marshall tsl bias and hum problem

[tleach284]

Marshall TSL Board

I've been dealing with the same issues on my TSL100 for a long time. I love this amp but the thing is out of control. It's gotten so bad I have a multimeter fixed on it to check the bias. Some days are fine, some days are totally out of control..

I've done so much tweaking on the board I'm fed up with it.. I live in Holland and I'm clueless on how to get a board. The Marshall website states in the FAQ that they don't sell parts directly to users, only official techs which aren't any around here.

Can someone PLEASE help me get this board, I don't need warranty on the board and the warrenty on my TSL (1998!) is long gone..

Any help would be very much appreciated.

Sander

Hello I can help you I replaced my board not to long ago I have a TSL 212 Made in 2000 Here is a phone # you can call and these guys will take care of you and get you the parts you need. Also they can have you try a few thing before they sale you a board wonderful people to work with. The Name of the company is : Uk Amp Spares Talk with ERIC SNOWBALL and the price was cheaper than buying in the USA even with shipping. I have the old board and it still work fine but I play alot so I upgraded to the new style.
2 Upper Fant Road .
Maidstone
Kent
ME168DN
United Kingdom
Phone: 01622|673355
Fax: 01622-200010
Email: guy@esemusic.com

[trem]

Just about any other product in the world, and this would be a re-call. Marshall should be shipping these boards for free. I did TWO of these. Each time I ordered the board, Marshall refused to admit there was a problem. I'm glad Marshall does not manufacture automobiles......
Best

[Jazz P Bass]

The really sad part is that "Marshall" probably did not even "do" the board.
It was sublet out, to who knows where.
Some yahoo got the etching wrong or used inferior pcb board material.
This is where quality control comes into play.
You cannot assume anything, even if you do have total control of the process.
Reminds me of those faulty caps back in the late 90's.

[philh27]

Hey guys. Another newbie here with a similar problem with a similarly aged TSL122, except that the amp has just been back to Marshall with the following repairs/ mods being completed: Power PCB replaced. New reverb unit. Dry joints on rear PCB resoldered. New output valves/ tubes fitted and biased. All done free of charge.

Great news, except that the amp STILL hums. 'Possibly' not quite as badly, but in truth I'm not sure whether I'm simply wanting it to sound quieter.

I have a few questions/ would appreciate some opinions.

Firstly, is the 'Power PCB' the same as the Motherboard/ Mainboard? I assume that it is, but I'd like to make sure, as from reading this an other forums, the 'Motherboard' on older TSL's does appear to be the main issue.

As I said the amp hums, but it hummed from new. It hums without anything plugged into it and it hums on all channels. To be fair when you're playing you can't hear the hum and it doesn't really get much louder as you turn the volume up. It's slightly worse when the effects loops is used, but as I said it's there all the time. So for those who have/ have had a TSL122, can you tell me if a level of hum part of the deal? Again I stress that it's 'hum' rather than buzz and is nothing to do with cables, single coil pick ups etc. You can hear the hum inside the amp.

Curiously, if I use the recording output, with the speakers muted, there's barely any hum output to my recorder. Are the close proximity of the tubes/ PCBs to the speakers part of the problem? I've used Marshalls for years, but always heads and sperate speakers. I got this amp as I wanted something more portable.

Marshall didn't replace the pre-amp valves, so I'll obviously try that.

Any help or advic would be appreciated, as I'm very frustrated with it. I've always loved the tone and versatility of the amp, but I just want to enjoy playing through it and not have to constantly assess the noise levels etc.

Cheers.