I bought a smps with output of +30V and -28 v for use with LM 3875 Peter Daniel kit.
Is this imbalance acceptable and will it affect the DC offset at output?
Is this imbalance acceptable and will it affect the DC offset at output?
Hi. This asymetry will only cause unsymetric clipping on amplifier overload by too high signal level . In this case ,positive output will grow , negative clips, and you may get about 2v dc poaitive at speaker output.
Have you measured actual voltages from smps ?
Also , are the outputs ampere ratings identical ,just voltage different?
If -28v output is weaker than 30v , then this is more serious problem than assymetry itself. Just don't allow amplifier to clip.
Have you measured actual voltages from smps ?
Also , are the outputs ampere ratings identical ,just voltage different?
If -28v output is weaker than 30v , then this is more serious problem than assymetry itself. Just don't allow amplifier to clip.
Thank you all for the reply .
I am using it to drive easy load, Eikona fullrange and unlikely to play it so loud.
The seller didnot specify the amp ratings for positive and negative .
I have tried it on LM 3886 ( supergainclone from Mark Johnson here ))with dc offset correction. It works well and no dc offset at amplifier output .
However, Peter Daniel LM 3875 board has no dc offset servo correction.
I will test it anyway
I am using it to drive easy load, Eikona fullrange and unlikely to play it so loud.
The seller didnot specify the amp ratings for positive and negative .
I have tried it on LM 3886 ( supergainclone from Mark Johnson here ))with dc offset correction. It works well and no dc offset at amplifier output .
However, Peter Daniel LM 3875 board has no dc offset servo correction.
I will test it anyway
An asymmetrical supply will not cause any change in offset voltage in the amp, as has already been stated. The only real world effect, also previously stated, will be asymmetrical clipping when driven hard. If the power supply has adequate current capacity from both polarities, it will work just fine.
Mike
you can reduce or increase voltage by adjusting feedback resistor inside the SMPS or just put 2 or 3 high current diodes in series at the output of 30V SMPS to make it 28V