Marshall JTM60?

[meandmyfriends]

Anyone have have an information or personal experience with these? From what i understand they are a 60 watt head or combo, with less gain the the jcm900, from the mid 90's. I have an opportunity to pick one up for cheap for my nephew for the holidays, but its a long ways away from me, and i would like to get some 3rd party information before i go.
My nephew plays blues/rock (cream,zeppelin,hendrix,allman bros.) and has been playing for about 7 years. He uses an epiphone explorer, a les paul standard faded, and a fender strat. his effects are kept to a minimum from what i understand. Do you know how well this amp would suit him.

 

[KITTENFACE]

stay away

 

[Twinfan]

For home use, it'll be fine.

For gigging etc they are notorioiusly unreliable. I had one, blew the output transformer, fixed it and flipped it. It sounded nice at first, but it's no tone monster. Decent enough for home practice though but they mush up and break when cranked. Speakers are average. They were reasonably priced when new for a reason.

 

[KITTENFACE]

I thought they sounded shrill and harsh - I owned one for as long as it took to sell it - I played another when guest playing with a house band and was sick with my sound

spend your money on something that he'll actually enjoy playing at home and anywhere else

 

[kevmoe]

:jim i have the jtm 60 combo with the ext cab. .. this line from marshall was plagued with design flaws,tubes mounted sideways ,transformer problems,overheating...i was lucky none of the above mentioned problems caused any greif to me..the el34 tubes gave it a nice growl,independent channels,decent reverb. master volume so ya got a decent sound at lower volumes..and pretty nice tone when ya cranked it up,sounded best dimed...nice look with the ext cab,retro mini stack..harmony central.com has a lot of other reviews of this amp id read them if i were you..as always best to hear for ya self...i have other amps fenders,peaveys glad i have this jtm too...good luck happy thanksgiving :salude

 

[Kage]

I gig through a JCM 600 which is a later version of this amp and I love the sound. From what I understand the biggest issue with this amp is heat as the tubes are horizonal under the main board. At bedroom volumes that shouldn't be an issue. Mine has the vents in the top and I haven't had a problem.

 

[led zep fan]

I have a JCM 602, heard all the horror stories, NEVER had any of the problems assoicated with it.

 

[lp20th]

I've got a JTM60 combo also. I bought it used about 5 years ago for $250. It was in mint condition, barely used at all. I practice weekly and gig about one to two times a month with it.

The issues that I have had with it are; the foot switch cable broke, I replaced it with a heavier duty cable, The footswitch jack became intermittent, I realigned the contacts on the jack and its been ok since, and the heater fuse would pop on occasion, I read a tip where someone said the fuse was undersized for the design (6.3 amps). I bumped this up to a 10 amps which will still pop with a short and have not had this issue since.

I have done the following mods; vented the top to head off the overheating issues, added a fan under the power tubes to suck away more heat again to head off any overheating issues, bypassed the diode clipping in the drive channel to give it all tube overdrive, replaced the stock speaker with a Scumback H75, replaced the power capacitors just for preventative maintenance and I've re-tubed twice to try to improve the tone.

Its a PWB design so its not the easiest amp to work on, the tube sockets are mounted directly to the PWB as well, so you need to be careful swapping tubes. Heat is definitely an issue by the nature of the layout, a vent as a minimum is good idea. If the amp was never vented and was used a lot I would check out the power capacitors because that’s where all the heat will sit and they will cook. The power caps are located right above the power tubes.

The amp has decent tone; I think it’s more suited for classic rock then for something that requires a lot of overdrive. People have complimented me on the tone I get out of it.

Someday when I have the extra money I would like to get a better amp but would probably keep this one as a backup. All in all not a bad amp just needs some extra attention.

 

[dwagar]

I have the JTM60 2-12 combo with the 2-12 ext cab. I've owned it since new, I've read the horror stories too, but I have never, ever had a problem with it.

I run mainly the clean channel, with all knobs dimed, jumpered the FX loop and pin it too. Use the Master volume to control overall volume level. Let the guitar pickups control the breakup.

I don't care much for the gain channel.

LP20th, can you send me a link or something on the diode bypass mod? Or is this something I have to take into a tech for? I'm real interested in this.

Even though I've never had a problem with overheating, I am considering putting a small vent on either side to allow air to flow through a bit better.

I have a JCM800 at home, use it for jams etc, but I gig with the JTM60, have been for 11 years now.And I am quite happy with it.

 

[Kluson]

To be honest I just repaired one of these. The design of the amp overall is quite poor, The amp has been designed at a cost. The Filter caps are not really man enough for the job and the power transformer is very poor, once a few tweaks are carried out it is a very serviceable amp, but to be frank, there is better out there for the same cash.
Don't get me wrong it's not a bad amp it has just been built at a cost. If you get a good one great if you don't prepare to spend

 

[Kage]

Kluson, do you have a recommendation for changing the caps and transformer? And what would the changes do to the overall tone? Just curious about that and that diode bypass. I like the amp and it seems to sit well in our mix but improvements are always welcome.

 

[Tuco]

lp20th, I don't know why you would go to all that work, when there are far better amps out there that are worthy of your time and attention. Sure, projects are fun, but a turd is a turd is a turd. Oh well . . . .

 

[dwagar]

I do find it quite funny with this amp how many guys that own them really like them, and how many guys that don't own them have such strong opinions about them.

Keeps the price down nicely on them. I guess they can be problematic, but I don't know what you can find in this kind of price range that compares to it.

 

[meandmyfriends]

I don't think i can run the risk of getting a shoddy amp for this kid..He gigs, and doesn't get alot of free change from his job.
I considered getting him a fender blues deville, the 4x10. But his models and playing style are both pretty marshall driven, and his strat is one of the most shrill fenders ive ever heard. So anything to wildly treble ain't going to work.

Do you guys have any suggestions? I'm willing to buy offbrand/homebrew as long as it sounds good and is reliable. This is a gift, so my budget is fairly limited, about $6-800 max for a head/combo. Anything with a vintage look or non master would totally make his day

 

[dwagar]

I don't know the current market prices, but maybe you can find a JCM800 combo in that price range?

 

[Ad_02Std]

I've got a JTM-60 head that I ran through a JTM series 2x12 cab.

I gigged it hard for 5 years, never had any problems, always got complements on my tone.

Only retired it because I got hold of a 1981 JCM-800 2203 for £400 last year. Winner.

 

[lp20th]

Dwagar,

I did a complete bypass of the clipping diodes. Before I did that I would barely move the gain control past 1 and the amp was all distortion in the gain channel. Fortunately all the components in question are accessible without removing the main PWB (Printed Wiring Board) for this mod. What I did was lift the leg of C105 out of the eyelet where it junctions with D103 and D104. I soldered one leg of a 390K resistor to the lifted leg of C105, keeping it off the PWB away from the eyelets and other components. I used a little RTV silicone to hold the body of the 390K resistor to the PWB, right at the top edge of the board. The other leg of the 390K resistor was soldered to the eyelet where D101 and D102 come together. This effectively takes all 4 diodes out of the circuit but makes it very easy to put it back to the stock setup if desired. The clipping diodes appear to be in a negative feedback loop from the output of V102A feeding back to V101B. The 390K resistor is essentially taking the clipping diodes place. I played with the resistor value to try keep the sound level about the same as when the diodes were in the circuit. Too little or too much on the value changes the gain. Just removing the diodes yields an open loop gain. The end result was a much more usable gain control and all tube overdrive.

The schematics as drawn by Marshall are not very well drawn. They are drawn for circuit board assembly not for trouble shooting. To try to follow the circuit flow you are jumping all over the place. I did a partial redraw of the preamp circuit so it was easier to follow the circuit flow

Yeah the amp isn't the best design, mostly due to layout, but its what I got, its sounds OK in the Marshall tube amp tradition and I have the ability to tweak and tinker with it.
Someday when I have the extra cash I'll build or buy another amp.

 

[dwagar]

thanks man, I'm going to have to try it.

I DO like mine, but wasn't happy with the gain channel. This sounds like a perfect mod

 

[Thin_Lizzy]

I gigged my JCM600 head for lots of years running through a 1978 4x12" Greenback cab. I just love that amp. And never had ANY problem with it.
Retubed it with JJ which are great for this amp.
I believe the heat issues are mainly with the combo versions.

 

[cool hand luc]

I owned one for years and had problem after problem. Signal would go in and out, and the distortion on channel 2 sucked like a stock DS-1. The clean channel was nice, but to get it clean you had to turn the master down and then you couldn't get the channel volumes balanced. Overall I'd recommend something else. It did the marshall sound though. Just never could get it running 100%.