Marshall PA Amp's in for servicing...

[TubeGeek]

These just arrived today. 

I love this hobby.

These are gonna be interesting to service.

I think they are kind of rare, thought I'd show some pics.

If anyone has serviced these before, tips would be appreciated.

TG

[Willabe]

I think they are kind of rare.

I think your right.

I've seen a # of pics of English bands like, The WHO and others using those live early in shows. That's what was around at the time.


                          Brad       

[Ritchie200]

TG,

Can't really find any info on them.  I even asked Deep Purple's old tech/amp guy as they used Marshall PA gear early on, but that was before '72 and it was just the Major 1966 model. 

Are they just 4xEL34 voiced with a flat response on the preamp side?  It might be like the old PA's that were in a "traditional" cabinet, just in a new cabinet with a few more bells and whistles.  That old stuff is so cool!  Like a walk down memory lane!

Jim

[TubeGeek]

From what  I can see there isn't much info available for these amps.

The owner stated that one is a 69 and the other (with script logo) is from 1970.  I trust this because from what I have gathered so far, this PA was first introduced in the 1967 catalog.  I have a Marshall book with the 67 and 68 catalog's and they are in there.

Model 2003.

I have been meaning to snap some more pics of the guts and post, just been too busy.

These amps will be with me for a while, I've got a few amps to service and build before I can get to them.  In the meantime I will try and dig up bits of info on them.

It's looking like I will be able to keep the older amp for myself.  I've been looking for a PA for vocals in my studio for practicing, this may be the ticket.  And...it is tubed which is always great!  The last traynor PA I worked on was tubed but sounded terrible for PA in my opinion.

I'm hosting a jam this coming tuesday, I plan to test the amps out at that time to see if they even work.

[Ritchie200]

Cool!  You get to keep one?  Please take interior pics.  I'm sure the caps are taking a crap.  I've got an old catalog with the Master PA in it too.  I will also keep looking for info.

Jim

[TubeGeek]

Ok...time to work on these babies!

Here are some pics of the guts...

This is the one I get to hold on to.

[TubeGeek]

This is the second one...

This one will stay with the owner. 

Needs a good cleaning, the el34's look like they have seen better days. I predict they will be microphonic and un-useable because when I tap on them I can see the components move and rattle.  The preamp tubes in this one are all brimar(mullard?) and one rca.

There are a few differences between the two amps.  I'll be detailing this project as I work on them.  I have them on my bench for as long as I want.  In exchange for restoring, repairing, maintaining this head I will get to keep the other head along with several hours of my time to repair and service his other amps.  Just finished servicing a couple of his other Marshalls. (jcm2000, 20 watter head, jcm800, plexi)

[Screamingdemon]

Hallo i've got the same too.what pre amp tubes should i using.Greetings

[sluckey]

Hallo i've got the same too.what pre amp tubes should i using.Greetings

Most likely 12AX7. Do you realize this thread is over 11 years old?