'68 Marshall Super Tremolo

[shaunf]

Hey all. I bought this amp a couple of weeks ago. It was in pretty good shape for something nearly 50 years old, but did need a little bit of work on the headbox as well as some of the electronics.

Here's a couple of pics from when I got it:

[img576]http://img.photobucket.com/albums/v206/ ... 9q9wmp.jpg[/img]

[img576]http://img.photobucket.com/albums/v206/ ... tn0koc.jpg[/img]

[img576]http://img.photobucket.com/albums/v206/ ... tmtxzh.jpg[/img]

[shaunf]

Some circuitry weirdness:

[img:768:1024]http://img.photobucket.com/albums/v206/ ... mfw6zm.jpg[/img]

I can't understand why someone would have fitted this capacitor between the power selector and ground, but at some stage of its life, it went Boooom!

[shaunf]

The first thing that got removed was that popped capacitor. It shouldn't have been there in the first place. Now that it's gone, lets take a look at the rest of the circuit:

Original Power Transformer. You'll also note that in this pic, I had replaced that horrible blue Neutrik Powercon socket with a NOS Bulgin socket. I also replaced that mains fuse holder that had previously been replaced with an incorrect sized unit, and as result had a bit of old brown circuit board around it to make it fit in a hole in the chassis that was too big for it.

[img765]http://img.photobucket.com/albums/v206/ ... c6tm2r.jpg[/img]

Original electrolytic caps still in place. I reformed all of these caps and they seem to be working ok for now.
[img765]http://img.photobucket.com/albums/v206/ ... 1kltyj.jpg[/img]

[shaunf]

Casting our eyes further to the left, we are greeted with this sight:

[img765]http://img.photobucket.com/albums/v206/ ... f67oub.jpg[/img]
[img765]http://img.photobucket.com/albums/v206/ ... kwepwm.jpg[/img]

Most of the solder joints still contain the red dye Marshall originally marked them with. This amp is one of only a few that I have seen with Cornell Dubilier caps instead of the regular mustards one usually sees. The only component that has been replaced on the entire turrent board is one of the plate resistors on V1. The V1 tube socket has also been replaced at some prior stage.

By the time this second picture was taken, I had already replaced the 2 left most input jacks that had been previously replaced with incorrect regular jacks. I installed 2 new Cliff jacks.

The Tremolo circuit is currently disconnected and so this amp is currently operating as a straightforward Superlead.

[shaunf]

Restored rear view:
[img765]http://img.photobucket.com/albums/v206/ ... vug3mu.jpg[/img]
[img765]http://img.photobucket.com/albums/v206/ ... rafmut.jpg[/img]

[Reeltarded]

Super sweet!

[Progear]

Very very nice... Enjoy

[shaunf]

Front view, now sporting the replacement input jacks as well as a full set of vintage knobs:

[img765]http://img.photobucket.com/albums/v206/ ... dyf7vz.jpg[/img]

Fortunately both the front and rear plexi panels are both in exceptionally good condition, with no cracks, or oxidisation of the gold paint.

[shaunf]

Completed my usual startup procedure for amps that haven't been powered for a long period, including reforming the main electrolytics. I checked the onboard electrolytics for signs of physical leaks and couldn't see anything. Bias circuit was providing stable bias voltage. Once I was satisfied that the caps were ok, and that there were no shorts or anything major wrong, I brought up the voltage slowly on my variac with no tubes installed. All seemed good, so I installed a good known set of tubes, reran my tests, biased the amp and plugged in a guitar, and instantly she sprang back to life.

Over the weekend, I tackled some of the headbox cosmetic issues. In the first picture I posted, you will see that the headbox piping around the front panel had at some stage been "upgraded" to the white piping that the newer Marshalls from the late 70's and forward had begun to come out with. What is not obvious from the photo, is that the front panel had also been recovered with vinyl, instead of the original tolex. Although this vinyl quite closely resembled the tolex of the rest of the box, it was still noticeable to me, and so off came the vinyl, careful to preserve the original gold "string" that goes across the panel underneath the logo. I then recovered the front panel with original Marshall Levant tolex, reinstalled the gold string, and replaced the white piping with the proper gold mylar piping, and fitted an original Marshall logo. Here she is in top of a angled cab also from '68 that I had previously restored:

[img1365]http://img.photobucket.com/albums/v206/ ... fgayw7.jpg[/img]

[shaunf]

A pic with her and a few of her cousins. She is at the bottom of the pile. Above her is an absolutely pristine '75 JMP50 Lead spec that belongs to a friend of mine, that was visiting for some TLC, and on top is my '69 JMP50 small box.

[img1365]http://img.photobucket.com/albums/v206/ ... 5w5nag.jpg[/img]

[shaunf]

Finally, here is a family shot of my current amp lineup:

[img768]http://img.photobucket.com/albums/v206/ ... btwz92.jpg[/img]

[jelle]

Love it! Those are reel amps.

[rp]

Love it! Those are reel amps. Cool

Yeh, but everyone yells at you now when you try and play a real amp. One more reason to wish The Revolution had happened in '68.

[jelle]

You could play a kemper. *cross references to other thread*

[rp]

You could play a kemper. *cross references to other thread*

How do you emulate LOUD?