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

Willem

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#41
I am a happy user of the now discontinued Emotiva Control Freak volume control (rca version) in my desktop system. Desktop PC as source, into an ODAC usb DAC, into the Control Freak, into a pair of inline atenuators into a Quad 405-2 power amplifier into a pair of Harbeth P3ESRs. I added the inline attenuators because the ODAC's output voltage of 2.0V is a bit much for the Quad's 0.5V input sensitivity. Without attenuators there was a real risk of accidental damage to the speakers, and with the attenuators I also avoid potential channel imbalance at low volume settings of the Control Freak. Of course I have no way to measure, but the result sounds fine to me.
 
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#42
I am a happy user of the now discontinued Emotiva Control Freak volume control (rca version) in my desktop system. Desktop PC as source, into an ODAC usb DAC, into the Control Freak, into a pair of inline atenuators into a Quad 405-2 power amplifier into a pair of Harbeth P3ESRs. I added the inline attenuators because the ODAC's output voltage of 2.0V is a bit much for the Quad's 0.5V input sensitivity. Without attenuators there was a real risk of accidental damage to the speakers, and with the attenuators I also avoid potential channel imbalance at low volume settings of the Control Freak. Of course I have no way to measure, but the result sounds fine to me.
Nice. I didn't seem like the Control Freak had a remote control which is why I'm trying to mod the shiit sys with some sort of external motor. There seems to be a jump in price from 50$ for a passive attenuator without a remote to 300$ minimum with a remote. and I don't think that 250$ %/SQ improvement ratio is very good at all/worth it so i can keep my butt on the couch.
 

solderdude

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#43
The reason why I am using a SYS is because I have a turntable coming in on one of the channels. I guess that a switcher would do as I never use the volume on the SYS, but I simply did not know which switcher to buy. At least with the Sys, Amir measured it to be transparent.

Perhaps we could have for a RCA audio switcher roundup with all the measurements etc :)
In this case the Rout of the Sys = 0 Ohm (not 5k) and the Modi is loaded with 7.1k Ohm instead of 25kOhm.

The only difference some switchers could have is crosstalk or interference with unshielded cables or wiring.
The Sys works fine as the ground is very low impedance as it is made of the entire groundplane of the PCB.
Just switches and wires could well be worse in some aspecets.
 

Jimster480

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#44
I prob shoulda mentioned it was hooked up to a LKS DH-004, A Gustard U16 and a pair of EP 2.8's so keeping the chain as clean as possible is important.

No amp though he just makes me peddle a stationary bike reallly fast

We're using a custom built pc with a AMD 1950x 16-core CPU with HQplayer upsampling to DSD512 ( and poly-sinc-xtr-mp if you're familiar with hqplayer ) and its pretty freakin incredible.

My mom taught me the idiom pennywise pound foolish
A threadripper for playing music! WOW is all I can say!
 

la2ygoo

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#46
The output level , when at 3:00 is -5.5dB , at 12:00 is -16dB , at 9:00 is -32dB.
Base on output level , thd+n should be like this.
Schiit Sys THD+N measurement output level.png


With sys 9:00 volume , in % way , i think : THD+N(-30dBV output) = THD+N([email protected]) + THD+N([email protected]) , 0.0025% = 0.0002% + THD+N([email protected]) , so THD+N([email protected]) = 0.0023%

If a dac is 100 times worse than Ap, when it uses sys output -30dBV, THD+N = THD+N([email protected])*100(=0.02) + 0.0023% = 0.0223% , it become 9 times worse than Ap.
If a dac is 10 times worse than Ap, when it uses sys output -30dBV, THD+N = THD+N([email protected])*10(=0.002) + 0.0023% = 0.0043% , it become 2 times worse than Ap.

A poor dac can use sys(or another preamp) to greatly reduce THD+N at low volume output , is it right?
 
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#47
We ever do the measurements for the OL Switcher?

I'll admit after stumbling across this, I've been using my SYS to switch between 2 Tube Amps out of my RME ADI 2's single output. Granted there are no un used input or output. Everythings' hooked up to something
 

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