• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

Teac Amp Upgrade Questions

ivandezande

ivandezande

AK Subscriber
Subscriber
So I got a Teac AG-V8060 at a goodwill for $13, and decided to upgrade the internals since I got it so cheap.

So opinion on part selection time!

PSU: Main Chemi-Con SMH, 12V Supply Panasonic FM
Signal: Nichicon FG
Op-Amps: NJM2068, but I am leaving the 4558's in the voltage follower buffers because someone recommended it. Might put in a uPC4570 I have in one though. All are SIP8 which is a huge pain.

Anything I should watch for or to not do, please tell me. I have redone a Pioneer SX-205, but I think I got lucky on that one.

Thanks!
 
Register to hide this ad
Hey cool, :thmbsp:

I have a v3020 and I'm slowpokeing it through an upgrade right now.

I replaced my main PS caps, SAMWHA 8200 uF, 80v with 12,000 uF, 80v NCC SMH and the +/- 15V and +5V caps with Nichicon KWs. It sounded decent before but now the drums are slamming! ... Toms have a very realistic tone and attack now.

I'm also going to use Nichicon FGs in most locations that involve audio.

My V3020 receiver uses KIA 4559P (8-DIP) op-amps in the pre-amp and on the surround PCB.

After doing a lot of reading and research about changing out op-amps I finally made the decision to use the JRC/NJM 4580DD in the pre-amp section.

I choose the 4580 over the 2068 because the input bias current is in the same range, 60(100)-500nA, as the KIA 4559P. I'm not sure if that is a huge issue but I'm trying not to disturb the apple cart too much if I can help it.

I was also just looking over the schematic for the Sony STR-V777ES. The SONY uses the 4580 all over the place with some similar circuits. Looking at that gives me confidence that the 4580 will do a good job in my TEAC. :D
 
Good op amp selection, I'm pretty sure the 2068s in mine are not oscillating considering they're not getting warm so I'm happy about that!

BE CAREFUL hopefully you factored this in but the opamps you put in each add 2 ma to the line or more. I'm guessing a Zener/transistor network is doing the regulation, just like mine. Check how much the transistor can give.
I put in some 7812/7912 because the pin out worked and the transistor gave out 100ma tops and I was getting wayyy too close to that.

I put 10,000uF in each rail because I've read more than that is overkill, but to each his own. I didn't bypass them with films, thinking about doing that.

Or even getting 10 2,200uF of Nichicon KG and making a board for them since that would give a lot better performance, but I don't think it would fit in the case.

Good luck on the rest of it, you'll be very happy once you finish!
 
Thanks, I'll check the impedance when I get a chance! You're lucky having regulators in there already, I had to fit in 0.1uF caps and cut traces etc...but it works.
 
There is nothing coming out of the woofer when I hook speakers up but the hiss coming out of the tweeters is still audible in the room. Any ideas on how to fix this? Low freq I can do, but this....no idea. Op amp oscillation? Power supply? Or maybe it's just a bad amp!
 
You must log in or register to reply here.
Back
Top Bottom