Fuzzy sounding Tech21 Trademark 60

[aiyiadam]

I really hate this amp..

The owner of the amp claimed that the amp has lost its "sparkle" and brought it to me. Sparkle surely is a subjective thing, but changing the old 4700uf (G-Luxon) capacitors could improve the sound a bit. Unfortunately It won't be easy to find here good quality through hole capacitors.

I have also realised that the second channel sounds really fuzzy at high gain settings. The owner said that the amp had this problem since 6-7 years. He just keeps away from high gain settings.

The fuzzy distortion should have something to do with the preamp of this thing, which is a SMT hell.

Unfortunately Tech21 was unable/unwilling to help. Maybe somebody here has a similar experience with those things?

[glebert]

My experience with Tech 21 is that they will never, ever, ever give out a schematic or even a portion of a schematic. I was able to talk to the engineer (who I think designed the TM60) and he walked me verbally through the section of the amp that I was dealing with (the voltage regulators for the +/- 15V) and I was able to get my amp working. I actually talked to him for almost an hour, kind of just having pleasant conversation. Might be harder to do internationally.

I have no idea how to replace missing "sparkle" and it sounds like the owner isn't asking you to fix the the fuzzy high gain issue, is he now asking you to fix it?

[aiyiadam]

My experience with Tech 21 is that they will never, ever, ever give out a schematic or even a portion of a schematic. I was able to talk to the engineer (who I think designed the TM60) and he walked me verbally through the section of the amp that I was dealing with (the voltage regulators for the +/- 15V) and I was able to get my amp working. I actually talked to him for almost an hour, kind of just having pleasant conversation. Might be harder to do internationally.

I have no idea how to replace missing "sparkle" and it sounds like the owner isn't asking you to fix the the fuzzy high gain issue, is he now asking you to fix it?

Yes. Somebody from product support wrote me that the power section is based on the TI LM3876 circuit and the rest of the amp is proprietary.

I wouldn't call Tech21 for a repair job like this, but I wrote a few emails. I have even sent the product support a short recording. They don't think that there is anything wrong with the second channel. So they won't be much of a help.

The owner has learned to live with the fuzzyness and didn't ask me to fix it. I would still like to solve the problem, if it is an easy fix. Since this is a working amp, there is no reason to take big risks or spend too much time.

[g1]

That's a tough one to have an idea of the fault if you haven't been the one using it since new. Even an aged speaker would lose some 'sparkle'.

[glebert]

Couldn't hurt to try jumping the effect loop and see if it makes a difference, and send the DI output to a mixer and see if there is a significant difference from the speaker as far as sparkle. The power amp really should just be flat and clean with the LM3876.

[The Dude]

Buy him some new strings.

[J M Fahey]

I donīt think you are dealing with a *real* problem.

As said above, maybe old strings, bad cables, some dull effects pedal in the path (unless True Bypass, many suck signal,specially sparkle, even when OFF), tired ears, etc.
Nothing *you* can solve.

Fuzzy high gain distortions?
Thatīs the way it sounds.
Same thing.