Marshall Amp....Are you NUT'S !!

James Quackenbush · Post by **James Quackenbush** » 24 Jan 2006 7:06 am

OK, some of you guys are gonna think I'm crazy, and maybe I am , but that doesn't make me a bad person !!....
Yesterday Bill McCloskey came over to my home as he was searching for the ultimate amp to go with is 12 string SuperSlide ... I have a BUNCH of amps ..So many that we did not get to try all of them , but he got a chance to play thru 6 or so amps..... He would listen to the tone, and then go " OK , NEXT " and on to the next amp .... I recently bought a guitar head that was made by Jesse James of RockyTop fame.....He does a lot of clone amps, with his own touch to make them his own, for the better I might add.... I bought his clone of the JTM 45 which is a Marshall amp from back in the 60's that Eric Clapton made famous ....It's not your typical overdriven , in your face , Marshall...By Marshall standards it's very clean , and has a natural sustain and a VERY full bodied tone....Jumper the channels, and the you have 2 volume controls ....One is a "trebley" volume, and the other volume is more on the "bassy" side ....Mix and match to taste .....The power tubes are KT66's which have an incredible bottom end ...I had this head plugged into an Avatar 2-12 cab with Eminence Wizard speakers which are suppose to be somewhat of a copy of the G12H30 speaker ...Now , if someone told me that they were going to look for a Jazz/Blues tone, this is NOT the amp I would plug into ....HOWEVER, I WAS DEAD WRONG !!..... Bill started to play , and all of a sudden a big grin came over his face !!.....I was not believing what I was hearing ....This tone was FABULOUS
It was rich and full, and bloomed like only a tube amp can .... It's only rated at 30 watt's , but when you hear the punch , and the bottom end, and the overall tone from this amp you will not believe what you are hearing ...Bill played thru a Steel King, a Webb, a Carr, all expensive amps and great sounding amps in their own right, but when plugged into this RockyTop, the rest paled in comparison .....Of course your mileage may vary as tone is a VERY subjective matter ....I figured that since it sounded so good on the MSA SS that has a pedal steel pickup on it , that I would try it for pedal steel ....I plugged my pedal steel into it this morning ....WOW !! I can't beilieve what I am hearing !! and from a MARSHALL ??...... Call me nut's , but the next time you hear my playing thru a Marshall, you won't belive what you are hearing either !!.... This is one time when it pays to be crazy ..... Dare to experiment ...You just might find what your looking for ..Jim

Bill McCloskey · Post by **Bill McCloskey** » 24 Jan 2006 7:43 am

I have to agree with Jim.

BTW, thanks Jim for letting me be a kid in a candy store.

The point was I knew I wasn't getting the type of sound I was looking for through anything I had played up to that point. They all sounded nice and as we moved from the Steel King, to the Webb, and on, all sounded nice, but all sounded like everything else I had heard and I just wasn't getting really excited.

Then we plugged into the Rocky Top. The top of my head almost came off. The bottom was unbelieveable. The highs were silky smooth, without the harshness I hear in ohter amps. It was incredibly full bodied rich sound, and the strings just popped when you hit them.

We went on to try out a few others including a classic 30, and it was again, nice sounding but there was absolutely no comparison.

Mind blowing.

Erv Niehaus · Post by **Erv Niehaus** » 24 Jan 2006 8:00 am

I had a similar experience with Marshall's acoustic amp. It is loaded with a lot of good features and sounds GREAT for a resonator or lap steel.
Erv

David Mason · Post by **David Mason** » 24 Jan 2006 8:12 am

There's a good deal about tone that can be learned from rock guitarists, in my opinion. There are concrete reasons that Carlos Santana, Jeff Beck, Eric Johnson etc. sound the way that they do, and the information is readily available. That's the Clapton "Bluesbreakers" amp clone, right? Funny it should sound good....

Andy Zynda · Post by **Andy Zynda** » 24 Jan 2006 9:48 am

Stevie Ray Vaughan used to play through a few Marshalls, and he used them for their clean tone, not for distortion. I also have a JTM60, that sounds wonderful both clean and dirty. Their (vintage tube only) clean tone is every bit as good as a Fender, just different.
2 cents.
-andy-

Joey Ace · Post by **Joey Ace** » 24 Jan 2006 10:15 am

This is a photo of me at a show last summer.
The Marshalls weren't mine, but the old Push Pull sounded pretty good thru them.

James Quackenbush · Post by **James Quackenbush** » 24 Jan 2006 10:47 am

There are not a lot of JTM45's out there ..The newer Marshall reissues are not using KT66 tubes which are a BIG part of the tone of this amp ..The EL34 which is the common Marshall tube is much different in tone and character .....It's much briter, and comes off with a gritier tone ...The KT66's are just BIG and Bloom like crazy ...Very rich and smooth ....not like an EL34 at all ...The KT66 allows for more of a "clean " overdrive ....More like a sweet sustain , than an overdrive .....Add an overdrive pedal to the KT66 and you're in heaven !!....Just plain SWEEEEEEET !!...Jim

Bill Hatcher · Post by **Bill Hatcher** » 24 Jan 2006 11:29 am

Why not just give the credit to Leo Fender. All the original JTM45 is would be Marshall copying the 5F6A circuit from the Tweed four 10 Fender Bassman.

Tweed Fender=Tone or E=MC2
Both expain a lot.

Edit. The KT66 is just a beffier 6l6 tube.[This message was edited by Bill Hatcher on 24 January 2006 at 11:32 AM.]

James Quackenbush · Post by **James Quackenbush** » 24 Jan 2006 11:46 am

Bill,
There are similarities as well as differences between the early Bassman and the JTM45.....

Bassman 2-5881 power tubes
JTM 45...2 -KT66's
Bassman .....50 watt's
JTM45.....30 watts
similar but different value resistors, retifiers etc, as well as different power and output transformers....
I give much credit to Leo .... Many amps were born because of Leo ...He's the man !!

Andy Zynda · Post by **Andy Zynda** » 24 Jan 2006 1:24 pm

James, one of the reasons for the tube dissimilarities is that 6L6's were not as popular or abundant as EL34's overseas. When marshall started shipping amps to the US, they found that the EL34's didn't tolerate the ride. They switched some the export amps to 6550's. (KT88)
By no means the whole story, but an interesting part of it. I also read somewhere that Jim Marshall tipped his hat to Leo's early designs.
Some great history.
-andy-

Post by **Dave Mudgett** » 24 Jan 2006 1:28 pm

Very early JTM-45 amps used 5881 power tubes, and were pretty close to Tweed Bassman knockoffs. The design evolved gradually, with a switch to KT-66 power tubes. These are all 6L6-style tubes, with KT being the M.O. Valve "Kinkless Tetrode" design, to help linearize the kink in the 6L6's response. Another difference is all 12AX7 tubes instead of the 12AY7 in the front end of the tweed amps. Of course, all these tube choices are user variable - I almost always prefer a lower-gain preamp tube than the 12AX7 in the front end. I also prefer KT-66s, but "real" ones are very difficult to find and stupid money if found. I've tried some supposedly "reissued" KT-66s, and was not impressed. There are good NOS 6L6s which sound pretty close to the KT-66, to my ears. Pretty hard to beat a nice black-plate RCA 6L6 or Tung-Sol 5881, to me.

In any case, this great response for slide guitar or lap/console steel doesn't surprise me at all. The Tweed Bassman and Pro are probably my favorite amps for slide or lap steel. I had a '57 Tweed Pro with the nice 15" Jensen P-15N which I very boneheadedly traded away several years back. They're stupid money now. That had black-plate RCAs in it.

I just picked up a used THD Flexi-50 on a trade. It's set up in JTM-45 mode, with 12AX7 and the new Groove Tubes "new manufacture" 6L6 tubes. It really has the JTM-45 sound - I say that because I owned an old one for several years. With remote-switchable master volume and boost, this amp gets a very credible Sonny Landreth or Dave Lindley - style sound as it sits right now, even with my Zum with 16.8KOhm TrueTone. The bottom-end is big and fat when pushed, the way it should be. The real nice part is that it's possible to use any "standard" preamp or power tube - it can be biased from the back of the amp with a normal millivolt-reading voltmeter. I haven't had a chance to fully explore the amp yet, but so far, so good.

To me, a good tube amp in this style should be fairly transparent and let the tubes speak freely. There are lots of designs which do this - old tweed amps, early Marshalls, this THD, and many others, I'm sure. The later Fenders used more negative feedback in the power amp circuit, which cleaned them up and extended the frequency response - good for some things and not for others. Personally, I prefer the later design for cleaner guitar and pedal steel tones, but prefer the earlier designs for slide guitar and lap steel tone. Tube choice is more critical for the earlier designs, in my opinion.

After listening to sound clips of Dan Tyack with his THD BiValve, I know I need to try one of those also. This is a class A amp, unlike the ones we're discussing here, which are class AB.

James Quackenbush · Post by **James Quackenbush** » 24 Jan 2006 2:55 pm

Very interesting .....I was affraid that the tone would be too dark running the KT66's , and also thought that the pedal steel would be better served with more of a BlackFace tone setup running 6L6's and while the Blackface tone is much briter , and sounds completely different , the KT66' s really fill a punchy bottom end, little mids , and just enough high's to really bring out a natural sustain that you don't get with the Blackface circuit ....It's a much thicker tone, and continues to get thicker the higher you turn it up ....Please don't get me wrong, I love the Blackface tone for pedal steel, and for guitar , but stumbleing on this was like finding a diamond in the rough ....Now for my next trick ...........JTM45 clone TOGETHER with a Steel King !!........."honey, the police would like to have a word with you " ...Jim

Bill McCloskey · Post by **Bill McCloskey** » 25 Jan 2006 8:18 am

I just placed my order for the Rocky Top. Very anxious to start experimenting with this sound.

James Quackenbush · Post by **James Quackenbush** » 25 Jan 2006 1:20 pm

You guy's interested in a great sounding Point to Point wired amp, built with all quality components, the 45 H is on sale from RockyTop .... One listen is all it takes, and this amp can be used for guitar or pedal steel, or even bass if your speakers can handle it !!.....Tell Jesse you heard about it from the Pedal Steel Forum

Contact Jesse for the sale price
http://www.rockytopelectronics.com
[This message was edited by James Quackenbush on 25 January 2006 at 01:22 PM.]

David Doggett · Post by **David Doggett** » 25 Jan 2006 4:43 pm

Any chance of one of you guys bringing one of those to Reece's workshop in NYC next month?

------------------
Student of the Steel: Zum uni, Fender tube amps, squareneck and roundneck resos, tenor sax, keyboards

Bill McCloskey · Post by **Bill McCloskey** » 25 Jan 2006 6:36 pm

A lot to haul down' to Howard's.

I think we should convince Howard to buy one for us all.