Quote:
Originally Posted by analogpajamas  Brad,
Not to derail your thread, but as a 110A owner, I'm curious as to the 'mods' you did to your cards. Mind explaining? Feel free to PM me, as to not further clog the thread. Thanks! |
If you want, I can send you more details in a PM, but just in case there are other JH110 owners reading this here's the basics of the mods done to all repro and record cards:
- replace all electrolytics with Nichicon HE, same values
- replace all equalization film caps with Wima FKP-2, same values
- replace all 2003(5534) can op amps with TLE2071A DIP op amps using sockets and Brown Dog adapters (there is one exception)
TO-99 to 8-pin DIP Adapter (p/n 020601B)
- exception: replace the op amp that drives the output transformer with an OPA604 (or something that has good current drive and can run at +/-18V)...I forget which card this op amp is on so consult the schematics
- replace the NE5534 input op amp on the audio motherboard with TLE2071A
- replace the two electrolytics in series that act as a bi-poplar coupling cap on the audio motherboard by the input op amp with a Nichicon Muse bi-polar or Black Gate if you are a big spender.
- most importantly, replace all VU lamps with blue LEDs!!!
By the way, I have an 18V "A" revision with repro head transformer on the repro card, and an output transformer on the audio motherboard. If you have the earlier 24V version then you'll likely have to do some different things and find op amps that an run at +/-24V. The OPA604 might be a good canditate. The "B" and "C" versions don't have the discrete circuitry and tranformers that the "A" does. But the upgrades are still applicable. It's basic electrolytic, film cap, and op amp upgrades. Depending on op amps selected you may need to increase PSU decoupling or add bypass caps, or limit bandwidth to prevent oscillation. The TLE2071A's aren't too high bandwidth and high speed so seem to fare well in the stock circuit. Just don't use them where you need current drive.
I think I may have some before and after clips I printed using a Smashing Pumpkins track. I'll have to look.
Brad