Marshall JCM800 - Service, Tubes & Cab

[Whitey-on-the-moon]

Hi there,

Here's the situ. I just bought an 82 JCM800 2203 and I have a few queries on pretty much everything from servicing, tubes, setup and what cab/speakers will help most towards the sound I'm looking for. Here goes...

Servicing - I haven't had the back grill off yet but the person I bought it from told me there was a sticker in there from when the amp was last serviced at Marshall around 83/84. As much as I want to get the most from this puppy, I don't want to mod the amp as I'm aware these are becoming quite sort after and modding can affect the value if I decide to sell it on at any point. Does anyone know a good place in the UK to get this amp checked so that it sounds as it should? Should I get it serviced at Marshall or not?

Tubes - I've no idea whats in there at the mo, could it still have the original factory tubes from 82? Or is there no way the originals would have lasted this long? What were the original tubes? I know these amps don't produce fender crystal clear tones but I am after getting the cleaner sound as I use tube screamers for adding overdrive. I'd like to get some natural overdrive from the amp if I fancy but don't want tubes that cause alot of distortion to stop me getting the clean sound. I like playing alot of blues stuff and am aiming to achieve a warm sound. Stevie Ray Vaughan, John Fruscinate, Jimi Hendrix etc. I believe certain tubes can effect the response you get from the EQ? Obviously I'm after as much diversity from the EQ as I can get.

Setup and what cab/speakers - At the back of the head theres these things which can be set at 8 or 16 ohms, what are these for? Same on the back of a Marshall cab, I assume they have to be set the same? Does it effect the sound or is it somthing to do with the speaker load? What cab would best suit the warm Stevie Ray Vaughan meets Frusciante sound I want? I only checked this amp through a no name chipboard cab with Kensington speakers and it sounded horribly bright, really nice in that it had plenty of balls and growl on some settings, but generally very bright. So I'm hoping I can resolve this with new tubes, a service and a decent cab. I'm looking at getting a 1960Ax cab with the 25 watt Greenbacks but apparently a power brake is recommended. Is this because I'd risk blowing the speakers with them only being 25 watts? Can anyone explain the relationship between the speaker wattage and the 8 - 16 ohm thing on the back of the head and cab?

I know theres alot of questions I've asked here and for anyone who's had the patience read this post any comments and advise are most welcome.

[stokes]

As to your service question,I cant help as I am in the USA.As for tubes you will have to experiment,as you are looking for 3 different sounds,SRV used Fender amps and Jimi Hendrix used Marshall for the most part.So you will have to settle for something in between.About the cab question,if you use a 4X12 cab with 4- 25 watt Greenbacks your cab is only capable of handling 100 watts.If you push that amp hard,you will put more than 100 watts into those speakers,thus the power brake thing.Dont mismatch the out put of that amp.Make sure the output selector matches the cab impedance.i.e. with an 8ohm cab use the 8ohm selector on the head.

[Rick Erickson]

The JCM800 2203, especially if you're trying to run it clean is going to be a very bright, thin sounding amp. You could try to couple it with a dark sounding speaker, or just mod the amp for a warmer tone. This is why these amps were so popular for modifying in the first place. In their stock form, the Low Gain input had no drive and the High Gain input was very thin sounding and still didn't have enough gain for many players. The impedance selector is to match the amp to your cabinet impedance. Most Marshall 4-12 cabs were 16 ohms - if you used one cab that's the setting you would use. If you added another cab you would set the amp's selector to 8. From the musicians you mention for tone I think you would be better off with a Fender amp, maybe a small combo - I use a Deluxe Reverb. The clean Hendrix tones on "Axis - Bold as Love" sounds more Fender than Marshall to me. I have heard that he used a Twin Reverb for that album. don't know for certain though. One of my favorite local players uses a Re-Issue Custom Vibrolux Reverb that I converted to original '63 Vibrolux Reverb specs. He gets some of the best clean tones I've heard live.
For distortion he has an Ibanez TS-9 and a Boss DS-1. For Chorus he uses a Boss CE-2. It helps that he is an extremely acomplished player - he has the chops and knows how to set his gear to sound great. His tubes are nothing special - he uses current production stuff. I see lots of amps getting damaged by swaping preamp tubes with different gain types - especially people plugging in a 12AU7 where the amp was designed for 12AX7 operation. I personally don't think the NOS stuff being offered for extremely high $$$ can justify the cost/performance ratio. Having said that - New Sensor just raised their prices through the roof on tubes that have been marginal quality at best right out of the box lately - really a shame as their 12AX7EH WAS one of the best new tubes on the market. Their power tube matching has never been as good as I would like to see though and other companies are now offering very competitive tubes with better quality control.

RE

[Enzo]

And keep in mind that though there are subtle differences between brands if tubes, no matter what tubes you select, it will ALWAYS sound like a MArshall 2203. Just like changing brands of strings will not make your strat sound like a Les Paul or something.

[Whitey-on-the-moon]

Jcm 800

Guys,

Thanks all for the helpful replies. I guess I was swooped into thinking the JCM 800 would produce a warm thicker sound. I've be a J Frusciante fan for aslong as I can remember and I believe he used a JCM 800 on the Mothers Milk album and alot of the B.S.S.M. stuff. On various youtube videos of early J.F. gigs theres an 800 in the background and I have read up that Stevie Ray used an 800 aswell. I guess now I'm gonna have to study the Fender amp market. Does anyone know what model Stevie's using on his version of Highway Chile (slight return) on youtube? I'd paste the link but my work computer won't let me do youtube. Howcome it seems that the 800 J.F. gets is so much thicker than my 800. Do these rockstars use alot of E.Q on stage do you think?

[Rick Erickson]

Howcome it seems that the 800 J.F. gets is so much thicker than my 800.

You don't suppose he had it/them modified do you???

RE

[Wakculloch]

Suspect its not the eq on stage, but the fact that as a stadium rock band they get to turn them up very loud. Things come alive at the edge of full volume.
I've come to the conclusion that for pub/ club gigs i can get away with 15W and a 4 by10. ....Just!

[Whitey-on-the-moon]

Possibley Rick, maybe it/they were modified. I know that nower days J.F. gets his clean sound through a 200 watt silver jubilee. I don't think he uses an 800 anymore. Anyway, the last thing I want is to spend my music days trying to clone J.F.'s sound, it's just that his sound has always been a good example of the warmer Marshall sound. Before investing in the 800 I've been using a 100 watt TSL combo but I'm not into the modern Marshall distorted sound. It seems very fuzzy and synthetic. Also the 2nd lower gain channel is very muddy sounding. I tend not to use crystal clean sounds which is another reason I went for the 800, although I'm sure this amp has alot more to offer if I get it linked up to a decent cab, I'm thinking probably a 1960Ax with the greenbacks. From what you've had to say Rick I assume you're an amp tech. How much of an effect on the overall sound of the amp can a service have? especially if it's not had one for twenty odd years?

[Rick Erickson]

From what you've had to say Rick I assume you're an amp tech. How much of an effect on the overall sound of the amp can a service have?

Depending on the condition of the amp, a general servicing can have a profound effect on the sound - or little to none. If an amp hasn't been serviced in years it's a good idea to start there with the basics. I almost always urge my customers to let me get their amps running correctly & play them before they have me modify anything. The only reason I suggest modifying a stock JCM MV amp is that I have been doing them for many years (since the early 80's) in my shop at the request of players who have the same complaints you are voicing. My recent clients for this work have included such local Seattle bands as Heart, Pearl Jam, Queensryche & Death Cab for Cutie as well as many less notable names & probably a few I've forgotten - oh yeah - Me! I modified my own JMP 50W MV (Virtually the same as a JCM800 MV) 2-12 combo amp as a showroom demo. I've found it is much easier to sell a mod if you can show the customer what their amp will sound like before you tear into it.

RE

[Whitey-on-the-moon]

Awesome! Shame your not based in Manchester England otherwise I'd have you get my amp sounding as it should. I don't suppose you know what model of Fender amp Stevie's using in this vid do you?

http://www.youtube.com/watch?v=1GSpbuFSr2o

You can only see a snippet of the amp about halfway through the clip but maybe you can tell from the sound.

Also a mate has recommended getting an EQ pedal for removing the harsh high end from this 800. Whats your thoughts on EQ pedals? I'm suspecting one of these pedals would also prevent the amps natural mojo from coming through? Any thoughts or experiences to share anyone?

[dai h.]

wasn't Mother's Milk supposed to be an Soldano SLO100(IIRC)? Definitely gained-out sounding.

[Whitey-on-the-moon]

wasn't Mother's Milk supposed to be an Soldano SLO100(IIRC)? Definitely gained-out sounding.

I'm not 100% sure to be honest mate. Not from what I'm aware of though. As far as the youtube evidance suggests Mr Frusciante has always been a Marshall man.

http://www.youtube.com/watch?v=8JBXcS6TLy0
http://www.youtube.com/watch?v=7gf4mRdd5DY
http://www.youtube.com/watch?v=2pgYrRQvDnU
http://www.youtube.com/watch?v=nXWzbsnb638

Infact I'm even contradicting what I said earlier about J.F. using an 800 for his live sound. 3 out the 4 clips here he's using 70's superleads (I think), although in the 'subway to venus' clip thats definately a JCM and this footage is from the 80's so I assume it's an 800. But it's confirms my earlier point that J.F's Marshall sound is a hell of alot more mellowed out than my 800 sounds. I always believed the 800's where pretty much the same amp as the superleads though exept they have a master volume. Is this the case Rick?

[robinbowes]

Awesome! Shame your not based in Manchester England otherwise I'd have you get my amp sounding as it should. I don't suppose you know what model of Fender amp Stevie's using in this vid do you?

http://www.youtube.com/watch?v=1GSpbuFSr2o

Looks like a Fender Super (on the left) and a Vibroverb.

R.

[Rick Erickson]

I always believed the 800's where pretty much the same amp as the superleads though exept they have a master volume. Is this the case Rick?

The preamp circuit is very different. In the MV amps they cascaded the CH1 & CH2 preamps and changed both in the process. The Low Gain input was too low and the High Gain input was thin sounding and still not enough grind for many players. The JMP MV and the JCM800 MV amps are pretty much the same inside.

RE

[robinbowes]

I always believed the 800's where pretty much the same amp as the superleads though exept they have a master volume. Is this the case Rick?

The preamp circuit is very different. In the MV amps they cascaded the CH1 & CH2 preamps and changed both in the process. The Low Gain input was too low and the High Gain input was thin sounding and still not enough grind for many players. The JMP MV and the JCM800 MV amps are pretty much the same inside.

Interesting. I have a 2205 JCM800 head, and I feel pretty much the same about it.

I'm currently deciding whether to sell it on and get something else, or have it modified.

I love the sound of what this guy has done:

http://frankntone.com

I might try something like that in my Vibroclone.

R.