1

CP5176 FET compressor / Re: CP5176 only compresses in 20:1 / SLAM mode

« on: December 14, 2025, 07:12:20 PM »

Hi, and thank you for your help. I went through all the solder joints and cleaned up some of them. Everything is now working perfectly

2

CP5176 FET compressor / Re: CP5176 only compresses in 20:1 / SLAM mode

« on: December 04, 2025, 03:56:20 PM »

Measurements: U1 pin 1 = 1.10 VAC, U1 pin 5 = 0.55 VAC.

I inspected the solder joints around U1 and the checked resistors; solder joints look OK and the resistor values (R25, R27, R33, R34, R35) match the values.

3

CP5176 FET compressor / Re: CP5176 only compresses in 20:1 / SLAM mode

« on: November 26, 2025, 09:29:48 PM »

Thanks, here are the measurements

AC level on TP3:

• Ratio 2 : 0.65 VAC = 3,3
• Ratio 4 : 1.3 VAC = 6,58
• Ratio 8 : 2.1 VAC =  9,04
• Ratio 12 : 3.4 VAC = 11,02
• Ratio 20 : 5.9  VAC = 11,69
• Ratio SLAM : 6.6 VAC = 9,56

DC level on TP4:

• Ratio 2 : 0 VDC = 0
• Ratio 4 : -0.5 VDC = -0,5
• Ratio 8 : -1.3 VDC = -1,3
• Ratio 12 : -2.5 VDC = -2,5
• Ratio 20 : -5.5 VDC = -5,5
• Ratio SLAM : -0.6 VDC = -0,6

DC level on JMP1 pin 1:

• Ratio 2 : 0.6 VDC = 0,7
• Ratio 4 : 0.9 VDC = 14,42
• Ratio 8 : 1.2 VDC = 12,3
• Ratio 12 : 1.9 VDC = 11,78
• Ratio 20 : 2.3 VDC = 9,17
• Ratio SLAM : 7.9 VDC = 13,8

DC level on TP6:
      -4.5 to -1.2 VDC depending on P6 = -13,2

DC level on TP5 with jumpers JMP1 on 2-3 and 4-5 [o o-o o-o]:
      0.32 VDC =  0,32 

A 12,7
B -0,6
C 13,3
D -0,2
E 15
F -0,8
G -15,1

4

CP5176 FET compressor / CP5176 only compresses in 20:1 / SLAM mode

« on: November 25, 2025, 07:07:08 AM »

I have a problem with my CP5176: it only compresses in the 20:1 (SLAM) mode. In all other ratio settings (4:1, 8:1, 12:1) there is no audible compression and the gain reduction meter does not move, even with high input level.

All calibrations have been done according to the manual and the values are correct. The unit passes audio fine and sounds good in 20:1, but the other ratios seem inactive.