Damn it - Black Pearl Issues!! Can anyone help?

[ICBM]

You should use matched pairs unless you know the amp has separate, not a single common, cathode resistors. (I don't know.)

It does sound like it might be the rectifier - but if the new one fixes it, don't throw out the old one just yet - it could be simply caused by a bad contact between the socket and the valve pin, in which case it may just need the socket re-tensioning. Some modern valves have slightly undersized pins which can cause trouble like this.

[DrumAl]

GenzBenzBlackPearl005.jpg

I've no idea about seperate cathode resistors etc. but this picture does seem to show a resistor in line with each power tube socket input. (The power tubes are on the upper board in that pic along with the phase invertor and rectifier, apologies if you've already worked that out!)

I'll check the socket once the new one arrives, if that fixes it of course!

Cheers mate.

[thebeagle]

Black Pearl Issue?

[DrumAl]

Black Pearl Issue?

Arrrrrrrrrrrrrrrr Jim lad........:-)

[ICBM]

GenzBenzBlackPearl005.jpg

I've no idea about seperate cathode resistors etc. but this picture does seem to show a resistor in line with each power tube socket input. (The power tubes are on the upper board in that pic along with the phase invertor and rectifier, apologies if you've already worked that out!)

I'd guess the cathode resistors are the two large white 5W100R ones at the top of the board, in which case it's common resistors (one per pair), for the 15W and 30W settings. Those are the size/value I would expect and they appear to be paralleled with caps, which would be correct too.

Best to use at least reasonably well-matched valves.

[Dave_Mc]

just to point out- if the rectifier doesn't sort it (hopefully it will) you can always just send it back to GAK- they were very good in sorting out my problems, very quick and very apologetic (and they covered all postage costs and picked the things up at my house). Though- I just checked GAK earlier and they're not listing the Black Pearl 2x12 combo as being on their site any more, so if you wanted another one you'd probably want to check with them. Maybe if you got a tech to look at it they'd cover the repair cost or something like that.

[DrumAl]

Cheers ICBM, I'll stick to at least matched pairs then.

[DrumAl]

just to point out- if the rectifier doesn't sort it (hopefully it will) you can always just send it back to GAK- they were very good in sorting out my problems, very quick and very apologetic (and they covered all postage costs and picked the things up at my house). Though- I just checked GAK earlier and they're not listing the Black Pearl 2x12 combo as being on their site any more, so if you wanted another one you'd probably want to check with them. Maybe if you got a tech to look at it they'd cover the repair cost or something like that.

Hi Dave,

I'm hoping that they'd sort something out for me if needs be, they've been pretty helpful thus far anyway. I'd sooner keep the amp so hopefully something can be arranged!

[Dave_Mc]

yeah, I mean obviously it's nice to know you can get a refund if the worst case scenario arises, but that's of little consolation if you want to keep the thing!

Fingers crossed it's the rectifier. For me as much as for you, lol, I don't want to hear about any more dodgy ones in case I start to second guess keeping mine! Which I don't really want to do, I'm starting to like it.

But seriously though, hope you get it sorted. It's no fun when these things go wrong.

[DrumAl]

Cheers Dave, between us we've had some right dramas with these!!

Another quick question for all you techy types, would leaving the amp in a conservatory have any negative effect on the valves? I was just wondering if the colder temperatures in there would leave them prone to failing or are they not really susceptible to thermal changes?

Cheers!