Sound Skulptor forums

Build help and troubleshooting => CP4500 Stereo Bus Compressor => Topic started by: radar.rohan on August 08, 2023, 12:20:25 AM

Title: Comp not engaging when ‘in’
Post by: radar.rohan on August 08, 2023, 12:20:25 AM

Hi!

My compressor after working fine for a year + started behaving strangely. 

Now when the compressor is ‘in’ it passes signal and meters fine but the comp seems bypassed. 

When I first noticed this it was intermittent and I had some strange behaviour with the gain pot. But now it just seems dead.

The unit looks like it’s working and I hear the click when I hit the in button. But signal remains unaffected.

You actually helped set this unit up and did a basic repair when I first built it as I had the meter spade connectors attached the wrong way.

Thanks in advice for your help!

Title: Re: Comp not engaging when ‘in’
Post by: JPK on August 10, 2023, 05:33:33 PM

Does the makeup potentiometer increases the output level?

Title: Re: Comp not engaging when ‘in’
Post by: radar.rohan on August 17, 2023, 03:24:27 PM

No it acts as if it were bypassed. 

Though I did have it briefly engage when turning the gain pot. But only for a second. Behaviour I haven’t been able to repeat 

Title: Re: Comp not engaging when ‘in’
Post by: JPK on August 17, 2023, 05:02:49 PM

The unit stopped compressing on both channels at the same time, right?
Check if you get some side chain signal on TP11. It is a negative going DC level which reflects the input amplitude.
Then check if it is also present on TP12, added to a voltage controlled by the makeup pot.