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.

 

[Kain]

So I received by Bifrost 2/64 yesterday and I am using it with my MacBook Pro 14" and JBL LSR305 monitors and JBL LSR310S subwoofer. When I connected it to my Mac I noticed I had no control over the volume in macOS and it defaulted to max. I could only control the volume within apps that had a volume control. In apps that did not have a volume control, the sound was outputting at max volume by default. Then I learned that all Schiit DACs are like this on macOS, Windows, and Linux and that you have no control over the master volume and are expected to use a preamp or hardware volume control.

Wish I had known this prior to buying the Bifrost 2/64.

Anyway, I then ordered a Sys but haven't received it yet. I just want to know if there will be any degradation in sound quality when having a Sys in the chain? I read around and some say no while others say the higher end Schiit preamps sound better. But then I also read that the Sys actually sounds better than the higher end Schiit preamps. So what I have learned is all over the place because of the contradicting information.

 

[Guddu]

So I received by Bifrost 2/64 yesterday and I am using it with my MacBook Pro 14" and JBL LSR305 monitors and JBL LSR310S subwoofer. When I connected it to my Mac I noticed I had no control over the volume in macOS and it defaulted to max. I could only control the volume within apps that had a volume control. In apps that did not have a volume control, the sound was outputting at max volume by default. Then I learned that all Schiit DACs are like this on macOS, Windows, and Linux and that you have no control over the master volume and are expected to use a preamp or hardware volume control.

Wish I had known this prior to buying the Bifrost 2/64.

Anyway, I then ordered a Sys but haven't received it yet. I just want to know if there will be any degradation in sound quality when having a Sys in the chain? I read around and some say no while others say the higher end Schiit preamps sound better. But then I also read that the Sys actually sounds better than the higher end Schiit preamps. So what I have learned is all over the place because of the contradicting information.

Hi @Kain
Few points I want to mention, being a long term Schiit Sys user:
- I have used volume control on sys for short time and it did work just fine
- I normally use sys as RCA switcher 2 RCA IN and 1 RCA OUT, and have never observed any difference between direct RCA vs through sys. Here I keep sys vol to max
- A few times, I have used 2 RCA IN and 1 RCA OUT, to get DAC out to 2 different amplifiers, and it has also worked fine
At the end, primarily it is a switcher than a volume attenuator but still volume control could be used.
In your situation, I wish if I could find a better option sooner but sys could be useful until you find something better with remote control or something.

 

[Kain]

Hi @Kain
Few points I want to mention, being a long term Schiit Sys user:
- I have used volume control on sys for short time and it did work just fine
- I normally use sys as RCA switcher 2 RCA IN and 1 RCA OUT, and have never observed any difference between direct RCA vs through sys. Here I keep sys vol to max
- A few times, I have used 2 RCA IN and 1 RCA OUT, to get DAC out to 2 different amplifiers, and it has also worked fine
At the end, primarily it is a switcher than a volume attenuator but still volume control could be used.
In your situation, I wish if I could find a better option sooner but sys could be useful until you find something better with remote control or something.

Thanks. I have read that at 100% volume, the Sys should be 1:1 to a direct connection. However, what about at lower volume settings? Are they also not any different to a direct connection?

 

[Guddu]

Thanks. I have read that at 100% volume, the Sys should be 1:1 to a direct connection. However, what about at lower volume settings? Are they also not any different to a direct connection?

I did not find any perceived difference, volume control works just fine.
Its just that I am not using it for volume control, so I keep it to full.
I control volume on Topping E50, remote sucks (IMO) but still works.

 

[gvl]

I just want to know if there will be any degradation in sound quality when having a Sys in the chain?

There shouldn’t be, but don’t use long cables downstream from the Sys. That said, for the amount you’re spending a used RME ADI-2 DAC is a much better option if you need volume control on the DAC.

 

[Kain]

There shouldn’t be, but don’t use long cables downstream from the Sys. That said, for the amount you’re spending a used RME ADI-2 DAC is a much better option if you need volume control on the DAC.

The cables from the Sys to the speakers will be 10 feet in length. I assume this will be okay?

 

[gvl]

The cables from the Sys to the speakers will be 10 feet in length. I assume this will be okay?

Hard to say, the shorter the better. 10 feet is not exactly short. Longer runs may cause some high frequency roll off, how much depends on the cable capacitance and the volume control position. Guess you need to experiment with it and see for yourself if the effects are audible.

 

[Kain]

I emailed Schiit asking if 10 feet cables will be okay and they said they will be fine.

 

[Kain]

@Guddu

How long are/were the cables from your Sys to the amps when you were using the Sys as a volume control?

 

[Guddu]

@Guddu

How long are/were the cables from your Sys to the amps when you were using the Sys as a volume control?

approx. 1 meter each, I have also used 3 meter for about few weeks in past and worked fine as well

 

[gvl]

I emailed Schiit asking if 10 feet cables will be okay and they said they will be fine.

View attachment 365304

Should be. If you can find input capacitance of your speaker and capacitance of your cable per length unit you can calculate with better certainty here: http://sim.okawa-denshi.jp/en/CRtool.php

Sys is 5kOhm max output impedance according to Schiit (is it really 2.5kOhm and they don't know how to calculate output impedance of a potentiometer?). Say cable and active speaker input combined capacitance is 600pF, you get about 0.5 dB droop at 20kHz, which is likely inaudible. But double the capacitance and now you have a 2dB droop at 20kHz which may be audible depending on how young you are.

 

[Kain]

Should be. If you can find input capacitance of your speaker and capacitance of your cable per length unit you can calculate with better certainty here: http://sim.okawa-denshi.jp/en/CRtool.php

Sys is 5kOhm max output impedance according to Schiit (is it really 2.5kOhm and they don't know how to calculate output impedance of a potentiometer?). Say cable and active speaker input combined capacitance is 600pF, you get about 0.5 dB droop at 20kHz, which is likely inaudible. But double the capacitance and now you have a 2dB droop at 20kHz which may be audible depending on how young you are.

I am using these cables but in 10 feet length: https://www.amazon.com/gp/product/B001UJH0XU/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&th=1

The Sys will be connected using the above cables to the JBL LSR310S subwoofer (which acts as a 80 Hz crossover) and the 2 x JBL LSR305 monitors are connected to the LSR310S subwoofer (via XLR to XLR cables).

 

[gvl]

I am using these cables but in 10 feet length: https://www.amazon.com/gp/product/B001UJH0XU/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&th=1

The Sys will be connected using the above cables to the JBL LSR310S subwoofer (which acts as a 80 Hz crossover) and the 2 x JBL LSR305 monitors are connected to the LSR310S subwoofer (via XLR to XLR cables).

The amplifier input capacitance numbers are hard to find. Figure 100-150pF per meter for cables. The sub who knows, I don't think JBL specs input capacitance. Chances are it will be fine, unless the sub has high input capacitance.