T-Amp output biasing for better sound?

[soundcheck]

Hi folks.

I read the Trends-Audio T-Amp specs yesterday.

It says that biasing the output DC to 0V, as it is possible with their model, brings

a. cleaner sound
b. smaller switch-on pop

Does anybody have an idea how such a biasing circuit could look like?

Cheers
Klaus

[Pano]

The circuit is here:
http://www.tripath.com/downloads/TA2024C.pdf

See page 11.

You can see it in the Trends amp photo below. Look for the trim pots labled Rt.

[soundcheck]

Would it also work on a 2020? Cheers Klaus

[theAnonymous1]

Originally posted by soundcheck
Would it also work on a 2020? Cheers Klaus

Yes.

I am going to add the adjustment circuit to an AMP3 sometime soon. I already made the board, just have to attach it.

[soundcheck]

I guess you'll share your findings with us.
Looking forward to it.

Tweaking never stops! Amazing!

[kristleifur]

Originally posted by theAnonymous1


Yes.

I am going to add the adjustment circuit to an AMP3 sometime soon. I already made the board, just have to attach it.

Cool. Sounds like an interesting thing to implement. Do you have a picture of the board by any chance?

[BWRX]

Originally posted by soundcheck
I guess you'll share your findings with us.

What's to share? The circuit does exactly what it's supposed to. I implemented it on my Ref-T amp earlier this year and it works fine without negatively affecting the sound. You can easily trim the output offset to below a mV with a multiturn trimpot.

I guess no one uses the search function anymore, eh?

http://www.diyaudio.com/forums/showt...ht=#post890408
http://www.diyaudio.com/forums/showt...ht=#post915158
http://www.diyaudio.com/forums/showt...ht=#post906760

[soundcheck]

Originally posted by BWRX


What's to share? The circuit does exactly what it's supposed to. I implemented it on my Ref-T amp earlier this year and it works fine without negatively affecting the sound. You can easily trim the output offset to below a mV with a multiturn trimpot.

I guess no one uses the search function anymore, eh?

http://www.diyaudio.com/forums/showt...ht=#post890408
http://www.diyaudio.com/forums/showt...ht=#post915158
http://www.diyaudio.com/forums/showt...ht=#post906760

I just went quickly through the first thread you posted.
To me it's still not clear if the biasing improved the sound!

[BWRX]

Why would it improve the sound? All it does is remove the DC from the outputs. You can't hear DC...

A low DC offset is important for drivers with limited xmax because the more DC offset there is on the output the lower the usable excursion you have from your drivers. Any DC offset also causes a quiescent current to flow through the driver's voice coil. The larger the offset the larger the current and the more heat the amplifier's output stage and the driver's voice coil has to dissipate (even though the amount is really very small and is usually considered negligible).

[soundcheck]

Originally posted by BWRX
Why would it improve the sound? All it does is remove the DC from the outputs. You can't hear DC...

A low DC offset is important for drivers with limited xmax because the more DC offset there is on the output the lower the usable excursion you have from your drivers. Any DC offset also causes a quiescent current to flow through the driver's voice coil. The larger the offset the larger the current and the more heat the amplifier's output stage and the driver's voice coil has to dissipate (even though the amount is really very small and is usually considered negligible).

That's what I am refering to!!

Are 100mV or whatever offset, respectively the corresponding lower driver excursion, audible.

Or is the main thing to balance both channels offset so the drivers start at the same point.

Or should I better take it that way , as you nicely outlined:
Since DC is not audible. We shouldn't care about it!