Yamaha C-2

Yamaha C-2 "Control Amplifier"

Circa 1977 Msrp $2800 (Cost adjusted for Inflation)

$1277

Sold

FMI HiFiHealthCare@Gmail.com


Many looking at this piece already know about it's famed heritage, a piece built at a time when Yamaha was flexing its HiFi Muscle and producing no holds bared products.

The build on the C2 is as good as it comes. When you pick this modest looking piece up you are instantly surprised at the weight...is this an Amplifier or a Pre-Amplifier? The C-2 weighed more than some of the rack amplifiers that surfaced a decade later claiming "110 Watts Per Channel!"





Deceptively small and black looks concealing high-end layout, circuits and parts :


Yamaha ultra low-noise matched FET pairs for the EQ stage, precision four-gang volume control polystyrol and metal film caps, low-impedance outputs, deported selector shafts and double shielded phono stage.


The all-metal and all-aluminium chassis is divided into a four in one, with each of the three boards and transformer being entirely separated of the others.

As per Yamaha's habit in this time frame for its high-end components, there are no visible screws anywhere!




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

In alignment with the Yamaha Quest for ultimate fidelity, 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, lowering distortion and providing a 123+dB dynamic range and a square wave response with amazing fast slew rate!

The MC gain stage is set at 32dB, with an available dynamic range of more than 110dB.





A spring 1978 Stereo test shows that Yamaha's specs were easily surpassed on production samples. With the replacement of all the circa 1977 Electrolytic Capicitors with modern improved HiFi Equivelents the newly rebuilt version surpasses the original specs on almost all bench measurements!

The rebuild also payed special attention to the RIAA Phono section and an improvement in the curve was achieved with a precision selection of part of this circuit as well as maintaining a critical 'Yamaha' signature by maintaining the factory Poly's where they still measured within +- 5%.

Special attention was taken to match replacements in symmetry to both channels where any capacitors in the signal path were replaced.





All typical 'tune-up' attention was given to this piece as well such as cleaning of all switches and potentiometers and adjustment of all power supply rails.


This piece is better than new electrical and an 8.5 -9 / 10 Aesthetically. 

Buying a C2 or C2a that is over 40 years old and expecting to experience the 'Renowned Signature' is optimistic at best. Experience with these rebuilds shows that greater than 30% of electrolytics in equipment of this vintage is no longer within spec and the bench measurements prior to a rebuild show the degradation in performance as well, often reducing the actual performance to marginal at best.


This C2 is ready to perform better than the day it left the factory for at least another 30 years due to the quality and selection of the replaced components. The performance of the Yamaha C-2 is exemplified in this piece and is most likely the best electrically performing example available for sale at this time.



FMI HiFiHealthCare@Gmail.com