Well I finally got my new transport delivered and setup with the Bottlehead DAC. The DigiOne Signature/RPI is powered by an Allo Shanti dual output linear power supply. The Bottlehead DAC is powered with the supplied stock power supply. Experimentation with a 6V SLA battery for the BH DAC is forthcoming. The SPDIF signal is fed via a rather generic 75 ohm coax with BNC connectors at both ends. My OS/Music server software of choice is moOde. My music files reside on a network file server running a slimmed down Linux Debian distribution.
I had always run the BH DAC on the USB input in the past. And I could tell that there was some noise coming from my computer. I just never really knew how much. I never used a Mac Mini but I hear that they have one of the best USB ports for audio. Other computers may or may not fare as well. Anyway it was time for a new transport since my PC Engines ALIX computer was getting a bit long in the tooth and the OS I was using is no longer supported. I considered an Intel NUC and several other small format computers for the task. I've been monkeying around with Raspberry Pi computers since their initial release in 2012. There have been several upgrades since then and they are on Revision 4. Plugging a USB DAC into the Pi directly sounds pretty bad. It is after all a $35 computer so my expectation was low. Several third party manufacturers have been making DAC and Digi add on boards that output SPDIF for standalone DAC's. These too have been refined over the years. The company I've been smitten with lately is allo.com.
This getting a little wordy and I didn't want that to happen. So let me cut to the chase. It's only been a few of weeks but I REALLY like what I’m hearing. I wont get into the details of the DigiOne Signature too much since their is much to be gleaned elsewhere on the internet. But I will say that the engineers at Allo have put a lot of effort into keeping power supply noise in check. That coupled with accurate timing by implementing dual low jitter clocks and using high quality components provide a transport that performs much, much higher than price tag would suggest.
I’m finding that my listening sessions are longer now and more frequent. That's a good thing. Having good quality music in these trying times is essential IMHO.
Be advised that people who reside in the United States should utilize the local Allo distributor, "Chicago Electronic Distributors" or face extraordinarily high shipping costs from India. Especially if you buy something heavy like a linear power supply. (No affiliation just a satisfied repeat customer)
Now on to experimenting with the new 6v SLA battery I just bought to power the Bottlehead DAC.
