Bugera v55 need advice

[km6xz]

Thanks Enzo. Then it is a clipping circuit. Of sorts.

Well, sort of, no. It is anti-latching and is simply there to protect the IC from destructing. Some ICs have it internal but for safety, it is usually added to any line that may be driven past rail.

[Chuck H]

Well, sort of, no. It is anti-latching and is simply there to protect the IC from destructing. Some ICs have it internal but for safety, it is usually added to any line that may be driven past rail.

I only meant that the circuit clips voltage in order to reduce it's peak. But you knew that. Certainly not a clipping circuit for any audible benefit.

[km6xz]

I knew that you knew that I knew you knew....;>)

I still think the problem with the Bugera is not determined if it needs mods, more careful adjustment or sold off to get what the owner wants. I don't like to mod commercial amps, it loses its only real value difference between a home brew and commercial amp...that of being designed by a real engineer and is what it is. If an amp is not giving what a player wants and he has eliminated user error, the best way to solve it is to sell it and buy what does what he wants. Resale value is harmed by mods for good reason, most are worthless and lower reliability. For the sound it generates, the Bugera I have heard, in competent hands, are pretty impressive for the cost. They sound better than they are built. Someone really wants the sound it creates as it is, sell it to him.
The problem with mods as I see it is the disconnect between what people imagine they want and how that relates to the electronics. When trying to interpret how they describe the desired sound and translating that to circuit conditions requires more mind reading than engineering chops. Two different languages without translatable vocabularies.

[Chuck H]

Agreed. Having done my share of modifications to existing amps I've become of the opinion that the more complex a design, the better to NOT modify it. That's not rocket science and it's especially true of PCB amps. Even more so with modern PCB amps. Many of the more budget oriented models only seem to be repairable in the technical sense. With thinner, tighter traces, board mounted pots, jacks and sockets and just generally more fragile construction than amps of thirty years ago. A ham handed eyelet board guy like myself might do more harm than good clomping around in there The point just gets lost when there's as much potential for trouble as improvement. The way I see modern "affordable" amps is sort of the way I see things like boom boxes and powered computer speaker systems. You wouldn't "mod" those things. You use them until they break beyond a simple fix, then you toss them and buy a replacement.

[Leo_Gnardo]

The way I see modern "affordable" amps is sort of the way I see things like boom boxes and powered computer speaker systems. You wouldn't "mod" those things. You use them until they break beyond a simple fix, then you toss them and buy a replacement.

+100 !

Where's SGM when you need him? I'd mod that amp all right, got my 8 pound sledge hammer warmed up and ready to go.

[km6xz]

SMD is fine to mod but the light weight PC boards really are easy to damage in the cheap through-hole pc boards. You do not mod a Crate for example, their copper is so thin and board adhesive so fragile that it is hard to get a part out without loosening traces. I use ChipQuik low temperature solder on those so the copper does not get over 60 C. Surface mount is easiest to mod if one is set for it with a good inspection scope, desoldering tweezers and some pretty darn good eyesight. Traces on SMD boards seem to be tough, even Behringer. Components and solder joints seem more reliable on SMD since they have such kow mass, vibration is a non-issue, and the soldering automation is really good.