Jcm 2000 tsl....

[leftykingv2]

I was wondering if any of you guys know anything about this Marshall amp. I bought it from a friend dirt cheap last year and it doesn't seem to have the huge thick distorted sound it had when I got it. I know the pre-amp tubes may be going bad but my question is does anyone know if this model is self biasing or if it has to be biased manually. Any help would be greatly appreciated. Thanks guys.

[warlok]

http://www.marshallheads.com/viewtopic.php?f=8&t=5 Needs to be biased but looks real easy. I've never done it, as my MTS amps are the easiest biasing amps in the world.. But there's the process..

[leftykingv2]

http://www.marshallheads.com/viewtopic.php?f=8&t=5 Needs to be biased but looks real easy. I've never done it, as my MTS amps are the easiest biasing amps in the world.. But there's the process..

Thanks bro!! Doesn't look very difficult at all.

[DonP]

Preamp tubes don't need to be manually biased, only the power tubes. And pre-amp tubes last way longer than power tubes because they don't work as hard.

I'm curious as to what the problem is with your TSL100. You say it used to sound good but doesn't any more? Did you change speakers? Check to male sure the speaker load matches the amp setting in ohms.

I love my DSL100 but I've often heard people say DSL's sound better than TSL's. But I really would like to have separate EQ's for each channel like the TSL has.

[leftykingv2]

My impedance is good bro and with the way I drive amps I've always burned out pre-amp tubes before power tubes. It still sounds good it just seems to not have that really thick distorted sound it used to when I got it. I know the power tubes are good because when they go bad the clean channel of the amp starts to break up. The clean channel is still crystal clear this is why I am thinking it's the pre-amp tubes. If pre amp tubes don't need biasing I can just pop some new JJ ECC83's in there and see if that does the trick.

[VitaminG]

the tubes may not be bad. Your bias might have drifted. If one or more of the PTs are out of bias, your amp will sound less than optimal

[leftykingv2]

the tubes may not be bad. Your bias might have drifted. If one or more of the PTs are out of bias, your amp will sound less than optimal

I guess I am just going to have to pay my tech. the $35.00 dollar bench charge before I buy any parts. If the bias drifted he can fix it for the bench charge and it'll be all good afterward. Thank you bro! I totally forgot that this may be a factor.

[Hellbat]

Buy one 12ax7. Swap it in to each pre tube position to see if it helps. Or buy a set. I keep a spare full set of three 12ax7's kicking around for my amp. They are pretty cheap relatively speaking.

If you have another tube amp kicking around that you know is good, borrow a 12ax7 from it to try.

[leftykingv2]

Buy one 12ax7. Swap it in to each pre tube position to see if it helps. Or buy a set. I keep a spare full set of three 12ax7's kicking around for my amp. They are pretty cheap relatively speaking.

If you have another tube amp kicking around that you know is good, borrow a 12ax7 from it to try.

I have like 6 other heads here why the hell didn't I think of that!:think:

[leftykingv2]

Here I am once again proving the fact that having a Masters Degree doesn't mean you're smart.

[ulijdavid]

Lefty,
Here is a link to bias the Marshall TSLs. I used this on my TSL60 - very easy. The TSL60 has a nice set-up for easy biasing. I don't know if the TSL100 has the same features. Check out the video. They used to have a number to call for extra help. It has been around three years, but anyway.....

http://www.eurotubes.com/eurotubes-M...Bias-Video.htm

[Hellbat]

My job is troubleshooting. My brain goes for the cheapest, quickest fix every time. Then you escalate the effort and expense from there to resolve the problem if the easy stuff doesn't work.

[leftykingv2]

Lefty,
Here is a link to bias the Marshall TSLs. I used this on my TSL60 - very easy. The TSL60 has a nice set-up for easy biasing. I don't know if the TSL100 has the same features. Check out the video. They used to have a number to call for extra help. It has been around three years, but anyway.....

http://www.eurotubes.com/eurotubes-M...Bias-Video.htm

Thanks bro! And may I say you build some beautiful guitars man!

[leftykingv2]

My job is troubleshooting. My brain goes for the cheapest, quickest fix every time. Then you escalate the effort and expense from there to resolve the problem if the easy stuff doesn't work.

Thanks for the input bro. I am going to pull a couple tubes that I know are good from another amp and give your idea a shot.

[AdRock]

Here I am once again proving the fact that having a Masters Degree doesn't mean you're smart.

Unless your Masters is in "How To Miss The Obvious"

LOL, sorry man, had to do it.