Maestro Filter Sample and Hold

[Ry]

I have tried a boatload of different transistors for the noise source (including a couple bad ge's) and have always come back to a dirt cheap surplus 2N2222, with a 2n3904 being a close second.

[Fp-www.Tonepad.com]

LP, thanks!

Ry, I think the 2n2222 is quite noisy, I wonder if it can be made noisier by biasing it wrong for a while (in another circuit designed for that purpose) and then put it in the FSH1

Fp

[wui223]

I check out the store at my place and couldnt find a single piece of LM13600.
I think the circuit will work right. Coz the CA3080 which is single OTA is replace by a Dual OTA as suggested by Tonepad's designer.
And the single op-amps are replace by a dual op-amp. Others remain the same so there is no way it couldnt work unless soldering error or part failures.
Anyway mine still dont work and i wonder why

[Zero the hero]

Good job FP!
I always have to learn from you!

There was a post and we discussed about the differences between LM13600 and LM13700. Does it work with lm13700 too? Any difference in the sound?
Actually I have no time to build it and test by myself...

[Paul Perry (Frostwave)]

There was a post and we discussed about the differences between LM13600 and LM13700. Does it work with lm13700 too? Any difference in the sound?...

I havn't tried, but I'm sure a LM13700 or NE5517 would be fine. Or the Japanese 13600 or 13700 for that matter.

As for the person who asked about using a 'normal' diode, that won't work, you are relying on the diode sructure to undergo zener breakdown I think. Which a transistor might, but not a 1N4148 for example.

[Fp-www.Tonepad.com]

I didn't see that thread. But looking at the data sheet I don't see why not use either LM13600 or LM13700.

Fp

[wui223]

can someone help me coz i spend endless hours on this project but still fail
The filter is not working same as sample/hold.
I just can hear noise and constant "du du" sound. Why?
How to fix it? I use 2N5458 for FETS and a BC184 for the first FET ar input stage. Else is CA3080 and LM741. I really need help

[Ry]

Wui,

Just to clarify, does the filter setting work, but not the sample/hold?

Have you tried slowly adjusting the trimmer while listening to something constantly playing through the pedal (could be a cd player or anything, really) to see if you need to tune the noise in?

What are you using for a noise source and have you tried other transistors?

Ry

[wui223]

i try both 2N3094 and 2N2222A, how is the sound of working filter? i really cant hear an effect only noise

[Fp-www.Tonepad.com]

It's worth to mention that Mr. Wui is NOT building from the schematic I posted but from JD Sleep's schematic. He is also using perfboard.

Good luck with your project mr wui.

Fp

[wui223]

yes u are right. But what is the point the schematic is not much different only some part change so the concept still apply. And i am pretty sure my connection is done properly coz i redo the whole thing on a new board.

[soggybag]

I couldn't resist making another one. I think I had most if not all of the parts. I made the PCB yesterday and solder a majority of the parts.

[Fp-www.Tonepad.com]

Great!

NOW we're talking!

I hope it works  :!:

[Ry]

I etched a board yesterday, and it worked like a charm (my first etch)!  Thanks for the photo essays about creating a board using PNP, FP.  Now I just need to drill it and populate it.  I will post back when I get it done and compare it to the old version.

[wui223]

So Ry u have done a working version right? then what is the problem why i cant get it sound right i am really desperately need it

[moosapotamus]

wui -

perfboard = 1,000,000 opportunities to make a simple mistake that could take a long,long,long time to discover... especially when dealing with this level of complexity.

We have all been there, myself included... some blindingly simple wiring or connection error that you could kick yourself for once you discover it. The difficulty is discovering it.

You obviously have all the parts. If you can't run down the mistake(s) that are keeping your circuit from working, the only suggestion left is to try a verified PCB layout that follows the same schematic that many others here have had success with.

~ Charlie

[wui223]

Thanks for all of ur suggestions just that i cant make the PCB in an easy way, i dont haev access to press'n peel blues. Anyway the FET is choose shouldnt be problem right? Just the noise transistor, anyone got way to choose it to work?

[soggybag]

You should use the search above to search the forum for this effect. There has been plenty of talk about the FSH-1. I built one myself and it didn't work at first. The filter sweep mode still doesn't work correctly, though the Sample and hold mode is working.

I would not build a new one yet I think I would keep trying to get the first to work. Try tracing your circuit with an audio probe. If you figure out where the audio stops it might point to a problem.

If the sample and hold is not working. Try tracing the LFO. If you hear a ticking turn the speed knob to see if changes speed. Use your audio probe to check the noise. The noise should come out at one of the legs of the FET in the Sample and hold. Another leg of this FET should also be getting the LFO signal. If you have a scope you should scope all of these places. If not probe with the audio probe.

[markr04]

Thanks for all of ur suggestions just that i cant make the PCB in an easy way, i dont haev access to press'n peel blues. Anyway the FET is choose shouldnt be problem right? Just the noise transistor, anyone got way to choose it to work?

A laser printer and inkjet photo paper works quite well. I've done 20+ PCBs this way. PM me if you want more info.

[Fp-www.Tonepad.com]

... and that's what "hijacking a thread" is all about... I hope the guys that are building from my layout come back with a report.

Fp