Pearl 2 woes

[KatieandDad]

My Pearl 2 was working perfectly the other day. I've just turned in on again and it is terrible, it sounds as though there is a layer of tissue between the stylus and the LP.

I've checked and cleaned the stylus ??

 

[KatieandDad]

Something has gone wrong as it is now shutting down the PA when I turn it on.

 

[Gyuri]

DC at its output, perhaps?

 

[takitaj]

Shouldn't be any DC on Pearl2 output unless the output cap was bypassed. Check status of output mosfet as they are very static sensitive. Are you sure it's not an amp problem? Can't see how the Pearl2 would cause amp to shut down.


TJ

 

[jackinnj]

Q2 going dodo

 

[KatieandDad]

The PA is working fine.


It seems as though it's on both channels so one of the rails may have failed.


I'm at work at the moment, I'll check later.

 

[McQuaide]

The Pearl 2 will normally put an amp into protection mode if the amp is powered on first. I reported this in another thread a while back. Best to power on from the source and power off from the amp.



One of my Pearl 2s once got kind of silly with oscillation and needed to be powered off for a while before it returned to normal. Hopefully in your case it isn't too serious of a problem!

 

[KatieandDad]

Hmmm. +/- 35V raw supplies are good. +/-24V regulated supplies are good. No DC at the outputs.

 

[KatieandDad]

There's nothing wrong with the unreg raw +/- PSU.

 

[KatieandDad]

The main Pearl 2 uses genuine Pass PCBs.

 

[KatieandDad]

DC wise I can't find any problems. There is a slight deflection of DC at the output on switch ON but that rapidly diminishes to mV.

 

[McQuaide]

I have a doc that has proper voltages at various points on the board, can't remember where I got it but can send it to you.

 

[KatieandDad]

I wouldn't have thought that a brief pulse of 0.5V would blow the aux input of my PA. The output stages are all fine and still working.

 

[KatieandDad]

Unfortunately I don't have another PA to try at the moment. My Aleph 4 needs new PSU caps.

 

[KatieandDad]

I've got a headphone amp though, I'll try it with that.

 

[KatieandDad]

It still sounds like **** through the PA. I don't think the Pearl 2 is at fault. I'm going to have to commission the Burmeister 933 modules that I've got lying around to test it properly.

 

[daniii88]

Check DC offset on the offset measuring point on the board, not the output after the cap.
I had a similar issue after powering the Pearl 2 boards for the first time. S**ty sound. The cause was Q2, the ZVP3310 transistor

 

[KatieandDad]

I've finally got to test the Pearl 2 through my headphone amp, the Pearl 2 is fine, the problem seems to be with the PA.