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Hi folks,

Building a small pre-amp circulit to sit between the tone/volume control circuit and the (female) 1/4" output jack connector on an acoustic guitar.

Just now getting to the part were I wan't to make sure that the pre-amp circuit is only powered by its 9-volt battery when a (male) 1/4" jack is inserted.

I have heard that this can be done by ensuring that the female output jack (on the guitar body) is stereo and that the input jack is mono, and then running the negative off the 9-volt battery to the ring connector (on the stereo input) which is then shorted to the sleeve connector (on the stereo input) when a mono jack is inserted? But not sure if I have got all of that right as I cannot find any clear instructions :-S

But then I have heard others saying that this approach is a hack and not recommended ... and I do wonder what would happen if you inserted a stereo jack ... hmmmm?

And then I heard that there were "switched jacks" out there that had this power-on-off functionality built-in, but cannot find any clear information on them either that shows the connections, how they work, etc.

So that is why I am coming to you guys ... help!

Can someone explain all this to me ... or point me to a site that does?

Thanx

Ziggy

Hey folks,

I am brand new to building pedals, brand new to this forum ... but do have a little electronics background.

Was just searching around the net as I wanted to build a real small chorus pedal. I have a relatively cheap chorus pedal at the moment and only use the "depth" side of it which gives a fuller sound to my Ovation ... so was wanting to build a simpler and much smaller unit really with just a single control depth function running off a 9-volt battery.

Whilst searching, I saw lots of posts about Boss Chorus pedals to the effect "get the MN3007 chip, its the best and you won't be able to get them soon as they are discontinued and there are lots of fakes around ... yada yada yada"  ... so without much further research (i.e. just a cursory check that the Boss pedals have a depth function) ... and my usual impulsive behaviour ... I just (panic) bought the MN3007 & MN3101 pair from Doctor Tweek ... then thought "hmmm ... can I actually build what I want with this"?

I then found one circuit with that chip and it looked very complex ... but I think it was using all of the features of the chip with a bit more added on!

Was hoping even to build it first maybe on a breadboard, test it was all ok and then commit it to a PCB and enclosure.

I have the panasonic datasheet that has a sample application with about 4 op-amps to produce what they call an "echo effect generation circuit" ... but not sure whether that is really what I am after.

Can anyone give me any pointers? Can I build a fairly simple "depth" chorus effect with the MN3007? Are there any simple circuits out there explaining how to do this?

Any help appreciated

Thanx

Ziggy