NAD!!! 1971 Marshall #1992 Super Bass 100W

glpg80

glpg80

Well-known member
It's been in storage in a garage and in an attic for 25 years. The owner was an elderly man and passed away. His son is now selling his property and pulled it out of the garage. I drove 11 hours round trip over the weekend to go get it and paid cash on the spot.

It's also a rosemary amp which my 1974 isnt :rock:

I plan to restore it, all new bolts/screws (they're corroded to the point the screw heads are coming off), clean the original sockets, remove the death cap (I'll hang onto it for novelty), install a new 3 prong chord, remove the polarity switch, and order a new replacement faceplate with no polarity switch.

It came loaded with EL34s but I need to reverse engineer the circuit board to see what it was designed for. Since it has a polarity switch, my gut tells me it should be loaded with 6550s.

I wasn't looking for another marshall, but I came across it randomly online. I thought I'd never come across one in my pricepoint and always thought a PTP marshall was out of my reach. Super excited :rock:

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Looks like a nice project. Should clean up nicely. Watch out for the ink on the faceplate, it comes off easily. Will need a cap job. Let us know how it turns out.
 
Those can caps are 50 years old. But my opinion has no value, I'd rather have it function. A cap job is not a detractor.
 
Congrats! Looks nice n clean. I picked up a 72 SuperTrem for a good price a few months back; not a dent/tear/rip on it. I don’t miss my Wizard at all when I play it.
Just the real deal rock amp..put a boost or two in front and watch out.
 
Nope, stand up mains. The power transformer in this one is larger than the one in my 74, it’s massive!

I paid 1600 cash + 11 hour drive + too many tolls to count. I’d say it was a fair deal :)

I’ll post more pictures in the future. I just got it yesterday and was tired from the 700 mile round trip.

No worries on the mods guys. It’s in mint condition and I’ll restore I to safe and working order, only replacing electrically what is needed.

The two caps across the diodes need removed
The bias caps need changed
The filter caps need replaced
All socket and board mounting hardware needs replaced - the heads are corroded through.
Death cap needs removed
Polarity switch will be removed
I’ll do what I can to restore all of the original potentiometers
New 3 prong power chord is needed

Other than that, it just needs soap and water and a lot of TLC. The front faceplate will hopefully come clean with diluted rubbing alcohol and Qtips.
 
Very cool!
Regarding the power tubes, to me everything looks like it was for EL34's except that 10k dropper in the bias circuit. I would expect 15k there so that leans towards 6550 (or maybe different voltages from that fat PT).
 
If it's never been touched, you should leave it as-is... unless of course you're planning on using it. If not, and if it's stock, I'd leave it alone. Ah, fuck-it... play that bad-boy! :rock: Just don't "Jose" mod it.
 
Searay":2ll8jgkf said:
Looks like a nice project. Should clean up nicely. Watch out for the ink on the faceplate, it comes off easily. Will need a cap job. Let us know how it turns out.
Click to expand...
Maybe...without any bulging, leaking or 'thinner' tone those caps may be just fine. I've always changed them if there are any bulges, and always noticed a difference for the better. But my 72 has no bulging or leaking and sounds amazing the way it is. Collectors actually want the originals believe it or not. If you want the value to be optimal. This amp has been sitting for a long time so it's probably safer to change.

Those early 70s PTs came with over 500v...mine does have a replaced PT but it's still at 495v and out of a later 70s Marshall. The laydown PTs only came with Canadian and Northern EU Marshalls after 1970.
Really great amps; even a great 2203 does not measure up to these NMV Marshalls IMO. Every Marshall guy should try and find a vintage NMV at least once.
 
The caps will get changed - they've not been cycled in over 2 decades and it's not worth risking the PT being stressed at startup with a direct short to ground. I don't cater to collectors, I cater to players. Collectors can go jack off on another one somewhere else.

The transformers in this 71 are the same as what was used in a 68 plexi - they're extremely valuable. I plan to restore it to players condition and not collectors condition. No death cap, no caps across the diodes, new bias caps, and a properly grounded 3 prong plug. I'll probably splurge for NOS Mullards for tubes.
 
glpg80":1jj0cwda said:
The caps will get changed - they've not been cycled in over 2 decades and it's not worth risking the PT being stressed at startup with a direct short to ground. I don't cater to collectors, I cater to players. Collectors can go jack off on another one somewhere else.

The transformers in this 71 are the same as what was used in a 68 plexi - they're extremely valuable. I plan to restore it to players condition and not collectors condition. No death cap, no caps across the diodes, new bias caps, and a properly grounded 3 prong plug. I'll probably splurge for NOS Mullards for tubes.
Click to expand...
:rock:

Better to be safe than sorry, since it's been sitting. My 72 came with Siemens 34s and Tungsram pre tubes. Put some vintage Mullard pre tubes in and put the Tungsrams back in as they sounded better. Interesting note...I would play for a few minutes and then the 2A fuse would pop. Power tubes tested strong; my only experience with fuses popping ended up being a bad PT. Since this amp came from England it was used to running on 240v so the switch to 120 here meant the fuse needed to be 4A. Thankfully.
 
glpg80":p7xqftab said:
The caps will get changed - they've not been cycled in over 2 decades and it's not worth risking the PT being stressed at startup with a direct short to ground. I don't cater to collectors, I cater to players. Collectors can go jack off on another one somewhere else.

The transformers in this 71 are the same as what was used in a 68 plexi - they're extremely valuable. I plan to restore it to players condition and not collectors condition. No death cap, no caps across the diodes, new bias caps, and a properly grounded 3 prong plug. I'll probably splurge for NOS Mullards for tubes.
Click to expand...
You can't try to reform the caps on a Variac with no tubes in the amp and no signal passing through it ? I'd try that first...as long as they're not bulging.
 
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