1

CP4500 Stereo Bus Compressor / Re: Signal loss when CP4500 is on

« on: January 14, 2021, 07:31:51 AM »

I figured it out!

I had 2 THAT 1646 IC's on PCB 1, and 2 THAT 1246 IC's on PCB 2. There should have been one of each on both PCB's.

Well... Everyone's gotta start somewhere. Thank you for your help. This thing sounds great!

2

CP4500 Stereo Bus Compressor / Re: Signal loss when CP4500 is on

« on: January 14, 2021, 01:16:28 AM »

Checked all the VCA's, tried the 100Hz signal, and soaked all the PCBs in iso with another good scrub. I did all the tests again to make sure nothing changed, and the problem is consistent.

any other suggestions?

3

CP4500 Stereo Bus Compressor / Re: Signal loss when CP4500 is on

« on: January 12, 2021, 07:58:48 PM »

Alright, so I found some readings that were a little off

Test 6
TP2 1.35

Test 7
TP4 0.18

I should also mention that the T1 max's out at 0.4 VAC when the compressor is IN

Cheers

4

CP4500 Stereo Bus Compressor / Signal loss when CP4500 is on

« on: January 12, 2021, 06:39:41 AM »

Hi, I've just finished populating my CP4500, and am having some calibration issues. Right off the bat My V+ and V- are reading a little hot (and cold) at +/-16.3ish V. I don't know if this is a big deal, but the guide says it should be between 15-16.

The part I'm really stumped at is getting my output signal to read the same when the compressor is IN or not. Ive got a 3.0VAC reading while the comp is off (with the 1Khtx signal through my DAW), but I cant seem to get any more signal out of my T1 trimmer resistor no matter how much I turn it. I've cleaned the PCB's thoroughly, checked the polarity of all my caps and diodes, made sure that the T1 resister was working properly by isolating it with the DMM, but I cant get the signal up to where it should be.

Any suggestions?

Thanks in advance
-Brin