PI2AES vs. Allo Digione Signature based on blind test and something more…
Before I will go with results, I want to briefly describe how I get PI2AES for test.
After I get Chord DAVE in my system, I understand how nicely it benefits when good source provided. With Sennheiser hd800s directly connected to DAVE even changes in USB cable will effect sound. Therefor I was looking for good source and I liked the idea to have RPi based streamer for my audio collection hosted in local network NAS. First, I get Allo DigiOne and after a while Signature version from Allo. Later I also found many good reviews for 502DAC (from PI 2 Design), therefore I decide to get one as well. After I place my order, I found Michael’s posts regarding new PI2AES development. So, I wrote him and ask if he would be interested for test and compare his new device (PI2AES) with other boards I already have. He kindly agreed and send me PI2AES together with my 502DAC.
After small discussion and advices here, blind test approach was performed to compare Allo Signature with PI2AES. For this purpose two identical BNC coaxial cables was used to randomly reconnect them to DAVE inputs (BNC1 and BNC2). Then the same tracks was played simultaneously on two boards and evaluated blindly, selecting there and back different BNC inputs with Dave remote control. The same RPi 3+ and Volumio versions was used in each board. Digione Signature (DS) and PI2AES boards was powered separately from RPi. For Digione SIgnature a Li-ion battery pack from Allo was used as clear power source. Compact 12v lead battery was used to power PI2AES. Standard but good 5V power adapters used to power RPi in both cases.
Blind listening confirmed Allo DS and PI2AES sound different. First, I decide to go through different tracks, switching BNC inputs to find out which sound I prefer and why. Both inputs sounded very clear. The main difference I found was how echo extensions from instruments and voices was reproduced, how far and deep they propagate and reverberate. How the volume of instruments sound was represented and how well instruments separated from each other. After I clearly decide, which BNC input sounds better to me, I just unplug it from board of my choice to predict whether I right (true positive - sound disappears) or I am wrong (false positive – sound continuous to play). Then I repeat this test over and over… randomize BNC at the Dave inputs, listening both inputs, stop on the input I like, do my prediction which board is it, disconnecting BNC form this board and see if I right or wrong. And the winner of this tests is… PI2AES! Period. Blindly, after few iterations I was able to reliably identify sound of PI2AES many times in a row in the different tracks and albums. Sound of PI2AES was always better to reproduce soundstage scene depth, instruments and voice volumes and separation. PI2AES has sound that hypnotize you somehow, bringing you inside of the scene, very holographic and realistic. I think part of the credits can go to Chord Dave, let’s beck to this later. As for Allo Digione Signature, yes.. I know its measurements is very good, and it sound good indeed. It’s very clear and transparent. Black background, the soundstage is wide but for some reason it feels like echo can’t propagate in depth well, like some wall behind the stage truncate it and block this propagation. It give impression of restricted depth space. Otherwise, it sound very good. Most probably without PI2AES reference in my case I would not say it flat or not dimensional. But when I blindly compare two inputs, one of them was continuously sound better from this aspect. And it was PI2AES. More natural, more spatial, more holographic and realistic. Even more credits go to PI2AES for more output options (full size AES, Buffered I2S, optic). Which is important. BNC was used during blind test to have the same interface from two boards, but AES from PI2AES sounds even better than its BNC, jaw dropping experience as I mention in my first impression posts before.
To finalize this report I decide to include one more thing
I was wonder and ask myself whether this nice holographic 3D representation may come from digital “manipulations” within digital pathway/gears (Dave, PI2AES, Volumie..) or it could be signature of the well reproduced recording. Therefore, I decide to compare one of my favorite album “Autour de Chet” that I have in Hi-Res and in LP vinyl. For this Digital vs Analog test, I connected LP Turntable and Dave DAC (PI2AES and Allo Digione SIgnature) to the Brystone BHA-1 amplifier. The album play was simultaneously started on LP and both boards, the sound was evaluated by switching amp inputs (analog vs digital), and DAC inputs (PI2AES vs Allo DS). It was very interesting listening session. To make long story short... PI2AES connected to Dave was really close to the analog reproduction in a way of sound stage image representation, depth extension and instruments layering. Of course, PI2AES was brighter and less low frequency extended sound in compare to the LP analog reproduction (very warm, deep, dark and flued). But they were very close to reproduce sound volume and space, I actually was surprised how similar they are. For me, it’s just confirm that correct special representation can indicate more precise digital source and its conversion to analog.I want thanks’ again Michael for development of this product for us.
RPi DDC Borads: Allo Digione Signature, PI2AES (v.P3)
DAC: Chord Dave
Headphones: Sennheiser hd800s, Grado RS1 (pink driver) HP1000, PS1000.