hi there,
well, i breadboarded again the circuit
RG, this time the oscillator worked perfectly but, sadly, my recording means (a small cam-recorder) are so lo-fi, that the captured sound of the samples doesn't do any justice to whats really sounding -so you could tell it really does the fender thing- ..besides, i did record it on bass, then it's somewhat muddy
anyways, what i can report on the circuit is:
-Vref 15uf cap must be upgraded to 100uf at least, to prevent oscillator thumping
-for a more pronounced effect (depth), i changed both 3.3m resistors for 1.2m resistors
-a LED freq indicator mod suits it really well
(think p45)
-if one takes Q2 out (the fet on the treble path), one get a pleasing bassy-phasing.. pretty cool
-i get the best performance out of the circuit biasing the fets at 0V (is that a bad thing?)
now,
markm, on the Swamp Thang issue... i did a little research, and got some info that might interest you:
you like the Swamp Thang, right? ..then we know this effect is a modded Diaz Tremodillo (according to Jack Orman, the most noticeable change, is the true bypass conversion)
take a look at this:
http://www.pedaldoctor.com/images/DiazBrd6.jpgright, thats a tremodillo board
if one looks at it, having in mind its an npn based tremolo, and taking note on the number of electrolytics it has, the resistor values, and number of transistors (besides the number of pots and the 1/2 freq switch), it seems to be none other than this:
http://topopiccione.atspace.com/pjimages/SchallerTremolo.sch.jpga schaller tremolo replica ( a very sweet tremolo on its own)
so.. if you clone a Schaller Tremolo, and true bypass it, you might get a very close Swamp Thang
cheers
