Marshall Major Help

[JackBootedThug]

Michael r/T modded a few and got them sounding killer. He changed his name on here and disappeared after some issues with his work. Shame. He could play and seemed really likable and knowledgeable…

 

[NowYou'rePlayingWithPower]

Yes, some people actually play what's known as "music" through their "music gear," instead of letting it collect dust in their mancave - which is why I noted both options

My concerns are very little if any about collectible value, more or less if I'm going to fuck up his tone dreams through replacing parts. I try not to let things collect dust if possible, though am guilty of it with some guitars, but mainly due to them being family heirlooms. The rest is just because I'm crazy and like to try as many things as I can, but pass them on if I get too bored or not used.

 

[DanTravis62]

My concerns are very little if any about collectible value, more or less if I'm going to fuck up his tone dreams through replacing parts. I try not to let things collect dust if possible, though am guilty of it with some guitars, but mainly due to them being family heirlooms. The rest is just because I'm crazy and like to try as many things as I can, but pass them on if I get too bored or not used.

I would suggest just doing a three prong cord mod to begin with then

And then play it by ear if he decides he wants something different from it

 

[NowYou'rePlayingWithPower]

Michael r/T modded a few and got them sounding killer. He changed his name on here and disappeared after some issues with his work. Shame. He could play and seemed really likable and knowledgeable…

R/T? 440Cuda, maybe? ?‍

 

[NowYou'rePlayingWithPower]

I would suggest just doing a three prong cord mod to begin with then

And then play it by ear if he decides he wants something different from it

Kinda the route I'm leaning. Was just seeing if there were any must have mods. I think I'll go with that advice. Did you see the added pics on that post, btw? Not sure about the transformers being original or not off the top of my head.

 

[DanTravis62]

Kinda the route I'm leaning. Was just seeing if there were any must have mods. I think I'll go with that advice. Did you see the added pics on that post, btw? Not sure about the transformers being original or not off the top of my head.

I did, I can't tell from the pics if theyre the originals or not

I think that's a great idea, let your husband decide if he thinks it needs any extra sauce on top

 

[M@ttC3]

What mods are common? Is it dumb to mod one if it's original? Not that it's super important because it would probably be a lifelong amp. Was def feeling adding a grounded power cord, but what else do you think is a good idea? Here are some gut shots. There are other pics that look like the caps are probably NOS or original, but have pretty much everything in that department on hand if needed. Not seeing any service labels, either. Not the best pics, will probably try and get more to get a better idea before heading to Seattle this weekend to check it out. It's $3500.

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Wow- that's pretty damn cool.

 

[PatF]

Hi, that is really clean. Maybe a few caps have been changed. The orange drops. No big deal. I used a '69 for many years with two blackback cabs. It had a cascaded V1 and master volume like a JCM800 2203 / 2204. Michael R/T used to post his here and it sounded great with the cascade and a LarMar master volume. It would help to get a heavy duty variac (10A) and knock it down a good bit.

Risky advise, but I don't think a Tubescreamer with the gain on 0 and volume on 5-6 would kill it. I don't know because I used to always run straight in.

 

[glpg80]

The ultra linear power transformers hit like a fucking truck. It’s way more efficient than triode strapped or current pentode designed power supplies use today. Screen grid resistors act as shitty current sources for the screens - this PT has a dedicated tap right off of the PT hence the ultra linear design. It will sound more HIFI with gain, think super detailed and less bark/growl. I also think these power transformers are really high plate voltages.

I imagine my Aldrich++ in this would literally shake foundations. I’m not even running high B+ in my prototype or KT88’s or even high efficiency speakers.

I’d probably remove the stock OT as the windings are likely paper insulated and can’t take the heat my design would throw at it. Id also remove in tact the original turret board. Id go to Mercury Magnetics and have them supply an axiom OT that can handle the abuse. I’d put in an aftermarket 2203 PCB. My mods to require drilling the chassis though all over - PCB mounts, pots, certain components straps, etc. it’s quite invasive and not something a purist would approve.

As far as current mods, get rid of that red death cap on the top right. 3 prong cord immediately and drill a dedicated hole in the chassis for a bolt and standoff to solder to. Anyone that cries foul with these suggestions should never touch a solder iron.

It needs filter caps replaced and do the bias caps as well. These are all regular maintenance items and safety items. If it has a polarity switch disconnect that as well.

 

[GOHOINC]

It's had work, that's for sure...

 

[NowYou'rePlayingWithPower]

The ultra linear power transformers hit like a fucking truck. It’s way more efficient than triode strapped or current pentode designed power supplies use today. Screen grid resistors act as shitty current sources for the screens - this PT has a dedicated tap right off of the PT hence the ultra linear design. It will sound more HIFI with gain, think super detailed and less bark/growl. I also think these power transformers are really high plate voltages.

I imagine my Aldrich++ in this would literally shake foundations. I’m not even running high B+ in my prototype or KT88’s or even high efficiency speakers.

I’d probably remove the stock OT as the windings are likely paper insulated and can’t take the heat my design would throw at it. Id also remove in tact the original turret board. Id go to Mercury Magnetics and have them supply an axiom OT that can handle the abuse. I’d put in an aftermarket 2203 PCB. My mods to require drilling the chassis though all over - PCB mounts, pots, certain components straps, etc. it’s quite invasive and not something a purist would approve.

As far as current mods, get rid of that red death cap on the top right. 3 prong cord immediately and drill a dedicated hole in the chassis for a bolt and standoff to solder to. Anyone that cries foul with these suggestions should never touch a solder iron.

It needs filter caps replaced and do the bias caps as well. These are all regular maintenance items and safety items. If it has a polarity switch disconnect that as well.

TY!

 

[paulyc]

They dont blow up with boost pedals. Cripes Blackmore used his with an Akai tape recorder to use the preamp of the recorder for more gain. And I believe the traditional Marshall master volume circuit is from a modification done to Richies amps…

 

[Jdub]

I had a '69 Plexi panel Major for a few years back around 2002 to 2005. It was cool to own and sounded pretty good but was actually painful to use it was so damn loud. But once cranked, I thought it sounded much like a regular plexi. I used it with several different drive pedals with zero issue. It really liked a pedal called the"boiling point". I forget the maker of that pedal, but it had some "swirl dip" looking paint job. I later read that is was unsafe to use with a boost pedal, but I never had an issue, so not sure if that is correct or not... maybe it already been altered to render its safe.? Not sure, but nowadays, with the advent of gear like the fryette powerstaion etc they would be much more practical. At the time, not so much, but it did sound good. Not my favorite Marshall I have had, but it sounded like what you would expect from a 4 hole Marshall. Sold it for 1500 btw.

 

[NowYou'rePlayingWithPower]

I had a '69 Plexi panel Major for a few years back around 2002 to 2005. It was cool to own and sounded pretty good but was actually painful to use it was so damn loud. But once cranked, I thought it sounded much like a regular plexi. I used it with several different drive pedals with zero issue. It really liked a pedal called the"boiling point". I forget the maker of that pedal, but it had some "swirl dip" looking paint job. I later read that is was unsafe to use with a boost pedal, but I never had an issue, so not sure if that is correct or not... maybe it already been altered to render its safe.? Not sure, but nowadays, with the advent of gear like the fryette powerstaion etc they would be much more practical. At the time, not so much, but it did sound good. Not my favorite Marshall I have had, but it sounded like what you would expect from a 4 hole Marshall. Sold it for 1500 btw.

We live in the middle of nowhere, so practical is not a problem My only concern after reading some responses is that I don't want to have to replace every part in it otherwise it seems to make more sense to just build something from scratch or just pass on it. Dunno, gonna check it out on Saturday.

 

[Jdub]

We live in the middle of nowhere, so practical is not a problem My only concern after reading some responses is that I don't want to have to replace every part in it otherwise it seems to make more sense to just build something from scratch or just pass on it. Dunno, gonna check it out on Saturday.

Wear a kidney belt! That amp will rearrange your innards. If it has sentimental value to your husband and it is not stupidly overpriced I would get it If I was you. Certainly a cool piece of Marshall history