Any Marshall experts out there ?

[heartfielder]

I need some advice. I have a 1970 Marshall Tremolo 50w head. I want to know if it is all original. I have pics of the inside that can be blown up pretty big on the screen. Please let me know if you can help me and I'll send pics.

Thanks in advance.

[charvelguy]

That 70's era had point 2 point and mustard caps. If you don't get what you need here.. Plexi Palace forum.. Marshall section will likely get you a reply to your pics and query.

[siggy14]

yeah i would say those two places, however dont let anyone talk you into selling it cheap, those are pretty good amps.

[adrenaline junkie]

If it's a '70 it's going to have a brown circuit board. All of the solder joints should have some dark red dye on them. You can tell quite a bit about if anything has been tampered with by that. Post some pics, I'd love to see them.

[adrenaline junkie]

I can't find any pics of my '70 Super Lead, but Here's one of a 69 Super Bass I had.

See the red Dye on the turrets?

[charvelguy]

You sure that is just a dye? I think of it as a threadlocker sealer like loctite red.
They used that same thing on the transformer bolts as well if I recall.

The drake transformer numbers didn't change on the output and the choke from like 69-into the 70's..so if you reference Drake transformers & choke model numbers for those years they should be the same..like 4 digits then three more stamped into the top. Just the power transformer changed over those years... JMP's had lay down mains up till like '73. So yours should have a lay down power transformer. I may have some pics of 71 tremelo.. I have a bunch of Marshall guts pics stockpiled but they are not on this harddrive.

Usually pretty common to see a grid resistor changed out.. or a tube socket. They did use different make resistors over the years... whatever they could buy in bulk and those did change in color from type to type.

[finnman]

http://www.marshallampforum.com/forum/
and
http://www.drtube.com/marshall.htm

[charvelguy]

yeah.. thanks for posting that,. I was thinking they have schematics.

[adrenaline junkie]

You sure that is just a dye? I think of it as a threadlocker sealer like loctite red.
They used that same thing on the transformer bolts as well if I recall.

The drake transformer numbers didn't change on the output and the choke from like 69-into the 70's..so if you reference Drake transformers & choke model numbers for those years they should be the same..like 4 digits then three more stamped into the top. Just the power transformer changed over those years... JMP's had lay down mains up till like '73. So yours should have a lay down power transformer. I may have some pics of 71 tremelo.. I have a bunch of Marshall guts pics stockpiled but they are not on this harddrive.

Usually pretty common to see a grid resistor changed out.. or a tube socket. They did use different make resistors over the years... whatever they could buy in bulk and those did change in color from type to type.

It may be a thread locker, but I don't see any reason why they would have put thread lock on every solder joint in an amp. I think it's a red dye they used and they put it on the tranny bolts as well so they'd be able to tell when people tampered with it.

Most amps from 68-73 didn't have lay down trannies, they used them off and on when the supplier had them cheaper or something, but there's no cut off date for them. The amp I took a picture of was a 69 Super bass, and it along with my other 4 pre '73's all have stand up transformers. Lay down trannies after 68 aren't all that common.

Marshall also use Mustard caps clear up into the mid 70's. Here's a 75.

[charvelguy]

interesting.. I've seen some '73's stock with lay down mains, they are usually UK amps..but.. I agree.. really more rare past 70 and usually seen in the much older JMP's as I had a '73 super lead with typical outputs. I have a '77.. it doesn't have mustard caps...but my '74 does.
Threadlock on every joint and post=reduced chance of coming loose when being shipped overseas or transported.. as well as serving as a means of being able to see if it had been worked on or tampered with.

[heartfielder]

Here are some pics. I'm not sure of what the value of these are these days. I have a few guys interested. I don't use it anymore, I'm playing through a Leslie 825 that belonged to The Runaways.

[IMG][/IMG]

http://img.photobucket.com/albums/v39/heartfielder/IM002679.jpg

http://img.photobucket.com/albums/v39/heartfielder/IM002678.jpg

http://img.photobucket.com/albums/v39/heartfielder/IM002677.jpg

Let me know what you guys think.

-P-

[charvelguy]

I'm gonna say that's likely been likely modded to a fair extent.. most look non invasive..probably disconected the tremelo circuit and use the 12ax7 for a preamp master vol thing. Green tolex, bitchin.

[heartfielder]

I'm gonna say that's likely been likely modded to a fair extent.. most look non invasive..probably disconected the tremelo circuit and use the 12ax7 for a preamp master vol thing. Green tolex, bitchin.

Tom,

Just so you know, this head is black as night, not green.

[adrenaline junkie]

Tom,

Just so you know, this head is black as night, not green.

If you put it next to a later amp (72 etc) you'll see it's definitely got a greenish tint comparitively. Mine are the same way.