Struggling with right/left channel balance, HELP?

Well I got my benchmark DAC1 HDR back today.
They "recalibrated" it, I listened to it for a few hours and I did not hear any imbalance. I will measure it this weekend and see how balanced it is.

"any changes in right ear vs left ear hearing at various freguencies and loudness? "

I you are asking about my hearing, not that I know of. I get a test every year at work and my ears are pretty good (I am 28...) hopfully they stay that way.

I measured the system with test tones and the imbalance was consistent through out the frequency range. Again in a mono set up for the test.

any changes in right ear vs left ear hearing at various freguencies and loudness?

Yes is have swapped the computer channels in the audio set up. I have also tried a CD player with the same results.

I talked to a few people at benchmark today. They seem to think the problem was my low level listening(70-75dB). The said the below "11:00" o-clock there would be a slight imbalance (but not two dB) and from 12-3 is should be VERY balanced. I was using the unbalanced connection and today I bought some balanced cables so I could adjust the internal gain. This allows me to turn up the volume know and keep the volume lower. This helped but did not get me all the way there.

I am still measuring 1dB off at 11:00 o-clock through 1:00 o-clock. At 2:00 o-clock the volume is balanced (way to loud for my normal listening levels)...

So I think I will have to send the unit back. I could almost live with one dB. It does not stand out unless I am looking for it.... but you know I will look for it... I try and send it back this week and get another unit.

As for the sound quality I have tried both the toslink and USB connections. I actually leave both connected and changed the out puts in my computer from time to time. I found the USB to be a little on the bright side and the toslink to be more balanced. I was not listening for dynamically punch or immediacy but I will give it a go. I only have the USB that came with it. Have you tried other cable with it?

My general feeling is that the toslink has a more "refined" top end. But the big difference for me was in the upper midrange. If you have Dave Matthew's Some Devil's listen to the song Grave Digger on both the USB and Toslink and let me know what you think. I found the vocals to be more natural and fleshed out on the toslink.

Furthermore, have you swapped outputs digitally via Audio Midi Setup to check the source?

If you are using mini with and HDR, please try it with the usb (it doesn't have spdif). I have experimented with quite a few DACs, and toslink has never been the best input on any of them. Typically dynamically soft and lacking immediacy. If it really is off by 2db, Benchmark will replace it. It is a preamp after all. There may be internal adjustments, or the back panel calibrations for the fixed output may effect the variable out. Call them, they are very helpful.