May 2009 \ Features \ 45 Degrees of Tone: The JTM45 Roundup

45 Degrees of Tone: The JTM45 Roundup

Steve Ouimette

Nearly 50 years since its creation, the Marshall JTM45 remains both a relevant and near-perfect example of what a great rock ‘n’ roll tube amp should be.


Premier Guitar May 2009
DIGITAL  RSS  EMAIL   SHARE   LINK   PRINT  COMMENTS

(2 of 8)


Original 1965 JTM45

To get our ears accustomed to the JTM45 sound, we began by firing up our ’65 head with a Les Paul. Normally, this head has EL34s in it, but we borrowed the Genelex KT66s from the Mojave and biased the amp to accommodate them. It made sense to us to use KT66s, because they were what the amp was designed for. With everything looking good, we flipped it from standby and beheld the beauty of this vintage masterpiece. It’s no wonder players and collectors are paying big bucks for these amps; everything we played through it sounded incredible.

What was amazing was how much of a rock ‘n’ roll amp this really is. Considering how long it’s been since it was conceived, the amp’s sound remains surprisingly current. The distortion is organic, full-bodied and earthy, and it allowed the personality of the guitar and player to shine through. While it was very easy to play, this is an amp that still requires a level of discipline and control to fully harness its capabilities. It makes sense that players who want to be heard would play on this style of amp, because like it or not, whatever you play through the amp is… well, amplified. It just comes out better.

We played through it for a good long time, switching guitars and speaker cabinets to hear it in as many different configurations as possible. Whether it was a Strat, a Les Paul, a 2x12 or a 4x12, the sound was always remarkable— perhaps the very definition of great tone. Subjective? Yes. Brilliant? Absolutely. Rolling back the volume on the guitars exposed a beautiful clean tone that was harmonically rich and defined, never muddy or dull. Even with the guitar’s volume knob all the way up, the dynamic response of the amp, and the way it musically fed back, was awe-inspiring.

Once we had established a base tone for comparison’s sake, it was time to play and listen to the other amps. Before I break down each individual amp and builder, I must observe that each and every one of the amps had ridiculously good tone, and they all sounded like JTM45s, but each had its own unique voice. Aside from the reissue Marshall, all of the amps are hand-wired. The reissue Marshall was of PCB-construction, and used the standard parts and components that Marshall was building their amps with during that era. I spoke with Mitch Colby from Korg USA (Marshall’s US distributor), who told me that the reissues have not undergone any significant changes since their reintroduction 20 years ago. While they are using the components that Marshall builds with today, they should yield very similar tones to the earlier reissue amps.




« Previous    1 | 2 | 3 | 4 | 5 | 6 | 7 | 8    Next »



Comments

(29 comments) display by
UsernameComment
Peter
on 07/24/2009
Just in reply to the man who said we are sheep... you're right :-) When you look at players in the sixties they were doing all sorts of wierd mods, slicing speakers because the distorted sound was groovy baby.... but they also used dual showmans, hiwatts, FUZZ boxes :-) My favourite amps at the moment are a Marshall DSL100 and Fender (red knob) Dual Showman head and they do everything, plus more, that I want... for another bloke it would be a Fender Twin or a Boogie... Don't get me wrong, these were great amps in their day... and when pushed they crank today... but again it's funny making big money from old technology...
Peter
on 07/24/2009
The reason why companies change their product is competition... idiots wanted more and more gadgets built-in to the amp... channel switching, overdrive, reverb, FX, lighter amps, etc... or be left behind in the rush...

You can't beat ONE great tone... and then play around with that... add one great guitar... and a guitarist with "the touch" and bingo... If I became a Satriani on guitar and used a TSL601 combo... and young pups looked up to me... they'd re-issue the TSL in 20 years time :-)

Cheers!
Frank M
on 06/24/2009
One thing I think needs to be pointed out about the Marshall Reissue in this roundup is that looking aththe PCB you can easily see that the circuit was totally modded from the original JTM45 circuit with those larger caps and how they're wired up as well as the fact that the orignal came with 5881s not EL34s so that was a mod as well. Still a great article and about the only one out there that compares them. Now if we could have a good Plexi 100 watt round up would be really great!
trippin
on 05/29/2009
Skeptical of "reissues"? Why did people stop making them? Easy. Making short term cost improvements and the typical kinds of model "upgrades" dictated by a competitive marketplace. The same reason Les Pauls were made with pancake bodies and poly finishes. So I'd say rather the opposite: the sheep were the ones lured to what was peddled as the latest and greatest iron at that point in time. Even the Beatles went all transistor, didn't they? Sputniks and all that mod stuff! That was like the cool thing: "Solid State." Since then we reflected on our musical history and discovered that, hey, whoa, we really liked those old records for a reason. Not everyone, mind you, but some. It's a conscious decision and a conscious goal that has nothing to do with wool bearing mammals, and it's not everybody's bag. So if it's not your bag, that's cool. But no one is "amending" the past. To the contrary, we're recreating it as true to original as possible. We do this because we HAVE learned the lessons of the past. You've got it all backwards, man.
Frank M
on 05/24/2009
Question: You say the JTM45 reissue sounds great as long as it's biased hot. What range would you suggest with KT66s? More than 38mA?
Frank M
on 05/24/2009
Well after reading this article, I remembered a used Marshall JTM45 Reissue 1999 model sitting at my local Guitar Center. I recalled playing it a couple times with a Zvex box of rock and thought it sounded nice but no match for my JCM 800 50 watt combo. Against my initial reaction, I decided to go trade my 800 + some other gear and cash to get it. So I took it home and it had amazing low end crunch through 2x12 Celestion G12C Greenbacks as used in the JH Hendrix 45/100 amp. Only thing it had no balls with the existing 5881s. So I popped a set of Valve Art KT66s no screen resistor change or any other alterations necessary and biased them at 36 & 38mA. Shazzam! I'm back on stage with Jimi in 68 and I ain't a kiddin'! Man oh man the thick gooey syrupy low end crunch I've been chasing all my life and thought it was in the speakers. This is a total different animal from every amp I've played including a Dr Z Route 66 based on the JTM45 circuit except it uses an EF86 front end instead of 3 preamp tubes. It was way too clean and needed a pedal to crunch up. Not this baby. I dime it and can nail any early or late Hendrix or Trower. So I changed out one Greenback for a G12H30 anniversary and that took a slight amount of the low end crunch and tightened up the bottom but gave amazing singing sustaining mids out the wazzoo! So now it has the best of both worlds, vintage Jimi with modern but through the mix that will open up a serious can of whoop ass on any Super Reverb, Twin, Bassman or 100 watt modern Marshalls. I just can't get enough of it. While the HW clones sound great on youtube etc, this reissue is everything I've been chasing for 35 years of amp after amp. When you rated the reissue up top, you were spot on because I think I have a very well trained ear and this baby rocks! Don't waste any time on modern amps if you want vintage Hendrix, Clapton, Trower, Free type sounds. The reissue is my choice hands down and I doubt I'll change or mod a single thing about it
gaz
on 05/23/2009
I am wondering if this should be my next Ceriatone, or the HRM (dumble)(hot) clone, I have the Overtone Special and it is my fave. A friend has a JTM45(Bluesbreaker, right?)combo, they are great sounding, loud though, a master volume could wreck the tone I suppose... any way Ceriatone will be my path...
mark lock
on 05/22/2009
i own a ceriatone jtm45 loaded with jj pre amp tubes and kt66 power tubes. the craftmenship of this amp is mind blowing. i play with some of the top players in the st.louis area and they all agree this amp is as sweet as it gets. less than a 1000.00 and shipped perfectly to my front door. i have played most styles of marshalls, fenders, mesa, vox and so forth. the jtm45 in my opinion is the most universal amp in the world, and second to none excepting quatlity pedals.
Anthony
on 05/13/2009
Great article! Very informative. I'd like to know what folks think of the Budda amp.
Frank McLaughlin
on 04/30/2009
Re: major issue with ALL "reissues". I see your point but if you look back on history, the only true lucious tones ever came from those late 60s amps. After that, it's all been garbage tones through particle board cabs till people started realizing they threw the baby out with the bath water. My beef about "reissues" is they're never really a true "reissue". Take the Vox V847 wah where they say "based on the design of the original pedal of the '60s". Well nothing could be further from the truth. if you open up an original you see a bunch of good quality electronic parts hand soldered to a circuit board. The new one is a bunch of surface mounted chips on a green circuit board with a ribbon cable coming out and bears no resemblance at all no does it sound anything like an original to my ears. I think The Metro Amp folks seem to follow through to the closest approximation and the fact that the reviewers thought it sounded the best proves it out so kudos to them and to the others who without tweaking there'd be no innovations. My money would be on Metro though. I would like to hear though about Ceriatone as well from some pros in the know.



Your Comment:  

All comments are subject to editing or deletion by the Premier Guitar staff.

Your Name:  


Please enter the text you see in the image:  
10