'67 Super Trem - thoughts?

[playloud]

This one has been listed on Reverb a few times now:

https://reverb.com/item/76107248-marshall-plexi-jmp-supertremolo-1959t-superlead-1967

It has the Drake 1202-132 OT and other features (e.g. single rectifier) seem to point to late '67, right before the introduction of Dagnall iron.

I'm a little perplexed by the Hunts PS caps, as I don't recognize that type/value, and the date code (7th week of '68) seems too late. I suspect the area around the power supply has been reworked a fair bit (see also: switches). I also see less amber dye on the solder joints than expected, but appreciate this can be hard to make out.

Perhaps the more experienced members have thoughts?

 

[TAZIN]

This one has been listed on Reverb a few times now:

https://reverb.com/item/76107248-marshall-plexi-jmp-supertremolo-1959t-superlead-1967

It has the Drake 1202-132 OT and other features (e.g. single rectifier) seem to point to late '67, right before the introduction of Dagnall iron.

I'm a little perplexed by the Hunts PS caps, as I don't recognize that type/value, and the date code (7th week of '68) seems too late. I suspect the area around the power supply has been reworked a fair bit (see also: switches). I also see less amber dye on the solder joints than expected, but appreciate this can be hard to make out.

Perhaps the more experienced members have thoughts?

It's a mid 1967 build with replaced caps for the power section. Originally they would have been 100uF/350 volt caps with black text.
EDIT:
Admittingly in my haste I failed to view the rest of the amp instead of just the power section caps. As Ned pointed out the Mullard signal caps do look like they have D8N codes. Also interesting is that the power section filter caps are 16+32uF/350v axial caps which I don't recall ever seeing in any other builds. Also Ned mentioned the perforated preamp board along with the two B+ dropping resistors which is something you normally don't see with a mid '67 build. Interesting that the two B+ dropping resistors are butt soldered together. Plus, the NFB resistor is a Piher brand 47K. Bottom line is if it is a factory build then it's one that used up old parts sitting on the shelf. It could be a factory rebuild possibly or maybe just a lash-up build.

 

[Ned B]

I tried to get mustard cap date codes. I thought I saw an "8" on one, but I'm not sure. I'm thinking this is a late amp for the last Drake series, so maybe completed in early '68 is actually the case here. The 105XX serial #, later turret type and 2 dropping resistors seem consistent with '68. I have an earlier trem with the 1202-119 OT. The main board is solid on it while this one is perf.

 

[Ned B]

It would be interesting to compare with 10546 that was subject of a thread in 2015.

First Post: 1967 Marshall Super Trem

Hi, Lots of great info on this site. Here is a first post from me. I recently acquired what i believe is a '67/early '68 super trem. Serial number 10546. Has original Drake 1203-80 power transformer and 1202 132 output transformer (not the more common 1202 119). Tesla blue bottle EL 34...

www.marshallforum.com

 

[Beryllium-9]

This is a killer amp! My SB is 10550..

 

[shakti]

My late 67 SB has butt soldered 8.2+10k dropping resistors, so nothing unusual there. Even if the amp might have been somewhat re-worked or maybe even a lash-up that is actually a fair price these days. It won’t last long.

 

[TAZIN]

My late 67 SB has butt soldered 8.2+10k dropping resistors, so nothing unusual there. Even if the amp might have been somewhat re-worked or maybe even a lash-up that is actually a fair price these days. It won’t last long.

True about the two B+ resistors just being soldered together...I had to look at my files to refresh my memory regarding this era of Marhsall's. I also noticed that the B6N Mullard date sometimes can look like B8N if the printing isn't crisp and that very well might be the case with this amp given that the photos aren't the best resolution. Overall this amp is pretty close to the others I have on file representing late Summer - early Autumn of 1967. Obviously with this amp the power supply filter caps don't jive but as I mentioned earlier they might be replacements. Most of the amps I have on file use the solid main/preamp board, like Ned mentioned, but some of the later builds do have the perforated.

 

[playloud]

Well it's gone now (again). Let's see if it reappears in a few weeks!

I thought those mustards read "B8N" on first inspection too, but on closer inspection, I think they're simply blurred.