Yamaha C-2

Bestselling slimline preamplifier, companion of the non-slimline B-2 V-FET... bestseller.

Deceptively small and black looks consealing high-end layout, circuits and parts :
Yamaha ultra low-noise matched FET pairs for the EQ stage, precision four-gang volume control (I believe home-made), polystyrol and metal film caps, low-impedance outputs, deported selector shafts and double shielded phono stage.

The all-metal and all-aluminium chassis is in fact four in one, with each of the three boards and transformer being entirely separated of the others.
As per Yamaha's habit between 1976 and 1982 for its high-end components, there are no visible screws anywhere revealing the attachment points.

The phono stage allows connection of three turntables/tonearms, phono 1 & 2 being MM and identical, phono 3 being MC for low-output cartridges.

The EQ amp is made of three stages : cascode-bootstrap current mirror differential amp (1st), Darlington connected constant-current load common-emitter amp (2nd) and fully complementary parallel push-pull Class A (output).

This circuit maintains constant the same voltage across the FETs regardless of signal level or impedance, thus lowering distortion, allowing a 123,5dB dynamic range and excellent square wave response.
The MC gain stage is set at 32dB, with an available dynamic range of 111dB.


A spring 1978 Stereo test shows that Yamaha's specs were easily surpassed on production samples.
This doesn't put the C-2 anywhere near a match for the contemporary Sony TA-E88B but it nevertheless makes it a fair preamp which can be found at very affordable prices.

After seeing a near-Invisibilia export version in silver, the C-2 was replaced by the visually equivalent but very different C-2a which sold even better because it was... much better.



Nudies aplenty at the indspensable amp8.com, page 1 and page 2.