Schiit Pi?

Those of you who saw the John Darko interview of Jason Stoddard and Mike Moffat filmed at the 2018 RMAF know that both have a passion for Schitty puns. During this interview, Mike teased a “Schiit Pi” concept. Mike’s idea was to embed an ARM processor in products to pick up additional digital signal processing tasks beyond the abilities of the Burr-Brown parts he had been using.

Jason is adamant that Schiit will not become a “software company”, that is offer IOS and Android apps or make devices having a significant user interface say like Roon Controller or Volumio remote. The ongoing maintenance of these products is simply too costly for the Schiit minimalist value first design esthetic.

A Minimalist Streaming Player

So can we make a minimalist streamer using a hatless Raspberry Pi? If we did, how would it sound? This product is as basic as a Roon Player can get. It turns out to be a very good one. Will Jason put it in the catalog? Probably not. Volumio got there first with more software integrated.

Those not wanting to tinker with hardware and software will find Volumio Primo a good alternative that provides a SBC and DAC supporting AirPlay, Rune, Roon, Spotify, and others but excludes the headphone amplifier. John Darko’s review is excellent and he likes the sound of Primo and the value offered. Primo is comparable, maybe not quite as sweet as the Allo Digi+ Signature. However, the ALLO devices requires you to bring your own DAC.

References

Bill of Materials

For this build I used the following materials

Raspberry Pi 4B (has WiFi)
Raspbian Lite (Desktop but no Apps)
Roon Bridge for ARM v7 from RoonLabs downloads
16 GB micro-SD card
Schiit Modi 3 and Magni

Install Raspbian Desktop

I installed Raspbian following the instructions for an install without games and LibreOffice but having the window system and basic desktop environment. Note that you unzip the archive and copy the file system root tree to the root of the SD card. No need to use Balena Etcher.

First launch

To get things going, I connected the Pi 4B to my TV and did the initial startup. I also did the Roon installation using a terminal launched while in this mode. Once installation is complete, change the pi user’s password and set up SSH access and VNC access if desired. This lets you use your Pi for other things. Setup WiFi if desired. Then shutdown using the Linux shutdown command.

Configure Raspbian WiFi to join your home WiFi nework. This allows you to use your Schiit Pi away from an Ethernet outlet.

Change the pi user’s password. Use Diceware to pick an easy to type but hard to guess password. I roll 5 dice 3 times to pick 3 words and juggle the order to be pleasing or more easily remembered while typing.

Install Roon Bridge

With the Raspbian install completed, I followed the Roon Labs Roon Bridge for ARM v7 installation. Roon dependency installation was easy. Just apt-get install them in the order mentioned. Some are already installed but others will download, unpack, and configure. This is OK.

Download the Roon Labs easy installer, make it executable, and run this script. It will do the rest. Accept the default user and location.

Setup your Schiit Pi

Move your Raspberry Pi, Modi 3, and Magni to its new home and cable everything up.

Pi to its power supply
Pi to Ethernet (if available)
Pi to Modi 3
Power to Modi 3
USB from Pi to Modi 3
Audio from Modi 3 to Magni
Power to Magni
Modi 3 source switch to USB (up)
Magni gain switch to Hi
Modi 3 power to on
Magni 3 power to on
Headphones plugged in
Headphone gain to 9 o’clock

Jason knows his stuff. No rude noises from Magni when powered up and down.

Add as a Roon Endpoint

In any of your Roon controllers, your new RaspberryPi will show up in the Settings -> Audio page under the Roon endpoints. Select it, give it a name, and enable it. Use it as you would any Roon endpoint.

Listening Impressions

My first impression is that this lash-up Raspberry Pi, Roon, Modi3 and Magni sounds just like Modi3 and Magni connected to USB on my MacOS Mohave Retina iMac Intel Core i7 desktop machine. I can’t hear any significant artifacts from the omission of a bit-serial interface. Jason’s contention that Schiit Audio has tamed USB for audio appears to be an accurate one. There’s no stuttering, wow, or flutter audible in the playback. There is no analog noise slipping through the USB cable into the DAC. On a mostly idle Pi 4B, there are no stalls. Linux keeps the bits moving and the Modi jitter buffer never empties. Voicing is what I’ve come to expect of the Sennheiser HD555 (out of production).

Phones VS Speakers

Shifting from phones to speakers has a bigger effect on presentation than switching from one of my 3 DACS (P5 built in, Modi3, and GUMBY) to another.

The headphones deliver left channel to left ear and right channel to right ear. No acoustic mixing or room reverberation are present. When listening with speakers, the left ear also hears the sound from the right speaker at reduced level. This changes the stereo image. Room reflections add reverberation and room modes can fatten the sound.

Ranking my 3 DACS, you can’t beat GUMBY for small detail retrieval. Modi3 is within a length. The P5 built in is a couple of lengths behind. The P5 is pleasant but cant match the other two on Scarlet Town.

Source Material

I’ve listened to the following while writing this note up

Trinity Session, Cowboy Junkies
Amir, Tamino
Colors of the Day, Judy Collins

The Trinity Session is the classic headphone record. Cowboy Junkies opened the Acid Folk era by producing this record. Being a poor beginning band, they made the record on the cheap by hiring a church (Trinity Chapel) for a day, a recording engineer, and went to it by gathering around an Ambisonic stereo microphone. The Ambisonic mics are buried in cavities in a bowling ball sized sphere to simulate the directivity of the human ear. The band performed in a semi-circle around the array. Nothing was pan potted in. Mixing was performed by moving band members in or out and by playing or singing louder as needed. This is a good record to use judging cans.

Tamino is a rising star Belgian about 22 years old. Though recently signing a record contract, he’s been playing out since he was old enough to shave and has a modest stage presence and a winning smile in his live show videos. Of Egyptian parents, he has learned traditional Arabic voice technique and can sing quarter tones and pull notes. He sings in a slow style smokey that smoulders. His voice is wonderfully natural. Although his records are somewhat produced, things are simple enough that they are easily performed on stage by a traditional quartet, Tamino out front on guitar, bass, drums, and keys. His first record was well tracked and mixed.

Judy Collins’ Colors of the Day is a compilation from her early Elektra records. The album includes the best tracks from Wild Flowers, the Farewell to Tarwathie track, and the Amazing Grace track, and In My Life and Suzanne from the In My Life record. On vinyl, Amazing Grace is the innermost track on side one. It is merciless at revealing poorly set up turntables. In Farewell to Tarwathie, humpback whale song backs the recording.