Revised Tonepad FSH-1

[oldrocker]

Has anyone who built this already know what the best components would be for this.  The Tonepad layout mentions 3 fets and 2 duel opamps.  What would be the fets and duel opamps that you used for best results.  For fets I was going to use 5952's or MPF102's.  For the duel opamps I was going to use 1458's.  Maybe TL072-82 would be better?  Anyone who has built the tonepad version and had decent results I would love to hear from on the subject.

[Fp-www.Tonepad.com]

Oldrocker, we're trying to find out which one works best right now

Fp

[oldrocker]

Thanks Francisco,  OK I'll be watching to find out what you came up with.  I will of course be socketing all the fets, and duel opamps so I'll change them out if I finish building it before you get done experimenting on what's best.  It will be interesting to see what works best on this.

[Barcode80]

please spell "duel" as "dual," it's driving me nuts. 

[Fp-www.Tonepad.com]

we're just waiting for moroco to finish his build and post some results. I am only just ordering the parts from small bear.

[oldrocker]

Whoops.  Sorry about that.  Yeah I know better.  I meant dual.
OK Francisco, thanks I'll keep watching out to see what you come up with.

[Morocotopo]

More detailed build report.

Subs/parts used:

.03 caps: .033
.05 caps: .047
MAX1044: ICL7660S
Opamps: TL072
FETS: MPF102
1N4001 diodes: 1N4007
Q1: 2N2222 handpicked for best result from a 2N2222 and 2N3904 bunch
Multi turn trimmers
1M rev log pot: 500K log dual with the carbon tracks flipped and wired in series... works perfectly!

Filter:

After I got the thing working, there was ticking in the filter mode(s). But I noticed that when I put my finger in the PCB between the left resonance pot pad and the 1M resistor just to the right, without touching the pot wire or the resistor, the ticking was greatly reduced. I concluded that my finger was acting as a shield, so those parts of the circuit were interacting to create the ticking.  I  moved the connecting pads for the resonance pot to new locations:

As extra insurance, I used shielded cable for the resonance pot´s wires, but that didn´t give any extra benefit. Now the ticking is barely audible, only when I max my mixer volume can I barely hear it.
The controls are very touchy! It´s kind of hard to get a useful setting, or getting all notes to trigger the filter equally. Since it´s my first ever filter, I don´t know if this behaviour is normal or not (I once tried a Boss one, I remember it being a bit more "smooth" in use).
There´s "ripple", I think (I´m not even sure that´s the correct word...¿decay warbling?) Kind of interesting...sometimes. Settings dependent/normal? Or it shouldn´t be there?
There´s distortion in some settings. Again, settings dependent/normal? Or it shouldn´t be there? I´m pretty sure it´s not the recording, but the circuit that saturates. ¿Use rail to rail opamps (I don´t know if that´s applicable here)/higher voltage?

Audio:
Click here to watch S-H-filter-down-2
Click here to watch S-H-filter-down-2
Click here to watch S-H-filter-down-chords---ripple
Click here to watch S-H-filter-up-background-noise
Click here to watch S-H-filter-up-chords-distortion
Click here to watch S-H-filter-up-chords-odd-decay---ripple
Click here to watch S-H-filter-up-chords
Click here to watch S-H-filter-up-fast-picking-tracking
Click here to watch S-H-filter-up-single-notes

Sample/Hold:
You can hear the LFO ticking away, the testing was done with resonance at maximum, when at minimum, the ticking is less obvious. I haven´t tried to solve this yet. Any suggestions? Shield everything and wrap myself in aluminum foil? The thing is not boxed yet, a mess of alligator clips and wires, but moving wires around doesn´t diminish/make worse the ticking. Now, when I put my finger over the LM13600 the ticking gets worse... hmmm.

Audio:
Click here to watch S-H-res-max
Click here to watch S-H-res-max-background-noise-shielded

Regulated, filtered power supply at 9.31V
ICL7660S voltages:
Pin 1: 9.31V
Pin 5: -8.92V
A 10uF cap missing from Geofex/Datasheet schem?

To be continued.

EDIT: I forgot, guitar: 335 direct into mixer