Sample and Hold Effect - possible 500 series?

A client that beat me before wanting some effects that I didnt have and just yesterday stumped me again.  A random step filter (as korg used to call it) or sample and hold filter as others know it by.
After searching around a bit, i found a schematic for it (or something close)
https://www.generalguitargadgets.com/diagrams/fsh1asc2.gif?phpMyAdmin=78482479fd7e7fc3768044a841b3e85a
I've seen a board made for a guitar pedal that was rather small.  Im thinking that I can either un-balance a signal coming in using IC's then rebalance it going out same way (can't see the need for transformers when the amount of times this thing might be used could be counted on one hand)
First question is since this was originally designed for guitar, any problem sending it a line level signal (besides running out of headroom)?
Second, would it be worth bringing the volume down after un-balancing it, then make up before re-balancing?
Haven't really seen very many "effects" in either 500 or rack versions for that matter (probably because everything is DSP these days) but still might be kind of cool to try.  Looks as though the guitar version uses 8 and 9  volts. 
Third, Any issue with stepping down the voltage from a 500 PS?

sr1200 said:

First question is since this was originally designed for guitar, any problem sending it a line level signal (besides running out of headroom)?
Second, would it be worth bringing the volume down after un-balancing it, then make up before re-balancing?

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Basically, you've answered your own question. Gtr FX are designed to operate at -20dBu nominal. Some would tolerate 0dBu, most wouldn't. Make the attenuation and make-up adjustable, so you can optimize S/N ratio. Many gtr FX are somewhat noisy; noise is somewhat concealed by the poor HF response of guitar loudspeakers. You may have to LPF the output.

Looks as though the guitar version uses 8 and 9  volts.

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Most gtr FX are designed to operate on batteries; depending on type of batteries (dry batteries have higher voltage than rechargeable) and freshness, the voltage can vary from 6 to 10 V. Please note that the supply is negative relative to ground.

Third, Any issue with stepping down the voltage from a 500 PS?

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None other than using the negative rail. Use an LM7909 or preferrably an LM337.
You may want to use remote ground sensing (see attachment).

You could use the rails as they are and not use step down voltage in order to better headroom and S/N.

You can use an LM13700 instead of two 3080, both can work at ±18V. You will have two darlingtong for buffers. You may want also to lower Z to get lower noise (not much lower with any OTA anyway) but input at 100K are for guitar, you can use 10K for R2 and R14 line applications and R1 1K just to use something, C1 and C4 much bigger for better LF response, baypass ofcourse different. R1 to R14 may be scaled with caps C1 to C5, make sure all your transistors and fets can manage 35V or 40V at least.

I've seen a guitar FX that make stepped filter, uses 8 little pots to control 8 steps values and one other to velocity, output was a voltage to a led and LDR in the audio FX to control the value you want, I can't remember where it was now, but you can use something like this and use any filter you like at the level you want. It had layouts with a wah, a LPF or HPF, a tremolo and a vocalizer I think...

The other option is a microcontroler riding a vactrol and posibilitys are unlimited... Here in Argentina some guys make some pedals like this, a great ones! http://www.dedalofx.com.ar/

Good luck with this, nice thing!

JS

ANyone remember who had breadboard type 500 series boards? 

sr1200 said:

ANyone remember who had breadboard type 500 series boards?

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AML does.

http://www.audiomaintenance.com/acatalog/blank_pcbs.html

-Casey

Thanks,  ;D ;DI gotta place an order with Colin anyway.

This is the Roland SH9 S&H which I have built and can vouch for it, it´s simple but in a good way & does all it´s supposed to do...
http://members.tripod.com/urekarm/synth/sh09_shn.pdf

I´d say combined with a state variable filter- check out this thread for one built with THAT vcas for cleaner sound then OTAs
http://www.muffwiggler.com/forum/viewtopic.php?t=72845&postdays=0&postorder=asc&start=0

I´m all over THAT one!
Edit: But just for curiosity since for this application LM13700 would be fine anyway...
        Also I think -24dB is the much better sound for S&H with LP/BP/HP switch