am I missing something- I tried made passive I/V (and lso active with opamp) WITHOUT SUMMING 1853 (or 1794) postive and negative current output phases. usuing opapam as IV (and in 1794 i used 22ohm resitors) output offset postive or negative phase to GND is whooping 5V according to Fluke tester(it works but my digital volume control is very unhappy-loud pops and clicks when adjusting sound ) I tried coupling caps for both phases (voltage goes down to 3V) even for ground- nothing helps. if I measure voltage betweet positive and negative i get only 1-3mV. i have laying dac with 4 x ad1853 which i would love to paralel for more current then convert I/V with resitor KEEPING BALANCED signal.


in the past i tried same trick with pcm1794 and it didnt worked also ( with 1794 voltages betwen +gnd and -gnd vere unequal, in ad1853 they at leat equal)

I loved the unibox excell software for designing and comparing bass speakers:

http://audio.claub.net/software/kougaard/ubmodel.html

I'm having a lot of trouble trying to make it work on recent OS system. It doesn't work with Office365 pro cloud account, same issues with excel for MacOS. I had to install a Windows 10 with an old version of MS Office under virtual box with all the associated woes.

The software is also password protected so I can't just make any mods to it. Do you have any hint to make it working properly on new OS? Can you suggest another software of similar quality?

Hello everyone,

A question on possible Bluetooth input for this model. I do have the companion 2nd channel Box and I am curious about the aux. input as it is a single RCA jack.
Is it possible to get stereo out put using this jack from a bluetooth adapter, or is Mono even a hope? There is a back panel selector switch on the chassis. I am assuming it is expecting a mono audio feed. I am also assuming that the MPX processing will not apply to a line input, but you never know what might be out there to fool this old radio into bluetooth playback in stereo.

thanks for any insight on this!

Hi, I found a broken akai 1700 reel to reel player at the local thrift store for the crazy prize of $5.

I ripped everything out and dismantled most of it and rebuilt it as a two channel amplifier for my office.

Now, I kept the VU-meters and after checking the schematic in the service manual I found online I drew the conclusion that it should only be a matter of connecting the VUs parallel with the speaker outputs and use a 10k resistor to ground..
This doesn't work.

I have read that some have integrated diodes and parts and since the schematic doesn't show these I drew the conclusion that the meters had them integrated.

So, could someone have a look or point me in the right direction?
I'll attach original schematic, new schematic and some pictures of the build.

Hi,
TPA3116 ZK-TB22 Wuzhi Audio
I had cutting sound problems and occasional reboot ones from new. Reboots occured rarelly, sometimes 1/24h
I observed that cutting sound problems occures when i use high voltage eg. 24V(not right away but after eg 30min and when it start to occure it will finally be occuring constantly) and on 12V the problem was almost non existant, but...
yesterday i did firmware update....to 1.7 and things got worst.
I'm not 100% sure but i think this is new: wuzhi added function that when input is silence eg i mute my pc(i use minijack), amp automatically cut of speakers making at the same time pop sound - it is exactly same sounding to those sound cuts when using 24V
But now those 2s mutes accures very often (around several times for an hour) at 12V.

So i suspect that, in all cases some protection system activates mute on board or there is wrongly detected silence on input? I tested several power adapters.
I wrote to wuzhi official website, that would be nice that they give us possibility do downgrade firmware, but don't expect any answer
Anyone experienced similar problem ?

Hello dear diyaudio friends


For sale are two Soekris dam1021 dac modules. One modules is brand new and one is slightly used. To the used one, the VREF mod that Soeren recommends was applied.

The brand new module is the dam1021-12: 0.012% resistor version,
it was purchased in February 2016 directly from Soekris (still have the invoice).

The slightly used module is the dam1021-02: 0.02% resistor version,
it was purchased in June 2015 directly from Soekris (still have the invoice).

For the brand new module I want 300 Euro,
I'm also willing to trade, please look below (I paid 341 Euro with VAT and shipping)

For the slightly used module I want 200 Euro,
I'm also willing to trade, please look below (I paid 267 Euro with VAT and shipping)

Included with each dam1021 board is the standard set (all brand new) of connectors that Soekris is delivering with each module


I also have a lot of brand new Nichicon FP caps, to upgrade the modules.
If you are interested, I will sell them to you for the current mouser price.
The following values are in m stock
1500µF/6.3V - 820µF/6.3V - 690µF/6.3V - 470µF/6.3V


I’m also willing to trade for one or more of the following items:
(Of course, I will pay difference in value)

Manufacturer sealed bags of:
2SJ74-BL
2SK170-GR
2SJ74-GR
2SK370-BL
And maybe other rare signal JFETS or dual JFETS

BurrBrown PCM1704-K DAC chips

Analog Devices MAT02 and MAT03 dual monolithic transistors

2 x Starkrimson® Ultra Amp Module

XRK Audio RTR TPA3255 Reference Class D amplifier

Please also take a look at my other offers in the Swap Meet


Here are some different shipping rates:
They may differ a little from country to country, for a exact quote for your country please ask.
Of course, I will charge only the prices I will have to pay)

Small DHL package worldwide (up to 2KG):
Without insurance and tracking: 10.99 Euro
With insurance up to 50 Euro and tracking: 14.99 Euro
With insurance up to 500 Euro and tracking: 47.99 Euro (DHL insanely raised the prices, this package is also up to 5KG)

Small DHL package within Europe (up to 2KG):
Without insurance and tracking: 5.99 Euro
With insurance up to 50 Euro and tracking: 8.49 Euro
With insurance up to 50 Euro and tracking: 13.99 Euro

Shipping within Germany will be cheaper, please ask.

I will ship anywhere in the world. Shipping costs strongly depend on the shipping method you prefer. Of course, I will only charge the real costs, I won't charge anything for packing materials and effort. I prefer to use Deutsche Post/DHL, but you can decide which shipper and which shipping method (letter, registered letter, small package, normal package, insurance, tracking) I should use.

As payment method I prefer PayPal for friends and family, so no extra fees will be added. Of course personal collection of modules in Cologne (Germany) and payment in cash is also possible.

Kind Regards

Phil


The

NLA.

Grabbed these for a project very recently to see if I'd like horns in my space. Turns out I didn't really care for horn and CD. I also have some Eminence WG10's that make for a very good combo.

CD's were picked up just a few weeks ago but I lost some of the manufacturer packaging so I can't return them. Pretty much pristine condition otherwise. I have the box for one but lost the box for the other.

I can do $60 shipped for the CD's or $100 shipped for the CD+Waveguides within the U.S.

PM me for paypal.

I have Iron pre se to sell because I decided to build balance version.

450usd+ shipping(100usd for USA,120usd for most of Europe depending on country)

30VA 18V secondly 0-115v-230v
Chinese rcore trafo in iron case
Schaffner
Vilab rn55 23stepped attenuator
Chercroft zfoil 330R
Cmf55
Nichicon gold tune
DIY manganin resistor 100r for offset
(0mv-0.1mv)
Mogami solid core cable
RCA - Tellurium copper x1 , Mogami x1
Gold plated RCA jack x4
https://shop.oyaide.com/products/p-3071.html


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SOLD

Hi all,
I have a nearly complete FC100 Kit for sale. When the FC100 thread first started, I followed it closely and purchased all of the parts (PCB's, several sample ThermalTraks for future matching, matched inputs (J1 & J2), most the rest of the caps, resistors, components, heatsinks, toroidal transformers - basically everything but the enclosure and a couple of the other matched transistor sets. For the longest time I held out hope that I would get to complete the build, but, alas, that phase of life has passed.

My offer consists of the following items:

• 2x FC100 Boards
• 2x front end power supply Boards
• 2x toroidal transformers
• 2x large heatsinks
• 1x mini board for measuring ThermalTraks for matching purposes
• several sets of ThermalTrak transistors
• almost all of the components, most of which are labeled and in their packaging
• to the best of my knowledge the only missing components were a couple of the matched transistors, but I can't guarantee

I've tried to post some pictures below, but please let me know if you want to see more. There's also a lot of paperwork that I can include: diagrams, invoices, BOM's, etc. I don't know exactly what I paid for all these components but i think it was over $500. I'm not sure what a fair price would be, but I would sell the complete kit for $200 plus shipping. I'll consider offers, and separating the toroidal transformers, since shipping those might get pricey. Obviously, a local pickup would be preferable - I'm in North/Central Virginia, USA (22701).

I regret not having the opportunity to hear this design in action, but I would be happy knowing someone else could put the parts I collected to use.






Ted

Is it someone that have experience with this?
This is faulty,SMPS is burned,blown IGPT,FUSE.
Owner said that this had another service attempt but SMPS burned again immediately.

Is there any way to tell what the values of these air core inductors are? This is the crossover for a Vienna Acoustics Maestro center speaker.

I am planning on swapping out the tweeter, (which sounds harsh), and replacing with a ScanSpeak Classic to match my main speakers.

It is odd...the original versions of the Maestro came with that ScanSpeak tweeter. This version seems to have a much cheaper tweeter (I picked it up secondhand off Ebay a few years ago). This tweeter has the same impedance as the ScanSpeaktho, so I think I can start simple. I'd like to try a straight swap first, listen, and then adjust the crossover values once I understand what needs to be adjusted.

I plan to use my studio mic to capture the freq response.

I have a Fluke189 multimeter. Any way to run a test to find the mH values without desoldering?

For sale a SP14 preamp board octal partially assembled.
Bought in 2018 but but never managed to finish completelly and now I am interested in other projects .
Price 125 Euro + postage.
I also have a Bendix 5852 aka 6X5GT,bought it specifically for SP14.It was sealed in a original box,I opened it, powered to see if it works and it did.
Price 150euro + postage.
I also have a NOS RCA JAN CRC-6X5GT bought from Tube Museum New York,price 30Euro+postage.

Sold.​

It powers up and is not in protect mode or anything. Nothing on the board looks burnt. I am a new guy at this. Where should i start testing?

I want to sell my partly finished AJ-X, as I don’t find the time to build a suitable case.

The boards are fully assembled, mounted on heatsinks and tested.
All transistors are matched and only high quality parts are used (PRPs, mills …).
Heatsink dimensions: 40x20x8,5cm

Price: 550€ + shipping






Optionally I can offer transformers (2x18V, 500VA, shielded), parts for PSU (Capacitors: 33000µF/50V) and additional stuff (see picture).
(for dual mono setup)

Price 220€ + shipping





Remark: with some minor modifications, it is possible to build 4 AJ (mono) amps instead of the 2 AJX (mono) amps.

Local pickup in Salzburg, Austria or shipping

Ok, I put it here because this is not for audio. But I'm trying to get an old camera working again. First step is getting to understand the electronics and so far I have been able to trace the pcb (good thing is was only double sided) and find almost all the components. But a single component so far is missing.

Does anybody has a datasheet for a NEC AC06DGT? This is a part in a TO-66 (*) package, which looks like a small TO-03. I did find some references to NEC ACxxxx parts and those are thyristors. But I'd like to be sure about this.

(*) or TO-123 or TO-124 or TO-213 depending on thickness of the base

I have for sale some SANYO / FAIRCHILD NOS transistors for audio.

The goods will be shipped in a cardboard box , transistors will be packed in antistatic bags. Ship from Poland.

Payment: PAY PAL , wire transfer

I don't send to RUSSIA , IRAN , SYRIA , IRAQ , LIBIA , VENEZUELA , NORTH KOREA

Shipping to EUROPE ( including ISRAEL & CYPRUS ) - registered priority mail - 5 EURO

Shipping to NORTH AMERICA (registered priority mail ) 6,5 USD

Rest of the WORLD ( registered priority mail ) 10 USD

Prices in EURO / USD


1) KSA1381-E i have 150 pcs.
PNP , mfg - ON SEMI , hFE 100 - 200 , package TO220 isolated
MOQ = 25 pcs. or more

KSA1381-E x 25pcs. = 10,04 euro ( 0,40 euro / 1pc. )
KSA1381-E x 25pcs. = 10,71 usd ( 0,428 usd / 1pc )

Complement to 2SC3503-E ( KSC3503-E - obsolete part )

2) 2SC3503- E i have 325 pcs
NPN , mfg - SANYO ,hFE 100 - 200 , package TO126 ,
MOQ = 25pcs or more

2SC3503-E x 25 pcs. = 12,50 euro ( 1pc = 0,5 euro )
2SC3503-E x 25 pcs. = 14,25USD ( 1pc = 0,57 usd )

3) 2SC3382- S + 2SA1391-S i have 300 pcs + 300 pcs
NPN / PNP low noise ( 50V / 200mA ) ,hFE 140 -280 ,mfg SANYO , package; TO92 ,
MOQ = 50pcs. 2SC3382-S + 50 pcs. 2SA1391-S or more

2SC3382-S / 2SA1391-S ( 50pcs + 50 pcs.) = 21,00 euro
2SC3382-S / 2SA1391-S ( 50pcs + 50 pcs ) = 23,50 usd



Below original photos + datasheet

hello-
i have a few tested ecc82 for sale.
i can post pics if wanted but for now i only add the quick test reports made on utracer6, fillament is powered by rigol dp832a, set to deliver exactly 300ma current.
test is set up as per datasheet, typical values.

hello-
i have a few tested ecc81 for sale.
i can post pics if wanted but for now i only add the quick test reports made on utracer6, fillament is powered by rigol dp832a, set to deliver exactly 300ma current.
test is set up as per datasheet, typical values

The output transistors had low R-values, short when powering up, desoldered the ones that were bad and the amp powered up normally.

I couldn´t find the datasheet on the web, https://www.jotrin.com/product/parts/MAP6808, I asked jotrin via e-mail and they don´t have it.

https://www.made-in-china.com/showroom/musitech/

Musitech themselves aren´t better either, I found at least someone with their name on the internet, but they only have a phone number after the resgistration, I will try to inquire over the website, maybe in the meantime anybody knows this transistor, or can navigate the web better than me.

thank you all in advance.

got a lot of 12 6GM5 to sell and trying to think of ways to promote its use.

- know it can be used push pull :

Hi quality Push Pull Amplifier with PL500 / PL504/ EL500 / EL504 / 6GB5 /6P41S /27GW6 and 12AU7 /ECC82 and 12AX7 / ECC83 | TUBES.RS – Tube Amplifiers & NOS Tubes

https://i.imgur.com/A7uB7fS.jpg

https://i.imgur.com/eHTgtr9.jpg

- - how it might fare in SE or PP triode amplifier use? or perhaps regulator pass element?

So I was thinking of safety features for my tube amp. B+ (plate) HT is 1.5k VDC , and max current is 295ma - can I use a 300ma RCD on the plate HT to help with safety?

I am migrating from moOde to piCorePlayer. in moOde I had scripts to control a fan based on cpu temperature and a 12v trigger to turn on my amp.
I am a novice as far as programing goes. I made the scripts for moOde by cobling together different tutorials and forum posts. I can't find anything similar for piCorePlayer.

I need:
GPIO12 to be a pwm signal to control the fan

GPIO16 to go high when playback starts, and go low 120 seconds after playback stops.

I used the proportional version of this for fan control:
https://www.the-diy-life.com/connecting-a-pwm-fan-to-a-raspberry-pi/

And this is what I did for the 12v trigger:

---

enter:
nano /home/pi/autoamp

paste:
#!/bin/bash

# This Script is to read the Alsa Sound State and Automatcally
# swing a GPIO pin to allow auto switch on / off of an external
# amplifier, its crude dirty and badly written any sugestions
# or criticism welcome
#
# Trevor Cockayne trevoml@gmail.com



# Exports pin to userspace
echo "16" > /sys/class/gpio/export

# Sets pin 16 as an output
echo "out" > /sys/class/gpio/gpio16/direction


count=0

time=120

let count=$time

for (( ; ; ))
do
if grep -q "closed" /proc/asound/card1/pcm0p/sub0/hw_params; then
# echo "DAC IDLE"
let "count++"
else
# echo "DAC Playing"
count=0
fi
if [[ $count -gt $time || $count == $time ]]
then
# echo "Amp Off"
echo "0" > /sys/class/gpio/gpio16/value
count=$time
else
# echo "Amp ON"
echo "1" > /sys/class/gpio/gpio16/value
fi
# echo $count
sleep 1
done

enter:
chmod 755 /home/pi/autoamp

enter:
nano /etc/systemd/system/autoamp.service

add:
[Unit]
Discription=Automatic Amplifier Control
[Service]
ExecStart=/home/pi/autoamp
[Install]
WantedBy=multi-user.target

enter:
systemctl enable autoamp.service

enter:
systemctl start autoamp.service

---

Will these work for piCorePlayer?

Thanks,
freebirb

Like the offered AJX, I want so sell my partly finished pumpkin preamp, as I don’t find the time to build a suitable case.

The boards are fully assembled and tested.
All transistors are matched (by ZenMod 🙂 ) and only high quality parts are used.
Kit includes O-Core transformer, XLR Sockets (5x In und 1xOut, more available) and additional stuff (see picture), but I would also sell just the assembled boards, if preferred.


Price: 350€ + shipping

I can also offer a set of blank boards (pre + shunty).

Local pickup in Salzburg, Austria or shipping

I want to build the OddWatt Riaa Phonograph Preamplifier Groovewatt.
I have some "unknowns" in the schematic.
No experience with MC cardridges, but I want to build it to be ready.
In het schematics, there are 4 resistors, which can be added to change the load value. (RED)


Second, what is the MC jumper which add 100pF used for ? When do I need this ?



Kind regards,

I was just wondering if anybody remembers the name of the 12 inch (I think) driver with a tweeter attached to the
frame with a small metal bracket. They are likley long out of production but were featured in Speakerbuilder magazine
or elsewhere - 1990s.

My memory was jogged from looking at speaker builds on youtube.

It has been a while since I posted on the forum. I fell in love with another hobby and although I enjoyed my audio system, I didn't do much with my test gear. I wanted to buy a bench meter that could display audio Watts. Most have a math dB or dBm function, but the references usually only go to 50 Ohms. There are a few that do measure at 4/8/16 Ohms, but they were not in my price range. So I decided to build my own using an Arduino. I'm not much of a coder, but I did fall in love with the Arduino because of the amount of information (books, kits, forums, etc.). So here is my project in it's finished form. Due to the 4 line display having such a large circuit board, the final enclosure is a bit larger than I prefer. I did find an OLED display that has a large display and small board footprint. So there will be another revision forth coming!

The small 2 line display under the finished 4 line completed unit is my single channel prototype. I created my own circuit board and then populated myself. The fab house had some minimums, so I just had the board made. The magic of the circuit is the LTC1968 RMS to DC converter. Unfortunately, the max input voltage is 1V AC. Therefore, reducing the input requires quite a ratio. I buffer the output with a simple gain of 5 buffer to give my ADC full range. There are some other minor tricks in there, but not much else. I could have added another unity gain stage, but it didn't improve the performance. The most important thing in all of this was to have my bench meter calibrated. It was only a few years, but I sent it out for official calibration. There is absolutely no way to build and calibrate this without an accurate meter. For the final unit, I have a SS amp on the bench and I'm measuring both channels under load.

Below are some pics. The board on the bench and the displays show how accurate the circuit can be. Don't mind the decimal point on the measurement; I was messing around with the scale in the software. I can measure against 8/4/2 Ohm loads, there is a mode to measure in single channel only and then you push-hold the buttons for other modes.

Can we combine the advantages of line- and point-source technology into one speaker?

I'm now inspired by vintage ADS L2030 speakers. They're described as being designed to combine the benefits of both line- and point-source technology in a single speaker. They use four midrange drivers and have a midrange toggle switch for switching between line-source and point-source operation.

According to the brochure, the main bigger midrange is more efficient than the remaining three smaller midranges. In point-source mode, only the main bigger midrange sings, whereas, in line-source mode, the four midranges sing concurrently. The line-source mode is advertised as "weighted line-source", which is also promoted as combining the advantages of both line-source and point-source technologies.

However, these speakers were produced in the early 1980s. I have never heard the sound of these speakers, though.

I'm curious whether this idea should be revived in modern design. I'd like to hear other people's thoughts.

Hey and Hi to all of the Audiopliles here who made my life much easier, with some vintage Hi-Fi amp circuits and questions that I had concerning things that were driving me crazy for a time. There are too many names to repeat, but you probably remember the dimwatt who asked those questions and struggled to understand some for a time. I am going to be posting a little on the musical instrument side of the forum and will hopefully be welcomed and tutored like I have been here. I have completed my first really challenging project with your advice and great experience based know how, and I am quite happy with the results. One Can take a vintage tube Hi-Fi and with the proper Science, a little cash for parts, and patience turn it into a fine, although basic guitar amplifier. I wish that I knew how or even if it is possible, to let you here it in action, although you might not like the musical "talent" behind it all. I doubt very seriously that Mr. McGohan would recognize his creation now, but wherever he is, I thank him as well for turning out such fine work back in the early "60's.
Don't get me wrong, I am sure to be back here as I am going to continue to pick up bargain's, like the McGohans, Harmon Kardons, Layfayettes, and Marantz' amplifiers that I already have purchased to experiment with, and perhaps make useful again. They are so much more reasonably priced than the usual guitar amps. If a guitar amp has tubes in it, the seller usually think it's worth a mint. I know that I will need some ,more advice here though. I realize that to the experts Here, a circuit is a circuit in a major way. However, when all you have ever tinkered with before had names like Fender, Gibson, and Vox on them, it is like a whole new world is opened up with vintage Hi-Fi. I can see the similarities to be sure, but there are many "head scratchers" as well for one who picks a moniker like dimwatt. I hope that sometime in the future, I too can be of service to someone in need of advice here, and be able to give them the benefit, that in my opinion, has been like conferring with the contributors to the Radiotron Designer's Handbook. Thanks !

Hello everyone!
I have a pair of nearly pristine NS200M speakers and want to re-cap/ re-build the crossovers. Can anyone tell me the exact location of the crossovers?
Are they behind the woofer or higher up? (I just don't want to remove more than needed.)

Thanks!

Hi. what is the proper way to make the trace for NFB from the output to the diff ( long tailed pair ).
use a via from the output , " continue the trace and use from there?.

- Bruno.

This circuit is from "Low Noise Electronic Design". It inverts the ripple on the input and modulates the drive of the pass transistor base. I suspect that it isn't too stable.

1) Motchenbacher, C.D. and Fitchen, F.C. "Low Noise Electronic Design", John Wiley & Sons, 1973

I found a very large United Electronics 805 tube recently at an estate sale. (In good shape). I’m trying to identity and date it.
I understand these United tubes are USA-made WWII era. Is there any way to find out the year and place of production?

Hello

I'm certainly not an expert with LTSpice but many years an electronics designer ..

I'm doing a hopefully low noise jfet pre-amp for the 34mm condenser insert I just bought but not sure if I have LTSpice doing the right thing, it's reporting an unusually low-noise level on the output of the pre-amp. I temporarily have the input 1G resistor set to noiseless to get a noise floor level on the pre-amp itself, but the noise floor seems way too low for the humble 2N3819 to me, the gain of the pre-amp is only *9 to *10 voltage gain, but that ought to be enough for input to a 24-bit 100dB+ S/N ADC.

The aim isn't for best THD etc, the desire is to get the lowest noise floor with the available parts we have laying around here. Spending £30+ on digikey etc just for a single low-noise op-amp design is not desireable (at present).

Any ideas what I might be doing wrong with LTSPice ? .. it's a new install with default everything.

Hi All,

I bought a couple of these old transducers a few years ago at an electronics surplus store. At the time, I was thinking I could use them for DMLs, but I'm afraid DMLs won't pass WAF muster. Any suggestions for how I can discretely incorporate these into my system? I'm thinking bass augmentation for my Frugel Horns w/ MA Alpair 7As...

I have two amps (ignoring the brands to avoid bias, but they are both known and credible brands) , 5 watts, with push-pull 12bh7 cathode biased power amps.

Actually one is marketed as a class A amp, the other doesn't say. Yet the latter is louder. Not incredibly more loud, but quite noticeably so. As I bought the class A amp B stock, I am getting paranoid that the output transformer is damaged. I have run into that problem before many years ago. The amp sounded fine, but power was very low. Replaced the output transformer (I don't even know how I managed, as my electronics knowledge is extremely low, I am just a musician) and the amp came back to life (loudness wise).

So what I am asking is, is it possible that the 'class A amp' doesn't sound as loud simply because it's a different design? Thanks.

Thank you again to everyone for your help on this.

I know my low-powered JLH amp has plenty of room for improvement. Does it sound like I'm getting sucked into this hobby? 🙂

- Should I replace my 12V laptop power supply with higher voltage/amperage? Is the JLH69 amplifier sensitive to power supply differences? In other words, is there any difference between internal (like a toroidal) vs an external (like a nice laptop-type) power supply?

- Is a JLH circuit like the one I built sensitive to component quality? Would replacement with tighter-tolerance resistors/caps/etc make any sonic difference?

I have recently purchased a series of Ian Canada products, to build a flagship streamer for my non-oversampling DAC (LAB12 DAC1+). The streamer consists of:

• StationPi Pro
• LinearPi Dual
• Salas L-Adapter
• 3 UCConditioner MkII boards
• FIFOPi Q7
• TransportPiAES

I have put (almost) everything together, apart from the 3 ultracapacitor boards, which will be placed and connected after a few days.

I am using Gentooplayer with Logitech Media Server, Squeezelite and Qobuz.

Although the system works fine, when streaming directly from the Rpi4 USB port (positioned on the StationPi Pro board), the IAN Canada stack does not send music to the DAC, when the TransportPiAES is connected via the SPDIF coaxial cable to the DAC. All lights of the various Ian Canada cards light up as expected, and the streamer 'locks' fine with the DAC, when the SPDIF cable is connected (see photo with arrows).

Initially I used the 'IanFifoII' DAC in GentooPlayer. But I have also tried other DAC options, but without success. I am not sure whether I have a hardware (FifoPi Q7? TransportPiAES?) or software problem (GentooPlayer?).

Does anyone have any suggestions about what might be wrong and what I should test?

Thanks in advance for the support.

Panos
Athens, Greece

My simple solution was to use an

AC Power Relay that was able to be triggered with a low voltage.
https://dlidirect.com/products/iot-power-relay

A simple IR remote-controlled relay for the control.
https://www.amazon.com/dp/B0BNBNF5MJ?psc=1&ref=ppx_yo2ov_dt_b_product_details

A cell phone charger to provide the needed 5VDC for the
IR Module and the triggering voltage for the AC Power Relay.

I mounted the IR remote-controlled relay in a small plastic box and
put the AC Power Relay and Charger behind the Hi-Fi and out of sight

A simple solution, and fairly clean.

Hi all, I need some help trouble shooting an HTPS 7000 MKII. This is isolater/filter that has multiple uses. It arrived two days ago and doesn't power up. Generally, it is pretty well built. I removed the top cover and didn't see anything immediatly that stood out. However it does have a strong electronic smell around the main power supply board which resides by the two torroids. It is not an ozone smell, rather a deeper type burnt smell also like a burn in smell. Now I"m wondering if the chips are fried in it.

Put it on a variac and added a fuse to F402. plugged it in and attempted to turn it on. Fuse blows. A few more times attempting to isolate the problem. Completely isolated the P/S board and the main fault lies there, somewhere. Currently I have it where I can keep it from blowing a 1 amp fuse in the F402 position by putting a 100 watt bulb in series with the unit. At about 15 VAC the bulb starts illuminating and remains that way up to 120 VAC. I don't want to keep it that way so I tried to find the fault at 30 VAC so far haven't found it.

There are a lot of little chips that not easily accessed with the unit assembled. So I'll have to pull the board again for testing. My guess is one or more of the chips is shorted but not sure which one and don't have a schematic. The manufacturer, Monster, refused to provide me with a schematic as it is not their policy, they stated they won't fix it. I tried to explain to them that is what I was going to do, fix it and need a schematic. I've not had problems obtaining schematics from other well known companies, Fluke, HP, Mesa, Fender, Peavey, etc. So it will take some time for me to get up the learning curve. Here are some pariculars

Power Board: PC Board T2, 7000 MKI Issue 1, REV 1 Here is a list of the chips: Philips 5349 MOC3083 MJE13005F JC448 L78L05 1N4742 MPSA42 Mystery 7MK2-T142 (looks like a quad opamp?) The Zeners 1N4742 look to have been over heated as they are no longer orange and black but grey silver. I'm going to try searching for data sheets. I am not here to bash anyone or any thing. Just documenting what I find and how to go about fixing something that might be of help to others in the same situation. Anyone with experience with these units I would appreciate some assistance and guidance.

Thanks in advance.

I have some Pics and I post as I can get them out of the camera, alsways a challenge. iPhone pics while convenient are typically blurred for some reason. Here are pics of the unit.

Front:


Top down view:


Board view:
]

Board back view:


The back of this board had crap all over it. I wiped it clean with ISO-OH. It cleaned up nice and shiny while the wipes were brown. Smoke from something that burned or was it Tars from being in a smoke filled room? Doing some basic measurement with the board removed: Upper center board: Two 5W Cement resistors 62K and 39K measured abnout 1 ohm. The diodes and the resistors didn't read correctly.

The diodes read in both directions, .547 on the resistor check and 1.08 the incorrect direction. Pulled one leg up on each, and the resistors measured properly. Do did the diodes. I replaced the diodes just in case, didn't need to because the new one measured the same when installed. Next came the the two watt resistors to the center right. These were 330ohm and 560 ohm wired in series. 330 ohm were find but when checking 560 ohm they were both open.

Pulled a leg each with the same result, open. Removed them and meausred them. 560 Ohm each. WTF over? Turned my meter off and on meausred 560 ohm. Decided to replace them with 600 ohm 2 watt dale wire wound that I had on hand. Reinstalled board, same result...still have the burning 100 watt bulb. Found some of the problem by letting the unit warm up. It appears the MJE13005F and the JC448 are the problems as they are both on a heat sink. at about 15 mins at 60V with the 100 watt bulb...the heat sink burns to the touch.

It might also explain why have have AC on both sides of F401 fuse when the fuse is NOT installed. I don't know why they fried though and that worries me. Wondering what else they take with them? 1N4742 zeeners show signs of heat problem. More pics soon. Update on Data sheets: Philips 5249 is a BT136 Triac, 600V 4 Amp. JC448 my bad is a MJE13003 or 2SA1709/2SC4489 NPN my guess is the MJE13003 and/or 2SC4489 NPNHV Switch. 700Vdc peak, from Ic 1.5 Acd, Ib .75 Adc, Ie 2.25 Adc continuous. MOC 3083 is an opto Isolator powered by 240 VAC. 4n35 are opto couplers w/input to output peak @ 3.55KV. The specs on these are pretty beefy though. These things are pretty beefy, I hope it isn't that quad opamp that fried.... Light of my life:






Voltage Reading:


Focused Board Closeup:


Update, Well as long as I'm here and going to pull the board again might as well shot gun it. First though I'll pull the mystery chip...just to be sure and then see if it still pulls current. That will rule out that part of the PS I'm thinking. Then, I'll pull the SS units and go from there. NOTE: When you link pics from the Gallery here for some reason I don't have ability to zoom in. : ( I was wrong again on some of the parts. Some of the parts I couldn't find readily but will substitue some of them. For some of the parts I wonder if it hasn't been already replaced with a lower speced part before I got it. I don't know. As I don't have a resource.

Hi!

I want to build a bass bin! My excuse is i need more bass extension for my synergy horns to listen to music. And i thought maybe maybe it could run as a kick in between the synergies and my 15" TH at parties. That is, it is my third project, it absolutely is not necessary to make it as complicated as you are about to witness, but i'd like to figure this out.
Conditions are:

• doesn't need to run terribly low, tuning around 45Hz, as i am many direct neighbours and flatmates.
• should be smaller than the tapped horn. decided to go with about 60/40/30cm
• high efficiency of the horn in the kick region for nice transient response and to be able to use it with the tapped horn (as an experiment at least).
• i already bought a mivoc awm 104, seemed to fit well for that project

This is what i came up with:



The port is oriented like that to be able to reach the driver from the top plate.
What i am unsure about is:

• is this how you take the ground extension of the horn path into account?
• how to make sure the BR-port is tuned correctly with the expansion at the end and the kink at the inside.
• am i an idiot? 😉

i'll put my simulations in the next post.

I am just a musician, but usually with cathode biased amps you only see a resistor for the bias, not a trim pot. But this amp is similar to other cathode bias amps, i.e. 5 watts amps with a 12bh7 in the power amp. But it has a trim pot for the bias (page 2, on the right of schematic). Is that a cathode biased amp with a trim pot to get the cathode resistor into a wider range? Or is it fixed bias with a trim pot? I have this amp and on first guess it sounds like a cathode bias amp (the power amp distortion is spongier and sweeter than usually on fixed bias amps, which is harder. But I might be wrong, and maybe this amp is fixed bias and just sounds and feels the way it does.) Thanks.

Hello people,

I m an electronic repair hobbyist who learning more and more everyday. I enjoy putting myself in bad situation and the one following is the worst i had to deal with when it comes to electronic repair...

The last broken unit i purchased is a Terror Bass amplifier, the 500w version for around 70 euros. I knew it was for parts but i was not aware someone tried to fix it.. and it's a mess cauz the transformer from the PSU is (almost) missing in the unit, only the ferrite is left (good condition) and 2 turns of one of the windings... The rest is bad but fixable : bad power transistor cross reference put in place, awful soldering.... The main problem is this tranformer.... 🙁

On internet, i can see the transformer is labeled TB500 from Yuyao Huachi... and luckily there is a schematic online for this amp..

I contacted Orange Amp with no answer yet... the product is out of warranty and buying the whole PSU would not make sense as it's over 500 euros so way too expensive.

I would like to know what you think about this ? Is it game over ? If im correct its a half bridge transformer with 2 primary and 3 secondary windings..

Im a bit stubborn and i love learning new things about electronics, i could go for building my own transformer but i think its far from being easy...

Thanks for your advices 🙂

I am currently pondering different biasing schemes for an estat headphone amp using DHT output tubes in push pull configuration (see here for a very early concept drawing). Looking at many posts, blogs and websites I found a lot of information about good old cathode bias (be it with a simple resistor or something slightly fancier like a LED). There is also filament bias, which is also a form of cathode bias, but does away with the high impedance cathode resistor. However, it consumes a lot of power and dissibpates a lot of heat.

I couldn't find much about fixed/grid bias (except maybe Valve Wizard). Why does grid bias not get more love?

My current thinking is that fixed bias would be a nice biasing scheme for my application because it provides the following advantages:

• It's easy to adjust bias for various tubes (so the amp could work with slightly different tube types)
• The cathode can connect directly to GNC/B-, so there is no need for a cathode resistor at all
• Bias current is essentially zero, so it should be easy to minimize ripple and noise on the grid DC bias voltage

Disadvantages:

• Grid bias requires a dedicated power supply (oh well, should not be a big deal)
• what else?

Is there any drawback of with fixed/grid bias? Am I missing something?

is it safe to attenuate a solid state guitar amp with an attenuator/powerbrake (with line out) for tube amps IF the objective is simply to get a line out signal at the power amp level? That is, I am NOT using the attenuator to push the amp hard, but only enough to get the line out signal from the powerbrake. The amp is a hughes & kettner hybrid, the amp has two power transistors tip 147 (schematic shows on page two, bottom right area).

Any thoughts? Thanks!

For your comments:

I have two speaker concepts I'm working on, and I'd like to invite your comments on each given only a single point measurement for each with no further info on the designs. In particular I'm interested in the way each interacts with the room, as observable in the impulse response and the wavelet analysis.

Measurement conditions:
Mic at 1 meter from the tweeter diaphragm, centered on the tweeter axis. Dayton EMM6 mic, hand traced cal file from the supplied printed curve (before cal files were available electronically), Motu M2 interface with loopback into REW.
Measured in my small den, which measures 14' x 11' x 8' high, with the DUT and mic as far from the walls as I can manage but no additional acoustic treatment (no pillows on the floor, etc.).
The measurement level for each was reported as 86 dB in REW, though the level of Speaker A looks maybe a dB lower. FR is displayed with an 8 ms window for each, 1/48 octave FDW.


Here are impulse and FR graphs for the two speakers:




And the wavelets:




I will attach the .mdat file with both measurements should anyone want to take a look.

Clearly reflections and in particular floor bounce dips are visible in the response. What I think is interesting is the difference in the number and strength of the delayed energy as seen in the wavelet. Would you expect one to sound 'cleaner' than the other based on this measurement alone? What else would you observe? Any interpretation or comment is welcome!

Bill

Hello
I'm building this preamp inside a roberts Akai unit.

I built using parts on hand that were close to the needed values and it worked very well, and sounds good, so I bought all the correct bits.
However I have a couple questions if someone doesn't mind indulging me.

Why is the output cap so large (3.3uf) when the cap between the stages is comparatively small (.02) ?

I have some .22 high voltage orange drops needinga home. Coul they be used in the output application?

And is there any advantage to using a larger cap (say .1) between the stages?

Thanks

My understanding of the theory is that:

• low bass, it doesn't matter for those frequencies - a few mm (or even edge reflections from the cabinet) don't matter much
• frequencies in the midrange and up where the driver is not beaming may be impacted by an effect from the driver's own flange, and also any other driver that is 'nearby' - especially if a bass or midbass has a deep flange
• can impact midrange and also tweeter

Its not obvious however to what extent I should care if:

• I have a (sub)woofer cabinet below the mid/tweeter and there's a cabinet break/step?
• I have a stepped cabinet (Troels G does this quite a lot it seems) - I'd expect so but maybe time alignment trumps it
• I have a largeish coaxial driver and upper midrange upwards is already bouncing around like anything - none of them (or full range) seem to have smooth trebble on axis, albeit off axis suggests that sound energy is more linear
• I have a surface mount driver with a tapered flange (I'm thinking GR Research and perhaps other Peerless India customers [guess!], but access to a 3-printer could probably make an adapter for arbitrary small drivers)

It seems to me that for ease of construction, having to make a hole sufficient for the basket or tweeter magnet system - but not necessarily tidy, or even exactly the right size - has a lot of advantages. One might even use a jigsaw, for example, and any untidiness around finishing veneering or PVC wrap is coverred up too.

Troels G seems respected despite many designs having stepped baffles. GR Research seem to do OK, though I suspect a combination of a recessed tweeter and a surface mounted driver can yield a closer driver spacing.

I know there will be diffraction issues from the cabinet edges and no practical roundover is likely to make much difference. Would we just better not obsessing about it, maybe add a bit of felt? Don't see that very often these days.

Hi Thanks for readings. In a 3-way open baffle speaker it is recommended to use a bass driver with a high qts, 0.7 or greater to ensure good bass response.

Are there any specs to ensure suitability of a driver for midrange duties, over 120hz - 3khz. Low qts is supposed to give a more snappy mid, so is a low qts specification necessary, or are there any other specs to be taken into consideration

In the spirit of DIY I finally created these two files for 3d printing your own pin straightening tools. They may look like sliced carrots but they are indeed petg plastic. Material type shouldn't really matter, I just happened to get my new printer tweaked in for the higher temp petg filament. They're pretty sturdy with 20% fill. Enjoy

Hey there, I lately rebuild a Sugden A28II, after i recived it with several burned resistors in the left channel, but also defective transistors on both.

After rebuild everything worked fine, but I probably messed up, setting the left channel bias way to high, so one of the output transistors blew up.

Since, i again changed every transistor, diode and capacitor, even if they wasn t defective as I measured them.

But I can t adjust the bias, it is at a constant high of 1,2A and rising, till it blew the transistor which is marked in the scematics.

Could anyone help ?

Hi, i‘m repairing old Radian 835 CDs, however i‘m struggling a bit with the phase plug.
It has come loose on both of my units and i‘m a bit hesitant to glue them back in. Dry fitting them they seem to sit way too low, it‘s certainly a lot more distance to the diaphragm than what‘s written in the service instructions (.5mm). Also when the glue fell off the plastic stubs on the plug i had the impression that it added some height. Unfortunalety i didn‘t keep the glue residude to measure the thickness. Also inspecting the edges where the plastic dome should go into the metal structure there‘s probably half a mm or more missing. I know it from other manufacturers that they note down the height of the assembly and diaphragm to match the distance with mylar shims, but the service bulletin just instructs to use whatever shims are included with replacement diaphragms (mine came without any).
Could it therefore be, that there is extra tolerance in the motor assembly, to be aligned and fillen with glue at the factory? Do you have any idea how i could do this myself with diy tools? I‘m already afraid to build some kind of a test device with a dial indicator or similar 🥲

Any help is much appreciated!

Hello Ladies and gents.....
i have a question related where to start from when choosing my driver for lower frequencies... i need it to cover bottom to 150Hz max....
.
thing is - my room is brick walls and concrete floor and ceiling (European homes).... 16m2 of area... not to big of a room.....
.
so i have been changing my mind between 12inch or 15inch and i am worried then one 15inch per channel would be to much when put it in a H baffle without active crossover - all passive....
so i am kind of more for 12inch and if needed, i can always put two of them (one on top of the other)....
the downside of the 12inch driver is that it does not go as low as 15inch....
so...
i was checking SB Audience bianco 12OB150 and compared to Monacor SP-382PA..... (they seem to be nice options for Europe - any better suggestions?)
seems that 12inch Bianco has better "air moving capabilities" even when compared to 15inch Monacor.... higher sensitivity also ... and is also a little bit lighter in weight of the membrane....
Donwnside is that Fs for Bianco is 44Hz and for Monacor 25Hz..... also Qts is a bit lower then Monacor (0.63 for Bianco and 0.75 for Monacor).....
....
Bianco 12OB150 looks better in some parameters but not so good in others - do i need my woofer to go lower then Bianco goes... do i need that much "air moving" in my brick/concrete room .....
if i go for Monacor, i will have it go low and with less SPL maybe it will do the job even better then 12inch Bianco in my room
...
What to take and start playing with .... that is the question now....
....
need to say also that i am listening to electronic music, blues, rock, experimental, acoustic, basically everything but classical......

Its a NOS unit, (see inside Pictures for no dust from no use) .i only used few months to play from local SSD disk, which It made smoothly, except for the moose software ,that sometimes hang to load file. Patience to simple wait self solve the issue. They Say Roon ready but never tried. At his time was extremely expensive and One of the First well built streamers. Much of info online. You control It from your smartphone by finding its network address. Digital output AES EBU or BNC coax. Sell for 450 Eur + shipping. Its 230V version for EU.
Will find a proper box to ship safely. Original(not a Copy) manual available.



.

Hi all community. I found those pics in two different books from some decades ago. It's very simple: two stage germanium transistors (PNP) with the input base resistor bootstrapped and helped with NFB. IMHO too many lytics but not easily to save them.

Do anyone tryed it? Who is the creator (has a particular name)? Some other examples?

I have a dismantled ZOUDIO 4-channel DSP board for sale. It is fully functional. Included with the board are a few of the flying lead cables, antenna mounts, RCA jacks, a couple LED cables and rotary encoder. This is sold as is and only includes what is shown in the attached pictures. This is not a complete, original kit. Useful for parts. Asking $20 plus shipping.

PM me if interested. Paypal ONLY.

Thanks,
Rick

Hello I am looking for a schematic/diagram for the HIFONICS ZXI 9400, can anyone help me? I am stuck into protect led.

My first DIY project will be to build new enclosures for a pair of Cerwin Vega AT-15s. As part of that process, I would like to be able to test individual drivers, crossover components, and the loudspeakers as assembled units.

My equipment currently includes a laptop loaded with REW, a UMIK-1, a Dayton DATS V3, and a digital multimeter.

What other equipment and/or software do I need in order to optimize the performance of the AT-15s?

Thank you for your recommendations.

Hi Community,

I’ve recently acquired this amazing player in an almost perfect shape where the vast majority of my CD collection is read perfectly and track skip usually happening in a couple of secs.
That said there is an handful of disks that, despite their TOC is read in a glance, the first track takes forever to start.
Lens has been cleaned, linear guides have been greased but those few CDs really hurts.

I’m keen to think of the focus bias non being perfectly set but given the lack of a service manual I can’t even look for the RF pin

Any suggestions? On the pick-up I see the typical APC the TB and the FB triggers.

Thanks for any hint you’re willing to share

I need min. 6 pieces to build 3 psu's. But i con't get them anywhere. Only China website and Mouser where i don't have a account.

So i recently got my hands on a Arcam A85 and A80

the A80 work fine (little testing)

All was good and working with the A85 (turned up loud wanted to see what it could do) till i plugged it in for some fun a week later and it had no signs of life no standby light nothing and wont turn on i did some digging and found it to be the 750mA surface mounted fuse on the PCB (i bypassed it with some tweezers) and it came back to like then i turned it off after a sec or 2.

now my big ask is do i replace it is a regular fuse or a resettable one?

non Resettable : (HERE)

resettable : (HERE)

it was in a very very damp/humid room for one night although i had my cd Player and 2 other amps and a pc in there and they were fine so idk.

the Arcam service manual only says 750mA nothing else i thinks its on a 5v or 9v psu so i guess anything above that is fine?

Side note:
the A85 tone controls also don't work if you mess with them then move the volume the tone changes like if i put -1 bass then turn up and down the volume the bass and treble will change up and down and make cracking noises.


Really appreciate any help thanks!

How I built a high quality multi-room sound system for less than 200$​

This is my first project using Arylic products. My goal was to build a tailor-made multi room sound system for my new apartment using my existing speakers:

• a pair of passive Beovox S4500 from Bang & Olufsen (without amp)
• a pair of active Yamaha HS3 which I used to produce music with

My vision of this project was to use vintage Beovox Bang & Olufsen speakers which I found on an auction for my living room, and my HS3 for my work station in another room. For a long time I thought this would be impossible. I thought I would have to invest in new smart speakers to get a multi room experience, such as Sonos which are already designed to connect to the network of your home. But then I found out that Arylic have a great DIY amplifiers and products designed for this purpose.




Beovox S4500 from Bang & Olufsen





Yamaha HS3

First I setup my Up2Stream Amp V4 with my Beovox in the living room. I have easily connected my two speakers to the board using the authentic B&O wires (you just need to cut the edge to divide the wire into two, which is equivalent of having one black and one red wire for each speaker). These are the white cables you see connected to the green cube in the pic below. And on the left of the green cube, connect to a 12V power charger.

You can choose with a switch on the amp between either Mono/Stereo. I have it switched to stereo mode and then built a nice transparent plexiglass case to avoid accumulating too much dust on it.





Up2Stream Amp V4

The challenge was also to be able to use them to connect my turntable using bluetooth. With the Amp v4, I can switch between Wifi and Bluetooth very quickly using the remote control, or simply by pushing the dedicated switch button on the backside of the amp. I can now enjoy listening to my vinyl collection using my sound system, or watch a movie with high quality sound connecting it to my smart TV (this works the same way with any bluetooth unit you want to connect).





Vinyl player and smart TV connected to the Beovox

Then I’ve setup my Up2Stream Mini V3 with my Yamaha for the workstation. My Yamahas are active speakers which means they already have an amp integrated in them. I have connected the Mini V3 using a jack cable (as seen in pic below) and simply connecting it to a USB C power charger.





Up2Stream Mini V3

To finish, how do I connect the multi room?

Now I’ve got both my living room and workstation setup. To enable a multi room experience, I download the 4stream app available on IOS and Android. I used the app to connect my amps to my WIFI network and setup a name for each of them (in my case . Once that is done, one can simply use the interface to control all speakers. Either you want to use them as multi room system or as separate ones. I can even control the loudness for each of the speakers to have louder in one room and a lower volume in the other.





4stream IOS app & Spotify Interface connected to Beovox

In conclusion, you can build a multi-room sound system for less than 200$ very easily with high quality speakers.

List of products:

Arylic:

• Up2Stream Amp V4, 99$
• Up2Stream Mini V3, 49.99$
• 3.5 mm Jack Audio Cables, 2.50$
• 4STREAM App, Free

Other suppliers:

• 12V power charger, ca. 15$
• USB C power cable, ca 10$

n.2 TR100A Hypex power trasformer, primary 115+115V center tapped secondaries 2x31Vac + 2x12Vac. 50€

I have Ian's Isolator pi first version for sale.
25euro + shipping (5euro for USA,Europe etc)

I have 38 pairs of these, NOS condition.
(30 pairs still in their anti-static tubes).

Selling them for $16/pair + PP fees + Shipping (min buy 4 pairs).

Estimated Shipping: $8 to EU & $10 to the US/Canada (up to 8 pairs).
Other countries please ask!

PM me if interested

Thanks

Can someone point me to a Windows 7 pspice type program. One that may have models for IRF-610. I played around wioth Duncan PS designer and quickly looked at lLTSpice but they appear to be unsupported now on Windows 7 so I figured Id ask
Thanks
Tom

Hi. I am looking to purchase a transformer coupled line stage that employs 600 Ohm to 10kOhm transformers with a 10k volume pot.

My amp has an input impedance of 100k. Are they compatible?

So, I was futzing about on the interwebz, looking at single-driver designs, and I ran across the Jordan Triangular Array design. And I thought to myself,

"Self, Our small living room requires speakers to be placed in the corners. Corners are triangles. I have basically no woodworking skills. Hmmm..."

So, what might happen if I cut a triangular base to fit the corner, and put a vertical board that would fill the gap, so that the corner would make the rest of the triangle. Then put a single, (or maybe double) pair of full-range drivers in the upright part. Basically, using the room corners as the other 2/3s of the enclosure. But with a semi-open, kinda-sorta-dipole backside.

And then I thought, "This can't be a new idea, because there are very few new ideas. Somebody must have tried this."

So...

Has anybody tried this?

--Shannon

If any of you local to the USA have a pair of blank Milpitas daughter boards please contact me.

I will also consider overseas but do prefer USA due to faster shipping times.

Thank you!

Anand.

Edit: FOUND A PAIR! THANKS ALL!

Edcor Tube power transformer Dual 120v 50/60hz primary. Secondary 360V 250ma CT, 6.3V 3A . $70 plus shipping to the lower 48

AnTek AS-2T350. 200VA. 350V Tube Transformer. 115 or 230v 50hz or 60hz. Dual 350v 0.25a and dual 6.3v 4a secondary 6lbs each. $75 for the pair plus shipping cost to the lower 48.

Hello everyone,

Greetings from LiubinCalvin. I've been away for some personal endeavors. Recently, while relocating to my new residence, I came across a significant collection of devices stored away. In an effort to declutter, I've chosen to host a flash sale.

I discovered a substantial amount of devices in my storage room. To free up space, I've decided to hold a flash sale.

Terms & Conditions:

1. Due to limited time for packaging, the minimum order amount is set at $100.
2. I aim to dispatch parcels approximately once a week. Your patience is highly appreciated.
3. All items are 30% off. For orders exceeding $300, you'll receive a 40% discount.
4. For items sold as matching pairs, the provided data is based on my previous measurements. Unfortunately, I don't have the equipment to re-measure them, so only the existing data will be available.
5. If anyone is interested in purchasing my entire remaining stock, please get in touch and we can discuss a bulk deal.
6. Payment via my PayPal account.
7. Other T&Cs in my old post are still effective

To see what's available, refer to my previous post. I'm immensely grateful for your continued support. Wishing you a fulfilling DIY experience.

https://www.diyaudio.com/community/...ng-some-very-rare-toshiba-transistors.291486/


A gentle reminder: It's important to clean the metal legs of devices before soldering them onto the PCB or performing any tests. The humid conditions in Singapore might have caused some rusting on these metal legs. Unaddressed, this rust can result in poor connections between the metal legs, the PCB, and the solder. For effective cleaning, using sandpaper or a knife is recommended.

Please inform me if there are any issues. 🙂

Hi Folks – I’m rebuilding an old pre-amp and want to add a switch to bypass the gain stage leaving just a buffer with unitary gain when switch is on.

I run multiple dif sources and power amps off it and many of the combinations don’t need the preamp gain – basically it just seems unnecessary in these cases to attenuate the majority of the signal (by turning the vol right down) just so the preamp can them amplify it back up again.

The circuit is attached below. Basically, it is a cathode follower input buffer, cathode-coupled to a non-inverting gain stage with a cathode follower serving as an output buffer.

My initial instinct is to inject the signal (via a switch) to the plate of the second triode to bypass the gain stage and just leave the output buffer.

Will this work? I’m guessing I will need at least a coupling cap to block DC from flowing back to the source?

It has also been suggested to me that i could bypass the feedback resistor to provide 100% feedback and therefore unitary gain – is this a better option?

My circuit knowledge is a bit basic – so be gentle!

Amanero 384 never used bougth from the original supplier 30€ Sold

Hello everyone,

About a year ago I built a set of C-Notes last year from a flat pack kit & painted/veneered them. I enjoyed the project quite a bit and the speakers have treated me quite well as the primary speakers in my apartment living room.

I'm itching for a winter project and would like to take on something a little more complicated. I have access to woodworking tools, so I am able to build my own cabinet. I would like to make a second pair of speakers for my room/office to listen to music while working from home. I'm a bit torn between going for some tower speakers for the living room & moving the C-Notes to my office or building another set of bookshelves and keeping the C-Notes where they are.

The more I research the more I realize that beyond entry level DIY kits like the C-Notes there's no clear "best" DIY kits in my price range of $300-600. I see a lot of comments that in 2023 it is harder for DIY to compete both on price with commercial offerings and technologically e.g. in terms of dispersion. I'm no expert so I'm not sure how seriously to take those claims - part of the value for me is the enjoyment and learning I get out of the project. I like good sound but I'm hardly an audiophile.

Some speakers that have piqued my interest and which I'm curious to hear opinions on:

• Amigas - Right now on sale for $300 w/ baffle only at Parts Express, which is enticing. I've heard some criticism that the design is outdated, but it also seems widely built.
• Speedsters - Ribbon tweeter is interesting and folks seem to enjoy the sound profile a lot. A bit expensive right now since no full kit exists.
• Hivi 3.1A w/ Sehlin mod - On paper looks great.
• CSS 1TD - Higher end on price but seems to get rave reviews & has upgrade path to 1TDX.

Any other suggestions are appreciated!

I am in dire need of a print for a Crate PCM 8 powered mixer, I saw some posts on here talking about it. If someone could help I will be eternally grateful. rvaughn@cinci.rr.com.

thanks

Hi guys.
I have a Sunn Beta Lead, and I'm wondering where to get these particular potenciometers for this amp. For example, the "drive" pots are 1 Mohm dual gang, with the 3 pins of each gang assembled 180 degrees opposite of each other. And the rest of them are 100k pots with a 4th pin to each one. They are beginning to fail on location, and make a crackling noise, and I just cleaned them with contact cleaning spray.
Any ideas where to buy them? Or a complete set of new ones (13 pots in total)?

New in the original anti static bag. Out once for the photos. Never got around to using it. Make me an offer. Buy pays shipping.

data sheet:

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Hello Experts/Enthusiast

I am interested in a DIY Tube-Preamp. Can someone share where should I look for circuits and guidance.

Thank you all in advance.

Cheers