Building a MC pre

Are you looking to build an MC head amp, or a complete MC phono stage with RIAA?
I built this MC head amp for feeding into various RIAA preamps I have; designed it with Sean Collins, based on input and prior design for another preamp by Wyn Palmer, designer of many op amps and other items at ADI for 40 years.
Very low distortion, lots of adjustability for R and C loading with dip switches on the bottom. I built mine with an outboard power supply using a flat pack transformer; the regulators are SMDs on the head amp board.
Fits into a pretty small chassis, but you would have some metalwork to do to create openings for the DIP switches. I used my milling machine.
PM me if you'd like more info.
Cheers,
Greg

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The Marshall Leach design is time tested and still holds its own. It has been copied/modified many times over the years (Marcoff, Lee, etc.). Built my first one in '88 (crude hand-made boards). Built a 2nd one 4 years ago w/real boards. Simple, effective and very quiet.

Design & build thread: The Leach moving coil pre-preamp

See last page for end result photos.

It can be built in original Common-Base or Current-Mirror configuration, using either discrete transistors or the "THAT-340" monolithic matched NPN/PNP pairs chip (used in my build).

... or ...

A dirt simple 1 chip (AD797 opamp) circuit is equally as good, perhaps a bit better, but requires a dual-polarity power supply.

While this is a bespoke design, it shows an example of low parts count and small size capability: Apt Holman plug-in MC expansion board
 
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