Hello, running SE for testing purposes. JFets from diyaudiostore kit, all parts tested before installation. Solder joints inspected and look good to me, as does the part positioning. Do you know what input voltage for a 1kHz sine wave would cause clipping? The distortion is definitely reduced at lower input voltage.
With a 24 volt supply and 8 ohm load you should be able to get to around -/+10 volts output voltage (so around 7 volts rms). Input voltage for that would be around -/+3 volts on a scope.
That assumes R12 is 39.2k. If you have fitted 68k then the input voltage would be around -/+ 2 volts.
(the results deviate from what theory might suggest because of the very high output impedance of the ACA and its very low open loop gain)
That assumes R12 is 39.2k. If you have fitted 68k then the input voltage would be around -/+ 2 volts.
(the results deviate from what theory might suggest because of the very high output impedance of the ACA and its very low open loop gain)
The different parts of different psus modulate the signals different. The earing does listen these differences.
Try: set some cables and a switcher between the psus. Listen and switch;-)
If anybody looks for more separation of channels: Move the speakers further apart.-)
No, the offset is set to 0mV.
Question, though... based on the topology of this amp, if I feed a signal only into the left input, should I get an output at both speaker terminals? I'm thinking yes, because the reds are tied together (to ground), but if that's the case, it makes it tough to troubleshoot which one is my problem channel.
Question, though... based on the topology of this amp, if I feed a signal only into the left input, should I get an output at both speaker terminals? I'm thinking yes, because the reds are tied together (to ground), but if that's the case, it makes it tough to troubleshoot which one is my problem channel.
No, in stereo mode, but in that mode, the positive speaker outputs are tied to ground, which (if I'm understanding correctly) is different from most amps.
My test rig routes the black speaker wires to oscilloscope ground, not the reds, which has never been an issue before now.
Maybe I'm misusing the term "bridged"...
My test rig routes the black speaker wires to oscilloscope ground, not the reds, which has never been an issue before now.
Maybe I'm misusing the term "bridged"...
The red terminals are grounded because this is an inverting amplifier. It is typical of a common drain if I am right.
The only reason that the terminals look confusing is because for topology correctness, they are not reversed, since the amplifier is inverting and so is the polarity of the output. Switching around the jack colours would do nothing in terms of driving it (except that when doing parallel you still need to connect the right terminals regardless of colour. )
The only reason that the terminals look confusing is because for topology correctness, they are not reversed, since the amplifier is inverting and so is the polarity of the output. Switching around the jack colours would do nothing in terms of driving it (except that when doing parallel you still need to connect the right terminals regardless of colour. )