Soundstream Class A 10.0 problem

[azvrt]

Originally Posted by MOER

This is NOT a class A amplifier. Have you any idea how large a 25w/ch 4 ohm pure class A amplifier would be?

True, it however is a high bias amplifier with a pretty high idle current for a car amplifier, and yes they run warm even at idle.

I agree with the person mentioning the switches. Apply some contact cleaner spray in there. They do cause these kinds of problems. Especially the 2 / 5 volt gains switches are problematic.
You should definitely apply some solder to (refresh) the solder joints of the perpendicular driver PCB's. Might as well do the control boards while you're at it. These very often cause problems like no sound.

[AKHeathen]

just an update-
i got a wild hair to start digging out all m soundstreams, lol... anyways, i was looking for revisions/difference between the reference s/sx, and i see my verry first soundstream. i traded it away, and then got it back shortly after blown. the biggest thing i saw, is that the power supply section is changed to pretty much the same as what you have going on there. that part you are wondering about as a repair, looks to be a revision from the 5watt 1ohm resistors, so you have now basically 10watt 1ohm resistors as it sits, which is what i have in the sx. same omitted ts2, etc. more curious, is the same damage, and then some. i can tell an obvious arced out crater of a dry connection around the inductor, which i believe is likely the main root cause. i know the guy abused the heck out of the amp, too. anyways, the left 4 fets, resistors, and driver (q10;11;12;13;14) are all just as well cooked as that resistor. all of the soundstreams similar that i have seen, even the usa amps use a 10ohm/1w resistor, save for the rub1002, which does not use one, just a strait connection between the 2. furthermore, that doesn't just feed the output rca shield, but is basically the "ground" or common of just about all the preamp sections/circuits, so i imagine that you would not get any sound ever without that resistor in place. first thing i would do, since you can still power it up to idle, is go over the power supply circiut and rail voltages to make sure they are working correctly and switching. good luck, and let us know. hope this helps some.
-Heath H-

[pergo]

Originally Posted by MOER

This is NOT a class A amplifier. Have you any idea how large a 25w/ch 4 ohm pure class A amplifier would be?

quote

it's a soft switching classAB amplifier

[azvrt]

Originally Posted by pergo

quote

it's a soft switching classAB amplifier

And they are oh-so very nice. Yummie