hi all,
I am building a rangemaster clone and am going with the input cap blend option. For the caps, I am planning on going with the 5nf for standard/high frequencies, and something between a 15-22nf for mids/low mids. Anyone foresee any trouble with these choices? If you've done this mod also, what cap choices did you use?
Also -- what value pot would you suggest using? I am going off of the schematic for Joe Gagan's Easy Face, which seems to utilize a 100K Linear pot...but since that component is geared for a fuzz circuit and significantly different cap values, I wonder if a diferent blend pot value would be more effective?
There's nothing wrong with whatever values you want to use for caps and a B100k pot will be just fine. Easiest thing to do is breadboard it and see what you like best.
I preferred the switched capacitors for input select because it introduces lower passive losses at the input.
A switch in the signal path wire from Ckt to Sw is easy, no board work, and can have whatever value capacitor you decide sounds best when seriesed with the 'big' capacitor, when the switch is open, both capacitors = input cap value [=smaller], throwing the switch defaults to the 'big' capacitor value.
I liked it because it was the footprint of a switch and it's lugs hold the capacitor.
Well, on the GGG layout for the Easy Face, there are two separate inputs on the PCB that lead to the independent input caps. If I wanted to incorporate the 1M pulldown resistor at the outset of the circuit, would I need an independent 1M resistor for each input, or is there a way for them both the share the same pulldown resistor without mucking up the independent function of each input cap that the pot will subsequently blend? Is there a benefit to having each input run to an independent 1M pulldown resistor? Or perhaps a pitfall to doing this?
You might want to go a little lower than 5nf.
With two caps and the 100k pot you get a little higher capacitance
than you would with two separate caps. And since you can tune
it in, a lower cap value isn't a big deal, just a hair lower than
normal and you can adjust for it.
Quote from: John Lyons on May 30, 2011, 07:49:26 PM
You might want to go a little lower than 5nf.
With two caps and the 100k pot you get a little higher capacitance
than you would with two separate caps. And since you can tune
it in, a lower cap value isn't a big deal, just a hair lower than
normal and you can adjust for it.
Thanks John...so, something like 4.7nf, then? Or would you suggest going even lower?