Building a tuner out into any pedal

Started by YouAre, January 29, 2007, 01:40:16 AM

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YouAre

I'm building a pedal for a guy that wants a tuner out in it. Basically he wants the the signal going to the pedal at all times, even when the effect is bypassed. Is it going to be as simple as adding a wire from the input jack to the "tuner out" jack (in addition to the wire from the input jack to the switch). Or will i need a simple splitter from the input jack that goes from the input jack out to the switch and to the tuner out

heyniceguy

basically, all you would have to do is keep your normal wiring the same and add a wire from the input jack and send it to a simple op amp buffer (HI-Z) and then to the tuner out. if the input Z is high enough, it will never load your signal.

YouAre

hmmm so would the first buffer thats described in http://www.muzique.com/lab/buffers.htm work?

Also what jfet would you recommend using?

heyniceguy

go to radio shack and buy an MPF102.

and i should (technically) rephrase my last sentence. anything added to the signal chain like this will "load" the signal, what i should have said is it wont "aubidly" load the signal, as the loading is really high on the frequency spectrum, much higher than what humans can hear.

YouAre

Quote from: heyniceguy on January 29, 2007, 12:57:12 PM
go to radio shack and buy an MPF102.

and i should (technically) rephrase my last sentence. anything added to the signal chain like this will "load" the signal, what i should have said is it wont "aubidly" load the signal, as the loading is really high on the frequency spectrum, much higher than what humans can hear.

i just happen to have mpf102's. Of those buffers, which would you suggest to the simplest answer to my issue. The first one?

jakenold

Try to build it with what you have. Your primary goal is to not load the signal so it can be heard in the other end. The quality of the signal to the tuner however, isn't all THAT important. So my guess would be any easy-to-build buffer will do. I've built one with the one you have, and my KORG still tracks excellently!  :D

heyniceguy

when i have done tuner outs, i used a TL072 as a unity gain buffer (usually i have an extra gain stage leftover from the chip so i just use it up), and i just so happens the TL072 has a FET input device which makes for reallly high input Z and low power consumption and low output Z. Your tuner will track that supah fast.

so yeah, use that MPF102 the way AMZ shows it.