Clean`67 Super Bass pics + Q

[Travis Tritten]

My trade secret for logos:
NEVER GLUE A LOGO TO A VINTAGE AMP OR REPAIR A BROKEN ONE!! Use clear silicone ;-) It will hold well, won't be seen, and can be removed completely if ever desired. It doesn't ruing the tolex and is not a permanent move like glue it. Plus, you can use modern logos, cut the pins, and attach with silicone to older Marshalls having different pin spacings. Neat.

Great tip, thank you!

 

[Travis Tritten]

The knobs for your amp used to be really quite cheap, but they're now creeping up in price.....

Awesome — I’ll pick up one of these. Much better than the Stew Mac one.

 

[Travis Tritten]

Nice looking amp. The octal sockets have been changed which explains the somewhat messing wiring and screen resistor placement along with the 'buss' wire fed from the 8K2 dropping resistor. As mentioned earlier, the DCC sand block screen resistors are original and have a correct date code for this era.

A bit of an odd amp serial # wise compared to the circuit which Ned mentioned. Typically, your more apt to see this circuit in a 103xx amp (like noted on the tag sheet; 10305) verse an amp in the mid 400's. I have seen a couple of other examples where the serial # on the rear panel didn't match up with the number on the tag sheet so I wouldn't necessarily throw a 'red' flag up. The use of the Murata 250pF ceramic disc cap for the tone stack is fairly common for amps in the mid 400's whereas earlier amps tend to use the rectangle RS silvered mica cap.

The font & text alignment for the serial # and related text seems correct. The "O" in 'NO.' is slightly shorter compared to the 'N' like it should be. The 'SB' part is slightly crooked which is on par for other examples in the # range and the forward slash "/" is taller than the 'B'. The kerning on the fonts (serial # & text) looks good. The dymo label for the fuses is the correct values & style for these early US export amp.

The gray colored cap (RS 0.05uF/1000Vdc) siliconed in place is for the Polarity switch and is grounded correctly at the mains transformer. Additionally, this particular brand of cap is typical for this era Marshall which utilized a Polarity switch.

Fantastic info, thanks!

 

[Travis Tritten]

Three observations:

There appears to be a length of heavy buss wire soldered to the octal socket and running on top of the large 8.2K resistor to the left of the leftmost blue bias cap. This appears to be just an added wire going nowhere. I can't imagine that's supposed to be there.

The screen resistors...should they be ceramic bathtubs in a 1968 amp?

In the bias circuit, two resistors are end to end with leads twisted together and soldered over the twist. That is not original. At least one of those resistors has been replaced.

Your knobs...are the caps German silver? If they are...I think I have the correct knobs, with caps, for you. A full set of six.

I noticed that weird “wire to nowhere” too. What the heck? Thanks for info, very helpful.

 

[Matthews Guitars]

Please do me a favor and post some close-up photos of the knobs on your amp, showing the gold discs as clearly as possible. I want that so I can compare to what I have. I mentioned I may have some matching knobs, and I want to verify it, which will help me to date them.

 

[tomsvintage]

My trade secret for logos:
NEVER GLUE A LOGO TO A VINTAGE AMP OR REPAIR A BROKEN ONE!! Use clear silicone ;-) It will hold well, won't be seen, and can be removed completely if ever desired. It doesn't ruing the tolex and is not a permanent move like glue it. Plus, you can use modern logos, cut the pins, and attach with silicone to older Marshalls having different pin spacings. Neat.

Good advice !!

MG does have the correct spacing 6" logos.

Rather than trying to find the correct spacing 6" logo I have removed all pins except the middle pin from a repro logo ~ voila Fits with one middle pin and a pinhead amount of Elmer's glue or silicone !!

 

[Travis Tritten]

Please do me a favor and post some close-up photos of the knobs on your amp, showing the gold discs as clearly as possible. I want that so I can compare to what I have. I mentioned I may have some matching knobs, and I want to verify it, which will help me to date them.

Here’s a pic

 

[Travis Tritten]

Thanks for all the great responses. Very helpful! The amp may definitely have had some work done. But what puzzles me about that is, if somebody did work on the wiring and/or board, why would they have left the original two-prong plug? It was totally deteriorated. It’s the first thing I asked the amp tech to do. Also, I can’t prove this, but the tubes all look like they could be original. The preamp Mullards are British made IEC branded from that period. Somebody could have put vintage preamp tubes in it, sure. But the power tubes are GE branded (I assume Mullard) made in Great Britain. The plates were white and they would not come out of the sockets. Stuck with corrosion from being in so long, I’d guess. If anybody can definitively date them, please let me know. Again, nothing I can prove but they gave off the vibe of being original. I know it sounds crazy. But I picked up this amp from an estate auction. No telling how long it was stored away.

 

[Fernieite]

We would need to see the date codes which are printed lower down closer to the pins. They could well be Blackburn Mullards. Looks like the EL34s are single ring getters, so late 68 or newer.

I don't want to alarm you, but there seems to be a little man living in one of your power tubes!

 

[Seanxk]

Awesome — I’ll pick up one of these. Much better than the Stew Mac one.

They will have to be bored out to 1/4'' as he mentions in his listing, still a good price for something that was fitted in period. From 69 on they changed manufacturer but were almost identical, mid 70's they just got cheap and nasty, oh and bigger.

 

[neikeel]

Presume your tech is going to variac it or preferably use the self regulating current limiting resistor method of cap reforming on an amp like this? Those RS caps often reform 100% if you do it properly. Of course if you are going to tour and gig with it 5 nights a week you may want the security of a recap.

 

[Travis Tritten]

Presume your tech is going to variac it or preferably use the self regulating current limiting resistor method of cap reforming on an amp like this? Those RS caps often reform 100% if you do it properly. Of course if you are going to tour and gig with it 5 nights a week you may want the security of a recap.

I’ll ask about that - thanks!

 

[neikeel]

I take it your tech didn’t like my suggestions?!

 

[Seanxk]

I take it your tech didn’t like my suggestions?!

Unfortunately we found in the other thread he wasn't actually a tech, not in our sense of the word anyway.

 

[Jeff West]

Nice amp! The EL34s look like Matsushitas, with 6/74 GE date code visible on the one. Look for seam across the top as well as two raised ridges running around the plates, above and below the rectangular holes.

Oh, I just saw the second set of photos- yes, Matsushita El34 and Blackburn 12ax7

 

[Goldsmithmill]

I own SB #10443 and its a version 6. The serialnumbers are usually quite reliable at this time. This is the first time I´ve seen an earlier amp in this serialnumber range.