Pioneer SX-3400 distorted sound

[Joeharts]

Hello all, I acquired this SX-3400 not too long ago for cheap. I noticed that the speakers sound distorted when the volume is turned up even slightly and the more the bass, the worse it is. I deoxted everything I could and order a full set of replacement caps. I thought it may be the two main filter caps at 4700uf 35v, but I just switched those out with new ones and the problem still exists. I will go ahead and replace all the caps, but does anyone have any ideas? The idle voltage is pretty close to where it should be. However the right is 2.2v and the left is 1.3v. Also to be noted, the headphone portion works perfectly fine.
thanks,

 

[j_garcia]

Tough to say, but the x-over is probably not the first area where I'd think the problem is. Far more likely you've got a cooked driver or a rotted driver surround and that's what I'd check first.

 

[Rickster71]

I'm pretty sure the SX-3400 a receiver.
My guess a bad output transistor.

 

[j_garcia]

Sorry, didn't look it up. Though it might be a receiver because of the SX, but some of their speakers are SX as well.

 

[TLS Guy]

Hello all, I acquired this SX-3400 not too long ago for cheap. I noticed that the speakers sound distorted when the volume is turned up even slightly and the more the bass, the worse it is. I deoxted everything I could and order a full set of replacement caps. I thought it may be the two main filter caps at 4700uf 35v, but I just switched those out with new ones and the problem still exists. I will go ahead and replace all the caps, but does anyone have any ideas? The idle voltage is pretty close to where it should be. However the right is 2.2v and the left is 1.3v. Also to be noted, the headphone portion works perfectly fine.
thanks,

What do you mean by idle voltage, and where did you measure it. That voltage is far too low for the power amp stage at any time.

If the headphone works then the low voltage stage is OK.

You need to measure the line voltage to the power amp board.

I would bet it is low and you have either a fialed power transformer, a failed rectifier, or a failed voltage regulator. I highly doubt this is a cap problem.