Marshall: JTM or JCM whats the difference?

[Jeff_H]

Re: Marshall: JTM or JCM whats the difference?

I've got a JCM 800 4212, which is the 2205 (50watt, 2 channels) circuit in a 2x12 combo. There is a 4210, which is the 1x12 version. Both of these are 50 watts. The 100 watt versions have a 1x12 and a 2x12 combo as well, which are the same circuit as the 2210...100 watt, 2 channel head. Yeah, it's a little heavy, but IMO the sound of a 2x12 is closer to the sound of a head and cab than a 1x12. It all depends on what you want.

Mine weighs in at over 50 lbs, but I wouldn't trade it for anything. It was a pretty good amp stock. Useable clean channel and an awsome crunch channel. I had it modded an now it's fender clean and all the marshall tone you could ever want.

[ErikH]

Re: Marshall: JTM or JCM whats the difference?

With the JCM2000 series amps they got away of having combo amps that were essentially using the same chassis as that range's 50 watt, or in rare cases 100 watt tube heads.

This isn't anything new. They've been doing that since the JCM800 era. All they'd do is flip the chasis upside down so the tubes hang down, apply the control text in the readable orientation and wala, combo chasis.

[Lake Placid Blues]

Re: Marshall: JTM or JCM whats the difference?

I'm sorry for possibly being confusing. They don't do this with the DSL range. The DSL combos use a different circut from the heads, although the 2x12 TSL combo is essentialy like the TSL head. The DSL combos use EL84 tubes. While this seems like a very good idea ( easier pushed EL84's at a lower volume), it's too bad that they didn't simply take the DSL50 chassis and flip it over blues breaker like, as the DSL head looks to be superior to the DSL401 in terms of build and parts quality. Moreover the DSL heads seem to be the best sounding of the modern Marshalls, even run through 2x12 open back speakers.

[ErikH]

Re: Marshall: JTM or JCM whats the difference?

I'm sorry for possibly being confusing. They don't do this with the DSL range. The DSL combos use a different circut from the heads, although the 2x12 TSL combo is essentialy like the TSL head. The DSL combos use EL84 tubes. While this seems like a very good idea ( easier pushed EL84's at a lower volume), it's too bad that they didn't simply take the DSL50 chassis and flip it over blues breaker like, as the DSL head looks to be superior to the DSL401 in terms of build and parts quality. Moreover the DSL heads seem to be the best sounding of the modern Marshalls, even run through 2x12 open back speakers.

No wonder I don't like the DSL combos. For some reason, I could never get them to sound good to me. I guess I'm just not an EL84 guy. Too used to the sound of EL34's.

[JeffB]

Re: Marshall: JTM or JCM whats the difference?

They don't make any other DSL combos besides the 40 watter... It's just TSLs ...60 watt and 100 watts

[flipside]

Re: Marshall: JTM or JCM whats the difference?

Someone said that the JCM2000 series doesn't use diodes for clipping. I believe, though not 100% certain, that all modern Marshall's, except for the JCM 800 2203/4 use diode clipping. I think Marshall realized when they made the JCM 900 that it was missing something that the JCM 800 had, so they came out with the SL-X, which has an added preamp tube. I have no idea who thought of putting 5881's in Marshalls but whoever it was should be shot. I believe that the SL-X is the true bridge between the JCM 800 and the JCM 2000. Because the DSL series is essentially(so to speak) the SL-X just with a Tone shift button, and Deep switch button. But like somebody previously stated, the simpler the circuit the better the sound. Which is why i'm a huge SL-X fan. Slap a Zakk Wylde Overdrive in front of it to give it that extra low end chunk, and voila, DSL sounds!

[J Moose]

Re: Marshall: JTM or JCM whats the difference?

Unlike, the channel switching amps from the previous two decades the DSL doesn't use diode clipping. Not that Diode clipping is real bad or anything, as it works fine in Silver Jubilee, and JCM800 2105 type channel switching amps.

I was under the impression that the Silver Jubilee's use LED clipping and not diode like the channel switching 800's...at least that's what the schematics I've seen say.

[Lake Placid Blues]

Re: Marshall: JTM or JCM whats the difference?

Right you are. Of course LED stands for "light emitting diode". I can actually see the LEDs light up when I play either of my Silver Jubilee amps with opened up on the work bench. The harder you play the more they light up. Picking softly they don't light up much. The main gain and distortion stage on the SJ amps is Valve IB, when using the gain mode though. The signal by- passes this tube triode and the LEDs on clean mode. There are some regular non LED diodes that can be brought in on the clean mode by selecting "pull rythin clip". Pull rythim clip isn't a very usefull feature unless you want AC/DC type distortion at low volume IMO.

It's been a few years, but the last time I looked over a DSL preamp schematic it was indicating that they don'tuse diode clipping.

[joelap]

Re: Marshall: JTM or JCM whats the difference?

Dont Jubilee's have a Plate follower tone stack too, versus most other marshall's that are Cathode follower? There was a time I was almost about to buy one... then christian told me that and it scared me away.

This thread is really informative.

[Lake Placid Blues]

Re: Marshall: JTM or JCM whats the difference?

Looking at a schematic it is off the plate for the Jubilees. So it is with the 2205/2210 too. Plexi's and 2203/4 types are off the cathode according to the schematics.

[joelap]

Re: Marshall: JTM or JCM whats the difference?

Looking at a schematic it is off the plate for the Jubilees. So it is with the 2205/2210 too. Plexi's and 2203/4 types are off the cathode according to the schematics.

It's off the 2205/2210 too? I never knew that... I always thought they had Cathode as well.

[JeffB]

Re: Marshall: JTM or JCM whats the difference?

It's off the 2205/2210 too? I never knew that... I always thought they had Cathode as well.

You guys are gettin way too technical now, it's not that tough

Here's the secret to Marshalls...

MV or NMV single channel = Good Marshall

Multi Channel Marshall= Not nearly as good Marshall



Thats not an absolute of course....but IME there's more truth in it than falsehood

[joelap]

Re: Marshall: JTM or JCM whats the difference?

^ I also have to agree with you on that.

I really want a single channel Plexi head that I can mod. But I want to build the whole damn thing from scratch. Once I get the cash/balls to go for it, I'm gunna build a 1959 replica, but get rid of the second channel, and turn the second half of that V1 12AX7 into a switchable gain stage. I might add another tube too for another extra gain stage, to make use of that other hole that would have been used for the second channel.

I also found this online that I really liked: https://weberspeakerscom.secure.poww...re/chansw1.htm To make use of the 4th input jack (if you're only using 1 channel, you only need 1 anyways), pop another Volume knob on it, and use this channel switch thing from Weber to use it for a second volume... set one loud, set the other louder!

On that same page there's also a low power switcher... well, if I do decide to add an extra hole for another 12AX7 (the second additional gain stage), I'd still have the other half of the 12AX7 to work with... why not make that half a footswitchable gain boost right?

I always do this to myself. I say "ok joe its time to build your own amp clone". Then I start thinking of options and it turn into Dr. Frankenstein (or maybe Dr. Kevorkian, because I'll probably kill most of the components instead of making them work right).

I love threads like these.

[J Moose]

Re: Marshall: JTM or JCM whats the difference?

You guys are gettin way too technical now, it's not that tough

Here's the secret to Marshalls...

MV or NMV single channel = Good Marshall

Multi Channel Marshall= Not nearly as good Marshall

Truth.

But 'ya forgot the other part of it!

All tube Marshall = Good Marshall

One tube or solid state Marshall = Not nearly as good Marshall

[Jeff_H]

Re: Marshall: JTM or JCM whats the difference?

Here's the secret to Marshalls...

MV or NMV single channel = Good Marshall

Multi Channel Marshall= Not nearly as good Marshall



Thats not an absolute of course....but IME there's more truth in it than falsehood

Them's fightin' words there fella!