replacement electro for smallstone

[jimbob]

I need 2 33uf electros but I have none. Would a replacement of 22uf or 47uf make a difference in this circuit?

http://www.tonepad.com/getFile.asp?id=7

[Seljer]

C1, the 33uF at the lower half of the layout shouldn't really have any problem if its larger, its just there for the bias voltage for the opamps.

C12, the other 33uF might be different though, I believe its part of the LFO, making it smaller would speed the thing up a bit, and larger would slow it down. I guess you could try it, otherwise just wire a 10uf and 22uF in parallel

[Mark Hammer]

That"s pretty much what I was going to say, too.  The one in the bias circuit can be bigger or smaller.  If you make that 47uf cap in red 100uf, then you can probably get away with 22uf instead of the 33uf in the bias circuit.  Much easier to smooth out somethng that's already pretty smooth.

I can confirm that the 33uf cap in the LFO circuit does set the LFO range.  Using a 22uf or 47uf (the next common values over from 33uf) will provide some overlap with most of the range of speeds produced using a 33uf, just not the entire range.  So, 22uf will get you all the same medium speeds, some faster speeds, but not the slowest speeds.  47uf will get you all the medium speeds, none of the fastest speeds and some much slower speeds.

Unfortunately, I don't know how to do the sweep width trick I described for the Ross and old Small Stone on this particular SS issue.  You can, however, make the DPDT Color switch into two SPDT toggles, one for more/less regen and one for more/less width.  The stock wiring gives you one Color setting where the speed is shifted slightly slower, the sweep width expanded and the regen turned up; essentially optimized for slower sweeps.  The other eases back on the regen and width, and nudges the speed up a bit; optimized for faster sweeps.  Sometimes you want slow with little or no regen, though.  Turning the Color switch into separate Width and Regen switches will let you do that.  Alternatively, you can simply use one switch for the width, and replace the 270k resistor with a 500k log pot wired as variable resistor and have variable control over regen.

[jimbob]

Thanks all. Ill probably want the slower speeds on this.