The cap across his 470K was a Murata hollow round 330pF. canĢ.His treble cap was a 250pF Murata flat ceramic one. It was bypassed with a blue 330uF resistor. (3) Plaap (a friend of Peter Van Wheelden who restored Eddie's amp.)Įdwards amp's internal measurements were as follows:ġ.The first 820 ohm resistor (carbon type) measured a little over 1K. The value of the coupling cap between V1 and V2a.022uF. Rear cap on top of chassis was a royal-blue HUNTS 32uF or 16uF.need to check notes. The voltage doubler were 2 100uF DALY royal-blue caps. The screen filtering was 2 DALY 32uF light-blue caps in series. The filter cap in the center of the board was a dual 16uF gray RS cap. I am pretty sure the feedback resistor was a 47K. Oh, BTW those 820 ohm resistors were carbon-comp and drifted in value up about 1.1K and make the amp much more gainy and warmer, since these re-bias the 12AX7 valves in a bit more non-linear region. and this my friends is how the "brown sound" with that added compression happens. The real kicker, his phase-inverter "get-rid-of-the-FIZZIES" cap was a 100pF instead of the normal 47pF. If memory serves me right on the value, or it was a 330pF.I will check my notes. One of the 470K mixer resistors was bypassed with a round hollow tubular MURATA cap 500pF. His treble cap was a round shaped ceramic that was a 250pF that said MURATA. His head was a 67/68 and he had the first stage valve with BOTH cathodes tied together sharing the same 820 ohm resistor that was bypassed with a 330uF blue cap. The post that is pressed in looks stock too witch tells me more than anyone could.In the pics the serial # is 12301. From the circuit card It looks like it came stock with this arrangement. its a 2.7k/.68 and the resistor looks like the stock part(but I don't think it is)but the cap is one of those yellow square type from the 70' Marshall's. I do have pic's so I CAN physically see that the amp has a split cathode arrangement. There ARE small tone altering and/or gain altering mods. It's pretty much the "SIR" mod from the layouts that were floating around on the Metroamp forum with the added feedback/loop/depth Not 100% sure if its wired correctly but it doesn't sound like shit so I guess it is? Can only tell once I get some more volume on this thing.(1) By Mark Cameron by pictures taken in the early 80'S. If anyone want's to try out the mod let me know and I can send you whatever I have on doing it. No clue how it sounds at higher volumes yet since I can't play it loud but its sounds pretty good with the Pre-PIMV. Amp has more balls now for sure, not a crazy amount of gain, will probably have to tweak some values but so far it's pretty cool. Thread is probably useless without clips but oh well, will try to get some up next weekend when I have a camera. The ordering of the circuit got shifted over, so the extra tube is the 1st stage but I had a extra half of a preamp tube left so I just bridged the 2nd half for a extra amount of gain. depth knob (placed right after impedance switch) feedback knob (Variable from 1 to 250k) (To the right of the FX loop) Gutted the superlead circuit and changed it to a 2203 and added the following:
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