Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: TubeGeek on March 13, 2012, 08:07:33 pm
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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
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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 :icon_biggrin:
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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
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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.
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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
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Ok...time to work on these babies!
Here are some pics of the guts...
This is the one I get to hold on to.
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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)
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Hallo i've got the same too.what pre amp tubes should i using.Greetings
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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?