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previous: Carl Hello anyone,I'm un... -- 9/4/2000 11:15 AM

Re: Can anyone explain parts in '64 Vibrolux Reverb?

9/6/2000 8:17 PM
nuke	Re: Can anyone explain parts in '64 Vibrolux Reverb? "(1.) The coupling (or bypass?) caps for the pre-amp and reverb tubes are usually 25uf 25v, but in this amp they are small and silver (like Spragues) with "PCM 35v 22uf" written on them in black letters." They've been replaced at some point in time. The originals would have been dual section 25u @25V, either Mallory or Astron. (two caps in one can with a brown cardboard tube covering it.) "(2.) Instead of a 25uf 25v cap going to pin 8 on the vibrato 12ax7, there is a 2mf 25v Astron Minimite cap." Either a replacement or a production variation. Not a critical value though. You might want to refresh the part for reliability. "(3.) There are two resistors (100k, 1m) soldered in parallel which go to pin 6 on the phase inverter 12ax7." The phase inverter should be a 12AT7, not an AX7. Perhaps someone tweaked it for more gain using a 12AX7. "(4.) The main power transformer has plastic leads instead of cloth leads. On the top of the transformer (inside the chassis), "B4064" is stamped in silver. On the bottom, it reads "C.S.A. TEST" "125P26A" and "606402." The red, green and yellow plastic leads say "CANADA" on them." Sounds like the real thing. The part number sounds like a Fender number. They may have second-sourced the part from Hammond. The date code sounds like the original part to me. CSA-Test is an agency approval marking, not an indication of prototype.

9/6/2000 8:17 PM

nuke

Re: Can anyone explain parts in '64 Vibrolux Reverb?

"(1.) The coupling (or bypass?) caps for the pre-amp and reverb tubes are usually 25uf 25v, but in this amp they are small and silver (like Spragues) with "PCM 35v 22uf" written on them in black letters."

They've been replaced at some point in time. The originals would have been *dual* section 25u @25V, either Mallory or Astron. (two caps in one can with a brown cardboard tube covering it.)

"(2.) Instead of a 25uf 25v cap going to pin 8 on the vibrato 12ax7, there is a 2mf 25v Astron Minimite cap."

Either a replacement or a production variation. Not a critical value though. You might want to refresh the part for reliability.

"(3.) There are two resistors (100k, 1m) soldered in parallel which go to pin 6 on the phase inverter 12ax7."

The phase inverter should be a 12AT7, not an AX7. Perhaps someone tweaked it for more gain using a 12AX7.

"(4.) The main power transformer has plastic leads instead of cloth leads. On the top of the transformer (inside the chassis), "B4064" is stamped in silver. On the bottom, it reads "C.S.A. TEST" "125P26A" and "606402." The red, green and yellow plastic leads say "CANADA" on them."

Sounds like the real thing. The part number sounds like a Fender number. They may have second-sourced the part from Hammond. The date code sounds like the original part to me.

CSA-Test is an agency approval marking, not an indication of prototype.