AndrewT said:gross distortion if the amp operates on the ramp?
The mute function is intended as mute and my gut feeling says that this is not a good idea.Tcheko said:Hello,
I was wondering it the mute pin could be of any use for controling volume. The documentation shows a nice ramp from 0dB/0.5mA to -100dB/0.01mA. The ramp is not really linear but a tweaked log pot may do the trick.
Any insightful though about this?
Czk.
Dxvideo said:No...
Because the op-amp becomes unstable under 10 V/V gain. Just a question;
Why do you need a volume control except "normal" ways?![]()
peranders said:
The mute function is intended as mute and my gut feeling says that this is not a good idea.![]()
A good pot will do and let the gain be fixed, my recomendation.Tcheko said:Would it be more efficient for adjusting volume to change the gain ?
peranders said:
A good pot will do and let the gain be fixed, my recomendation.
peranders said:It's quite uncommon to change the gain because the amp will also get more unstable at lower gains and in performance it's a waste to have the amp stable at 0 dB gain. If this had been a good idea it would have been more common, I'm sure.
fit a shorting plug to the input RCA and re-measure the output noise.Tcheko said:my gainclone.
This is my first electronic device and so far, I am quite surprised to have succeeded. No hum, no shhhhh and 11mV at output
AndrewT said:fit a shorting plug to the input RCA and re-measure the output noise.
Aim for <0.2mVac
no,Tcheko said:How can I remove the 11mVdc offset? Do this come from the slight difference between +V and -V rails?
AndrewT said:fit a shorting plug to the input RCA and re-measure the output noise.
Aim for <0.2mVac
AndrewT said:no,
it comes from the input offset current which flows from both the inverting and the non-inverting inputs.
These currents pass through the resistances attached to the inputs and generate a voltage.
The difference in the input offset voltages appears at the output multiplied by the gain of the amplifier.
If you need to reduce the output offset, then you can manipulate the input terminal source resistances to get that balanced input offset voltage. But as the chip changes temperature the input offset currents will probably change giving rise to temperature induced drift of output offset.
Output offset of 11mVdc is pretty good. How far does it drift with temperature?