Fender type tremolo schem. Opinions?

[Morocotopo]

Update: with the thing plugged into a guitar amp, I get LOTS of hiss...



More fiddling to come.

[Morocotopo]

Allright, still struggling with this. This is the current state of the schem:



All the changes are to try to get less hiss, but till now I haven´t been very successful. I managed to reduce it to an -almost- bearable level, but I´m not still satisfied. Seems that no matter what changes I make to get more gain in places or to optimize signal to noise ratio, there´s a noise floor that´s inherent to the schem, or the chip used, I don´t know. I´m kind of disenchanted with this, I´m just a step away of striping the breadboard clean and to hell with it...
I even tried feeding it 18V, to see if that bought me more dinamic range, not much change.
Maybe i´ll try to make this using LED/LDR technology.

Grrr!

[R.G.]

Try putting a ceramic cap of 100pF to 1000pF between pins 3 and 4  and also between pins 13 and 14 of the LM13700. Excessive hiss like you're describing sounds to me like RF oscillation. It probably makes sense to tie a 0.1uF ceramic cap between pins 11 and 6 right under the chip.

[Morocotopo]

RG, tried your suggestions but no dice... maybe just a liiitle tiny change. I don´t think the circuit is oscillating.
I´m giving up on this, maybe the technology is inherently noisy, maybe I´m not experienced enough to make it work (wich one you think is the most possible?  ). I searched for other schems that use this technology to see how they implement its use, but found none of a similar topology.
Thanks RG for your guidance and everyone that chimed in. Now I´m gonna go the led/LDR route. Yes, I want this FX! Yes, i´m stubborn! Yes, I like to spend hours over my breadboard!