Review and Measurements of Schiit Sys Passive Pre-amp/Switcher

[TrippRyder]

I know this is an old thread, but does anyone know how the Alps pot is wired in the SYS ? Is it a series connected variable resistance inline with the + of the RCA, or is it a shunt style setup?

Based on Schiit's spec of output impedance being maximum of 5k ohms, im guessing it has to be a shunt style with a fixed series resistance of about 5k ohms.

 

[gvl]

It’s wired as a potentiometer, if wired in series it would be a rheostat.

 

[TrippRyder]

It’s wired as a potentiometer, if wired in series it would be a rheostat.

There are a couple different ways a potentiometer could be wired.

Based on the specs for the SYS, it would appear to be a shunt style with a series resistance.

 

[gvl]

There are a couple different ways a potentiometer could be wired.

Based on the specs for the SYS, it would appear to be a shunt style with a series resistance.

There is no series resistance on the PCB or other parts for that matter apart from the input switcher. It's wired as a vanilla potentiometer- across the input and the wiper connected to the output.

 

[TrippRyder]

There is no series resistance on the PCB or other parts for that matter apart from the input switcher. It's wired as a vanilla potentiometer- across the input and the wiper connected to the output.

Then how can it have an input impedance of 10k ohms and a max output impedance of 5k ohms?

 

[gvl]

Then how can it have an input impedance of 10k ohms and a max output impedance of 5k ohms?

Beats me. In case of an ideal voltage source, the max output impedance of a pot is 25% of its nominal value so should be 2.5kohm max, not 5k for a 10k pot. I just checked and the SYS's pot actually clocks at 9.1kohm on my DMM, so not sure where 10k is coming from either, it could be earlier versions used a 9.1k pot. Better ask Jason how they arrived at these values.

 

[WOLFAGRAM]

Bought a Schiit Sys some two weeks ago together with Orpheus Ludic interconnect RCA cables. No perceptible hiss from listening position, no distortions while moving the pot and no further degradation of sound. Very satisfied.

p.s. Using only one input connected to Marantz CD6007 and output leads into KRK S8.4 to KRK Rokit 5 G4, which leaves the switching button for mute function.