I run my S2 DAC with toslink now, prefer the sound over the USB from Allo USBridge and through ethernet/fiber. Previously I preferred Allo USBridge and USB, but I think since I started running my DAC on battery that changed. The disadvantage is less sample rate and no DSD.
I use a 6V 12Ah sealed lead acid battery connected directly to the DAC (I have heard that LiFePo4 batteries should be even better due to less internal resistance). Fully charged its 6.7V so a little over the 5V but worked for several months so seems fine (the DAC gets a little warmer though).
100% galvanic isolation from everything except the battery is nice though, no more âsounds better at nightâ
For MQA I let Roon do first unfold, then I upsample everything (including non-MQA) to 192khz
Another thing is the Swenson grounding trick was specifically advised for use with grounding specific network switches (like Netgear GS105/108 for example).
It appears a lot of people have gone grounding every SMPS in their system, to reduce leakage currents.
However if you ground the DACâs PSU and you have a grounded USB source, you can now created a nice groundloop and create groundloop hum (depending the rest of the system connection to the DAC).
Johnâs recommendation is still to have only one component grounded but I think this has been missed by some.
Not a comment at you but just a general comment for those maybe getting carried away with the Swenson grounding trickâŚ
Yea, its a nice DAC, but it needs a proper LPS/battery for power and a good USB input. With stock switched power and USB directly from the computer itâs far below what it can sound.
Could you please explain in detail how the sound of the Pre Box S2 digital is improved by using a âproperâ power supply and USB input. I ask because I have a pre Box S2 digital which I use with the stock poer supply and the coax input and it sounds fantastic!
Specially do you actually hear ânoiseâ from the stock power supply and how does the sound improve using USB input instead of coax input. Again I ask because the fully functioning human ear/hearing that I was born with cannot hear picosecond jitter.
The designer of this DAC himself has mentioned performance is improved with a good quality linear PSU (youâll need to read at the top of the thread).
That doesnât mean everyone will necessarily hear improvements or difference, when he says performance is improved⌠so I wouldnât stress too much about it.
Better power gives better clarity, quieter backgrund and more details. Part of it is because the power is better (more stable, less varied), but also because switched power supply tends to inject lots of electronic noise which is nice to get away from.
The best sound I could get from the Pro-Ject DAC is with this chain:
Computer/Roon server -> ethernet switch -> FMC -> fiber -> battery powered FMC -> Allo USBridge -> UpTone USPCB A>B -> batteri driven Pro-Ject Pre Box S2
Lots of tweaks I know, but they do make a difference.
All those tweeks might be too much for me. I love that way the Pre Box S2 Digital sounds in âstockâ mode driving my Beyerdynamic T5ps - clear as a bell with lots of inner detail.
The only knock on this great little giant killer is that it really doesnât enough power to drive full size high impedance headphones, like the Sennheiser HD800s or the Beyerdynamic T1s. But when using lower impedance, easier to drive headphones the Pre Box S2 Digital is wonderful.
BTW âŚjust picked up the massdrop thx aaa 789 (used) even-though I got in on the last drop (462 gone in 2 hours) but shipping in the middle of May,
I will sell the new one and keep the used one.
I like monoprice (I live in LA not far from them).
Iâm gonna make my own cables using higher end Mogomi.
Pacific sales in Burbank carries it in bulk.They work with a lot of the film studios in town.
