amp clipping earlier than usual?


I have a pair of mono amps with clipping indicator LEDs. One of the amps' indicators is lighting up for the first time. I've never been able to make them light up before. But it only happens on one of them. It lights up way sooner than as loud as I typically max them. I don't hear any distortion. So I'm thinking it's not an output transistor. These are LSR&D Superamp monos, 300wpch. Anyone? TIA
csontos

Showing 3 responses by atmasphere

Ralph- yeah, more like 3db, noticeable. But if there's no distortion, and not a blown output(maybe yes?), what could cause that? My main concern is the transformer.
The fact that the power transformer is running warmer is a bad sign and I agree with others that the filter capacitors in the power supplies are suspect (and cause this sort of thing) especially given the age. If left unchecked it could lead to transformer failure.

It is also a good idea to check the bias points. This is not particularly hard to do; with the cover off a tech can do it easily in five minutes.

So there are the two things that really should be sorted and it could well mean that they sort out the problem too. But even if they don't this sort of service would be prudent.


Hey Ralph. Actually, that amp seems to be down about 2db. I switched sides to check. I have several of these sets so I'm certain.
You switched amps, so it follows the amps? (2dB isn't much but if you didn't use a sound pressure meter for that I bet its a bit more.)

If yes that suggests some sort of damage to the amplifier.
Does the system sound OK and the channel to channel balance is good?
If so, it could be a problem with the indicator itself.