Is it time my Marshall had an overhaul?

[Rich_T]

It sounds good to my ears, but as far as I know it hasn't been looked at in 27 years since it came off the production line. Jeremy mentioned in another thread that filter caps need replacing every 20 odd years, so I guess I would be due for some? I know it needs a re-tube, I'm getting round to that. Any suggestions for tubes?

For those who dont know, its a Marshall JMP 2204 50 watt master volume.

Thanks! Rich

 

[75lespaul]

Re: Is it time my Marshall had an overhaul?

I wouldn't even play it again until the caps have been changed. Keep the originals in case you ever sell it, but don't use them! If one explodes you could ruin the whole amp. I love the Groove Tubes 12AX7-M Mullard reissue preamp tubes, if you can get a set that isn't microphonic. The JJ power tubes are also a great option.

 

[Rich_T]

Re: Is it time my Marshall had an overhaul?

I wouldn't even play it again until the caps have been changed. Keep the originals in case you ever sell it, but don't use them! If one explodes you could ruin the whole amp.

Blimey, didn't realise it was that serious. Better look for a tech then!

 

[Luke Duke]

Re: Is it time my Marshall had an overhaul?

Filter caps ARE a big deal, but if an amp has been used regularly then it's really just a matter of degrading tonal quality until the amp doesn't work. The ones that explode are "normally" closet pieces that go straight into heavy gigging.

In my 81 JMP I really dig the Mullard RI EL34s.

Luke

 

[ponch]

Re: Is it time my Marshall had an overhaul?

He he! I like the way that electro harmonix sound. My Brother has them in his bassman, and they rip.

 

[Dr.Mavashi]

Re: Is it time my Marshall had an overhaul?

I dont know about caps, but I've just had Pots and Jacks done with ohs selector replacement and re-biased for E34Ls. Do I motice anything different in the sesitivit of EQ knobs? not really but the amp does sound a bit ..... stronger ? my its all placibo though. But if you want your ohms selectors and jacks and pots to work you should take it couple of years for cleaning from what I've learned. JMP '80 huh? NICE back then Marshall cared about build quality ....

 

[75lespaul]

Re: Is it time my Marshall had an overhaul?

Filter caps ARE a big deal, but if an amp has been used regularly then it's really just a matter of degrading tonal quality until the amp doesn't work. The ones that explode are "normally" closet pieces that go straight into heavy gigging.

In my 81 JMP I really dig the Mullard RI EL34s.

Luke

Yes, those are the ones more likely to explode, but at 27 years I'm sure they're subject to failure. They may not pop, but why chance it. And yeah, I totally forgot about the Mullard RI EL34s. I've got them in my Silver Jubilee and they are outstanding. Great save Luke Duke!

 

[Ascension]

Re: Is it time my Marshall had an overhaul?

First off if there are no issues with hum or the like why do a re-cap job??
Now a re-tube thats a different story that amp is WAY overdue for a retube.
On the tubes for a Marshall they seem to really like the SED El34's that is the old Svetlana winged C. JJ EL34L's IMO don't sound right in a Marshall they are to "hard" and harsh.
On the pre amp Marshalls seem to love the Chinese Shunguang 12AX7's.
On the Mullard GT-12AX7 M's I have had big problems with all of those I have had. They sound great if you can find a good one but long term reliabilty is non exsistant.
Try this guy I have had great service from Doug over the years http://www.dougstubes.com/ .

 

[Gearjoneser]

Re: Is it time my Marshall had an overhaul?

Yeah, I'd just leave the components alone until you hear popping or humming.

Svetlana or JJ power tubes and Chinese Shuguang 12AX7's get my vote. If you don't mind paying more, the Tungsol pres are great too.

 

[Rich_T]

Re: Is it time my Marshall had an overhaul?

First off if there are no issues with hum or the like why do a re-cap job??
Now a re-tube thats a different story that amp is WAY overdue for a retube.

The tubes are only about 2 years old, they are the only thing that has been replaced from time to time, but it gets pretty heavy use, so they are overdue. Cheers for the suggestions guys.

I do have some minor pops and hum from her, but I've never been sure whether that is my over the top pedal board that needs maintenance or the amp itself.

 

[Forbes]

Re: Is it time my Marshall had an overhaul?

I'm in the same position, i'm running an 84' 800 and have no idea if any of this stuff has ever been looked at. I've owned it a few years but never got round to/been bothered to change tubes, and it does get a fair few hours of cranked play every week.

I'm guessing you will get yours looked at in Birmingham Rich? Mines in Bristol as am i at the moment so i guess i'll find somewhere here to have a look at it, plus i'm not sure how much i trust cheltenhams guitar shops...

How much should we be paying for a good over-haul, changing everything that tends to go over time? Mines a 50watt 2x12 combo if that helps.

 

[Rich_T]

Re: Is it time my Marshall had an overhaul?

I know Aroundabout Sound doesn't do electronics, just guitar repair, the only other guy I would trust would be someone John at Vintage Strings recommends, but that place is never open, so I'm not sure about the reliability there.

I've had a recommendation of a man who really knows his Marshalls up here in Birmingham at a place called Pacific Audio, so I'll give them a try.

As for Bristol, here is a recommendation from the Basschat forums:

"I use Soundburn Audio in Bristol (0117 9555766) - a one man outfit but he seems to be able to fix anything. Plus, he doesn't charge you 20 quid just to look at your amp."

Also, I know forum bro Octavedoctor does guitar repair at the Bristol Sound Control,he might be worth dropping a PM to, may well know some good Bristol based amp techs.