watt at every frequency, so a flat sounding speaker with 90db sensivity will give you 110db at every frequency( 100hz, 500hz, 10000hz), but how much power( watt) will it use. Is there some theoretical information about that...

An example - - > if I play a 100hz sinewave for 1 hour and a 200hz sinewave for 1 hour, what will the difference be.

I want to know because I have 4 drivers wich can take 6 watt RMS each so total of 24 watt RMS... I want to give it 50 watt RMS but highpass at 50hz, hope this will cut off some power...

I purchased an SM Pro Audio V-Machine standalone VST player for home use. It has its limitations, but for me the biggest issue is the fan noise. It is quite annoying especially in the evening (I use it with headphones, so that my playing does not disturb my family, but the fan does). There is a tiny 5V fan cooling the CPU, mounted on top of the aluminium heatsink. It is marked Arkua Everflow 5V/0.13A. The motor diameter is 21 mm, the outer diameter is 36 mm. I guess this is kind of a laptop fan. Anybody has an idea, what could I replace it with, so that I can reduce the noise?

For sale pair of compression drivers

Brand : JBL

Model : 2426J

Brand new diaphragm : Radian 1225-16

Better than the original ones - see : Radian Audio 475BePB vs JBL 2426H vs JBL 2426H/Radian - PDF Free Download

Price : 350 Euros + shipping costs from France

Hi Gents,

I am building the cabinets for my newly arrived Alpair 10Ps and am wondering about the best lining for the slightly modified (15L) Wooden Designs Simple Reflex 103 cabinet. The cabinet is built of 3/4" baltic birch with mitered joints.
I have several yards of 3/8" thick medium density jute headliner material. The plans suggest that "all internal sides of the cabinet" be damped. So, two questions:
1. Should the floor and the back of the baffle below the speaker be lined? And.

2. Is one layer of the 3/8" medium density jute suffiient, or do I need to glue two layers together to get a 3/4" thickness in order to reach the recommended "damping" level?
I know that the lining is not actually damping the panels to any significant degree, but is there to reduce internal reflections that may feed back through the cone. I'm just using the word damping since that is what is used in the plans.

Best,
Jay

Dear forum members

Anybody have experience with I2SoverUSB MK3 card and AD1865DAC? I tried to setup according to the user manual,
http://jlsounds.com/uploads/I2SoverUSB v.III.pdf
(J3 jumper closed, H1.1 connect H1.3 with 4.7k resistor), then connect the board to the DAC but no sound.

I checked the H3.9, H3.11, H3.13 H3.15 with my scope, I see the square signals, so the outputs are working, but maybe the data format not good...

What is MCLK_2/4 or MCLK_2/2 options?

Thanks
Laszlo

DHD ntx 3107


This amp had some bad primary filter caps.I replace all.


The next problem is the amp will start to distort very early when i start increasing the input signal.Both rail voltage will go from 35 down to about 21v when i start increasing the signal causing the reg voltage to fall down to about 4v.


If i used a current limiter to power the amp it will play good audio if i increase the signal way more than if i had just power it up directly . Any suggestions


PS FETs gate and drain cant remember which is which.

10/dv 10/us

Hi All

My first post 🙂

I recently got a pair of Mission 765i Towers from a yard sale almost free. However on one one of them the Tweeter does not work. The part # is R76/78-HFU-D26. Please advise where I can buy it. If it's no longer made, is there an equivalent I can use?

Please let me know if you have any questions and/or need any additional information.

Thanks a lot!

Hello,

First time here on Diyaudio.
Here's a quick intro before asking what really is on my mind.

I'm living in Lyon, France so you'll have to excuse me for a few mistakes from time to time.
I have been around audio from the 70's and 80's for a long time, the music as well as the equipment and recently I discovered the pleasure of opening them up and try to understand them a little more, repairing and recapping when needed. So I am looking around on the internet for nice pieces.

I currently have a Technics su 8080 with a pair of ditton 66 legends, a technics sl-B2, a teac UD-H01 dac and a philips CD 624.

As secondary setup I have a Dual Pa 5060 saved from being thrown away with technics speakers also saved from a horrible death, a technics SL-PG580A and an ITT turntable (quite rare apparently).

I'm here to learn mostly but will do what I can with my little knowledge to help.

So now the real deal, I'm looking for help with a Scott A 426 I picked up recently.

When I got it nothing worked so I started by isolating the problem : the power amplifier section. I checked all the transistors and most of them were shorted, never seen that much in one single amp. Also a few resistors and diodes were bad so I replaced everything (some with originals some with equivalents but same on both channels).
(the red circled ones have been replaced)


But after all of this the problem doesn't seem solved, I powered it up with a lamp connected in series and it lit up so there has to be something else.

I couldn't find anything so if anyone here has any idea of what could be causing this I would be very grateful.

Thanks

Well I did list this on the Devilbay only to have idiots bid and enquire so I thought someone on here may want to have a tinker with it .
It’s like the 596a model but with some extras.
It has not been tested or switched on for many years I’m told, it does NOT come with any plugs or cables.
£80 collection from Milton Keynes









View attachment 1

I'm putting together a two arm table. On the back side I want to use a Audio Technica ATP-12T tonearm. This came with no cable and the cue lifter was not a part of this design, it's a broadcast arm.
I need a DIN to RCA cable, I believe it's the standard DIN cable that fits a lot of the tonearms out there. Not looking for one sprinkled in fairy dust and diamond encrusted, just a decent quality cable that may have come with a tonearm and was upgraded, so now it's shoved into your closet. LOL
The Jelco tonearm lift is a nice quality piece that would fit right at home on the AT tonearm. I'm not sure if anyone might have one in there parts stash, figured I'd ask. I will machine a bracket to mount it to the tonearm post if I find one.
Thanks

BillWojo

Hi

Can anyone tell me how high the BIAS must be at the JL 300/4?

After changing the output section the BIAS is to high.

I've read in an other Thread (JL Audio 300/2) that the BIAS must be around 4mv. Maybe for the 300/4 it is the same?

Thx!

hi everyone do you recommend?
I would like to make a small economic system for the bedroom, intended to listen to white noise, FM radio, clock radio to get up in the morning. all this using a mobile phone and a pair of audio speakers that I have to choose and buy.
I don't want to use cables connected between cellphone and audio speakers but wi-fi technology (no Bluetooth), plus I want to use my voice to control the cellphone (I thought of google home-assistant) which must send music to the speakers (I don't know what range in terms of meters the microphone of the mobile phone can have).
at the hardware level I know some microPCs, the most famous is the raspberry but there are many others and therefore it becomes difficult to choose, then in cascade it also takes the DAC + amplifier and the price rises.
Alternatively there is the audio chromecast which is however out of production, perhaps there are others.
I don't want cables hanging around the room so I put everything inside the audio speakers except the mobile phone of course, consequently I think it takes 2 microPC or 2 audioCAST.
I don't know if microPCs or audio casts are better.
in the case of microPCs at the software level I do not know how it can be done. I think it takes software that acts as a server installed on the microPC and another software that acts as a client installed on the mobile phone. the problem is to be able to make google home-assistant work with the client software on the mobile phone.
I don't want to use the data traffic of the mobile contract and I don't want the wi-fi of the home line. so I use many audio files stored on the cell phone and the FM radio of the same.
I don't know if it is better to choose the hardware first and then the software or vice versa.
I'm not a programmer so I would like to avoid complicating my life with endless attempts at script settings and installations that never go to the first try and things like that.
bye thank you .

I had assumed that maybe half of DIY tube amps might use some NFB, but last night it was suggested to me by someone who’s built 3 tube amps that it makes things harder/ less stable, and few do.

I'm likely to go 2A3 PP.

Do the advantages outweigh the disadvantages?

I've run out of small signal diodes with >300V rating, and I need 6 of them now... But I have some small signal transistors such as FZT558 (pnp), FZT458 (npn), KSC3503 (npn), MJE340/350, and some others, rated at Vceo = 300V and above.
Can I use the collector-base diode? I know I can create a diode by connecting base to collector, but the reverse voltage it then handles only 5-10V in reverse. So what if I only use the C-B diode?
Thnx

(It is to protect grids on start-up where I have conditions where the grids get pulled positive before the cathodes get warm and they properly conduct. So I need to limit the positive voltage for just a moment when it is turned on).

Hi Guys, I finally got to powering up the first of my Aleph J boards this morning.

DC Offset 20V - I thought, "Oh my God !!"

However, I can adjust the offset down to zero and set the Iq to about 585mV across R16.

My question is, if I leave it for a few minutes the DC offset is back to +/-20V.

I can adjust it again back down to almost zero but it is just not stable.

I own a pair of NVA Cubix omni directional speakers circa 1991/2. The speakers set up correctly can sound absolutely wonderful, unfortunately I have damaged one of the 8" Electro Acoustic Industries woofers and as the original part is in all probability no longer available I am using my misfortune as an opportunity to upgrade. The NVA Cubix are a bit unusual in so much as there's no crossover, two 8" woofers, the lower one is totally enclosed with the 2nd sitting directly above. The tweeter and mid range employee a resistor and capacitor and that's about it. Any replacement woofer must work ok without a crossover as I want to remain faithful to the original design and as I said earlier with the correct stands, cable and positioning they are a very involving pair of speaker's.
The speakers are driven by NVA monoblocks with an NVA passive pre amp.
I am a complete audio DIY novice but I can follow instructions ok, use a soldering iron etc. My other question is will I be ok just upgrading the upper woofer in each speaker and leave the original lower woofer in situ or will I have to upgrade all four woofers?
Any and all advice is much appreciated. Thanks Paul

Looking for suggestion of high quality speaker kit with cabinets. I do not have the woodworking space, skills or tools to build my own cabinets and I can't find anyone in Houston to agree to build one for me either. So if you know of a kit that comes with cabinets that is truly exceptional, please let me know.
Budget: ~$2K

Only for 96KHZ LDAC , with the osc of 24.576MHZ , use two AD1865 R2R DAC

I’ve attached a couple images from a schematic showing -19 and -22 volt bias taps achieved by isolating the center tap from the ground with a 180R resistor. It’s a tad more complex as you’ll see in the schematic. The -19 volt tap is used at the output tubes in a very conventional manner. The other tap is used to cut off a triode and isn’t really pertinent.

I find this circuit incredibly cleaver. I’m wondering why I shouldn’t swipe the idea for a build I have in mind where I’ve got a bit more B+ voltage from the PT than I’d like. My thinking being that the voltage loss across the resistor would also lower the B+. A win-win so to speak.

I also wonder why I’ve not seen this design before? It’s simple, it seems like the bias supply would be reliable enough and the bias voltage would come up at about the same time as the B+. If you can think of some downsides, I’d like to hear of them.

The schematic is from a Hammond organ amp, an AO-29. I post here because the idea is pertinent to a hifi build.

For sale :
A pair of USSA5 boards from the first groupsbuy .
All the parts to stuff the boards are there .
Asking 200 Euro (fixed) + shipping and paypal fee if outside Europe .
Everybody can buy but I do prefer Europe sale .
Mail me for more info or if you're interested in buying .

Like the title says, I'm looking for the JVC or Victor UA-7082 tonearm. This is the long arm version of the UA-7045 arm. Might consider a UA-7045 arm as well.

Other things of interest are Victor TT 71 and TT 81 motor drives.
Thank you


BillWojo

I've heard that when crossing over from car woofers/midranges to subs to try to go as low as possible, like 80 hz. Why though? Personally, I'm planning on installing small 6.5 subwoofers in the rear doors and I feel like a higher crossover point such as 120 hertz would be more appropriate because the subs would be more suited to handle 80-120 hertz, right? Plus, wouldn't the woofers/midranges be able to play cleaner? Or am I making the wrong assumptions?

Waste of time

A TOTAL waste of time posting this question here. First two pages are uninformed guesses as to why, and all of the following pages are consumed by unrelated posts by a troll. Find your answer over at the forum hosted by Parts Express.

in PMD100 datasheet

CS8412 connect to PMD100

PMD100 in diagram is left data justified 16-24bit (pin13 to Ground), data latching on falling edge of BCKI (pin 14 +5VDC)


Question is can I connect CS8412 to PMD100 in 16bit Right Justified (pin 13 +5VDC)?


Another Question is 4 of 100R resistors between data and clock signals (BCKI XTI LRCI) of CS8412 and PDM100 are necessary?

I was asked to 'fix' a Spectron 1000 watt class D amplifier. This amp has very good reviews but the company has gone out of business.


Does anyone have a schematic diagram. I would be happy to make a good donation to DIY Audio.


Love this space, thanks to the many contributors, John

Hi,

I have old PS1 and modify High pass filter as follows picture.


How much the output impedance of this DAC?


is It 22K ohms?

My other DAC has output impedance of just 100ohms How to lower 22Kohms output impedance?

Hello... I haven't been around for a while but I thought I'd share my last project with everyone.
I bought an Acurus A150 about a year and a half ago and I've been using it since. since i got it I had the itch to upgrade it because I felt it had a lot of potential but was being held back because of some shortfalls. First off this is a very old A150, the heatsink is half the size of every other one I've ever seen. the only time I've seen one with a heatsink this small was on an article reviewing this amp when it was first released. I don't have a problem with this because my speakers are very efficient 8 ohms and I don't need more then 50 watts to really make them sing. also the device bonding surface of the heatsink is really rough. thousands of small grooves that should have been polished out but weren't, oh well.

the voltages rails on this amp are 77-0-77 with 120 volt AC and the main filter caps are rated for 80 volts! that is not a very comfortable margin for my tastes. The transformer is excellently balanced, when dc is made the rails are only 1 mv out from each other! that's a nice tight margin. the fact that this amp has lived 30 years and kept working is a bit of a wonder. recently I opened the amp and saw that a zener diode and small signal transistor were destroyed, literally split in half and the damn amp was still making music with little dc offset on the output. that's pretty amazing. it looks like it had been in this condition for many years.

okay so now to the refurbish and upgrading.
2sa1349GR replaced with 2sa1349BL
2sc3381GR replaced with 2sc3381BL
these are the input transistors and the stock transistors have between 200 to 400 gain the replacement are 350 to 700 gain. this is a LTP input and increasing the gain on these transistors isn't going to affect the gain of the amp but will make it far more sensitive to small signal detail and I feel just overall improve the sound of the amp. Of corse with the way the transformer is orientated to the vertical pcb using these ment I need to put the transformer outside the amp. I tried it with the transformer in the amp and with my sensitive speakers it just picked up way too much emi and such.

r10 and r12 are part of a cascode circuit (i think) and drop whatever isn't in the 12v zener diode
stock 22k 1/4 watt (pushed right to the limit! at about .2 watt) replaced with 1 watt 22k metal film.

r1 and r8 are part of a current source circuit
stock 390 1/4 watt replaced with 330 .6 watt metal film

I replace all the mpsa92 and mpsa42 with new ones

C4,5 changed from 39pf to 200pf cog type ceramic

c10 220pf changed to cog type

1k bias trim pot changed to sealed multi-turn

the ztx757, ztx657 were ganged up with their own emitter resistors which were changed from 47 ohms to 68 ohms on each transistor

when I first got this amp open I said darn there is a lot of space in there, so I knew I could stuff lots in. so I added a DIY audio soft start and speaker protection unit.

I guess the star of the show is really the powersupply now though. I had had some 3 mH 10 amp e-core inductors kicking around for quite some time now and this was my chance to use them.

22,000uF @80volts changed to 22,000uF @100 volts then the 3mH inductor and then a 15,000uF @100 volts.

I added post fuse capacitors 220uf @100volts and new bipolar caps on the feedback loop. as well new bipolar on the input. when I doubled up the ztx transistors I added a 10 pf miller effect cog cap to the underside of the pcb (basically I copied the A250 schematic).

because I don't need much power and my heatsink is so small and poor I made a decision to remove 2 output transistors per channel and that made adding the post fuse caps super easy.

input jacks changed to cardas rca's

I installed the new cap brackets with rivets so I had to use small spacers when I put the front plate back on to accommodate them.

rebuilt the power swich with a superbright white led and connected it to the protection indicator on the diy audio speaker protector so it flashes when first turned on or when the speaker protection kicks in

because the surface of the heatsink is so rough I didn't feel regular heat sink pads would do it so I went back to heat sink paste and insulators. I know they are not in right now but I needed to fill in all those tiny grooves and thats what was originally used so it felt safer.

A there you go, that's puppies totally rebuilt

so how does it sound, wow!!!

it is super quiet and sounds so clean and effortless. I find myself turning it up and just marveling at the impact I'm hearing. the detail and clarity are just astounding especially on good recordings. this is an amp that really is going to show the source material and capabilities of the rest of your system. I am totally pleased with my work and with the end result. I can't believe there is this much to be had from a quality class a/b amp. I can see why this amp is such a popular rebuild recipient. I bought the amp for $350 Canadian and I put about $350 into it. I think there's about 50 hours labour but then again I had to rework some stuff to get it to where I needed it to be.

I've tried to explain my upgrades as well as possible and I do not understand everything about the circuit so if I've gotten one or two things wrong please forgive a home diy enthusiast.

I have 24 NSB and 60 no-name tweeters that I will make available free for local pickup in the Chicago suburbs.

They were for a line array project that never got off the ground.

Has anyone tried this xover before? Here is the link:
AR-SXO - Acoustic Reality - Designed and built in Denmark


I did a simple simulation and it does surprisingly well. The downside is the low frequencies are not quite as efficient because some of the current will run through the resistor instead of the woofer. So the bass won't sound as dynamic.

The positive is it does not need a capacitor, but it will stress the tweeter more so you need some quality tweeter.

Here are two simulations: one with acoustic reality and one with a more conventional approach. The conventional approach is about 1.5dB more at the low frequencies vs. acoustic reality.

The below was instructions on Techtalk on how to attain VAS from DATs V2 when the you need to add more weight on the driver with the added mass method.

1. Take your first TS measurement. Let say you come up with a Fs of 50Hz. Deduct 25% off this value, which would give you 37.5Hz.
2. Add weight slowly while repeating the TS measurement until you obtain a Fs of about 37Hz.
3. Take the weight off the woofer, and do a normal TS measurement.
4. Add the weight back on, then perform the Vas measurement. If the weight is still insufficient, add additional weight in small increments until DATS is happy.
5. Hope this helps.


It seems like there is no in-between the original Fs and say 70% less. My tweeter is a paper cone vintage tweeter which is very stiff and I can't manage to get the VAS. I tried the above method but unfortunately once you put a weight on it reduces the Fs by about 80% and any amount of weight less than the one i had just put gives you the original Fs.

I can't find any other info no how to attain the VAS with teh DATs V2, the methods are not in any instruction other than the added mass method. Is there a way to guess it? Or can anyone tell me more about vintage paper cone stiff tweeter Fs is about 1300?

I never thought my first speaker design will be attempted on vintage speakers but it is the way it is. And Im a little stuck on deciding on the tweeter cabinet.

As it plays pretty low I am guessing it will need a cabinet? Small one im guessing....

Background and Design Premise

I built my first pair of DIY speakers 22 years ago, and despite planning something much more ambitious and expensive just a few years later, I managed to instead build speakers for friends and family and indulge other hobbies in those intervening years. Now I have made up for lost time by building something overly ambitious. I made the cabinet construction more difficult than it needed to be, not only to get an nth degree of additional performance, but to make something visually striking and different, to experiment with new techniques and materials, and to confirm I am capable of doing all of this. It had a lot of educational and entertainment value. Deliberate hurdles include:

• Physical design impossible with pencil and paper; blueprints needed to be created using CAD.
• Complicated construction techniques beyond my initial skillset.
• Unproven materials and joinery.
• Shape requires painting, which is 100x as difficult for me as staining and finishing real wood.
• I have never been happy with the reliability of my measurements <500Hz, and this is a 3-way.

A few years ago, I built a dual mono subwoofer using a pair of 12” subs facing each other and housed in separate cabinets that were coupled together with threaded rods. This is push-push (not push-pull), so there is no cancellation of even order distortion, but there is no exposed magnetry and the force cancellation does work. The current project is a 3-way tower that offloads bass responsibilities to that sub.

Project Highlights

• Unique, sculpted appearance.
• Cabinets are low diffraction, high mass, highly damped.
• Creative construction techniques to account for my lack of tooling and skill.
• All drivers from Scanspeak. Tweeters and mids decoupled from cabinet with Sorbothane gaskets and anchors. Construction-wise, this worked as anticipated, but I have no measurements to prove it was worth the hassle.
• Active DSP crossovers.
• Hypex amplification with one amplifier channel per crossover region.

Cabinet Design

All 3D modeling was done in Sketchup, although there is additional routing and shaping I do not know how to do in Sketchup that I did on the completed speakers. I designed the exterior shape first, then worked my way inwards placing collections of parts on a separate layer so I could work on them in isolation. What I ended up with was the ability to explode the speaker and dimension all parts. Anything too complicated to build from a picture was printed 1:1 and adhered to plywood for cutting. For example, the horizontal bracing that is not perpendicular to the baffle has a different shape on the top than it does on the bottom, as the angle to the side of the brace changes several degrees from the front to the back. I had to first cut to the larger of the top/bottom profile for these pieces and then cut/sand at a variable angle to taper to the smaller profile. This worked reasonably well, but with ~1mm tolerance on all finished dimensions, it added up to a lot of slop during assembly, and I had to fill a lot of gaps with glue or resin.



Project Details

TMWW + SS: 3-way active tower speakers plus dual driver mono sub with 8 channels of amplification.

Drivers:

• Tweeters: Scanspeak Illuminator D3304/6640 1” beryllium
• Mids: Scanspeak Revelator 18M/4631T00 7” slit cone
• Woofers: Dual Scanspeak Revelator 22W/8857T00 8” aluminum
• Subwoofers: Separate, part of previously completed project. Dayton Audio RSS315HF-4 12" Reference HF Subwoofer 4 Ohm

Cabinet:

• Portability of extremely heavy cabinets improved by building separate TM cabinets which sit on top of WW cabinets, isolated by Sorbothane sheets.
• 1-1/2” thick baltic birch baffle laminated from two sheets with silicone adhesive constrained layer. Exterior of baffle slightly curved horizontally, with 1-1/4” roundovers on vertical edges, expanding into additional shaping around tweeters.
• Driver recesses inside baffle enlarged with cove bits to improve airflow and avoid resonances.
• Mids and tweeters decoupled from cabinet with 1/8” Sorbothane gaskets, and are bolted to hurricane nuts which are also decoupled from the cabinet with Sorbothane isolation bushings.
• Woofers are rigidly mounted with T-nuts.
• Baffle tapers from the floor up, and is tilted back 5 degrees to improve physical time alignment.
• Skeleton built from dimensioned parts printed 1:1 and transferred to plywood using a light spray adhesive.
• Curved walls built using internal and external shells with a 3/4” gap and minimal use of spacers.
• Hollow cabinet walls filled with 60/40 mix of dry cement powder and epoxy to provide mass, strength, and damping. Exothermic heat is kept low via the mass of the cement and the use of a slow hardener. Experimentation has resulted in castings that are substantially more inert than baltic birch.
• Additional internal damping provided by aluminum-backed butyl sheets and 3M rubberized auto body undercoating.
• Internal stuffing is blue jeans insulation and pillow stuffing.
• Exterior seams sealed with shellac prior to priming to prevent showing through paint. This has worked well for me in the past, but did allow a few seams to show through this time.
• Painted with textured Rustoleum aerosol paint which provides a matte finish and some scratch resistance. However, getting an even texture on a large surface is difficult.
• All connectors are invisible, as is the star quad 14g cable run under the carpet.

Crossovers:

• Tweeter passive circuit:
  • 33uF Mundorf Evo Oil cap for protection, in series with
  • 2 paralleled 10.0 Ohm 12W Mills resistors to reduce hiss.
• Active: Pair of MiniDSP 2x4 HD, one per L/R channel
  • EQ each driver ~1 octave past each crossover point and apply textbook filters
  • Room correction of bass frequencies.
• Initial implementation:
  • LR4 IIR at 80Hz, 250Hz, 1.8kHz.
• Final implementation:
  • LR4 IIR at 80Hz, LR2 FIR at 300Hz and 2.5kHz made possible by well-behaved wide bandwidth drivers

Amplification:

• Tweeters: Hypex NC400 stereo amp with single SMPS600, already tested at ASR
• Mids: Hypex NC400 stereo amp with single SMPS600
• Woofers: Hypex UCD400 + HXR stereo amp with single SMPS1200A400
• Subs: UCD400 stereo amp with single SMPS1200A400

Sample construction details:



Full design and build galleries.

First attempt at a crossover

The full range mid driver Fostex FF125WK has a nasty bump at 7k, advice sought as to what values and what elements to use for smoothing ?

any experienced advice greatly valued and appreciated

my MacBook can’t find any free software that’s works

Martin

Hi, I have an old soundcraft 200/400b power supply that I am trying to use to power a very low wattage circuit.

I am getting exactly +48v and +17, as expected, but -23v out of the negative rail regulator, an LM337K TO-3.

Voltages before the regulators are the same between the positive and negative sides.

I also observed, on the 337, that the output pin voltage is the same -23v at the adjustment pin.

Is this an indication of a faulty regulator?

Thanks

Has anyone made upgrades/mods to this model of Rotel CDP?

How can improvements be made to this one?

I'm usually in the valve posts, this is new world to me.

I have discovered that my PC has very noisy USB ports.

I recently installed JBL 305P self-powered monitor speakers for nearfield use. I can hear a low level buzz and hiss. It's not the typical ground loop hum. The noise is worse when I hook up directly to the motherboard, and a bit less when I use the USB ports on my computer case. The noise is apparent only when there's no music playing or the music level is very low. Of course I would prefer a black background.

PC is a ryzen 7 2700 with 16 GB RAM, no soundcard. I use Foobar2000 as my media player.

Connections are as follows: Computer case USB port --> Audioquest Dragonfly 3.5mm out via balalnced XLR cable --> JBL LSR310S active subwoofer then balanced XLR cables to --> JBL 310P MkII active monitors.

Would some sort of USB filtering device work? I'm interested in getting a different outboard DAC but AFAIK, most of the less expensive ones don't advertise any type of USB filtering. There use to be a Schiit Wyrd but that has been discontinued.

This device would seem to work but it is not rated for USB 2.0 speeds, but the spec reading "upport USB 1.5 Mbps at low speed and full speed 12 Mbps and does not support pure high-speed equipment". Would this thing be fast enough when using high resolution files?Amazon.com: Nobsound USB to USB Isolator Module Audio Noise Eliminator Industrial Isolator Protection: Home Audio & Theater

Another filter is this dongle, which I just ordered to try. Amazon.com: iSilencer3.0 USB Audio Noise Eliminator/Suppressor - Remove Unwanted Noise from Audio - System Upgrade: Home Audio & Theater

Otherwise any of the more robust USB filters that are rated for USB 3.0 speeds are in the $350 range.

Has anyone had this type of problem and come up with a solution that works without spending a ton of money of an outboard box?

Basic question I'm sure but how do people test new drivers when they get them. Ive got some drivers and I want to make sure there isnt any fault with them before building the enclosures.
Visual inspection looks fine and no rubbing sounds when lightly pressing on the drivers.
At the moment Im just running some full range music through each one in free air for a few hours at very low output levels but not sure how to expand on this safely. Any help appreciated.

I am thinning out my stash. Up for sale are 60 pcs of PE 260-570


They are in original boxes and have been there since purchase in 2005. The boxes are very flimsy for the weight that they carry.



Buyer pays actual shipping. Payment will be Paypal "friends and family".


Parameters measured with a WT2. These are probably ok in an open baffle


Ask questions here. Send a PM if you are interested.



Re = 7.5913 ohm
Fs = 116.8097 Hz
Zmax = 51.3775 ohm
Ro = 19.7382 ohm
F0 = 95.0274 Hz
F1 = 147.7227 Hz
Fmin = 608.1130 Hz
Qes = 0.9998
Qms = 5.7668
Qts = 0.8521
Le = 199.7197 uH @1k
XLe = 8.3498 ohm @1k
PLe = 8.6436 Deg @1k

For sell pair in very good condition.

Asking 160 eur.

Scan speak D2905/9500 - Oglasi - diyAudio.rs

Hi All,

I’m in the process of rebuilding the voltage regulator for the preamp section in my Tandberg 3012 integrated amp. Over time, it has been damaged by heat and there have been some repairs that also have failed, and now some of the circuit traces are lifting from the board. The last person working on it has given up, as the time he needs to put into it would be problematic for both of us. He is of the opinion that one or more of the transistors in this section is failing and that is causing a voltage imbalance and that is causing the amp to shut down.

I, however have some covid-time available, and a few craft skills—although I need some advice in the electronic realm.

Here’s the plan as it stands:

I’ll pull all the semiconductors and get new ones. If I can get them off the board without wrecking it, I’ll replace them in the current board. If it’s beyond repair, I have a plan to make a small new board with all the regulator parts and stand it off the current board. I’ll be creating a heatsink for the power transistors, and move them to the top of the board to perhaps dissipate heat better (all the other parts are mounted on the bottom). And that amplifier is biased into class A, so it generally runs warm, which is likely the reason the regulator failed to begin with. I’m thinking of building a low-profile plinth with a fan to keep some air moving through the whole thing.

So far, so good?

Of course, since this is c. 1990 equipment, the transistors and zeners seem hard to find.

Here’s the list (Sorry, format here won't let me tab this into columns):

Part # Type Original Replacement. Alt

CR418 Zener BZX79-C62 1N565B
CR415 Zener. BZX83-C12 1NTE5021A 1N963B
Q435 NPN/TO92 BC447B BC449
Q436 PNP/TO92. BC448B BC450 BC450B
Q439 NPN/TO202. BD419 BD139 CEN-U57
Q440 PNP/TO202. BD420 BD140 CEN-U07

I haven’t run down all the numbers on these replacements beyond the general voltage and current specs. If anyone has thoughts on particular choices or better ones, I’d appreciate the input. Regulator is +- 62V. Circuit diagram and board layout attached.

I’d prefer to keep as close to stock as I can, but would I be much better served by an all-new regulator design/circuit, especially as I’m already considering building and mounting a new board? I do want to fix this once and for all. If so, any recommendations for a +-62V regulator circuit?

Oh, and does anyone know why there are two sets of 1N4148 diodes in series? What’s the purpose?

Hi,
I'd like to hear from people that worked with those DAC's.
My first question is how do you program them without an EVM?(I know about the SPI/I2C interface ,but my question is related to the Instruction Set or how do i use the DAC's DSP).
PurePath seems to want an EVM otherwise it won't spit out the cfg file or create the configuration instructions to be sent.

Second is where can i find an Instruction ISA handbook or documentation for the mini DSP core?
Let's say i have the Z-Transform/Transforms for my digital filter/filters,I load it into the coefficient memory.How do i specify the summation operations etc. and witch coefficients to some with whom or implement the Z^-1 delays?

Also do i have a chance of making PCM5252 work with the SmartAmp functionality without an EVM?
I understood the PCM5252 ROM has the algorithm loaded,i presume in some of those RESERVED pages of instructions.However i found 0 documentation explicating the memory map other than the general layout.(i only found the datasheet)

Feels like the only tool i have to work with is PurePath ,but support is not available("oficially") for PCM5252.

Worst case i'll use them as pure DAC's and do the DSP on a Cortex M-4 ,but i feel like i paid for features i won't use then.

I purchased this Bluetooth capable speaker a few years ago as part of a kickstarter and never ended up using it. The sound from it was muddy and the wood finish was too yellow. I have been wanting to refinish it and upgrade the internals/drivers for better sound. My goal is to have a Bluetooth capable speaker with decent sound quality (similar to the Logitech boom or other higher quality bluetooth speaker). It would be used in an office or kitchen.

I’m looking for suggestions about what to put in it. Specifically speaker drivers and amplifier. I have experience soldering and have put together a bottlehead kit in the past (crack preamp). I would prefer something that comes in kit form and has detailed instructions. Speakers have to be 2.5 inches.

Link to original Kickstarter project: QuarterWave - Coolest Bluetooth Speakers by SMARTWOOD ACOUSTICS — Kickstarter

Thanks for any suggestions

Hello.
I had in the shelf these midranges to build again the incredible Troels Gravessen Ekta Grande Kit, but I'm going to change my mind since I do hav floorstanders and I will swith to 3 way bookshelf Troel's SBA 741.

The midranges are in very good gondition althoug there are some scratches in the chassis that cant be seen at listening distance.

Apart from Ekta grande you can build, for example, mini monitors BONBON from Knalg & Ton (I can send you crossover):
Walter Frohlich - SPEAKER Vertrieb - Distribution von Softwaretools zur Lautsprecherentwicklung - Bausatz ScanSpeak BONBON
Bonbon
Bonbon Klang und Ton, Scan Speak 12M/4631G00, D200

NOTE: ONE OF THE DRIVERS HAS BEEN REPAIRED.
Its almost impossible to see even in the pictures but I put detailed pictures. The chassis has some deep scratch outside 2 holes for the screws, but it has been repaired with epoxy and it looks good.
I attach one quick measuremente in which you can see there is almost no difference between the repaired unir (pink) and the factory one (green)

There was no damage to the rubber or any important part of the speaker, and you will see the drivers are pretty similar avobe 300Hz (the measures are valid only avobe 350Hz).

I can assure they sound the same and perfect.


Because of this problem, I will sell very cheap, 240€ for the pair + Shipping + PP fees
Will be shipped in their original boxes.

The price for ONE unit is about 260e ($289) as can be seen here:
Scan-Speak 12M/4631G00 4.5 inch midrange low loss suspension sliced paper cone | Loudspeaker freaks
ScanSpeak Revelator 12M/4631G 4.5" Midrange


Some pictures:

Have a mtx ta92001, different from other one I had. Any how. The smd capacitors by the subwoofer output terminals was burnt. I've replaced replace them. Amplifier power up, but once i play any kind of music. It's plays for a few secs then but the power draw shoots up to 13 amps. And the subwoofer thumps ever 2 seconds. I've disconnected the rca. With no rca connected, I have a 8 ohms load subwoofer connected the amplifier swings back and forth between 13 amps and 8 amps power draw and every 2 seconds and the sub thumps in and out with the amp swing. Any idea where I should check? Also the power supply get section is very hot. 107f the power inductors are 150f. The out put suction is 96f

For sale Siemens CCa tubes.

Measured and all have 100% emission. Two of them are from the same lot (same serial number).

Price is 75 euro/pcs or 250 Euro for all 4 pcs.

I can send only in EU (20 Euro shipping cost).

For detalis, please send me private message.

parafeed | JLSemrad | Flickr

What is the purpose of the capacitor in the schematic on the right?

Thanks,
John

This thread was split from the AK4499EQ - DAC thread because this 'subjective vs objective testing' discussion belongs in the Lounge.

*****

"I really do not care if anyone believes me"

Then why are you here, proclaiming your "findings" so loudly? Your attitude and behaviour say otherwise!

I took the plunge recently and bought an Audioromy FU13 amp of leshele (on9mart) on ebay. The amp arrived on schedule in well padded boxes an plays wonderful music.

So now I am wondering if anyone has a circuit diagram of the amp and experience with bias adjustment or any interesting mods.

I have a class A 10.0 amp that came in for repair. The powersupply was burnt. I was able to replace the powersupply fets and the 2sa152 transistors and the powered up. The problem I have now is the audio. I only have audio on the left channel. If is switch to bridge position I can get audio out the right side but it’s actually Just the left channel audio. Has anyone had this problem or have a schematic for this amplifier?

Looking for some assistance in confirming the identity of this piece I just acquired. The seller listed it as a Marantz 7 clone. Apart from the 6 tube, 3 line 3 phono design I have no way to confirm this for sure. I researched different 7 style schematics and am trying to pin down if its a known design.


Dual bank 350v 220uf Elna Cerafine Japan caps
Elna Cerafine red elctro caps plus some unique kind of copper foil cap in translucent plastic.

Main board is all Wima caps and RN60. Whats interesting is there are resistors of different style and color than the normal RN light brown I'm used to seeing but almost all read RN60.

4 pieces of Philips ECG 5751 and 2 Jolida branded 12AX7. The tube board is mounted vertically towards the front.

ALPS Japan original black beauty large body controls for volume and balance.

Separate toroid power supply enclosure feeding via umbilical to main unit with MUR full bridge feeding the main B+ and separate regulated supply for heaters.

All wiring is very nicely done in what looks to be a teflon wrap over silver (plated?) wire. Closer inspection gives the impression the wire is wrapped like some Cardas where the teflon is wound around another inner conductor to separate them.

I've been very much enjoying the sound and was thinking of using it as a working platform to follow what others have been doing with respect to 7C restorations and mods. Arizona caps maybe a bit more adventure with Teflon foil in some areas.

Any insight into this one is greatly appreciated. The only other reference I have found to it is from an old Audio Kharma post from 2009 looking for details as well.

Wanted to buy Genesis Technologies Tweeter. Entire unit or the membranes.

Thank you.

///

I have pair of JBL 4301B monitors and as im a drummer and muso I fed them a little to much power whilst having a beer.
They started farting with voice coil to magnet rub .
So I trained them to play at a volume that they were happy with I then very slowly went higher and higher with volume and the result is that they are much better , and there must be clearance now.

Increasing the bias current on my NAKSA80s & Sorayas ... seems to be a good thing!!

In my system (actively tri-amped Maggies driven by 2x NAKSA 80s (for mids & ribbons) and a Soraya on the bass panels), I suffer from a lack of soundstage depth. Unfortunately, this is due to the (lack of) distance between the Maggies and the front wall - which is caused by the room dimensions. I may be able to improve soundstage depth by treating the front wall with diffusion products but, in the meantime, with Hugh's advice, I decided to increase the biasing of the amps.

Hugh told me that increasing bias delivers more soundstage depth and suggested I could double the bias currents without causing any problem for the output devices - this means:
* 70mv across the 0.33 ohm res (R22) on the NAKSA 80s (instead of 35mV), and
* 120mV across the emitters of the outermost output transistors on the Soraya modules (instead of 60mV).

As increased bias means increased heat into the heatsinks, I decided to go slightly conservative - so a bit less than twice the stock bias:
* 60mv across the 0.33 ohm res on the NAKSA 80s, and
* 110mV for the Soraya modules.

I'm hoping my heatsinks will be able to cope with this in summer - as the result is delightful! 🙂 Yes, a bit more depth ... but also more 'body' to the sound! 😀

So this is something that AKSA owners might like to try out.

Andy

...as one owner said to me recently. To my shame I didn't get his approval to quote him but I'm quite confident that he will forgive me! In fact, the whole statement was something like this: " It's the ultimate size! a miniature beauty." Partially I agree with him thought I'm reluctant on "ultimate size" since I know this design can be squeezed furthermore.

Hello guys,
I'm speaking about my latest board called BluWave made from pure love to build something good and affordable. I did spend some years now to build up this small PCB but I worked occasionally on it. Since I know this post can be edited later on, I'll attach two pictures of a dirty board, top and bottom. I'm sorry that it looks terrible but I'll get back later with updated pics. This board is based on my previous design (Wave IO) but I did make some improvements here and there. For those guys who are thinking about this board to be a second iteration of Wave IO I want to state form the beginning that it does output only SPDIF signal, nothing more! So, there are no I2S buses or something like it... not this time!

As for this new card, you will easily notice that I've learned the lesson of not using pin jumpers when it comes to ... everything. Instead of this I opted out for PCB-designed jumpers, made purely of copper pads and your solder. This allows you to choose a particular configuration without be worried about parasitic resistances which can develop mostly due to moisture. I do confess those PCB jumpers could be small for some of us...

What are those configuration options?
1. The most important one is related to on-board "audio"/main clocks. This board does own a pair of small NDK oscillators used to generate all the clock/data signals for the output SPDIF stream. Using local oscillators is the default configuration for BluWave. Alternatively, a pair of U.FL. coaxial connectors are available in case you like to use your own external clock generators. This external signals should run freely, wired to those two tiny uBNCs: one for 22.5792 MHz (J7) and the other one for 24.576 MHz (J6). The related PCB jumpers to switch the clock sources are JP2 and JP3.
In this mode and to minimize the noise amount, local NDK oscillators can be disabled by cutting default traces to JP5 and JP6 => both oscillators will become dead silent.

2. The second option - which I guess is not so important - is related to on-board LEDs. In case you want to see them disabled then cutting the wire on JP4 will cause all LEDs to stay dark. Regardless of JP4, the signals on closely related pin-header J5 will always be available to drive panel mounted LEDs, for example.

3. JP1 is not used in this hardware revision so please leave it as it is.

Other than that, this board does have:
* USB input completely isolated form the output side.
* USB receiver + processor powered form USB bus while the output side can be powered separately from whatever external PSU you like. You do also have the possibility to power all the board form USB Bus. Due to some technical limitations, there's no option to entirely power this board only from your external power source.
* reclocking stage on output signal's path.
* main NDK oscillators on the "quiet" side.
* plenty of filters and decoupling networks.

It's my belief that saying which kind of parts I'm using is simply irrelevant since implementation (layout + part choices) is equally important. Let's say that I did my very best to keep all of them aside one from another trying to minimize the noise on this board and keep it to the lowest possible value I could afford. On the other end, signal integrity was my second concern where plenty of my efforts were spent on making square signals "square", especially for SPDIF output.

The output pin header (J4 - 2.54 mm pitch) is used by this board to share signals with the rest of your system (white arrows will show you the direction of that particular signal: input or output / no bidirectional). As usual, PCB is made of four copper layers in 35 / 70 / 70 / 35 um layer stack config as my previous design.

I decided to open this thread to share knowledge and gather feedback about it so I can improve this design along the way. Let's see where it goes!

Update 03-March-2017: After reading below post I decided to share some of BluWave's key features that I consider worth to be mentioned and bring clarifications where are needed:
* This board does provide SPDIF output only acting solely as USB to SPDIF bridge.
* First choice for a four layer board topology applied to this board was signal's integrity and noise minimization. Signals are properly terminated so the over / under-shoots artifacts are kept to minimum values.
* The power rails for this board are the most addressed parts of this design. This board does have bead filters and plenty of decoupling caps all over the place. Second reason why I choose for 4 layer copper board.
* PSUs are made entirely of linear voltage regulators. Despite the fact that in most cases a small SMPS circuitry will do the trick and be easier to implement, especially for the core voltage of the processor, I decided to use linear Vregs instead regardless of the power dissipation involved. BTW, that is the main purpose for those two glued heatsinks present on this card!
* By default, the output side is completely isolated form the USB receiver. The single exception is where one is wishing to power up the whole board from USB bus. In this particular case, the USB ground layer will be directly shared all across this board. In any other cases, USB grounds (and all related noise) will be kept apart from the rest of audio setup involved.
* Output side consist of SPDIF circuitry + main oscillators + reclocking stage and related PSUs. The Vreg used here does have better specs compared to what I've used on Wave IO. Star power sharing and ground planes will try to preserve the desired low noise levels.
* The ESD trouble was taken into account by applying proper protection circuitry to important nodes.
* BluWave can have two sources for main clock signals: on-board NDK oscillators (finest available to me) and external clocks applied through U.FL. connectors. When external clocks are applied, local oscillators can be disabled... both of them.
* The output data rate can start with 24bit / 44.1 kHz and go up to 24bit / 192 kHz.
* This board comes with free future support for Windows drivers as many of Wave IO users are used with! And, yes, drivers are genuine! Not something like a hacked copy of "luckit drivers" which you'll find all over the internet! ... drivers that, at origin, were mine too.
* Possibility for future firmware update though USB DFU, in case it's needed.

Update 10-March-2017: I totally forgot to add the price for this board! And, since there are many asking for this info I thought to list it. Before doing that I want to say that all the BluWave boards I have here which are part of my prototype batch will get a 10 Euro discount from the intended price tag (99 Euro). So, pilot boards will carry a price of 89 Euro with Paypal and shipping charges included in it.

Update 22-April-2017 with board dimensions:

An externally hosted image should be here but it was not working when we last tested it.

Kind regards,
L

I am planning an external 8 x oversampling DAC, SPDIF input, based on CS8412 receiver, PMD100 Filter and a TDA1541A DAC.

Actually, I am preparing a block diagram about the mode setup and the interconnections of this three chips.

As I am not an EE, I have now (at least) two important questions:

1. Is the interconnect between PMD100 and TDA1541A correct?
2. I dont know, where to feed in what frequencies from the XO clock. Just know, M0 has to be 1 to set the CS8412 in "slave" mode.

Every help is very welcome!

Franz

Hi! Long time lurker, first time poster. A guy in the neighborhood passed away a while ago. He was a radio host, repairer and I guess station owner. I was invited in a day before his widow was having a huge garage sale to get rid of all his equipment. I didn’t know what this was, but I liked the case. If I had to guess, it was a preamp or some kind of headphone amp? She didn’t know either and just told me to take it. Just curious what it really is...

This is actually for my car.
It’s an Alpine F1 DVD-Audio headunit and DSP.
It has 16 channels of output for a 6 channel 3 way front/2 way center/2 way rears/2 way rear center.
It’s the only car audio DSP that will do active multichannel.
It uses a FireWire connection between the two pieces.
The FireWire is the only digital input into the DSP.
I’d like to use a PC as a supplementary source.
I’m looking for a way to send 6.1 channels from a PC into the DSP. Does anyone know of a PC driver that will emulate MLP/DVD Audio over IEEE 1394?

Essentially I want to use the PC as a player with a .vst upmixer (Penteo Perfect Surrround) and send those 7 channels into the DSP.

I built this simple RIAA NatSemi app. note circuit but need more gain. I suppose that 390R resistor must be replaced with lower value but I do not know exact value for 40dB (100 times) gain.

in the 80's and maybe 90's manufacturers used a glue mostly around caps that dried and became toxic to PCBs and other components.
as I try to rebuild some equipment I am researching what is the best way to remove that old crud
in the searching for an answer that I have done so far, I found info on how horrible that stuff is and peoples thoughts on how you COULD remove it from people who have never tried. I found one thread that the OP asked this question and he tried their suggestions and none worked. a working answer never got posted in that thread.

I am hoping to hear from people that have an excellent method that has worked for them.
I have taken some sample pics for people who have not seen it. if you look real carefully you can see some components that have been attacked by the corrosive glue.

I get 5 volts on pins 13,14,15 of the KA7500 bit no voltage on the gate pads .

I have no drive signal to any of the fets .

Any ideas on where to check ?

Hi folks. I would like to install a voltage divider network (hardwired/resistors) for one of my preamp's rca inputs. I need about 10db of attenuation. Can you guide me on how to calculate and construct this?



thanks very much


Roy C.

Hi...

Please i need schematics for this Model:

- amplified speaker DAG12 MKII

1000 Thinks