Tools, Tones and Toys for Guitarists
A great sounding and flexible 2-band baxandall eq booster that can get quite gritty depending how you set the internal gain trimpot. The Mid control is not actually an active mid band control, it is a passive variable resistor that changes the overall mid slope. Note that this seem to be an earlier version, the … Read more
The RCA BA-31C would have been found in broadcast consoles of the day (late sixties), as a microphone preamp module. I think it may have been the starting point for the Hudson Broadcast, as they look quite similar and I’ve heard some references made to RCA. If it is what they used, I can … Read more
Here is a heavy dirty booster that will melt your Orange, Green or Sunn amp head. And your one knob fuzz will love it.😈. The gain range goes from a fairly clean boost to a hairy and fuzzy overdrive. “Transparent” it is not… It is a fairly simple circuit that boost the whole sound spectrum … Read more
Another overdrive from Nobels which shares a similar topology as ODR-1. But this one appears to a have a bit more gain on tap and a more flexible eq section. The mid control is powered by a transistor gyrator while the Lo and Hi controls are Bandaxall. And the hard clipping diodes are germaniums so … Read more
A quite simple old japanese compressor by Univox. For part substitutions (since stock parts is long gone obsolete…) the transistor were a low gain NPN silicon so PN2222 or 2N3903 should work. MD234 were silicon signal diodes so 1N4148s is a near enough sub. The spec of the original vactrol remains unknown so socketing a … Read more
A Rat variant with some added features; a Fat control and a variable diode control called Comp.
This is the input amplifier from a Revox A77 reel to reel (circa ~ 1967) – which also happens to be almost identical to the mic preamp in Trident A-Range mixing consoles from the early seventies. So far out of the preamps that I’ve been working on, which is the Neve, RCA and this, I’m … Read more
Schematic avaiable at PedalPCB. Note that this layout is sligtly modified. The buffer bypass switching is subbed for normal true bypass.
