1

CP4500 Stereo Bus Compressor / Re: CP4500 Channels Have Different Volume.

« on: May 06, 2022, 07:13:14 PM »

Yea it was the cable... My apologies for having wasted your time.

2

CP4500 Stereo Bus Compressor / Re: CP4500 Channels Have Different Volume.

« on: May 03, 2022, 11:51:11 PM »

My bad for the late response, I suddenly got very busy. Okay so I just measured the output of my interface (using 10khz sine) and it looks like one of my cables puts out half the VAC that the other one does. I should have checked more rigorously. Ordering new cables now, I hope that was the source of the problem.

3

CP4500 Stereo Bus Compressor / Re: CP4500 Channels Have Different Volume.

« on: April 25, 2022, 12:06:46 AM »

So my lunchbox (Lindell 10 slot) doesn't give me any readings on the output when the CP4500's channel 1 isn't connected. I tested this out by connecting just channel 2 and fully disconnected. I can only read voltage when channel 1 is in. I'm not sure if this is a design issue with the box but I'm unable to run that test.

4

CP4500 Stereo Bus Compressor / Re: CP4500 Channels Have Different Volume.

« on: April 21, 2022, 07:36:05 PM »

I just got the chip out, and the prongs have bent again. I don't think they can withstand another removal after this.

With U11 removed I first measured the output from channel 2 out of curiosity.
The output = 3.14 VAC now whereas before output = 2.93 VAC.
This is when the compressor is off by the way, when it is on the reading drops to 0.

Both when the compressor is on and off, with U11 removed TP6 = 0 VAC.

5

CP4500 Stereo Bus Compressor / Re: CP4500 Channels Have Different Volume.

« on: April 21, 2022, 07:25:00 PM »

I am assuming that you mean the steps from "If your CP4500 is not working as expected":

The gain that I am talking about is the increase in volume that my DAW is sending to the interface then to the lunchbox. On channel 1 I am reducing by -4.59 dB to read 3 VAC on the output, and on channel 2 I am adding about +24 dB gain to get it to 2.93 VAC.

Channel 1 step 6: (input = 3 VAC, threshold = +15, makeup = 0) [-4.59 dB gain from DAW->interface]
    TP1 = 1.48 VAC
    TP2 = 1.46 
    TP3 = 1.48
    TP4 = 0.02

Channel 2 step 3: (input = 2.93 VAC, threshold = +15, makeup = 0) [+24 dB gain from DAW->interface]
    TP6 = 1.44 VAC
    TP7 = 1.44
    TP8 = 1.44
    TP9 = 0.02


I am going to take my time right now taking out U11 since it is difficult and fragile, then run the test. I will post results in a moment.

I hope that clears up what I meant about the gain. The gain is from the "external effect" plugin in ableton, it is what I am sending from the plugin through the interface into the lunchbox. I assume that the signal is clipping in the interface before reaching the chassis.

6

CP4500 Stereo Bus Compressor / Re: CP4500 Channels Have Different Volume.

« on: April 19, 2022, 09:00:07 PM »

No, it's the CP4500

7

CP4500 Stereo Bus Compressor / Re: CP4500 Channels Have Different Volume.

« on: April 19, 2022, 08:53:03 PM »

I'm not sure if this has something to do with it, but the difference in the amount of gain required to get the first channel (left) up to 3 V AC on the Lindell box versus the amount for the second channel is huge. For the second channel, I am close to 0 dB gain and on the the first I need +24 dB (completely red).

I am about to run a test with the next two channels and see if the issue continues.

8

CP4500 Stereo Bus Compressor / Re: CP4500 Channels Have Different Volume.

« on: April 19, 2022, 08:13:20 PM »

I tested TP6 with U11 removed. I couldn't get a voltage reading (V AC).
The chip leads got a bit bent while removing. Hope it's not a problem, I've manage to get it back into the holes.

I'm disassembling the module now to test PCB A. Might as well reflow now while I'm here.

9

CP4500 Stereo Bus Compressor / Re: CP4500 Channels Have Different Volume.

« on: April 19, 2022, 07:59:20 PM »

BR1 and BR3 are correctly oriented.

10

CP4500 Stereo Bus Compressor / Re: CP4500 Channels Have Different Volume.

« on: April 19, 2022, 07:56:21 PM »

TP1 and TP6 both get 1.47 VAC.
I will remove U1 and U11 now, then check the direction of BR1 and BR 3.

11

CP4500 Stereo Bus Compressor / CP4500 Channels Have Different Volume.

« on: April 19, 2022, 12:34:01 AM »

Hi, I'm not sure if I have done something wrong but channel 2 is far louder than channel 1 and the stereo signal appears to be panned pretty hard to the right.

So far I've tried turning T3 to adjust the balance but I ended up redoing the rebalancing with the DMM. It also appears that with the compressor off, the signal is slightly panned the same way, but significantly less (right channel louder).

Most of the measurements were correct, many were almost there, and a few were actually off. Here are the ones that were off:


(input signal = 3 VAC, makeup = 0, turn threshold +15 to -15)
TP4 = 0.026 to 0.23 VAC

(input signal = 3 VAC, threshold = -15, makeup = +20)
TP12 = 0.77 VAC

12

CP4500 Stereo Bus Compressor / Re: Calibration and Instruction Issues

« on: April 13, 2022, 07:26:16 PM »

Okay I understand now, thank you. I was able to read 3 VAC on the extender by cranking the gain in my DAW input by +24 db. I have also gotten the readings on TP1, TP2, TP3 = 1.5 VAC and TP4 = 0.06 VAC. Thanks for the help, will try to finish up tomorrow.

13

CP4500 Stereo Bus Compressor / Calibration and Instruction Issues

« on: April 13, 2022, 06:11:08 AM »

I'm having trouble understanding the instructions. On the setup guide step 6 the instructions say:

"Connect your DMM to the CP4500 output, between pin 2 and pin 3 of the XLR. "

What is the CP4500 output? Is it asking for me to attach the DMM to the literal pins on the male XLR? Very confused.

I've also been trying to measure TP1 and TP2 using VAC against 0V, and I've been getting no measurements. Is this because I'm not running a signal into the compressor? Or maybe something is wrong with my solder joints?

After following the "In case your CP4500 doesn't work as expected" instructions, I am getting the proper readings for steps 1-4, and am getting hung up on the 3VAC input signal step while getting no VAC readings from the corresponding test pins.

14

CP4500 Stereo Bus Compressor / Re: DMM readings wrong on PCB A for CP4500

« on: April 09, 2022, 02:23:17 AM »

Okay my apologies, disregard that post.
It appears to be the Lindell chassis that has either stubborn or faulty card connectors. The connectors barely accept a card, and I eventually noticed that the LED would shine brighter when I was holding the card forced into the slot. My partner measured while I held it in, and I got the correct readings. Will contact Lindell about this.

15

CP4500 Stereo Bus Compressor / DMM readings wrong on PCB A for CP4500

« on: April 08, 2022, 11:51:25 PM »

Hi there,

I am getting incorrect readings for the first stage of setup on the CP4500. On the negative pins the readings are correct, on the positive they are incorrect. Here are the readings:

V+ ->     -0.72V
V-  ->     -16V
+12V -> -0.61V
-12V  -> -12V

I've reflowed and resoldered the joints that needed them. Any help is appreciated.