Boots said:
But the nickname 'plexi' stuck to this circuit and people still refer to these amps as "Marshall Plexi's." Most people also only consider the pre-PCB amps to be plexi's.
Plexi's are usually considered non-master volume. There are mods that make these a master volume, but that's not a 'plexi' in my book.
Most amp manufactures based their circuits after the plexi circuit. Orange and Hiwatt to name a couple.
It's a popular belief that Marshall used the Fender Bassman cuircuit as the basis for their 'Plexi' circuit. Anyway, I hope this helps and doesn't confuse you.
Ok, a lot of guys/gals here know their stuff about recording but a lot less about the actual equipment that goes with the instruments
. mainly vintage stuff. I will straighten this "plexi issue" out hopefully.
Marshall was a music shop in Bletchley, which is north of London, sometime in the 60's Jim Marshall started making amps, the general basis of these were fender circuits. One day, Pete Townsend walked in, and slapped down his bassman, he asked for that amp to be made twice as loud and twice the size, Jim obliged and the Marshall stack was born. All these early amps had a plexiglass front to them, thus donning the name "PLEXI" and were originally based upon the jtm45's rip of the bassman circuit.
Marshall then went on to create a series of amps under the "plexi" name (please note that they were not referred to as "plexi" at the time.) these included,
the jtm 45, jtm45 100, superlead, superbass, major, PA100 etc.... And this continued happily right through the 60's. About June or July (I think)
of 1969 Marshall fluently ditched the plexiglass fronted chassis, in favour of the modern brushed aluminium one we have today.
Although the chassis changed, the circuits made little in the way of immediate evolution, Most Marshalls had their circuits alter by the week at the time in terms of capacitor values etc... The reason Plexis are more expensive is:
a) their exclusivity, they are more rare, and they are older.
b) most artists favour and used only plexi models (despite what they may have been endorsing for Marshall on stage, i.e. Angus young, evh (in the studio), Clapton, Hendrix........
c) The general myth surrounding them.
Marshall then went on till 1974 making tag board ptp wired amps, after which they moved to pcb.
Most people use "plexi" annoyingly freely, like to con people on eBay and the like, since not many people seem to cotton on to the real value of old Marshalls, not saying plexis are better though, I own only aluminium metal faced 70's Marshalls now, I sold my 67'superlead for an astonishingly large amount, and I didn’t really rate it as much as my 77'. Its all personal choice.
As for oranges and Hiwatts nicking marshal’s circuit, that is really, well, wrong. Hiwatt was Dave Reeves and Harry Joyce's company that evolved from Sound city, in the mid-late sixties the sound city circuit is nothing like Marshalls, in fact Marshall amps were mainly using kt66's when sound city were building their el34 based mark1 100's, and sound city is a massively clean, uncompressed amp, much like hiwatt, this cannot be said for Marshall. If you just plug into a Marshall and a hiwatt you can feel that they are totally different. Oranges are similar in feel to Marshall, but yet again a totally different animal.
hope that clears some of that up.
Oh, and then to also have to build the enclosure for it — I don't know, it just seems almost insurmountable with my limited abilities in the world of "hands on."