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Anyone interested in a preamp kit?

Hi makers. I am looking at making the Don Tillman preamp circuit available as a printed board for those who don't have experience in soldering up circuits. I've found the Tillman circuit to be very good for piezos and adding a preamp will make it the right impedance for amps and mixing boards while greatly improving the tone and output level. It also means you can add a proper tone control using a 25k pot and the usual cap. The board I have printed includes extra cap and resistor for greater FET tolerances, a tone/boost option, and a volume adjustment for matching a piezo with a mag pickup or bringing the output down (the Tillman gives plenty of level from a disc piezo and can be a little hot for some inputs).

The clearly labelled board alone would be $10 and the parts are easy to get. Board plus parts ready to solder in would be $20. Fully assembled - just needs the piezo, battery and outputs soldered on - would be $30. (Piezo, 25k pots, output jack, battery and battery holder not included).

Would come with set of instructions.

Any interest out there? I'd need to see a bit of demand to justify getting a sheet of them printed up.

cheers and Happy New Year

Glenn

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Replies to This Discussion

Permalink Reply by Glenn Reither on December 28, 2011 at 7:10pm

Here's a pic of prototype with and without components.

Permalink Reply by Sanddraggin on December 28, 2011 at 11:12pm

I'm interested, I've been wanting to try one but haven't got around to it. I wonder what shipping would be to the States?

Permalink Reply by Glenn Reither on December 28, 2011 at 11:58pm

It would be very little, maybe $4 or so.

Permalink Reply by Rick Guggemos on January 1, 2012 at 10:56pm

I'd take one

Permalink Reply by Rouxdy Blues on January 4, 2012 at 7:44am

Deal me in as well!

Permalink Reply by rich gallagher on January 11, 2012 at 5:33pm

glenn - you know i love these preamps and at $10 for the board i'd be in for a half dozen or so - what's the blue square resistor?

Permalink Reply by Glenn Reither on January 11, 2012 at 8:13pm

That's a volume trim pot. Sometimes the output of the Tillman, especially with disc piezos, is a bit hot for some inputs. Also if you are ganging a piezo with a mag pickup, the Tillman may be a bit louder. You can tweak the trim to match them up.

There's a spot for putting in a treble booster 0.05uf capacitor too if for some reason your tone is a bit muddy. I've only had to use it once but it was a lifesaver.

OK...we're getting there. Would need to see a few more potential buyers before I spring for getting a whole sheet printed.

Permalink Reply by Glenn Reither on January 16, 2012 at 5:40am

OK, thanks for your interest. I've checked out the costs and the only way I can justify the time and outlay would be to sell fully assembled units at $25. You'd have to solder on a piezo, battery and output jack (not included) and if necessary make a battery holder and access panel. All very easy. So still interested?