Hello Everyone,
I was given an older HIFI stereo radio, an Unitra Mercury. https://www.radiomuseum.org/r/diora_merkury_dsh_303dsh30.html
The PA uses STK-077 Sanyo hybrid chips, those are 20W amps, running from +/-21V rail voltage.
The output DC offset is bit more than I would like to see, those are 100mV and 85mV respectively, with no load, after about 15 minutes of warming up.
I do not want to replace the chips, I am thinking about adding offset adjustment circuits, like the Pioneer SX-1250 has.
Any comment on this?
Thanks, Peter
I was given an older HIFI stereo radio, an Unitra Mercury. https://www.radiomuseum.org/r/diora_merkury_dsh_303dsh30.html
The PA uses STK-077 Sanyo hybrid chips, those are 20W amps, running from +/-21V rail voltage.
The output DC offset is bit more than I would like to see, those are 100mV and 85mV respectively, with no load, after about 15 minutes of warming up.
I do not want to replace the chips, I am thinking about adding offset adjustment circuits, like the Pioneer SX-1250 has.
Any comment on this?
Thanks, Peter
I would not worry about 1/10th Volt DC. It is less than 1% of the maximum output voltage and 0.01% of maximum output power. The idea of "zero!!!" output DC came after these chips.
But yes, you can trim it out.
But yes, you can trim it out.
Thanks for the comments!
My apologies for the late reply, I was away for awhile!
The only reason I was asking about the output offset that there were some sticky threads some time ago advocating 10mV to 30mV max offset for low distortion.
I do not recall the technical argument for the lower distortion.
That thread also could have on another forum...
Thanks again, Peter
My apologies for the late reply, I was away for awhile!
The only reason I was asking about the output offset that there were some sticky threads some time ago advocating 10mV to 30mV max offset for low distortion.
I do not recall the technical argument for the lower distortion.
That thread also could have on another forum...
Thanks again, Peter