Help! Crest ca6 fuzzy channel

NickfromSOS · #1 09-07-2011, 06:45 PM

I have a crest ca6 and channel b sounds like a wind tunnel when I turn he amp on. Doesn't matter if volume s turned up or completely off. Same noise. It's not the speaker... I tried 3 different ones, and it's only channel b. Channel A is fine. Amp is in stereo mode. Not in bridged or parallel inputs. Any suggestions?

NickfromSOS · #2 09-08-2011, 08:44 AM

bump...

forgot to mention it's not the input cable either. It makes same noise with nothing connected to the input of channel B

bassgod0dmw · #3 09-08-2011, 08:47 AM

The amp itself emits the noise, or the noise comes from the speakers?

Jim Carr · #4 09-08-2011, 08:55 AM

Sorry to hear your CA6 is in distress. If it were me, I would get it in for service. These units often last forever, so a fix is probably not too hard.

Tber Ducatiman recommends these guys:

STEREO REPAIR WORLD
2 springbriar lane
kings park, ny 11754
phone 631-697-5850

see, long island (new york) amp repairs

projectMalamute · #5 09-08-2011, 08:56 AM

Those amps are totally modular. Swap the power amp modules. If the problem moves to the other side it's in the amp module, if it doesn't it's probably on the display/attenuator board.

If it's in the amp module you can swap the piggybacked preamp boards and see if the issue is in the output device/heatsink module or the preamp module.

Spares for all of these things are available from any Crest dealer or from Crest directly.

edit: I am assuming this is not one of the really, really old ones. Those are laid out a little different, the two preamp modules are on one board with the I/O connections in the back. You could still move the amp modules back and forth to trouble shoot but not the preamp modules. Also, you won't be able to get spare parts for one of those from Crest.

NickfromSOS · #6 09-09-2011, 03:33 PM

I did a little digging in the amp and i have more info...

It has a 1997 build date on it

I took a picture of the inside... The 4th (far right in the pic) blue cylinder in the pic is completely loose. Its still connected to the board but wiggles widly with the push of a finger. The other 3 are solid and tight. Im assuming thats where my problem lies. Can i fix myself? How much should it cost to repair in a shop?

Alex1984 · #7 09-09-2011, 04:22 PM

Those look like large capacitors, and I don't like touching them, especially if they have a specific polarity. I've seen some explode.

craig.p · #8 09-09-2011, 04:55 PM

The repair you asked about is trivial. New part cost approximately $20 wholesale, plus maybe 1 hour for removal and installation. Maybe around $80-100 total? But the big question is whether this is all that's wrong with the amp. If the power supply is common to both channels, then there's more trouble to be dug out, otherwise why would only one channel be noisy. If the power-supply filtering is done on a per-channel basis, however, then maybe the bad/loose cap really is the only thing wrong. First thing you should do is decide how much $$$ you're willing to throw at this thing, then tell your tech to estimate the repair, then compare the two numbers. You will have to pay a bench fee for the estimate. The other alternative is to silicone those caps in place to keep them immobile and use just the good channel. Regardless of what you do, the caps need to be supported in some fashion, either with silicone or brackets or whatever. The fact that they are not suggests -- to me anyway -- some lack of forethought.

bassgod0dmw · #9 09-09-2011, 05:05 PM

Quote:

Originally Posted by NickfromSOS

The 4th (far right in the pic) blue cylinder in the pic is completely loose.

Quote:

Can i fix myself?

General rule of thumb about electronics that can kill you: If you don't know what the part is question is called, let alone what it does, you have no business poking around in there trying to fix it.