Does Anyone Recognize This PC-3 Driver Board From Audio Sound Lab?

Hi All,

When I acquired my ST-70 I was given this PC-3 board but with no instructions on how to correctly install it. I have search every corner of the net and have found nothing on this board or the company who built it. As you can see its a very nice board. I would like to install it but I'm unsure of the correct wiring placement. Some of the wiring is self explanatory by the numbers but the rest is not.

If anyone knows this board and has the installation instructions or knows how to correctly wire it in, I would greatly appreciate any help I can get.

Dave

Hi Davidmac5 --- for what it is worth, there used to be a seller on eBay called tubes4pro, who sold various boards for the Dynaco line of tubed amps and preamps.

I bought from him Power Supply Boards for the PAS Preamp and the Dynaco Integrated Stereo Amp (SCA-35), but I know he offered other boards for dynacos.

His boards were always marked Audio Sound Labs and Made in USA and were of very high quality.   He does not appear to be active on eBay now.

Your Board looks like the boards that he sold.

The last time I bought from him was in October 2017 and he shipped from the following address:

Chart-Chung Chong
7951 Oakdale Ave
Winnetka, Ca 91306-2352

Winnetka is in the LA Area's San Fernado Valley

Chart was always good about answering questions, so you could try writing to him with a picture of your board or doing a google search to locate him or get an email address.

I did the google search on Chart Chong Winnetka Ca and he appears to be still living at the address the I have shown above.

Good hunting!!
Stew

David ---- take a look at these links posted by Bob Latino and Roy Mottram and compare your board with the picture/components that they show on their pictures ........

https://dynacotubeaudio.forumotion.com/t191-dynaco-st-70-pc-3-driver-board-parts-layout-photo

http://www.tubes4hifi.com/VTA70wiringdiagram3.jpg

Also look at the PCB wiring in the Dynaco ST70 User Manual ( http://www.tubes4hifi.com/downloads.htm ) versus the numbers on the boards and you might be able to work out the wiring. There is a PC-3 Driver schematic in the User Manual that shows the wiring connection numbers on the original Dynaco PCB along with the resistor and capacitor values, so that will help.

I also did some other google searches, but like you, could not find anything specifically like or for your board.

Stew

Thanks Stew, it appears that tubes4pro still has an active account on eBay and I was able to message him and send him the same photos I posted here. Hopefully he will get the message and if this is one of his boards contact me back, we'll see what happens time will tell.

Good news, C.C. answered my email and he was super helpful. He emailed me the installation manual for my board. All is well now. Thanks Stew for the information you posted, it worked.

Hi David --- Glad you could get the necessary info from Chart.
Stew

I can’t seem to raise the Tubes4pro guy on eBay, can anyone share an email address or contact number?
TIA

Hi Buckoff --- see Post #2 above where I listed his address in the LA Area. I dont know if it is still valid, but it was when I posted it.
Stew

stewdan wrote:Hi Buckoff --- see Post #2 above where I listed his address in the LA Area.  I dont know if it is still valid, but it was when I posted it.
Stew

Is like to have a 20th century type discussion with the gent but I appreciate your reply….