hifi engine

Yamaha CX-830


My Yamaha pre-amp only works correctly when the "source direct" button is on. Without the button pressed in, I only get muffled sound out of one speaker. Any ideas??? Thanks, Janet.

Yamaha CX-830

Hello jwilsoncta,

Sorry for my poor English.
Previously, I have also this problem on my preamplifier (also a cx 830 from Yamaha)
To determine the defective component, I have injected a sinusoidal signal with the signal generator to a line input (CD, tape, ...) (both on L and R channel) and I visualise the signal with an oscilloscope on the preamplified output (with the volume set to the max).
I have notified, the signal is not deformed (or not significantly) when the frequency is around the 1kHz, but for lower or higher frequency (100Hz or 10kHz) the signal was strongly deformed on the oscilloscope. Of course this problem come when the "pure direct" was in "off" state and the tone potentiometers increase this phenomen.
The problem come from the tone preamplifier IC, i have change it and now all work fine.
For the moment, i have not the reference under my eyes, but if you want more information I will search in my history, do not hesitate to contact me.
See you soon.