Schaller/Hearthrob tremolo rate pot issue

[skrunk]

I've got the Hearthrob trem on my breadboard right now but have a bit of an issue.
When the rate switch is set to fast and the rate knob is below 11 o'clock or so, I loose the trem effect.
I have to turn the rate knob back up full to get the effect to 'kick in' again.

I tried a 10uf instead of the 22uf for C4 and it was the same,
but when I put a 4.7uf in there (stock Schaller value) the problem goes away.
and it only happens when the rate switch is set to the faster speed.

all voltage check out, checked cap orientation etc.
I tried using a different 1m pot too but no dice.

I guess I could stay with the 4.7uf, but I like the slower speed of the 22uf, with the rate switch set to slow, where it works fine.

this ring a bell with anyone?
I take it everyone else's works ok with the 22uf in there?

the schem I'm using:

[skrunk]

of, fixed it by replacing the 2n3904 I had in q3 with a 2n5089.

I had 2n3904 in q1, q3 and q4 with a bc109b in q2.
I swapped out all the 2n3904 with 2n5089 and it gave a more choppy effect with a sharper curve to the trem attack.
I like the softer attack of the 2n3904s though, but noticed leaving a 2n5089 in q3 sorted my rate knob issue.

worth playing around with the trannys in this circuit, especially q1, seems to have quite an effect on the shape of the tremolo.

[wormfooduk]

Just made a pcb of this so i will try some different transisters in the Q1 posistion 

[skrunk]

do!
I noticed using a mpsa13 there makes the guitars note attack comes through sharper than say 2n3904, which is softer.
it's like the higher the gain of q1, the higher up the trem curve the effects starts.,
either that or the 2n3904 gives a deeper throb, hard to tell.

[skrunk]

I think a rev-log rate pot (c1M) works better too, more resolution over the 'fast' side of the pot.