Marshall TSL problem

sarahn11

Hello All,

Wondering if i can get some Advice/Info from you all.

Recently started jamming with a band again, it was great to finally get some use out of my TSL. so i was testing out a new pedal i bought yesterday and i heard the amp crackle. i thought it was the guitar lead as it was a particularly old crappy one. i taped it back up and it was fine for a while. today i turned it on and was playing for ~15mins when it started to intermittently crackle and pop, i looked over at the tubes and two of the power amp tubes were glowing significantly brighter then the other two. then all of a sudden the power dies on the amp.

first thing i check is the mains fuse, which is blackened and obviously blown. The other Fuse is still intact.

ok, so im wondering if i have done more damage that just a fuse? Bias needs adjusting perhaps? the tubes are relatively new, less than 100 total hours.(no blackened bits on the tube housing)the amp hasnt been used really in ~18months (ive been away) have played it a few times since ive been back, maybe 2hours total?

so,Where would i get a fuse to replace the blown one?
is it safe to replace the fuse and test the amp? if it were the bias or tubes would it do more damage?
anyone know a tech who could take a look for me thats not going to end up costing me a fortune?

Thanks for any help you can give me

Paolo_M

There could a few things at play here.

The check you can do yourself is to remove the power valves and replace the fuse like for like. You can get these fuses in any electrical suppliers.
The important thing is to get the right amperage and blow charactoristic.
If it's a TSL 100 then you need a 2 amp, slo-blo type and I think it's 22mm glass type IIRC.
If the fuse does not blow then the valves are the problem and you need to get a new set.
Hopefully it is this simple.

However, the DSL/TSLs are quite finicy (sp) amps and are prone to all sorts of problems.
A known TSL issue is bias drift. This will cause valve redplating (which is what you were witnessing with the glowing valves), fuses blowing. If you're lucky that's all that will happen, but further damage may be done.

Even if the problem is resolved by a simple valve replacement I'd be inclined to advise you to take it to a tech anyway just to have it checked over.

Where you based, for amp tech recommendations?

sarahn11

im in Arklow Wicklow, But travel to waterford once a week.

will get a new fuse tomorrow morning and test it out, but wont be able to get new valves just yet, no money and would have to order them online. would it be safe to just test that out? although it probably wouldnt make much difference as the fuse blew for a reason...

i would change the valves myself, but ide rathe give it to a tech as it has been laying up for quite a while

Thanks

Paolo_M

sarahn11 wrote: »

im in Arklow Wicklow, But travel to waterford once a week.

will get a new fuse tomorrow morning and test it out, but wont be able to get new valves just yet, no money and would have to order them online. would it be safe to just test that out? although it probably wouldnt make much difference as the fuse blew for a reason...

i would change the valves myself, but ide rathe give it to a tech as it has been laying up for quite a while

Thanks

It's perfectly safe to remove the valves, replace the fuse and power the amp up. If the fuse stays fine then a faulty power valve(s) is the most likley cause of the problem.
I think you're right to get the amp checked out anyway.
Don't know wicklow, maybe some of the other lads can help you with a tech recommendation.

sarahn11

thanks for the advice. am off to get a new fuse for it now.

Inquired in a shop in waterford this morning, they were less than helpful i have to say!! i was hard pushed to get eye contact out of any of the guys working there, but thats another story!

if anyone knows of a tech near wicklow/south dublin area who could take a look at it that would be great!

sarahn11

UPDATE: ok, i tried the new fuse. Removed Valves, replaced fuse, plugged in, power on, off standby. The fuse didnt blow and power was flowing thru the amp.

when i went to plug the amp in i noticed the socket (its a really old one) was alot more dodgy than i thought it was (blackened bits) . i plugged it into the other socket (a newer one) and it was working fine. Perhaps it was some sort of damage from the socket? the mains fuse in the house didnt trip so its doubtful....

Paolo_M

sarahn11 wrote: »

UPDATE: ok, i tried the new fuse. Removed Valves, replaced fuse, plugged in, power on, off standby. The fuse didnt blow and power was flowing thru the amp.

when i went to plug the amp in i noticed the socket (its a really old one) was alot more dodgy than i thought it was (blackened bits) . i plugged it into the other socket (a newer one) and it was working fine. Perhaps it was some sort of damage from the socket? the mains fuse in the house didnt trip so its doubtful....

The mains fuse/MCB will most likely be a pretty high value like 30amp. Individual plug sockets tend to be around 5 - 13amps, all of which would allow significant damage be done to the amp before blowing. That's why each amp contains it's own internal 1/2/3 amp mains fuse.
Problems from the mains side would not usually cause damage to the device itself, unless it experienced a surge like from lightening or something.
Hopefully it's just a matter of a new set of power valves, a quick once over from a tech and you'll be rocking again.

dermo909

I know that shop in waterford you speak of, my marshall jvm is in getting looked at also. Their amp tech seems a bit hard to get hold of and only comes into the shop when he feels like it. I need new power valves for the marshall(all 4 weirdly) and the marshall distributor was out of stock for the next couple of weeks. I offered to buy them elsewhere so they phoned another supplier. I should have it back next week all going well.
They're usually pretty good in that shop, maybe you caught them on a bad day.

sarahn11

Dermo@ dont suppose you have the Techs number by any chance? im finding it very hard to find someone around here. Also if you dont mind me asking, how much is it going to run you??

Im looking at These as replacements. i dont want anything too high gain, just something with a nice growl!

dermo909

I dont have the techs number, I've done all my dealing with the shop. I think the tech is in the shop today(monday) so hopefully he'll fix it today.

I dont know much about valves really but I've heard good things about sovtek valves.

Eoin Madsen

sarahn11 wrote: »

Im looking at These as replacements. i dont want anything too high gain, just something with a nice growl!

I wouldn't get Sovteks, tbh. Try and get some JJs from one of the valve shops.

I can vouch for these:
http://www.tube-town.net/
http://thetubestore.com/
http://www.watfordvalves.co.uk

As regards to high gain or not, that's not something which the EL34 power stage valves are going to have a huge impact on. The combination of 12AX7/ECC83 preamp valves are what will affect that.

sarahn11

Cheers Eoin for that

Dermo - Did you get your amp back? how was the service?

dermo909

sarahn11 wrote: »

Cheers Eoin for that

Dermo - Did you get your amp back? how was the service?

Just called them and the amp is back working again. Just needed some new valves. Picking it up tmro morning.
Service was fine, the delays were due to the tech not coming in and waiting for the new valves to arrive.

joeduggan

sarahn11 wrote: »

thanks for the advice. am off to get a new fuse for it now.

Inquired in a shop in waterford this morning, they were less than helpful i have to say!! i was hard pushed to get eye contact out of any of the guys working there, but thats another story!

if anyone knows of a tech near wicklow/south dublin area who could take a look at it that would be great!

i know the shop u are on about as its the only one in waterford. i wouldnt buy so much as a plectrum from them. ive probably been in there twenty times and i havent once, found them helpful. the shop is full of egos.