Hi everyone,
So i have just discovered an issue with my 1176 unit (a kit from PCB Grinder) where the left channel doesnt really compress unless i boost the signal like WAY up. I have been troubleshooting it myself so far but have hit a dead end due to lack of skills for the task and in hopes of not going as far as having to start replacing all components i was hoping someone on this forum would point out what to check next.
I do get signal through the channel without issues but compression doesnt really happen. After calibrating both channels on this dual channel unit i've got to the point where i want to rely on the right channel to work as expected and so i've done the channel comparison against it. On the right channel it immediately stats to reduct gain when compression is switched on and continues to do so in relation to raising the input signal volume. Left channels does nothing unless input signal is boosted like at least 20dB, and even at max volume from the source it reducts only 1dB whereas left channel goes all the way to -20dB. Also what is odd behaviour is that when i switch on mid/side mode, the left channel ouput falls back to 0 and slowly rises up to level where right channel is, so kind of doing a temporary voltage loss. The unit does this only once after each power up. Makes me guess it's still component failure?
What i've doublechecked so far is;
-Visual check of any component damage - didn't find anything that looks damaged
-All IC chips, which i have changed to brand new ones (all of them), and also swapped them between the channels. This didn't affect the problem at all.
-I've tried to look for cold solder joints but didn't find any. I also resoldered all the problem channel lugs just in case. This didnt affect the problem at all.
I've attached a short video to visualize the problem. Attached is also the schematics.
What should i be looking at next?
Kind regards,
Rasmus
So i have just discovered an issue with my 1176 unit (a kit from PCB Grinder) where the left channel doesnt really compress unless i boost the signal like WAY up. I have been troubleshooting it myself so far but have hit a dead end due to lack of skills for the task and in hopes of not going as far as having to start replacing all components i was hoping someone on this forum would point out what to check next.
I do get signal through the channel without issues but compression doesnt really happen. After calibrating both channels on this dual channel unit i've got to the point where i want to rely on the right channel to work as expected and so i've done the channel comparison against it. On the right channel it immediately stats to reduct gain when compression is switched on and continues to do so in relation to raising the input signal volume. Left channels does nothing unless input signal is boosted like at least 20dB, and even at max volume from the source it reducts only 1dB whereas left channel goes all the way to -20dB. Also what is odd behaviour is that when i switch on mid/side mode, the left channel ouput falls back to 0 and slowly rises up to level where right channel is, so kind of doing a temporary voltage loss. The unit does this only once after each power up. Makes me guess it's still component failure?
What i've doublechecked so far is;
-Visual check of any component damage - didn't find anything that looks damaged
-All IC chips, which i have changed to brand new ones (all of them), and also swapped them between the channels. This didn't affect the problem at all.
-I've tried to look for cold solder joints but didn't find any. I also resoldered all the problem channel lugs just in case. This didnt affect the problem at all.
I've attached a short video to visualize the problem. Attached is also the schematics.
What should i be looking at next?
Kind regards,
Rasmus
