The Yamaha Sound

The Yamaha Sound

No longer do you need to look wistful every time the guy on the TV rams home a power-chord on his big Yamaha DX synthesizer. With this ‘black box’ plugged in between your most non-descript organ and a good amplifier, you too can produce that very distinct but very familiar voice the zippy “Yamaha” sound.

The unit is nothing but a fuzz box commonly used for enlivening the droll sound of electric guitars. Acute distortion is created by passing the signal through a high-gain, 2-transistor amplifier where the 1 M-ohm preset control the working point of transistor T2, thus varying the degree of distortion or fuzz. The outcome is a sound laden with harmonics-the sound we want.

Any ‘Plain-Jane’ organ can be used, but a simple 555 contraption works our best. Adjust the two preset for best simulation and constant input and output signal level. To produce the replica of the original, digitally-produced sound, too little distortion does no good at all, and too large a volume can knock up a demonic scream!

PARTS LIST

Resistors (all ¼-watt, ± 5% Carbon)

R1 = 1 MΩ

R2 = 4.7 KΩ

R3 = 10 KΩ

VR1 = 1 MΩ

VR2 = 100 KΩ

Capacitors

C1 = 47 µF/12V

C2 = 0.047 µF

C3 = 0.01 µF

Semiconductors

T1 = BC148B

T2 = BC149