Marshall 6100 (non-LM) schematics

[Setneck]

Hi guys!

A friend of mine has a chance to buy early (1992) Marshall 6100 30th Anniversary which I want to verify if it hadn't been modded or messed up with (there's no sticker with sn on it). So I need a good quality schematics of first version of that amp (EL34, non-LM), especially poweramp schem and clean/crunch schem, which were modded to 5881 specs and later on to LM specs.

I've searched thru' ewerywhere for an original schems for that amp (Dr.Tube, Amparchives, MarshallSchematics, SchematicHeaven, etc). I already have 6100-63-04 Issue 2 (poweramp; gif) and 6100-61-04 Issue 4 (clean/crunch; gif), which seem to be the schems of an early version, but their quality is very poor and anything can't be seen properly.

So, does anyone have those (or other) schems and could post it somewhere or send me? I would really apreciate this.


Regards, Andy

[doctor]

Hi guys!

A friend of mine has a chance to buy early (1992) Marshall 6100 30th Anniversary which I want to verify if it hadn't been modded or messed up with (there's no sticker with sn on it). So I need a good quality schematics of first version of that amp (EL34, non-LM), especially poweramp schem and clean/crunch schem, which were modded to 5881 specs and later on to LM specs.

I've searched thru' ewerywhere for an original schems for that amp (Dr.Tube, Amparchives, MarshallSchematics, SchematicHeaven, etc). I already have 6100-63-04 Issue 2 (poweramp; gif) and 6100-61-04 Issue 4 (clean/crunch; gif), which seem to be the schems of an early version, but their quality is very poor and anything can't be seen properly.

So, does anyone have those (or other) schems and could post it somewhere or send me? I would really apreciate this.


Regards, Andy

I hope this complete schematics set may help you.

[Setneck]

Thanks Mate but I already have those schems. And these are for 5881 LM version unfortunately - I need for EL34 non-LM version . So early numbers of issues...

Regards, Andy

[g1]

Do you have numbers off the boards to tell which issue schem. you need?

[oc disorder]

This may help a little.
I saved a page from a GeoCities web site eons ago.
Details the component changes from a 6100 to a 6100LM.

[Jazz P Bass]

Cool!

[g1]

Also, it may not be possible to figure out if it came from the factory with 5881 or EL34 output tubes. If you run into "locks up and needs to reboot to switch channels" you should read through this thread from the archives.
Marshall 6100 5881 > EL34 - AMPAGE Archive
Seems to be an issue with versions that were switched from 5881's to EL34's however I do recall early EL34 versions having problems with lock up due to poor line voltage/brown outs.

[Setneck]

This may help a little.
I saved a page from a GeoCities web site eons ago.
Details the component changes from a 6100 to a 6100LM.

Thanks, it is big help for me Mate. Actually the amp seems to be original non-messed-up-with 6100. A friend of mine is very happy. But - unfortunately - made me missed my 6100 i've sold a while ago . So, the quest for mine 6100 has started

-> g-one: thanks for this thread, it also helped me a lot . The amp is so far good, I currently warm it up with fresh set of power tubes. We'll see what will happen.
Could You be so kind and write more about those "poor line voltage/brown outs"? What do You mean by saying that?

Best Regards, Andy

[g1]

What I mean about the line voltage problems is that the voltage at the wall outlet sometimes drops below acceptable limits. For example, where I am, we usually have around 123VAC at the wall outlets. I believe the power companies try to keep it within around 3% of that. So I should get at least 119VAC where I am. However during times of high demand, the voltage may drop below acceptable limits (brown outs). So maybe the line voltage would drop to say 100 or 105 volts. Or maybe you may be playing somewhere with poor wiring or overloaded circuits (like many clubs) and not getting the proper voltage from the wall. In these situations, the voltage regulator for the microprocessor in these amps may not be able to hold up the 5 volts DC. This may cause the microprocessor to lock up and prevent channel switching. There may be better regulators available now which is what I think was mentioned in that old post.
From what I remember, most of the amps I saw with this complaint usually worked fine in the shop, and the problems usually happened in clubs with questionable AC service.

[vintagekiki]

http://www.amparchives.com/album/Marshall/Schematics%20&%20Layouts/Marshall%20Amp%20Schematics/30th%20Anniversary%20Series/6100%20&%206101/index.html
quality is as as

[oc disorder]

more info and food for thought !
Do a web search for this 5881_EL34conversion.pdf
which begotted this !