2. amps-preamps
  3. 147940-3215

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
csontos OP
1,311 posts
 
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.
atmasphere's avatar
atmasphere
11,906 posts
 
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.
celander's avatar
celander
1,503 posts
 
OP: you said you switched sides. Do you mean switch preamp connections to the amp channels with respect to the preamp L+R channel outputs?
mrdecibel
3,065 posts
 
Unless they were rebuilt, these amps are close to 40 years old, so I totally agree with Ralph, although, " worn out " might be a better description ( such as capacitors ). Enjoy ! MrD.
csontos OP
1,311 posts
 
Thanks guys. No pre, Oppo CDP direct. So yes, switched ICs and speaker cables. These amps are completely rebuilt about 4 years ago.
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.
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