1969 Super PA head what to do..?

[Ned B]

Please post a shot of the label. It looks like the serial # is 1304A which would be early June '69 and pretty early for a metal panel 100W. Besides servicing and checking tube health I would vote for minimal tweaking in the form of a volume pot cap, mixer cap and maybe a fat cap across the V2 cathode resistor experimenting with values starting at .68. These can be done without disturbing the original soldering.

I think it's a real cool amp. I can see great applications for an amp like this when you already the "screaming" amp covered.

 

[Joethebh]

Please post a shot of the label. It looks like the serial # is 1304A which would be early June '69 and pretty early for a metal panel 100W. Besides servicing and checking tube health I would vote for minimal tweaking in the form of a volume pot cap, mixer cap and maybe a fat cap across the V2 cathode resistor experimenting with values starting at .68. These can be done without disturbing the original soldering.

I think it's a real cool amp. I can see great applications for an amp like this when you already the "screaming" amp covered.

I’ll double check it and post a pic of the label. I seem to recall something like June 3 1969…?

 

[Ned B]

That makes total sense. The label might say "Job 56." I have 2 50Ws in that serial range test dated June 4th that are wonderful amps.

 

[PentodeLicious]

Sounds good. I can get a “similar” tone from my stock 69 plexi with the presence rolled off. Volume on full. Straight in.

Sounds awesome. Only one problem. volume on full. I can't do that here I live in an apartment building

Once again, opinions vary. Even in the case of very heavy overdrive, I have yet to hear any pedal that matches, to cite a specific example, most any good Mesa Mark series amp from II to VII. But as my tastes tend to change from time to time, I don't want to hear that much drive out of a vintage Marshall. To me their sweet spot is in a lower gain range. Even when modded, I would not go for extreme gain/drive/saturation.

The Soundcloud clip referred to is just too much fuzz and buzz. I don't particularly care for it. If I want that kind of heavy overdrive my Mesa Mark III Blue Stripe does it MUCH better to my ears. Or I love to boost a Plexi/Superlead type amp with a clean boost pedal. But not an overdrive pedal.

I'm about to sell or trade off my only high gain Marshall, my DSL100H, because it's just not a high gain tone that pushes my buttons.

Well each entitled to his own opinion.
I would love to have me Mark III but they are non existent here.
Also it will not be as tight as the sound I posted.
Maybe chunkier but not tighter.
Even metallica tightened their mesa with a solid state EQ and went thru a marshall power amp.
But yeah it is a matter of preference.

 

[TAZIN]

Damn, that's a nice untouched circuit. The filter caps are original too.

 

[Ned B]

It is pretty unusual that a laydown PT on a US bound metal panel appears this late though being a PA would be the reason.

 

[Joethebh]

Any of you guys have a Marshall logo you’d sell me for it?
@Ned B @neikeel @TAZIN

 

[Joethebh]

Hit the front of it with a Mxr 10 band to boost it a bit. Just messing around with it. More bad playing.

 

[playloud]

Hit the front of it with a Mxr 10 band to boost it a bit. Just messing around with it. More bad playing.

Sell it and get a Mesa. It clearly needs more ribbon cables and bogus associated patents

 

[Joethebh]

Sell it and get a Mesa. It clearly needs more ribbon cables and bogus associated patents

Exactly! I never liked Mesa amps. The drive channels never did it for me. Not to mention the million stupid switches. If I want high gain I use my Wizards anyway.

I have been wanting to try a Schaffer replica… any experience with those?

 

[playloud]

Exactly! I never liked Mesa amps. The drive channels never did it for me. Not to mention the million stupid switches. If I want high gain I use my Wizards anyway.

I have been wanting to try a Schaffer replica… any experience with those?

Nope, but I'd be keen to hear your thoughts!

What model Wizard do you have? Those are interesting amps

 

[Joethebh]

Nope, but I'd be keen to hear your thoughts!

What model Wizard do you have? Those are interesting amps

W800 (which I’m currently trying to sell), Vintage Classic, Modern Classic II, mtl mk2. All 100 watts. W800 is huge and punchy. Loudest 100 watt amps on planet earth.

Modern classic II. Clean channel with the built in boost on.

 

[playloud]

W800 (which I’m currently trying to sell), Vintage Classic, Modern Classic II, mtl mk2. All 100 watts. W800 is huge and punchy. Loudest 100 watt amps on planet earth.

Modern classic II. Clean channel with the built in boost on.

Yeah you can hear the punch in this clip!

The schematics I've seen suggest the MC has a 4 gain stage preamp (no cathode follower)? Impressive that it doesn't descend into a fizz-fest if so. It still sounds like it has a lot of character.

Re volume, have you compared to a DR-103? I know they only bear a superficial resemblance, but I've A/Bed one with an early 70s Super Lead before and it was sounded significantly louder (through the same cab). I suspect the PI has a lot to do with it.

 

[Joethebh]

Yeah you can hear the punch in this clip!

The schematics I've seen suggest the MC has a 4 gain stage preamp (no cathode follower)? Impressive that it doesn't descend into a fizz-fest if so. It still sounds like it has a lot of character.

Re volume, have you compared to a DR-103? I know they only bear a superficial resemblance, but I've A/Bed one with an early 70s Super Lead before and it was sounded significantly louder (through the same cab). I suspect the PI has a lot to do with it.

Wizards are zero fizz, zero compression. Open, punchy and brutal in a good way. Tons of punch.

100 watt Hiwatts are stupid loud too but I still say wizards are louder in MY experience but again ymmv. The transformers that Rick at Wizard uses are just massive.

The thing about the wizards that I love is they have a very aggressive upper midrange “Kerang” to them that you don’t always find in all vintage Marshall’s. My 69 plexi does it and that’s why it’s my favorite amp. Here’s a clip of it.

 

[neikeel]

I’d have no guilt in putting a 560pF Lemco on channel 1 mixer and 100-1000pF bypass cap on vol 1 pot. Then leave the stock NFB resistor but move the feed wire to the 8ohm tap if you wanted more raunch (I probably would not as it affects the other channels too). I’ve done it to a few ‘worthless’ PAs of different vintages to make them like a Superbass/early Superlead.
I’ve just done a 69 with early Dagnalls to VH spec with split cathode (on a vintage paxolin stand off added electrolytic bypass cap to v3a (remember it’s a PA) 500pF mixer, 47k NFB and a 50k RS/AB mid pot
Kept it neat, saved the parts, no guilt!!

 

[neikeel]

Ps only place to get logos is a certain Denmark St vendor that has them made. Only ones that fit.

 

[giam23]

Cool amp, I’ve got essentially the same out from slightly later in 69 so it’s just got one long solid board. Those TCC caps are definitely original, I wouldn’t rush to replace them straight away, get them measured, visually inspected and reformed if needed as they look very clean.

As for mods I’ve got all my channels doing different things. If you want to keep originality I would just use different bright cap and treble mixer bypass caps on each channel. That way you are just soldering caps on top and not removing anything.

And for logos, as neikeel said, sadly that certain Denmark st vendor is the only place to get a good logos with the correct vintage hole spacing. It’s painful to give those guys business but there’s a reason their logos are decent sadly

 

[william vogel]

Most definitely without my playing!!

I think it sounds good. Hit it with a boost if you want more gain and jumper all four inputs with Y cables. You could easily add a bright cap to volume 1 but I’d just jumper the channels and that’ll give you more gain and boost the guitar. That sound was nice. An Exotic Super Sweet Boost mini is what I use and it has internal dip switches that let you adjust EQ.