Valentine Smith

Hi,

Here's a heart warming story! 17 years ago I bought a new SL-X 2500 and then a few years later had to sell it. Well I've just got it back again.

It has all the original valves (EL34 's for output) and I know that it's not been played much in the 15 years it wasn't mine. But now it's got some problems.

Here's the symptoms:

Both the master volume knobs are noisy and eratic. I'll put one on 2 and nothing and then it'll suddenly go really loud and then fade away again after a while. The other channel seems less eratic but is much quieter at the same number.

The pre amp knobs are similar but not quite as erratic. All of them crackle when I move them. The EQ knobs do not crackle and seem ok.

The first thing I was going to do was try cleaning them. How do I do this? Do I squirt in the cleaner (not WD40, I know) from the front or do I have to take the chasis out?

But I might just go ahead and put in new EL34 valves anyway. What do you think?

Adrian R

Hey Dude..

Definetly sounds like dirty pots. Get some contact cleaner at Radio Shack, remove the chassis from the amp and clean the pots and all contact points with the cleaner. Obviously make sure the amp is unplugged of course, and after you are done cleaning the pots and jacks let the amp 'dry' for a spell to eliminate any chance of a short circuit. You have to clean the pots from behind..there is a small slot in them if you look closely in where you can spray in the cleaner.

Might as well replace the tubes too while you are at it. Tubes are cheap..but the good tone that comes from fresh tubes and clean contact points is priceless! Also be sure to clean the tube sockets as well with the cleaner before you install the tubes. Just spray the pins on the tube you wish to insert with the cleaner and work the tube in and out a few times.

I've restored many old, neglected Marshalls and usually this all they need..and they sound brand new again...

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steelhorse

+1

A good contact cleaner w/lube like a DeOxit D5 works great fwiw.

Good luck!

I had a similar experience a few years ago when I wound up getting a PV Triumph combo back and it was flucked up. Looks wise she was still the bomb but she had become one by being with someone else and neglected.

I re-tubed, capped, changed a couple fried resistors, and the fuse in the ftsw, cleaned the pots, sockets etc., and she was a thing of beauty so much so that a guy from a band I know liked her so much he traded a head for it and I had to throw in a modded DS-1.....

for a pristine JCM900 SLX-2100!

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theflyingmat

Sounds just like my SLX before I put it in for a service. Hope to get it back next week all going well.

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Sir Don

Make sure you hang on to it this time!

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gtrman

Just had my SL-X in for service and retube/bias. The pots were as noisy as any amp i've ever owned.
Much better now and I'm definetly keeping mine ....

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Valentine Smith

Many thanks for the advice!

I've left it unplugged last night so I'll get started when I get in tonight. If I don't post again you know what happened. I do have a grounding in electrics but it's just a phase I was going through

I'll definately hold on to it this time. After twenty years I finally got good enough to appreciate it. But damn it was loud last night when I was trying it out, when it decided to jump to loud mode. I don't know what level it was jumping up to 'cos I couldn't trust the numbers but I had it set to 2. I had the guitar vol down to 2-3 so I thought lets put it up to 10 on the guitar and get some crunch but I couldn't get to ten and hit the strings without risking a Michael J Fox in Back to the Future.

Now I need to get some EL34's. The choice here Lisbon Portugal, is pretty limited, I've seen Electro Harmonix or PM. Can't buy from the states 'cos I get hit for import tax. I can buy from the UK and get them mailed but I'm not sure where to get them from.

I'll let you know how I get on. Thanks again.

Valentine Smith

I'm alive!!

Chassis out.
I've got hold of some crocodile clips with a resistor wired between them so tonight it's filter cap draining, switch & tube socket spraying, reasembly and playing.

Thank god for forums like this and youtube eh!

Now, what can I can I call my amp repair shop?

Valentine Smith

All done. Just plugged it in and it's as good as new. Thanks guys. I didn't change the tubes just the switch clean.

I did what I read here on the forum and put my MXR 10 EQ in the loop and it sounds great. I think I might get one of the Boss Fender 63 Reverb pedals to go in there too and i'll be sorted.