yamaha CA-510 amplifier power supply issue

[desolationx]

I just bought a Yamaha CA-510 amplifier. I believe it's the same amplifier as a CA-410 II. The amp works great but the lights on the watt meters dim significantly during heavy bass. Is this a sign of a weak power supply? Should I replace the electrolytic capacitors? Also, does anyone have a service manual or know where to get one for this thing. Thanks!

[nigelwright7557]

Sounds like the large smoothing capacitors are past it.
You could measure them with an LC meter.

[Enzo]

You might also monitor the mains voltage to see if it sags under the load. Outlet strips, end of the wires family room, end of the country road power pole, worth checking. For that matter, power transformer secondary voltage could reveal something. If it dances with the signal, so would everything downstream from it.

Are the lights powr supply derviced from the main +/-V of the power amp? If not, they'd be on their own supply, and a good chance it has a pretty steady load.

[sakis]

MOST yamahas of that age like this one have a small secondary AC supply for the lamps if memory serves it must be 8 volt

ca510 is 35+35 w ...i wonder what exactly do you mean by """during heavy bass''''' .... a 35 W amplifier one way ore another cannot produce that ...

if you push an amplifier of this age to what you call heavy bass with aged caps obviously transformer is stressed resulting also dimmed lights on the VU

in between all electrolytics inside are to be replaced no questions asked and all means all

schematic and/or additional help is available email me if you like to have it

kind regards sakis

[desolationx]

Sakis, by "heavy bass" I mean when a kick drum hits or the bass notes of a rap song. Even though it's only 35 watts, it's loud enough for me and produces adequate bass. I can't hear any issues with the sound but I have never seen lights dim like that on a home amplifier.

I will change the capacitors anyway since they are probably weak and never been changed before. I will have to get a schematic to see whats powering the lights for the VU meters. Thanks for the replies.