So here's my first shot at a layout for my standalone effects thing.
It's got a harmonic trem and reverb that can either be used in an effects loop, or used with the unit's own preamp (then fed back into the effects loop return).
The vibrato/tremolo circuit is Fender's 5-triode lifted from 6G12a.
The reverb is also borrowed from Fender, with a couple of well-known mods like the dwell knob, and one mod I haven't seen elsewhere: two-triode reverb recovery. The original Fender setup uses a 3.3M resistor to tamp down the dry signal so it doesn't drown out the reverb. I wanted to try amping up the reverb so I don't have to put such a huge resistor in the dry signal path.
The preamp is the high gain cold clipped channel from the JCM800 family.
Some of this stuff, I am looking back wondering about things I did on the schematic, why I did them, and will they work.
Like, I don't know why I didn't use a cathode bypass cap on V8b.
On V3 and V4, the load resistor is just bridged across pins 1 and 6
V3 is borrowed straight from the Mojotone JCM800, and V4 is borrowed straight from Fender 6G12a - but it looks like pin 6 would not be getting a load resistance, only pin 1.
In the filter caps, I'm not sure I need both FC6 and FC7. FC6 is the tail end of a Fender type reverb power node, and FC7 is the front end of a Marshall power node. I'm tempted to eliminate FC6 and move everything one slot to the right.
I've been through tracing and error corrections a couple of times, but probably still need a few more.
I would not ask anyone to go through this with a fine toothed comb, but if anything jumps out as obviously wrong, or an obvious easier way to do things, please holler!
Topic: harmonic vibe - reverb - preamp thing: Layout First Draft (Read 2007 times)