Marshall TSL100/1960A ... Buzz !!! Plz Help..

[CJ2RIDE]

Hello , I have a "New" (10 hrs) Marshall TSL100/1960a Half Stack . This thing was a "tone monster" and sounded sweet for awhile and then one day I turned it on and when I hit my low E string , it sounded like a bad radio station (static buzz). It gets worse as the vibrations peak and then it fizzles out. It also seems to have a volume fluctuation when it get bad. At other times it works fine. I have only had it on 100watt channel once just to see how it sounded, but in a one bedroom apartment , you know I didn't get too far ! LOL...Normally I play it on 25watt channel for 45min at a time. I always let the tubes heat up and cool down for at least 5 mins. I have had this amp a year now and like I said I don't play it much . I have used three different guitars including a New $3200 Jackson Custom shop , so its not the pickups or fret buzz. Could this be a bad tube noise and when should I replace them ? Would it have anything to do with the electricity in wall outlets ? Any Advice would be helpful ! Thank you Very Much...... CJ

[Amp Kat]

Sounds like a bad preamp tube so try swapping the 12AX7's one by one and see if it clears it up. Could be a connection problem too on the pcb board. Process of elimination first.

[Peter Clothier]

You say that you have owned this rig for a year now. The real question with a TSL is, when was it made? There should be a label on the rear of the head which indicates the manufacturing date. There are a number of mods and enhancements which are needed to get a TSL to perform reliably depending on when it was made. This can be done quite easily providing it is a post 2000 model. Suffice as to say. If your rig is using the stock original valves then these may need to be changed. Before you do though, I suggest that you have it properly checked over first. If you're not familiar with the safety issues regarding tube technology, then leave it in the hands of someone who does.
If you need further assistance..... let me know.


Peter.

[CJ2RIDE]

Marshall Buzz !

Thanks Peter for your help ! This amp has a 2005 date code. I turned it on the other day and I could not make it buzz. After I was done jammin I heard it a little bit. It Really sounds like a bad jack or solder joint but I don't know why it only does it sometimes. When it does act up it seems there is a volume loss. I must send to Korg for warranty, I just can't beleive that after 10 hrs of use its already down and out. Doesn't souund like "Marshall Standards" to me. Not for $2500...Oh Well.... Thx again !

[Amp Kat]

Doesn't souund like "Marshall Standards" to me. Not for $2500...Oh Well.... Thx again !

Those Marshall standards of the old days are long gone I'm afraid to say. The new standard is called cheap at the same price and the shabby labor that goes with it. PCB 's are done thru a wave machine and thru hole parts added after and I've seen some real bad looking stuff and some not so bad. I would almost bet that yours has a loose solder joint and when you move it or it vibrates a certain way you hear it.

[CJ2RIDE]

Thanks Kat ! I have now discovered that when I wiggle the cable in the Input Jack , the Buzz /Crackle cuts in and out. Would you say that was a bad solder joint on the jack and how hard is it to get to ?

[Amp Kat]

You'll have to take all of the knobs and nuts off of the pots. Then pull any screws and jack nuts holding the board in. Pull the board out and solder the jack back to the solder pads and put it back in. If it's a single board those are harder because you have to remove wires and mark them where they go if they hopefully have connectors which Marshalls generally do. Weigh it out and if you think you can do it it would save lots of time as when you get it back may be six months down the line. Now if you lived in England it would be a week.

[CJ2RIDE]

Marshall Buzz/volume drop !

I have now discovered that my volume has dropped quite a bit even when the buzz is not happening . I read what Enzo said to eonblue about plugging guitar in to effects return. In doing that , it now sounds great ! That tells me problem is in Pre-amp , correct ? How come it sometimes sounds fine and other times this fluctuation ? The 100 watt channel sounds like a 15w amp ! Can barely hear the 25w channel . Thx

[Peter Clothier]

Oh dear.
These TSL's are such a bitch (but I luv em)
OK.... There are 2 preamp valves before the effects loop. So check them out first. If you haven't got spare valves then get/ beg some from somewhere.
If that fails then you'll have to open her up again and go over the mother board around the valves with your soldering iron looking for dry joints
Finally, Marshall use really shit quality BR62 6A bridge rectifiers.
Russian 12ax7 valves can draw 2/3 less heater current than a decent Ecc83. So if you have changed your preamp valves then you have probably introduced a little extra loading on the preamp BR.
Dump the BR62 regardless. Replace with a decent 10A+ substitute.

Make sure all the 1/4" tab / recepticle connection that this model is plagued with are all firm and tight.

Rock-on

Peter.

[SG standard]

more tsl whoas....

hello,

i joined today in hopes of finding some solutions to my marshall whoas. everything so far has been pretty helpful as far as tips go but i haven't tried them yet. my setup is a jcm 2000 tsl 100 head on a 1960a cab. i run my pedal board which consists of a podxt live and various other stomp boxes right into the input on the front. i play on the 100 watt channel always unless in a really small venue. and i play on average 3 gigs a week. when i engage the crunch or lead channels there is a loud hiss or hum but playing drowns it out. the clean channel is very quiet until recently. the other night at a gig, the hum on the lead and crunch channels seemed to be louder than usual and when i selected a particular patch in my pod that was set to a rat some noise gate and some delay. which is usuall extremely quiet played through the clean channel was noisy as if i had one of the overdrive channels selected. other pedals on my board were fine though. does this sound like a bad tube or another problem. i am an experienced electronic tech but i am new to tubes and tube amps. i know its not my sg or my les paul they are fine through other amps. if it is a tube can i just change it out or should i do the whole byass thing and if so where can i find a guide for that seeing as how i have never performed a bias adjustment.

any help is much appreciated.

SG standard

[Peter Clothier]

Patrick,
Could it be that on that night you had a lot of Flourescent or other discharge lighting nearby? At some of my gigs we do get plagued with it occasionally.

Try it without any FX pedals. What's it like then?

It's normal to expect lead and crunch to be a little hissier than clean but not much.
You might try inspecting the input socket first for dry joints.

Good luck.

Pete.