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Question Stereo power amp R - L volume mismatch

barwell1992

Active Member
Hi everyone,

I seem to have a gain/balance issue with the Sony TA-N55ES power amp that I’ve just set up.

Using Audyssey on my denon pre to measure levels it reads about 4db down on the right channel, my processor can adjust for this but obviously there’s an issue somewhere inside the amp.

I’ve had to repair a dry solder joint on one of the binding posts also on the quiet side, I wasn’t getting any audio through the tweeter (Bi-wired using A+B speaker outputs) however now it’s fixed the speaker seems balanced in terms of tweeter vs bass so I think that’s just a coincidence.

Caps look good nothings bulging etc, sounds really good.

So I’m wondering do I just live with it, try and repair it myself or get it repaired?

(FYI it’s on loan from my brother in law who’s had it stored for about 6 years)


Measurement data attached, 2db if the difference show is room responce the rest is the amp. Matched cable lengths etc and short runs.

B88E830C-B46A-41E2-BA71-E7FFB001EE24.png
958C1816-DA87-4F18-AFCB-ECDD2047B06D.png
07D81DB0-6C85-4158-A311-6AE9FD45743A.png
CED1066B-65E1-4F93-A35D-4E316E6A16BB.jpeg
71E8D4E4-B592-4419-B81A-AA4F7323BC07.jpeg
 

barwell1992

Active Member
So decided to strip the amp down last night and remove the solder on all of the inputs and outputs as well as reflowing the solder on the transistors.

Amp now produces perfectly balanced levels.

D442EFAE-BBD8-44F6-AC65-6D086A35B43E.jpeg
238C25D7-32FB-408B-94A8-1CB41A0DFE3D.jpeg
B00FC7DD-8481-45C0-93FB-13D93A321166.jpeg

07952616-BC02-40E4-8D0F-566327F6E7FD.png
 

Paul7777x

Distinguished Member
That’s bizarre... I would have expected perhaps crackles, buzzing or failure to play at all, but a 4db dip from dodgy soldering? Curious indeed.
 

barwell1992

Active Member
That’s bizarre... I would have expected perhaps crackles, buzzing or failure to play at all, but a 4db dip from dodgy soldering? Curious indeed.

Yup very odd, I did remove all the boards as well as a jumper board that wasn’t particularly well inserted but still it was inserted, redid the ground for the Class A board. And resoldered the RCA jacks.
 

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