Strange DC offset on T-amp

[Lostcause]

Hi people, I wonder if you can shed any light on this one?
I have completed my minimalist combo amp that basically takes the signal directly off the pins of a PS1 dac (with 2VDC along with it) through my pot and then through input caps to a Charize.
The Charlize has a servo on the inputs to null the DC.

OK, so the sound is well....excellent! No complaints there at all.

But! if I quckly turn up the volume there is DC offset at the speakers and I can hear it… the quicker you turn it and the louder you go, the more DC! You can make the speakers go in and out using the volume with no disk playing!
Now this doesn't really bother me because I just turn it slowly! but I was wondering if anyone could explain this phenomenon?

I originally thought that I was just hearing the DC arching across the pot but when I looked at my speakers I was somewhat surprised

I also noticed that the DC was moving my speakers in oposite directions so I wonder if they are out of phase with the amp?
I have always followed the orientation on Yeo's website......

[Pano]

Hey Cuz,
You're charging up the Charlize input caps with the 2 volts from your PS1 - via the pot. Things may balance themselves out over time, but when you turn the pot you change the DC levels on the upstream side of your input caps. Thus the offset on the other end.

At least I think that's waht's going on.

Your PS1 can't be very happy about its DC being shunted to ground via the Charlize pot.

And yes, the amp inverts.

[Lostcause]

Originally posted by panomaniac
Hey Cuz,
You're charging up the Charlize input caps with the 2 volts from your PS1 - via the pot. Things may balance themselves out over time, but when you turn the pot you change the DC levels on the upstream side of your input caps. Thus the offset on the other end.

At least I think that's waht's going on.

Your PS1 can't be very happy about its DC being shunted to ground via the Charlize pot.

And yes, the amp inverts.

Thanks for the reply Sir, I think I understand you, it's just that I thought caps couldn't pass DC..

When you say my PS1 can't be happy shunting it's DC to ground.... it sounds damn good to me... can I be doing some damage here?

[Pano]

Originally posted by Lostcause
When you say my PS1 can't be happy shunting it's DC to ground.... it sounds damn good to me... can I be doing some damage here?

Doubt it, it just isn't the best operating condtion. You are shunting it thru what? 20K? 50K? Not going to blow anything up, but it may not be the best idea.....

You are correct, the caps do not pass DC, but you are screwing with the operating points.

In the morning, it may all come clear to me. But not now.

[Lostcause]

Originally posted by panomaniac


Doubt it, it just isn't the best operating condtion. You are shunting it thru what? 20K? 50K? Not going to blow anything up, but it may not be the best idea.....

You are correct, the caps do not pass DC, but you are screwing with the operating points.

In the morning, it may all come clear to me. But not now.

50K..... and thanks for taking the time to answer......
Now go get some sleep!.... it's the weekend!!!!!