jensenmann

DOA riddle solved
« on: November 25, 2020, 03:40:27 PM »
Here´s some pictures about a mystery DOA riddle which I have solved:

https://ibb.co/4VXXfZG
https://ibb.co/0FPdnf6
https://ibb.co/KKb1Gjv
https://ibb.co/cbbs0C1
https://ibb.co/nB0pZLq

Guess what that is....
 8)
Jens
Quote from: PRR
The tubes of course don't care what frequency they distort


wlinart

Re: DOA riddle solved
« Reply #1 on: November 25, 2020, 04:19:56 PM »
Sontec?

ruffrecords

Re: DOA riddle solved
« Reply #2 on: November 25, 2020, 05:06:03 PM »
15 transistors!!!

Cheers

Ian
www.customtubeconsoles.com
https://mark3vtm.blogspot.co.uk/
www.eztubemixer.blogspot.co.uk


'The only people not making mistakes are the people doing nothing'

jensenmann

Re: DOA riddle solved
« Reply #3 on: November 26, 2020, 01:39:26 AM »
Sontec?

Exactly. That was fast...

Since I repair Sontecs quite often I ran into the problem to repair defective DOAs at some point. Thanks to Corona lockdown early this year I had enough time to reverseengineer a HS2030 DOA. I made a PCB layout and finished my first DIY HS2030  last night. It´s working. Happy camper here :-)
Jens
Quote from: PRR
The tubes of course don't care what frequency they distort

wlinart

Re: DOA riddle solved
« Reply #4 on: November 26, 2020, 02:09:51 AM »
Great job!

OneRoomStudios

Re: DOA riddle solved
« Reply #5 on: November 26, 2020, 05:08:06 PM »
Have you seen Joe Malone's (JLM Audio) work on these?

https://www.jlmaudio.com/shop/hs3030-opamp.html

He's done quite a bit of work on Sontec opamps, including the HS2030, an adaptor for the HS10** opamps, HS2000, and the HS6000, among others.


jensenmann

Re: DOA riddle solved
« Reply #6 on: November 26, 2020, 05:44:37 PM »
Yes, I did. I´m using his DOAs in my Don Classics 250. They are spot on. That combination is as close as you can get to a real 250c. I had them side by side. Joe´s DOAs are available with 2520 pinout, so he´s doing us DIYers a big favor.

Joe´s DOA came out when I was in the middle of reversing the HS2030. I don´t know if I´d done all that work if they were available earlier. Anyway, his DOAs are SMD and my version is all original THT with all those obsolete unobtainum transistors. As I said before I repair Sontec, mostly for mastering studios here in EU, and most clients want it to be as original as possible. That´s what I was trying to accomplish with my PCB. From a commercial POV it doesn´t make sense to do it other than SMD. But paranoid mastering guys love that minute detail ;-)
Jens
Quote from: PRR
The tubes of course don't care what frequency they distort


 

Related Topics

  Subject / Started by Replies Last post
9 Replies
2917 Views
Last post October 31, 2004, 09:46:04 AM
by Bear
33 Replies
15720 Views
Last post May 26, 2010, 03:30:08 AM
by Kingston
15 Replies
3607 Views
Last post June 25, 2008, 01:31:13 PM
by JohnRoberts
17 Replies
2102 Views
Last post November 05, 2018, 02:51:51 AM
by ruffrecords