JTM 45 or Plexi??

[jmv]

So, at the moment, i'm just trying to figure out what to drool over next, cuz i've got bad g.a.s., and want more gear really bad...

I think it would be super cool to have an old marshall to compliment my bassman. Some of the possibilities would be... JTM-45 RI head, a RI bluesbreaker combo, a 50w Plexi RI, or maybe a beat up 100w Super Lead from ebay...

Now, i like the idea of having an original, because its nice to have the handwired amps rather than the PC board stuff, ya know?? But 100w would be too much for me... so i'd have to have an attenuator around all the time. the JTM and bluesbreaker seem like they would be cool, but i'd be concerned that maybe they'd be too similar to my bassman, with the 5881s or KT66s or whatever it is that comes in those RIs. So, an EL34 amp would be cool in that respect... but the only option that leaves is the 50w plexi RI, which again is a PC board type thing. I could go blockhead or something, and get a replica thats built the exact same... but those are SUPER expensive, would you think it would be worth it?? I mean, are they good enough to justify paying 2x as much as the Reissues??

What are your thoughts on this??

 

[mrid]

Re: JTM 45 or Plexi??

You are sick, man. :laugh2: I'd drool over a plexi, since the JTM 45 is so similar to a bassman.

 

[Lewguitar]

Re: JTM 45 or Plexi??

So, at the moment, i'm just trying to figure out what to drool over next, cuz i've got bad g.a.s., and want more gear really bad...

I think it would be super cool to have an old marshall to compliment my bassman. Some of the possibilities would be... JTM-45 RI head, a RI bluesbreaker combo, a 50w Plexi RI, or maybe a beat up 100w Super Lead from ebay...

Now, i like the idea of having an original, because its nice to have the handwired amps rather than the PC board stuff, ya know?? But 100w would be too much for me... so i'd have to have an attenuator around all the time. the JTM and bluesbreaker seem like they would be cool, but i'd be concerned that maybe they'd be too similar to my bassman, with the 5881s or KT66s or whatever it is that comes in those RIs. So, an EL34 amp would be cool in that respect... but the only option that leaves is the 50w plexi RI, which again is a PC board type thing. I could go blockhead or something, and get a replica thats built the exact same... but those are SUPER expensive, would you think it would be worth it?? I mean, are they good enough to justify paying 2x as much as the Reissues??

What are your thoughts on this??

Unless your Bassman has been heavily modded, it will sound nothing like a JTM 45 or Plexi. They are radically differant preamp designs with very differant tones. The output stage is similar, but the preamp design of the Marshalls is a knock off of the 59 Bassman...not your blackface Bassman which is a totally differant amp. Why not consider a RI Vox AC30 with Celestion/Vox Alnico Blue speakers? Those sound superb, especially with the Top Boost channel goosed with a DS-1 or Tube Screamer: Brian May/Eric Johnson violin tone or days! Also killer Beatles tones from the AC30.

As for the JTM45 vs the Plexi: both Reissues sound great. The JTM45 uses a rectifier tube and the Plexi uses a solid state rectifier if I remember correctly. (which I may not be!) The JTM45 is closer to the 59 Bassman Bassman as the Bassman used a rectifier tube also. This gives a little more touch sensitive response IMO...the solid state rectifier design of the plexi is a little harder sounding.

And the output tubes are differant too.

I should have looked up the schematics before making that last comment...but I think I'm right about that.

Lew

 

[jmv]

Re: JTM 45 or Plexi??

yeah, i knew the jtm45s were based on the 59 bassman... but i thought they might be similar, since the output tubes are the same. I guess its not though...

But thanks for the info... sounds like maybe the JTM-45 would be better for me... not that i can afford it soon, but it helps me to make sure i know what i want by researching while i save my money, rather than saving and then just buying on an impulse... and yeah mrid, i know i'm sick.

Oh, and the AC-30 is an interesting suggestion... i'll have to check into those, i've never really played through one before... my guitar teacher has 2, i'll have to check em out...

 

[STRATDELUXER97]

Re: JTM 45 or Plexi??

yeah, i knew the jtm45s were based on the 59 bassman... but i thought they might be similar, since the output tubes are the same. I guess its not though...

But thanks for the info... sounds like maybe the JTM-45 would be better for me... not that i can afford it soon, but it helps me to make sure i know what i want by researching while i save my money, rather than saving and then just buying on an impulse... and yeah mrid, i know i'm sick.

Oh, and the AC-30 is an interesting suggestion... i'll have to check into those, i've never really played through one before... my guitar teacher has 2, i'll have to check em out...

Many amps have the same output section and the same compliment of output tubes,however most of the overall voicing is done at the preamp...Most mods done on amps to change the tonality,gain structure etc. are done at the preamp also..

John

 

[kevlar3000]

Re: JTM 45 or Plexi??

If you buy as used RI for 600 to 800 and tweak it to vintage specs you can get spectacular results. I have two early 70s amps, my Traynor Bassmaster is PTP and my Carlsbro is an early PC as is my 96 Plexi . The PTP Traynor is not better sounding in any way than my PC amps, the tweaks are what will give you the tones with the RI. Outside of being easier to work on the debate of PTP vs PC is IMO way overblown in terms of sonic differences. I hear my three amps daily and don't believe one is tonally superior to the other because of the way it is wired. The Plexi is my Fave with the Traynor and Cbro right behind.

I personally love the solid state rectifier on the Plexi, if you have a Bassman the 45 will be very close so I would vote for a different flavor. Of the gourmet $$$ brands there is some very cool stuff out there, I have read of some issues with the Blockhead line and I would go for the Mohave or Roccaforte offerings ahead of the BH. If you got the bucks it would be real fun... If I had the bucks I would actually wait til next month when the Marshall 1959 SLPHW hits the shelves. Sounds like that is gonna be the goods.

It is a fun dilema to have!

 

[Lewguitar]

Re: JTM 45 or Plexi??

If you buy as used RI for 600 to 800 and tweak it to vintage specs you can get spectacular results. I have two early 70s amps, my Traynor Bassmaster is PTP and my Carlsbro is an early PC as is my 96 Plexi . The PTP Traynor is not better sounding in any way than my PC amps, the tweaks are what will give you the tones with the RI. Outside of being easier to work on the debate of PTP vs PC is IMO way overblown in terms of sonic differences. I hear my three amps daily and don't believe one is tonally superior to the other because of the way it is wired. The Plexi is my Fave with the Traynor and Cbro right behind.

I personally love the solid state rectifier on the Plexi, if you have a Bassman the 45 will be very close so I would vote for a different flavor. Of the gourmet $$$ brands there is some very cool stuff out there, I have read of some issues with the Blockhead line and I would go for the Mohave or Roccaforte offerings ahead of the BH. If you got the bucks it would be real fun... If I had the bucks I would actually wait til next month when the Marshall 1959 SLPHW hits the shelves. Sounds like that is gonna be the goods.

It is a fun dilema to have!

From the picture in JMV's avatar, it looks like he owns a 60's Bassman...not a 50's Bassman. Two very differant amps. Alot of guys assume the blackface and silverface Bassmans from the 60's are the same amp as a 59 Bassman in a differant box. They're not! The preamp design is as differant as night and day in the two versions and they sound very, VERY differant.

The Marshall JTM45, model 1987 Plexi, and even the Vox AC30 are similar to the 50's Bassman and have the all important 1/2 of a 12ax7 tube used as a Cathode Folower...that's where the crunch associated with those amps comes from. The blackface Bassman doesn't...and has alot less gain and a differant tone stack too.

Lew

 

[jmv]

Re: JTM 45 or Plexi??

The blackface Bassman doesn't...and has alot less gain and a differant tone stack too.

Lew

Thats kinda interesting... i'm not questioning your authority or anything, cuz i know you know your stuff, but i mean, i can get quite alot of gain from my amp, at least IMO... if you bridge the channels and crank it up, it gets pretty darn dirty...

Anyway, it'd be real cool to play an original 59 bassman and compare... but its likely i'll never get my grubby mits on one of those.

 

[mrid]

Re: JTM 45 or Plexi??

How much trouble would it be to mod the cathode follower so that it's driving the tone stack in a blackface?

 

[Vasshu the humanoid typhoon]

Re: JTM 45 or Plexi??

Hehe an old 59 is way more dirty cranked than a blackface, plus the sound is not the same.

 

[Lewguitar]

Re: JTM 45 or Plexi??

Thats kinda interesting... i'm not questioning your authority or anything, cuz i know you know your stuff, but i mean, i can get quite alot of gain from my amp, at least IMO... if you bridge the channels and crank it up, it gets pretty darn dirty...

Anyway, it'd be real cool to play an original 59 bassman and compare... but its likely i'll never get my grubby mits on one of those.

Sure...I'm not doubting that you get a tone you really like out of that amp. But your amp is still very, VERY differant from a tweed Bassman and the preamp designs are differant as night and day: not even close!

Lew

 

[STRATDELUXER97]

Re: JTM 45 or Plexi??

Sure...I'm not doubting that you get a tone you really like out of that amp. But your amp is still very, VERY differant from a tweed Bassman and the preamp designs are differant as night and day: not even close!

Lew

Yep..Coming from another guy that tweaks on amps,Lew is 100% on the money...An early Marshall is a 59 Tweed Bassman copy for all intense and purposes...The later BF and SF Fender amps are completely different as far as how the preamps are designed..This is the simple explanation of it,but Lew knows what he's talking about! :wink:

John

 

[Vasshu the humanoid typhoon]

Re: JTM 45 or Plexi??

It is one of the best overdriven sounds ever....

 

[Falstaff]

Re: JTM 45 or Plexi??

BF Bassmans do sound pretty darn good cranked up, no matter what!

 

[STRATDELUXER97]

Re: JTM 45 or Plexi??

BF Bassmans do sound pretty darn good cranked up, no matter what!

Yep and they make great blues amps...Lots of blues guys used the BF Fender stuff also..

John

 

[jmv]

Re: JTM 45 or Plexi??

Yeah, they do sound great cranked... but its pretty loud.

So, which would you guys reccomend, the JTM-45 head or the Bluesbreaker combo?? It seems like its supposed to be the same circuit, only the bluesbreaker has tremolo, but the bluesbreakers controls are somewhat different from that of the JTM45, theres not just 2 knobs added for the tremolo.... does anyone know what the tonal differences are??

 

[Pandemonium]

Re: JTM 45 or Plexi??

or maybe a beat up 100w Super Lead from ebay...

Now, i like the idea of having an original, because its nice to have the handwired amps rather than the PC board stuff, ya know?? But 100w would be too much for me... so i'd have to have an attenuator around all the time.

Jumper the channels and you've just described the best all out rock Marshall sound I've ever had.

 

[jmv]

Re: JTM 45 or Plexi??

Oh, and in adition to my question about the differences between the bluesbreaker and the JTM-45, i'd be interested to know... whats the differences between the plexi Super Leads and the early metal-face Superleads??

 

[jmv]

Re: JTM 45 or Plexi??

Oh, and in adition to my question about the differences between the bluesbreaker and the JTM-45, i'd be interested to know... whats the differences between the plexi Super Leads and the early metal-face Superleads??

anyone??

 

[kevlar3000]

Re: JTM 45 or Plexi??

anyone??

The RI Plexis are actually early 70s metal faced specs. Early plexi's through mid 68 I believe, had a shared cathode vs split on V1. Shared is warmer and a bit less gainy and the split is more aggressive and typical of 69 or so and beyond marshals. I have tried both, I like shared better, but you gotta lower the overall bass of the amp before it will really shine with a RI. It gets way too tubby, once it is dialed in it is wonderful. The filtering on the Plexis is typically lower, 32+32 vs 50+50 in the 70s Marshalls and the RI. I hugely prefer the lower filtering, there is more dig to the note and the bottom is richer. If you listen to Jeff Beck truth you can really get a feel for it.

In general the metal faced amps are brighter and more aggressive which was a reflection of the evolution of rock. Both can sound amazing, and also Marshalls varied greatly from one amp to another in this era so that is why so many sound different from each other. Surely some more circuit specific folks will add much more detail to my general response.