Offset is fine/not alarming.
For Iq you can measure DC voltage drop across a few of the source resistors on either OS, and post here. Wayne will be able to tell whether or not it is in the ball park or not. As will others.
Regards,
Andy
For Iq you can measure DC voltage drop across a few of the source resistors on either OS, and post here. Wayne will be able to tell whether or not it is in the ball park or not. As will others.
Regards,
Andy
The DC offsets are fine; you can find the published specs here: https://www.passlabs.com/wp-content/uploads/2020/01/Int_specs.pdf
If you did, how's that you don't know that +/-100mV is more or less industry standard for normal range of amplifier output offset?
cut that in half, for amps driving sensitive and fragile speakers .......... and you're still waaaaaaay down
As far as I know, there is no industry standard for DC offset. The lowest possible DC offset is always recommended.
Each manufacturer has a set up procedure in their service manual and it is highly recommended to check and set it up.
You should know that.
Each manufacturer has a set up procedure in their service manual and it is highly recommended to check and set it up.
You should know that.
I have actually measured lowered distortion in loudspeakers with modest amounts of DC offset, so it's a bit of a crapshoot. At those levels I wouldn't give it a second thought.
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I was thinking there was a short write up somewhere about this "intentional" DC offset and it's effect on distortion. But I can't find it now. I've mentioned it before, but normally I'm smacked on the head by the "DC offset can only be 0.0000mV dum dum!" crowd...
A DC voltage offsets shifts the voicecoil position up or down, so distortion reduction really depends on the rest position the coil, and the symmetry of the Bl curve. There are assembly tolerances for loudspeakers so there are inherent variations in the rest position and Bl curve.
Worrying about a few mVs of DC offset is a fool’s errand unless you work in a laboratory.
Worrying about a few mVs of DC offset is a fool’s errand unless you work in a laboratory.
Hello.
End of story. After corresponding with PASS USA, I obtained the exact BIAS settings for the L and R channels for the mentioned piece and set the Differential offset and Absolute offset values after warming up to operating temperature.
That's all, thank you.
With that, I would like to close this topic.
End of story. After corresponding with PASS USA, I obtained the exact BIAS settings for the L and R channels for the mentioned piece and set the Differential offset and Absolute offset values after warming up to operating temperature.
That's all, thank you.
With that, I would like to close this topic.