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-   -   Strange problem with Pearl 2 and SAE Cartridge (http://www.diyaudio.com/forums/pass-labs/232327-strange-problem-pearl-2-sae-cartridge.html)

McQuaide 18th March 2013 10:11 PM

Strange problem with Pearl 2 and SAE Cartridge
 
I've had this problem on and off with a NOS SAE1000e for a while now. The cartridge produces incredibly loud white noise when on the tonearm rest, but only with the Pearl 2. It's quiet with other phono stages. When the stylus hits the groove the noise quiets down.

It also makes strange sounds and loud snaps when the TT muting kicks in and out. Pulling one RCA cable kills the noise, and touching one of the signal terminals quiets it.

It only happens with the combo of the Pearl 2 and this HOMC cart. The cart is fine on other phono stages, and other carts are fine on the Pearl 2.

Any ideas Wayne?

Mark

Russellc 19th March 2013 01:21 AM

Well Bugger. My current fav is the SAE 1000 Lt....

Russellc

McQuaide 19th March 2013 10:51 PM

Bump...

McQuaide 22nd March 2013 03:58 PM

Here's an update on my troubleshooting -- The noise seems to be related to C22. I have these caps in sockets now, so I can vary the load on the cartridges.

When I pull C22 from the right channel but leave it in the left, the noise goes away from both channels. If I pull C22 from the left channel, the noise stays in both channels, regardless of whether C22 is in the right channel or not.

This noise existed on and off before I installed the sockets, and with different caps.

Any ideas?

Wellerman 22nd March 2013 08:51 PM

So if you pull c22 from the right channel, the noise goes away in both channels, and if you then also pull C22 from the left channel, the noise returns in both channels? ( I might have misread)

I would try soldering C22 in both channels to see if that works. Or alternatively, try without C22 in both channels (cable capacitance ot the TT interlink mightbe enough). I have silver mica ones in my Pearl.

bnorrish 22nd March 2013 11:09 PM

I left off C22 in mine as a few suggested most cartridges do not need. I would leave them both off.

McQuaide 23rd March 2013 08:33 PM

Solved
 
Well, it was something simple. This cartridge wants the TT ground to be earthed. Without that, you get blasting white noise, or crackling, or wierd tones slowly rising and falling, or radio stations, or sometimes nothing. As soon as I connected the Pearl ground post to earth it went dead silent.

My ground scheme was identical to 6L6s.

I'm now enjoying my best cartridge through the Pearl 2-Mezmerize-F5, and it sounds like I died and went to heaven :D:D:D

McQuaide 23rd March 2013 10:18 PM

The saga continues...

After listening for a while, the left channel slowly fades and the some of the noises come back. None of the extreme noise from before I grounded it, but some squealing sounds.

Unplugging and re-seating the RCAs from the turntable returns everything to normal.

Does this sound like a grounding problem? It seems to deteriorate over time.

McQuaide 24th March 2013 07:33 PM

The noise is back with a vengeance today no matter what's grounded or not grounded. I measured it and it's up to 3.7 VAC coming out of one channel and .5VAC from the other of pure static.

I took voltage readings and here they are:

R33: -24 -24
R4: 23.5 23.5
Across R6: 1.6 1.8
R6-Q4: 19.8 19.8
R9-R7: 19.5 19.5
R8-R10: 9.6 9.5
Q3-Q7: 8.9 8.9
R11-Q3: 14.4 14.5
R24-Q9: .27 .26
Q10-R28: 22.9 22.8
R28-C24: -24 -24
R25-R27: -22.2 -22.2
R29-Q11: -22.9 -22.9
R6-Q4: 19.8 19.8

Touching the bare signal connections inside the unit kills the noise temporarily.

bnorrish 24th March 2013 08:22 PM

Possibly a component on the ground plane is not properly soldered, especially one of the caps? Also check the input and output hookup soldering on the board. I had noise on one channel. I found I had a couple bad solder joints on a few caps on the ground plane, plus the input ground solder point on board was bad.


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