Marshal Major?

pinkphiloyd · Post by **pinkphiloyd** » Tue Mar 27, 2012 5:59 am

I had never actually heard of this model until tonight when I was looking into John Frusciante's tones. I'm interested, but I can't find much info and what I have found seems shaky and often contradictory. And I've wanted a KT-88 amp for awhile. Anybody have any suggestions of something that might put me in the ballpark of the Major? But down around 100 watts or so, if possible. What about just re-biasing my super reverb for KT-88s? Possible? I'm not at all familiar with the tube. And I'm currently stoned on Lorcet and don't trust my own research/ critical thinking ability.

rdjones · Post by **rdjones** » Tue Mar 27, 2012 6:05 am

pinkphiloyd wrote:I had never actually heard of this model until tonight when I was looking into John Frusciante's tones. I'm interested, but I can't find much info and what I have found seems shaky and often contradictory. And I've wanted a KT-88 amp for awhile. Anybody have any suggestions of something that might put me in the ballpark of the Major? But down around 100 watts or so, if possible. What about just re-biasing my super reverb for KT-88s? Possible? I'm not at all familiar with the tube. And I'm currently stoned on Lorcet and don't trust my own research/ critical thinking ability.

KT88 is a variation on the 6550.
The Major uses an ultralinear OT.
Is your Super Reverb ultralinear ?

rd

rdjones · Post by **rdjones** » Tue Mar 27, 2012 6:17 am

The Sunn amps are ultralinear, some with KT88s or 6550s.
Still not gonna bark like a Major, though.

rd

Luthierwnc · Post by **Luthierwnc** » Tue Mar 27, 2012 6:25 am

The Pig!

Your poor Super Reverb doesn't put you there. IIRC you are talking 600+ volts, bias around -80 volts. As rdjones mentioned, ultralinear taps on the OT.

Other than the power section, it is basically a plexi. Start there and consider how to heat it up. sh

pinkphiloyd · Post by **pinkphiloyd** » Tue Mar 27, 2012 7:03 am

Is your Super Reverb ultralinear ?

Nope. It's a '72.

Other than the power section, it is basically a plexi. Start there and consider how to heat it up.

That may be the ticket right there. Thanks.

Reeltarded · Post by **Reeltarded** » Tue Mar 27, 2012 7:35 am

I accidently bumped into a plexi style circuit that mimics it fairly well, but mostly it's about 820R V1B and 100k NFB on 16R tap. Just degain the amp to about 6-7. 47k/556p tone stack, 470 bypass brite mixer, and .047 PI couplers. The Majors use .047s, and the 556p, and UL sounds sort of like mondo NFB. I have several working examples, all very loud, and not as fun as they used to be... sort of..

rdjones · Post by **rdjones** » Tue Mar 27, 2012 9:14 am

Deep Purple was the first band to be listed by Guinness as the world's loudest during the period when Blackmore was known to have used Marshall Majors.

Yes, very loud.

rd

Bob S · Post by **Bob S** » Tue Mar 27, 2012 10:37 am

Don't stand too close to your cab - these things are destructive to ear drums.
I blame a pig for my partial deafness. Fun days back in the 70's.
At least my sight & sense of balance settled down after a couple of days.

selloutrr · Post by **selloutrr** » Tue Mar 27, 2012 3:18 pm

almost as much to retube as they are to buy - just an FYI

Firestorm · Post by **Firestorm** » Tue Mar 27, 2012 4:14 pm

pinkphiloyd wrote:What about just re-biasing my super reverb for KT-88s?

Your Super almost certainly doesn't have enough filament current to heat KT88s. 1.6-1.8A per KT versus 900mA for 6L6. You would need to add a filament transformer. And you will not get to 100W with the Super's supply voltages.

Reeltarded · Post by **Reeltarded** » Tue Mar 27, 2012 6:02 pm

selloutrr wrote:almost as much to retube as they are to buy - just an FYI

This is my problem. Good thing I only like Majors as practical jokes on the people who like to sit close. I am mellowing though, and too old for fun.

mAx___ · Post by **mAx___** » Wed Mar 28, 2012 5:16 pm

Luthierwnc wrote:The Pig!

Other than the power section, it is basically a plexi. Start there and consider how to heat it up. sh

I also want a Major-sounding amp, less the volume. I'm interested in starting with a Plexi kit and modifying the preamp section to Major specs, as well as using a cathodyne PI, leaving the power section alone. Can this be done to an 18W or 50W kit? I'm sorry if this question is too silly, I have no technical background.

Reeltarded · Post by **Reeltarded** » Wed Mar 28, 2012 5:41 pm

The preamp is the same as a JMP 50 (1987/1986) of the same vintage.

Just do like I said above and turn a 50 into a "sounds like". Totally go overboard with the NFB to make it sound more like the completely unforgiving UL Major output.

The "sound" of a Major *is* the output. It sounds kinda shitty... are you guys sure you want this thing? I have some because they were cheap, and hilarious -ONLY-. Turn a Superlead without a bright cap and no master to about 4, and there you have it. Quacky clean with an edge of treble knives cutting into your wishful ears. Seriously, these amps get a reputation for being great when they were more than a 50% failure in design. The Pig model was 100% failure in design, that is why Genex designed the output section in the later models instead of Marshall. They couldn't make 180 watts without fires, and failures.

They are rare. There is a reason. If you have your heart set on one, BUY ONE, delete the UL, kill off the insane B+, and load it with Sylvania 6550s.

If you want to sound like Ritchie Blackmore on Machine Head, use an AC-30, just like he did.

mAx___ · Post by **mAx___** » Wed Mar 28, 2012 6:43 pm

LOL, I already have an ultra-modified handwired AC30 to emulate Ritchie Blackmore's "Machine Head" sound, you read my mind!

Here are my results so far, before and after the mods:

http://www.youtube.com/user/mgalbu?feature=mhee

But IMO he did use the Major in that record on at least one song. One of my favourite sounding solos is his second on "Maybe I'm a Leo". So far, and with a variety of VOX amps and treble boosters (including an exact clone of the silicon Hornby Skewes I built), I haven't been able to even get close to that sound, leading me to believe it could be the Major.

So my best bet would be to get a 1987 kit and modify it so it has way more NFB, correct? Any general advice on how to achieve that? Can it also be applied to an 18W Plexi kit?

Reeltarded · Post by **Reeltarded** » Wed Mar 28, 2012 8:22 pm

That is a GREAT solo, and a very cool sound. There is a lot of cut going on in that sound post facto. It's in the mix.

If you build a 50 you can fake that noise. Follow the simple changes I stated up thread, using 100k on the 16 ohm tap for NFB, then two master types that work for you to keep that sound, the PICMV. lmao PI Cathode Master. It's a 50kRL (reverse linear) pot in series with the 470R in your PI. Good for about 1/2 reduction before you hate it. Jose with a .022 coupler sounds great, and actually accentuates the part of the sound you are looking for.

Simple master won't drive the PI, and a PPIMV kills the NFB.

18 watt amp? What's that? Is it true-bypass so all your signal still gets to the big amp? haha

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