smsl SU 10 technical question

[Guldis]

Hi

What function has the 2 trimpots in my SU 10 dac? And does it affect sound if not properly set?

 

[BR52]

It seems they are for adjusting the virtual zero in I/V stage. Because it’s not really well defined for Ess- chips.
Edit: It can be done active and need no human interaction anymore. Additional long time drift is compensated as well.
This seems to be an older design for the I/V stage. Ess recommend in the active in their design notes.

 

[Guldis]

It seems they are for adjusting the virtual zero in I/V stage. Because it’s not really well defined for Ess- chips.
Edit: It can be done active and need no human interaction anymore. Additional long time drift is compensated as well.
This seems to be an older design for the I/V stage. Ess recommend in the active in their design notes.

Thx!

Can I check the zero voltage with a multimeter? I see there is 3.3 and 5 volt test pins on the board, but where do I find virtual zero test pin.

If the virtual zero is drifting, how will it affect the dac?

 

[BR52]

Thx!

Can I check the zero voltage with a multimeter? I see there is 3.3 and 5 volt test pins on the board, but where do I find virtual zero test pin.

If the virtual zero is drifting, how will it affect the dac?

Don’t change a running system

 

[Guldis]

Don’t change a running system

Understand your concern but it won’t still my curiosity . Question remain how to check and impact if not set correctly

Cheers

 

[BR52]

Understand your concern but it won’t still my curiosity . Question remain how to check and impact if not set correctly

Cheers

The problem is, there is no schematic of the SU-10 available. For this reason, all we discuss here is more or less speculative. I would recommend you to dig deeper in the reverence designs of the ESS-DAC's. Unfortunately, they are a not really taking care of the paralleling of the I/V stages. Especially, the current mode has a huge tolerance for the reference point.
Back to the impact: you can see more or less common mode DC at the balanced output, depending on the adjustment. My speculation is the "Ess-Hump" is also influenced by it. (this need a long in deep discussion with specialists).
Again, from the questions you ask here, I highly recommend leave it as it is!
Cheers