Re: Did EVH really steal Soldano circuitry for the 5150?
....just my lowly .02 on this subject
Although it's getting harder and harder these days to be truly "innovative", it is not impossible.....(if you doubt that, come visit me!), there have actually been quite a few design's that almost nobody has even bothered to "explore". Most of these are assumed to be variations of "other designs, but there are some notable exceptions:
1. Early Orange amps.... one of the very few Class AB amps that have no phase inverter (in a conventional sense), rather a single gain stage with the cathode driving one pair of output tubes, while the plate drives the other pair.
...why does this work?.......the ouput from the cathode is 180% out of phase from the plate out.
This is true for all triodes and the reason for the "cathode follower" circuit found in most amps. Conventional plate driven circuits when pushed will only "distort" the positive aspect of the waveform, leaving the negative portion virtually intact, until it too reaches it's limit's. But by this time, although the signal is "distorted", it is so assymetrical that is sounds horrible! The cathode follower is specifically designed to reverse the phase and insure "equal" response, most notably when "pushed" or distorted. (Both pos. and neg. will "square" at a much more equal rate.) This does however, come at the expense of the actual voltage out of the circuit.... cathode drive is only 1/10 the levels achieved with plate driven.
There is a way to actually "balance" 4 consecutive plate driven stages where equal OD is achieved, and it works quite well... It has never been commercially made and the only design that uses it is .........mine! (so much for the "no new ideas" theory!)
anyway....
#2.... The great Magnatone "pitch shifting" vibrato..... Few know about this, but it's old, revered but never even attempted to be duplicated.....no clue as to why. The theory was simple, by cancelling out the signal at the PI via "phase inversion" a very simple level increase/decrease was achieved. But it also had the "side effect" of actually pitch shifting the signal, or "chorusing" it. My guess would be that in the late '60s, this was considered as a "hindrance" rather than an attribute. (of course, "distortion" from an amp was in it's early stages too!)....worth checking into..
#3.. my personal favorite... Marshall JCM800 ch. switching amps....there is no better example of "unconventional" thinking done in history than these!....
Somebody, somewhere finally figured out that "distortion" was very simply the squaring of the guitar signal. The more uniform it was, the better and there is nothing to achieve this more efficiently than the lowly regarded "diode". Although the early versions of these are so bad that even I can't stand them, the later versions had a balance that is almost impossible to duplicate.
Even more amazing is a '89 2210 is only one component away from "perfection"....(IMHO, better than a Diezel Herbert, but not a VH-4...again, just my opinion!)
As far as the 5150, I doubt that few know Peavey has been making really good high-gain amps for a very long time, but few could get past the Peavey "stigma".... I really don't think they sound anything like Mikey's amps! (of course, never really paid that much attention either!)
As always, I'm sure this more than you wanted to know.. but there it is!
Jeff Seal
Well some of the customshops are quite nice, but most are run of the mill stuff.
