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I have been given a JTM60 1x12 combo, one of these things:

NB: Pic copyright someone .

It had a curious fault; cold, it was fine, but as it warmed up it got to the point where every time you struck a chord the sound would fizzle out; if left for a few seconds it would return. The owner, who has a good deal of money, decided he didn't need a 60W amp as he only plays at home, so went out and bought "a practice amp". He works with my son and mentioned that he had this broken gutar amp he was getting rid of, so my son baggsied it for me.

I noticed one of the preamp tubes was not fully home in the socket. I pushed it in and now the amp seems fine.

Now tell me how good/bad they are..... I find the tone controls aren't as effective as I'd like them to be.

They sound great, as you have experienced they can suffer from issues when overheated.

You may need to reflow the joints around the rectifier.

And he just gave it to you? Brilliant!

A friend of mine tried to sell me the 30 watt version, was nice but not loud enough for my band at the time. He installed a new transformer and fan assembly to keep it cool. Apparently the (output?) transformer gets super hot and can cause some problems.

You are a lucky man! I have a JTM 30 with 12 inch speaker and its my main amp. I bought mine new and so far have had no issues with it. It honestly has the best clean Marshall I have ever heard. Supposedly Marshall was trying to create a Fender like clean amp and they really succeeded. The overdrive channel is warm and vintage sounding Marshall. The knobs are not very sensitive when using tone controls, but in some ways it's not a bad thing. The reverb is not very "Fenderish", but it keeps the tone from being flat. I use a EHX Holy Stain for more defined Reverb. It has an emulated output in the back that is great for recording. I send mine out to a Digidesign MBox so I can record or turn the volume off on the amp and practice with my headphones. It has a separate volume for each channel along with the master volume. It handles pedals really well into the front of the amp and also has an FX loop. I just saw a JTM60 with extension cab go on ebay for $500.

For a complete overview check out: http://www.drtube.com/marshall.htm

Known Issues
Overheating: Lots of people complain about these amps over heating. I have my amp on a tilted amp stand and I have had no problems. Some people have actually drilled holes or attached external fans to keep it cool.

General quality issues: Mine has been awesome, but have been some general quality issues with reverb and other components.

Drop me a line if you have any additional questions. I am definitely jealous. The JTM 60 has full tone controls for both channels where mine has Volume and gain for the OD channel.

taylornutt wrote:For a complete overview check out: http://www.drtube.com/marshall.htm

Hey, thanks for reminding me, I've picked up the user guide and schematics.

and he also wrote:Known Issues
Overheating: Lots of people complain about these amps over heating. I have my amp on a tilted amp stand and I have had no problems. Some people have actually drilled holes or attached external fans to keep it cool.

I was just reading about that. I might strap a fan on mine. There's a suggestion that just standing the chassis off the top by a fraction of an inch will stop the internal components baking, so I've just done that.

Thom wrote:And he just gave it to you? Brilliant!

Yes. I feel a bit guilty since all it seems to have needed was the valve re-seating, I think I should give the guy something for it. It came complete with boxed footswitch, too.

I have nothing other to say in this thread than: hello Nick.

benecol wrote:I have nothing other to say in this thread than: hello Nick.

Hello Tim. Yeah, I've been a bit quiet as I'm working in London again leaving the house at 6:55, getting in at 18:45 and no Internet access at work. Half term this week and I'm under the weather. Koff, koff, wheeze, sneeze.

definatly jealous of that amp. Nickd's JTM sounded amazing at doogfest. Definatly something i want to look in to.

I thought about buying one that I saw on craigslist for super cheap, and read up on them and it seems that the output transformer is a common problem on those amps but if you fix that then they sound great and are really reliable.

Billy3000 wrote:I thought about buying one that I saw on craigslist for super cheap, and read up on them and it seems that the output transformer is a common problem on those amps but if you fix that then they sound great and are really reliable.

From my reading, output transformer issues may be related to poor connections or dodgy jack sockets.

Someone at TGP wrote:The most common faults on these (which could cause this problem) are: OT (including loose push-connects); speaker wiring (again including loose push-connects); speaker jack; the large resistors on the center board near the PT end.

It's worth replacing the incredibly poor quality speaker hookup cable and soldering all the speaker connections, whether or not you think it's the cause here; leave a little extra length and the zip-tie the cable to the underside of the tube cover to prevent it getting snagged and stressing the jack.

I have the 15 inch speaker version.

I bought it NOS for £250 about 4 years ago and it's been great, no issues so far, even being used solidly for 2.5 days at Doogfest.

NickD wrote:I have the 15 inch speaker version.

I bought it NOS for £250 about 4 years ago and it's been great, no issues so far, even being used solidly for 2.5 days at Doogfest.

Didn't know they made a 15" speaker. Got any picks?

NickD wrote:I have the 15 inch speaker version.

I bought it NOS for £250 about 4 years ago and it's been great, no issues so far, even being used solidly for 2.5 days at Doogfest.

i want it, sound fucking amazing!!!

It does have a silly little reverb tank. I'm considering upgrading it.

NickS wrote:It does have a silly little reverb tank. I'm considering upgrading it.

I wouldn't even call it is spring reverb. More like hologram reverb cause you can barely make out that it's there.