I want to share my comparison of different power sources on DI and their differences with Audiophilleo 2.
Equipments:
1. NFB-10SE (Filter: 5; Gain: Low), RCA coaxial input changed to Canare BNC.
I think the DI's BNC is better than its RCA, it sounds clearer although it is said to be the same.
2. DI-V1 (No upscaling)
3. HD650 (with DIY balanced Neutrik jack)
4. USB isolator (No brand)
It must be powered by an external power supply, battery powered is the best and different power packs have different sounds.
The power is directly feeded from the external power supply without regulation.
5. Audiophilleo 2 (Thanks to my friend, David)
Power sources:
1.1000mah unprotected 7.4V lithium polymer battery
2. Linear power (8.4V, ripple noise < 0.5mVRMS.)
This power supply is for mobile phone maintenance. It is a cheap Chinese brand and the spec might not be accurate.
However, I believe it is better than an average one.
Player:
Battery powered Lenovo Notebook, foobar v1.1.11, Windows 7, WASAPI
My comments:
If the DI is lithium powered, it is very bright, clear, bass well definited and the soundstage is large. However, the vocal seems to be moved to the both sides instead of the center which might be becasue of the larger soundstage. Upscaling makes it too bright and unbearable, especially string sounds. Even without upscaling, I feel fatigue after 2-hour listening because the sound is sharp.
If I add a battery powered isolator to it, it will be less bright and others are more or less the same. The vocal moves back to the center. DI sounds the best with it and I do think it is 60%-70% of Audiophilleo 2.
The linear power supply is not as good as lithium battery, although it is definitely better than USB powered. It sounds not as clear as lithium battery.
Audiophilleo 2 stills shines, it is more musical and smooth. It is even better if I add a battery powered isolator. However, it carries a too hefty price tag.
My DI with lithium battery
BNC to BNC adaptor
Linear power supply
Isolator with 5V directly feed from battery
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2 different power packs for the isolator
Compare with AP2