S5 11g help

[retiredmxer]

Hi everyone

I 've just recently purchased two of the S5 11g monoblock kits and have completed one of them.

I checked all of the wiring a final time, plugged in the input and outputs and turned it on. Waited a few minutes and then turned on the source(cd player). Nice clean sound came from my one speaker

I listened for about 30 minutes and then turned it off. The next day I started the second amp build and finished it later in the evening. I went inside and hooked it up also. Turned both of them on for a few minutes and then the source....and heard serious distortion with the music. I turned off the newest amp and unplugged it from the wall. I went back to the same configuration that I had the previous day(only the one amp plugged in) and tried to listen just to it. I still had bad distortion. The output is way down from when I first listened to it. I have to turn the volume farther up, and it occasionally resorts to its original ouput and the sound leaps out(way too loud)!

Does anyone know what could have happened between the day it was working fine and the next time I used it? Whatever it was seems to have happened to the second amp the first time it was turned on...

I'm very new to this and would like some advice before I go poking around. I've searched other threads on here, but didn't find an answer.

Thanks for any help!

Blake

[dsavitsk]

Sounds like a bad solder joint, perhaps.

[gofar99]

Hi, Could well be a solder joint. I believe I would start looking at the circuitry close to the volume control. Another prime area would be the coupling cap and resistor to one of the outputs. A bad connection here could cause one output to function properly and the other to distort severly.
my2cents

Good listening
gofar99

[Sherman]

Originally posted by retiredmxer
.. Turned both of them on for a few minutes and then the source....and heard serious distortion with the music. I turned off the newest amp and unplugged it from the wall. I went back to the same configuration that I had the previous day(only the one amp plugged in) and tried to listen just to it. I still had bad distortion. The output is way down from when I first listened to it. I have to turn the volume farther up, and it occasionally resorts to its original ouput and the sound leaps out(way too loud)!
...

Blake,

The output ground hole on the PCB is (or at least was in my stereo version) quite large. This make it more difficult to get a solid ground connection when soldering to that pad.

Double and triple check your solder connections and especially at the output ground.

[retiredmxer]

Thanks very much for the help guys.

The first amp had a problem with one of the connections to the volume pot.

The other had a bad connection on the rca jack.

I was really suprised as I had thought I made sure all the solder joints were really good. Live and learn I guess.

They're both up and running fine now

I can allready see a time when I'd like a pre with phono stage and volume so these two become just power amps.

Thanks again for the quick help.

Blake

[Sherman]

Glad you found the problems! Problems like that can be intermittent and those are usually the most difficult to track down.

I usually check all my solder joints with a DVM. I solder a few joints then check them one by one for continuity while giving the component a little wiggle. A lot of solder joint issues can be made to show themselves that way.