soundstream reference 700s

[mike49504]

Im rebuilding this amp pretty much all of it since more then half the parts are missing off the board.

My question is There are 1 ohm resistors in the power supply section there are 2 of them.

In the reference 700sx they are using sandstone resistors but in the 700s whats there now is just regular resistors 5 watt but they are to long and big to make it look like a professional job. Wondering do i use smaller resistors like 2 watt or do i get the sandstone resistors (the lenght i need)

[Perry Babin]

From the factory, lots of these snubber resistors looked less than professional. If it has a 5w, it may need a 5w. They run very hot and a lower wattage resistor may fail.

[mike49504]

Ok i put new emitter reisitors in the amp and rebuilt all of the power supply. i also put new driver boards in it. Right channel is dead left channel distorts like crazy wondering where i go from here?

[Perry Babin]

Run all switches and pots through their entire range (repeatedly for the switches) while the amp is playing to see if either channel produces clean audio.

[mike49504]

yeah a couple switches are dirty i messed with them and the channel that was playing now that doesnt work either and i get static like crazy through the speaker. so guess ill have to get some cleaner or some new switches

[Perry Babin]

Without exception, every soundstream of this era has problems with the switches. They should be checked even if all channels are playing because there's a good chance that they will cause problems when the amp is installed.

[mike49504]

ok the left channel distorts like crazy i tracked that down to the preamp board broken solder connection or something cause if i hold it the left channel plays fine


right channel is dead no output no static nothing wondering what i should check

[Perry Babin]

Did the right channel begin to play when you moved the switches?

You may have a broken trace on the driver board or on the main board where they connect. The first thing you would do is to re-solder all of the connections. If that doesn't work and you feel that the problem is definitely in that area, desolder and remove the driver board and examine all pads on both boards (where they connect) with a lighted magnifying glass. You may have to use desoldering braid to remove as much solder as possible to see breaks.

I always recommend using ChipQuik solder alloy and reduced soldering iron temperatures when desoldering these (and other) driver boards. It makes it almost impossible to do damage to the boards.

[mike49504]

ok i tracked the right channel down to one of the driver boards gonna resolder the thing and the left channel is somewhere on the preamp board gonna resolder that as well.

The other thing is when u turn the gains up on both channels there is no difference on sound doesnt see that either gain is working wondering what this might be

[Perry Babin]

Are you sure that neither gain works properly?

Are C14 and C38 in the circuit?