I'm looking at the Tonepad FSH, and notice its fairly different to the one on GGG which I built a while ago.
I'm thinking of having a go at this one as it would not need a separate power supply, and mine has always seemed a little quiet, plus I could actually make an effort to put it in a sensible box this time now I have some ability in the arena, instead of the gigantic ugly housebrick size Socket box thats currently cluttering the crap out of my pedalboard...

I will proceed in my usual psychotic stripboard manner (glutton for punishment).
Just wondering if anyone has been able to compare these two, and noticed any differences, or what not. Certainly will keep me busy for a while.

Also do 2m2 pots even come in the small size? I hate those big clunky pots.

As I understand it the Tonepad version puts a whine into the output. I also understand this is fixable. Otherwise it sounds the same.

I had no problems with the Tonepad build - no whining, no ticking. I fit it in a 90mm by 115mm enclosure with five pots, one switch and two footswitches. It runs off a nine volt supply just fine, and it used a LM13600 instead of two CA3080s and dual opamps instead of singles.

There's been a further revision of the PCB since I built it, to address any ticking problems - again, I had no problems. Once you box it, you should be fine. And it's a great and very singular effect.

Chris

Well I had someone etch me a PCB from the Tonepad FSH-1.  He did a great job.  I do have ticking in mine.  I usually perfboard build my boards so I can fine tune and fix any anomalies like ticking.  I really like it although it would be nice if I could fix the ticking.  The wah filter is fantastic.  I used it one time playing.  With a band playing it hides the ticking.  A dude asked how I was controlling the wah pedal.  He thought someone was off stage treadling for me.  He knew what an auto wah does but he said mine was so pronounced that it didn't sound like the auto wahs that he had heard.

I have built both and been able to get them to work without whine.  I like the sound of the Tonepad one a bit better.  Both can whine and tick if you aren't careful about the wiring.

Ry

OK thanks RY,
I'll revisit this and try a different wiring setup.

I got rid of the ticking by wrapping the PCB first in plastic bag paper and then around that I wrapped metal tape over the bag.   Of course then I had to insulate the pots, switches and jacks with black tape.  This seemed to work pretty decent.  Not the way I would fix all my noise problems with other pedals but for now it sounds great.  Thanks RY.

Ry, that looks great!

The latest layout should take care of the noises in the PCB, but I can't control how people do the offboard wiring, I guess that's where you got to be careful to avoid noises.

Fp

So is there a problem with running traces too close to the chip on the layout causing noise? How does this happen?
If you've essentially shielded the pcb by wrapping it in metal tape (was the tape grounded?) then that bleedthrough is more to do with the offboard wiring picking up some sort of ultrasonic emissions in the airwaves (?!) coming from the chip, surely if it can do that it can go to traces on the board just as easily if not more easy? theres no way to shield against that.. I just dont get it.

My one does tick. But I dont pay it any heed.

Anyone know if this replacement chip the LM13700 is any better?

Well the causes of tick noise coming through can have a number of causes.  When I realized through Ry that offboard wiring was the culprit then I tried the foil around the board to see if I could eliminate the tick without rewiring everything.  Fortunately that worked but I feel I just took a guess at it and got lucky.  No the foil isn't grounded it just prevents the longer wire lengths running across the top of the board from picking up noise.  When I tried the same procedure with a Zombie Chorus it had no effect on the ticking.  So it depends on the situation.  Some of the seasoned electronic veterens might have a better answer.

Maybe a little judicious use of shielded cable could help?

Those pics aren't me, they're Oldrocker's!

I tried using a bunch of shielded wire on my inputs, outputs and some jumpers.  It didn't do a lot.  The one thing that really helped me was to keep the wire runs short and tidy.

 

Hmmm well I've finally gotten round to it. Built it twice now on 2 different boards using 2 sets of almost identical components and got the same thing on both .. it doesn't work. I can hear the ticking faintly in the background but thats about all. I'm using TL072 opamps and an lm13700, bf245B for fets. Nothing, just the ticking which does vary with the speed pot. I really cant imagine I'd make the exact same mistake twice, and I've checked and rechecked on both attempts, all the parts are in the right places and seem to be getting the right volts, the board is very tidy on the copper side, it just does not work... I've seen build reports on tonepad claiming the 13700 works, I'm stumped..

has it been up on tonepad as this revision for very long anyone know?

Dont tell me.. Check the pinout on the FETS.. yes I know I got it wrong didnt I.
Fer christs sake... is there any particular reason I cant read fet datasheets right? I dont seem to have this problem with regular trannies.. just fets, they seem deliberately obtuse. STUPID STUPID STUPID ST >>> brb...

I have no experience with this particular build, but from similar situations, it is worth noting that the 'whine' and the 'ticking' are two completely different problems - and so they may need different solutions too!
The 'click' is I expect from the LFO doing the sample and hold. To reduce this, you want the wiring supplying the power to the LFO, to be as seperate as possible from the rest of the circuit. And maybe even isolated further via 220 ohm resistors with bypassing caps in the power going to the LFO section.

WOOO it works now. Yeah the tick is so very faint. I'll give it a proper try tomorrow but compared to the other one its barely noticeable, my other one sounds like a metronome at band practice and our singist is particularly perturbed by it I think, I have to pull the power plug when its not in use or it gets very annoying. Plus the filter is so much more adjustable with the tonda mods that I might actually use it at some point!!! shock!

Theres no whine that I can determine. Thanks for the suggestion on the LFO power, awkward to do though without redoing the board. Just so I know, resistor and bypass cap to ground? like a low pass filter in the power line? cos that could be done failrly easy by cutting the 8v trace just before the chip and drilling like 3 or 4 new holes, would look horrible but who cares about that? Bit more hassle if the -8v line would need it too.

Sample clips of the Maestro FSH-1 from my website.
http://randallbarnett.homestead.com/files/Fsh-1SampleHold.mp3
http://randallbarnett.homestead.com/files/Fsh-1EnvelopeFilter.mp3

Quote from: Hambo on May 26, 2007, 10:17:23 PM
Thanks for the suggestion on the LFO power, awkward to do though without redoing the board. Just so I know, resistor and bypass cap to ground? like a low pass filter in the power line? cos that could be done failrly easy by cutting the 8v trace just before the chip and drilling like 3 or 4 new holes, would look horrible but who cares about that? Bit more hassle if the -8v line would need it too.

yeah that is what I had in mind. My advice here is theoretical - I don't have the unit myself - but yes, that's how I have got rid of oscillator & LFO bleedthrough in other designs in the past. Also star grounding of course.
The problem is insuperable, when one is usign a quad op amp chip & the power inputs can't be split, of course.

Is there an specific reason you picked 220R and 220U for those parts or just experimentation? Could I for example use 1k resistors to a chip which doesnt immediately need much voltage like a tl072?

Well it's a compromise, it was a matter of experimenting, I didn't want to drop the voltage too far or I would have had to do some redesigning.
You can get even more noise out of the supply by splitting the dropping resistor in two, and putting ANOTHER cap to ground from the middle. But I have never had to do that..