Looks like Marshall have a new amp coming out this Friday

ICBM

earwighoney said:

The JTM was based on a tweed Bassman right?

Yes, a direct copy of the 5F6-A but with a different transformer ratio (for a 16-ohm output instead of 2-ohm).

earwighoney said:

A few modern(ish) amps favoured in the more traditional side of metal (ie bands that sound like Sabbath) use Bassman style circuits.

That's because the classic Iommi amp is the Laney Supergroup, which is effectively a Marshall Super Bass copy (although again with different transformers, and doesn't sound quite the same), and the Super Bass is not far from a high-powered JTM45... so still 5F6-A derived.

earwighoney said:

This new JTM amp sounds great, I think it would make a perfect combination to play Sabbath riffs with. 

If you want a low-power Sabbath sound, get a Laney LA30BL - it nails it dead on.

Dave_Mc

ICBM said:

earwighoney said:

The JTM was based on a tweed Bassman right?

Yes, a direct copy of the 5F6-A but with a different transformer ratio (for a 16-ohm output instead of 2-ohm).

That's what I thought.

From the MusicRadar review https://www.musicradar.com/reviews/marshall-studio-jtm-st20h-20w-head-and-st212-cab-review : 

"It can't be understated just how much of an impact Jim Marshall's JTM tube amp had on the emerging world of rock 'n' roll - with the "coffin logo" version from 1964 being seen as the holy grail by many players. Yes, the original may have been inspired by the beloved Fender 5F6-A Bassman, but the JTM was a different breed altogether - thanks in part to the use of British KT66 output and ECC83 preamp valves. This new class of amplifier delivered a tone and power that players of the day had never experienced and well, the rest is history. "



Hmmm. So a (more or less) straight clone of an already-existing amp produced a tone which no-one alive at that time had experienced. Or the newer, more modified version with KT66s did, I guess. Except this low power version is a copy of the original clone with 5881s, not the slightly newer-less-cloney KT66 one.

Who writes this crap? Does no-one check it? Even if you didn't check anything else, reading through that single review/article once would tell you something doesn't add up.

I mean I dare say it sounds great (and darned if I don't want one regardless... well, I'd probably get one of the other Studio ones first if I ever get round to it, but still), but come on.

(Can this new one take KT66s out of interest?)

EDIT: Might be best to ignore this... I had a migraine. That's my story and I'm sticking to it!   

ICBM

Dave_Mc said:

Hmmm. So a (more or less) straight clone of an already-existing amp produced a tone which no-one alive at that time had experienced. Or the newer, more modified version with KT66s did, I guess.

The different output impedance makes a big difference, because Marshall - Ken Bran and Dudley Craven - didn't correctly compensate for the much higher output voltage (the OT turns ratio is the square root of the impedance ratio, so 2.83 times higher), they just copied the circuit values exactly... the result is that the JTM45 has almost three times the negative feedback of the Bassman, and a very different overdriven sound.

The other huge difference is that the Bassman uses four 10" Jensens wired in parallel in a lightweight open-back pine cabinet with a floating baffle, and the Marshall uses four 12" Celestions wired parallel-series in a heavy closed-back ply cabinet with a firmly-braced baffle. The cabinet was actually all Jim Marshall's work and probably even more important than the OT ratio.

Both these are more important than the 5881/KT66 difference and the 12AX7/ECC83 *non*-difference - there isn't any, other than the minor difference between valve brands, 12AX7 and ECC83 are just the US and UK designations.

roberty

ICBM said:

earwighoney said:

This new JTM amp sounds great, I think it would make a perfect combination to play Sabbath riffs with. 

If you want a low-power Sabbath sound, get a Laney LA30BL - it nails it dead on.

Can't get enough of mine. My favourite amp ever

roberty

Might be looking to trade my big JTM 45 for something more modern. I have a lot of four hole amps

Dave_Mc

ICBM said:

Dave_Mc said:

Hmmm. So a (more or less) straight clone of an already-existing amp produced a tone which no-one alive at that time had experienced. Or the newer, more modified version with KT66s did, I guess.

The different output impedance makes a big difference, because Marshall - Ken Bran and Dudley Craven - didn't correctly compensate for the much higher output voltage (the OT turns ratio is the square root of the impedance ratio, so 2.83 times higher), they just copied the circuit values exactly... the result is that the JTM45 has almost three times the negative feedback of the Bassman, and a very different overdriven sound.

The other huge difference is that the Bassman uses four 10" Jensens wired in parallel in a lightweight open-back pine cabinet with a floating baffle, and the Marshall uses four 12" Celestions wired parallel-series in a heavy closed-back ply cabinet with a firmly-braced baffle. The cabinet was actually all Jim Marshall's work and probably even more important than the OT ratio.

Both these are more important than the 5881/KT66 difference and the 12AX7/ECC83 *non*-difference - there isn't any, other than the minor difference between valve brands, 12AX7 and ECC83 are just the US and UK designations.

Yeah I wondered that about the 12ax7 versus ecc83, I always thought they were basically exactly the same. But I didn't say that in case I was wrong. So I didn't say the bit I was right about and did say the bit I was wrong about, lol.

I'm sure I've seen that about the negative feedback before (probably posted by you, lol). But I forgot!

Yeah good point about the speakers/cab. I do know that bit, lol.

   

EDIT: Not sure what I was thinking when I posted... can I blame it on a migraine? Anyone who's paid any attention to my silly posts over the years might be tempted to think I get a lot of migraines... 

ElectricXII

Is it just me, or does any one else strongly dislike the aesthetics of these? The "coffin" logo is especially dreadful.

RiftAmps

Someone pointed out to me that this sounds very much like a HRD and now that's all I can hear when I watch the demos.

GavRichList

ElectricXII said:

Is it just me, or does any one else strongly dislike the aesthetics of these? The "coffin" logo is especially dreadful.

yeah I don't like that either...that said, if they did my preference it'd look exactly like the SV20. 

p90fool

ElectricXII said:

Is it just me, or does any one else strongly dislike the aesthetics of these? The "coffin" logo is especially dreadful.

That's what the very first Marshalls looked like, it's not just a random styling exercise. 

roberty

p90fool said:

ElectricXII said:

Is it just me, or does any one else strongly dislike the aesthetics of these? The "coffin" logo is especially dreadful.

That's what the very first Marshalls looked like, it's not just a random styling exercise. 

Someone should go back and tell them

stickyfiddle

I get that they're a call back to the first Marshalls, but they still look rubbish. 

Tbh I would happily buy the SV20H except I know it's still going to be stupidly loud in the real world and I can't be arsed with buying amps I know I'll need attenuators for before I even start. 

ElectricXII

p90fool said:

ElectricXII said:

Is it just me, or does any one else strongly dislike the aesthetics of these? The "coffin" logo is especially dreadful.

That's what the very first Marshalls looked like, it's not just a random styling exercise. 

I know. And they looked awful.

p90fool

ElectricXII said:

p90fool said:

ElectricXII said:

Is it just me, or does any one else strongly dislike the aesthetics of these? The "coffin" logo is especially dreadful.

That's what the very first Marshalls looked like, it's not just a random styling exercise. 

I know. And they looked awful.

I don't disagree, and they obviously changed to the classic Marshall look for a reason, but I guess it's like snakehead Teles - it lets your peers know you're "in the know".

RickLucas

I think I'd go for a small Friedman combo over one of these.

ICBM

p90fool said:

I don't disagree, and they obviously changed to the classic Marshall look for a reason, but I guess it's like snakehead Teles - it lets your peers know you're "in the know".

Except that snakehead Teles look like someone put a DIY neck on it.

With the original JTM45s, the DIY look doesn't really show until you open it up and look at the chassis...

funhouse

My decades-long hunt for a great sounding, flexible Marshall-style amp which covers NMV, MV and hot-rodded settings ended with a Brunetti Pleximan. It's also portable, sounds excellent on the 5W setting, takes pedals well and is a joy to play... as is my Laney LA30BL. I can't recommend them highly enough. I briefly owned an SV20 and SC20 and was disappointed by both, but each to their own...

GavRichList

My new setup, as of two days prior to the launch of this one. Wouldn’t swap it, but I sure do love a JTM45. 

Dave_Mc

RiftAmps said:

Someone pointed out to me that this sounds very much like a HRD and now that's all I can hear when I watch the demos.

No-one told me that but I definitely thought, "That sounds pretty Fendery" when I first heard it. 

There's quite an interesting video on Youtube where Johan Segeborn puts KT66s into the SV20H... it made it sound quite a bit more Fendery I thought (though not as Fendery as the JTM).

GavRichList said:

ElectricXII said:

Is it just me, or does any one else strongly dislike the aesthetics of these? The "coffin" logo is especially dreadful.

yeah I don't like that either...that said, if they did my preference it'd look exactly like the SV20. 

I can't quite decide if I like it or not (though I fear I'm liking it more the more I see it!), but the only better idea I can come up with is the SV20 look like you said. And as @ICBM said, they probably don't want it to look exactly the same for marketing etc. reasons.

Jonathangus

Personally, i like the look.  But all the other Studios have had the Design Store treatment, so there will probably be alternative finishes if it doesn't appeal.