Marshall Major #1978 from '69

StingRay85

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Made a deal on a 69 Marshall Major. Most problematic issue is surely the missing PT. It's from 69-70 (A serial number). The front panel and head shell look in relatively decent shape. No pictures from the inside. This would be a complete rebuild, but probably not into a Major anymore. Don't think I will find a good replacement UL OT, and probably also don't need this kind of 4x KT88 amp. So maybe just rebuild it into a neat 50W with Carlsbro Drake iron, or 100W with Partridge iron.

Marshall major.jpg
 
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D-Max

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At first sight the OT looks original to me, also looking at the colors of the wires coming out of the OT.
The PT is a replacement for sure. The rectangular cutout for the laydown mains TX is visible on the chassis.
 

mAx___

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You need a new PT. Unless is toast, the OT is original. Mercury Magnetics make clones of both. Their OT sounds identical to the original in my experience. There's also a provider in Europe that sells Major transformers, don't remember exactly atm.
I'd suggest, don't make it into something else, just fix it and sell it to someone looking for a Major <<
 

StingRay85

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You need a new PT. Unless is toast, the OT is original. Mercury Magnetics make clones of both. Their OT sounds identical to the original in my experience. There's also a provider in Europe that sells Major transformers, don't remember exactly atm.
I'd suggest, don't make it into something else, just fix it and sell it to someone looking for a Major <<
It's part of the dilemma. Maybe it makes more sense to remove the OT and pass it on to someone who's in need of an original one. I would rather run this amp on EL34 tubes. I pay a fair amount of money for this amp, but not with the intention to sell it again.
 

playloud

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Nice find, but it would be sacrilege to convert this amp into another in my opinion!

If power is the issue, get an attenuator (or two). You could run one speaker jack into a 100W load, and then use the other as usual.

If you're really not looking for a Major at the moment, why not sell to someone who is? There are almost certainly people here will pay what you did (if not more). These amps are highly desirable to many, and there aren't a surfeit of them out there.
 

AndyD

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I agree with playloud, Dom. This would be a brilliant restoration project. There are plenty on here who could help you with information and parts. The output on these amps is very misleading. From what I understand, this is an amp with bags of headroom and sounds wonderful at any volume. I'm sure others agree. Lets see some photos when you can!
 

StingRay85

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I'll at least wait to make a decision until I see the internals. See how butchered it is on the inside...
 

Gene Ballzz

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I'll at least wait to make a decision until I see the internals. See how butchered it is on the inside...

While I tend to kind of agree with @playloud & @AndyD , it is your amp, your $$$, your choice! Now, if it were a "Three Knob Pig" I'd be jumpin' up & down raving! :nutkick:


Still, the circuitry of these amps is quite unique, in many ways. IIRC, the preamp is so different, even on the unit you have, that for a conversion, you won't be using much more than the chassis and maybe pots, jacks and tube sockets.

Simply Thinkin'
Gene
 

Gene Ballzz

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One of the things that makes the sound and performance of these amps so unusual is the preamp configuration and what happens prior to the phase inverter, all aside from getting the power section cranked and blazing! Notice that there is no cathode follower and the very odd way the phase inverter is fed/driven.

1967u .jpg

FWIW, a goodly pile of these amps got hot rodded into 400 watt monsters for Ritchie Blackmore and Jon Lord, by a guy named John Stillwell, A.K.A. "DAWK" just outside of Cortland, NY, in the early '70s. While he had one of my amps on his bench, I had the opportunity to crank one of Ritchie's scalloped neck Strats into one of these stacks. Besides being "UNGODLY LOUD" the sound and response was astounding! The level of clarity and controllable harmonic overtone feedback available "WITHOUT" fizzy/fuzzy distortion was something other amps can only dream of! It was an experience I'll never forget!

I'm still jonesin' to try a genuine, elusive "Three Knob Pig" just because it's circuitry is so bizarre!

Think hard before bastardizing this amp, if not already destroyed!

Just My :2c:,
Gene
 

Matthews Guitars

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My opinion: Keep it as a Major. Don't try to turn it into anything else. There's enough of a collector's market for Majors that any working example has value and will find a buyer. If you want a project amp get something more commonplace to mess around with.
 

Gene Ballzz

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My opinion: Keep it as a Major. Don't try to turn it into anything else. There's enough of a collector's market for Majors that any working example has value and will find a buyer. If you want a project amp get something more commonplace to mess around with.

^^^^^^^ True words of thoughtful wisdom, right there! ^^^^^^^

Of course, taming some of the voltages involved, to allow the use of other power tubes, for a lower wattage version of the same amp might be a good consideration.

Although, as I mentioned earlier, "Your amp, your $$$$, your choice!" Just be prepared for the angry, torch bearing mob, brandishing pitchforks and axes showing up at your door! :p

Simply Majorin'
Gene
 

mAx___

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It's part of the dilemma. Maybe it makes more sense to remove the OT and pass it on to someone who's in need of an original one. I would rather run this amp on EL34 tubes. I pay a fair amount of money for this amp, but not with the intention to sell it again.
The oversized chassis of the Major makes sense only when in need of the extra space for those huge 200W transformers and big KT88 power tubes. If you're going to remove all that, you might as well use any widely available regular size chassis for your project. Keep the Major for posterity as original as possible and tell your children to sell it in another 40 years. Easy money.
 

StingRay85

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Its surely not about money. We'll see what happens. I'll pick it up on Saturday.
 

Matthews Guitars

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Majors have never been common. While with deep pockets I could buy twenty original JMP Superleads TODAY, there's not more than one or two Majors on any of the usual marketplaces today to choose from. And at price points around 3500 dollars or higher.

If JMP Superleads are at least uncommon, then Majors qualify as actually being rare. I know one person who has owned one since the 80s and it's allegedly a former Blackmore amp, and I've had the chance to buy exactly one other and that is the only one I've seen in person, and at a fairly large guitar and amp show at that. I was very tempted. I'd see such an amp as a reliable investment.

I see that when it comes to durable, long lasting products, we are just the custodians of them as they can outlast us and still be appreciated by generations that are yet to be born. So maybe we're supposed to enjoy them, and maintain them, and preserve them for the future.

The number of intact and unmodified Majors is limited. If you keep yours in this category, you at least won't be the one who makes intact examples that much harder to find.
 

StingRay85

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The point is, it is already modified and therefore no longer intact (PT was blown and replaced by something different). Maybe the best I can do is take one of my Partridge transformers (e.g. from my Carlsbro TC100) and use it to supply close to 500V anode voltage. If this somehow would be compatible with the current OT and winding ratios, and 4x Philips EL34, that's probably the safe way to restore it in an acceptable way leaving the original OT in there. When reading a bit more about it, a boost pedal creating a square wave was enough to blow up the amp. So there's not really a lot of point in restoring this original power amp design. Seems the sound and crunch was more in the preamp design and I just need to restore the tight power amp (Partridge and high value reservoir and screen caps).
 

playloud

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The point is, it is already modified and therefore no longer intact (PT was blown and replaced by something different). Maybe the best I can do is take one of my Partridge transformers (e.g. from my Carlsbro TC100) and use it to supply close to 500V anode voltage. If this somehow would be compatible with the current OT and winding ratios, and 4x Philips EL34, that's probably the safe way to restore it in an acceptable way leaving the original OT in there. When reading a bit more about it, a boost pedal creating a square wave was enough to blow up the amp. So there's not really a lot of point in restoring this original power amp design. Seems the sound and crunch was more in the preamp design and I just need to restore the tight power amp (Partridge and high value reservoir and screen caps).

I wouldn't describe it as "modified" just because the PT was replaced. It sounds like what you really want is a 50W/100W amp from the same era, in which case it might be more sensible to find someone who wants to swap.

I'm still jonesin' to try a genuine, elusive "Three Knob Pig" just because it's circuitry is so bizarre!

If it were a "Pig" I'd be suggesting an impromptu Marshall forum convention at @StingRay85's house!
 

Matthews Guitars

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Replacement of original components with equivalent components is a repair, not a modification. The amplifier remains intact.

I think you're just itching to mod something. In my opinion you should send the Major to someone who wants it because it's a Major, and pick up a JCM800 or JCM900 series amp and use that as your guinea pig.
 


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