Raspberry Pi

Yesterday returned to Mexico with my JLH 1969 Headphone Amp and TDA1387 x8 DAC very excited to get the equipment setup.   

First listen was Sony MDR-7506 > JLH 1969 Headphone Amp > TDA1387 x8 DAC > MacBook Pro.  I was immediately disappointed the Sony MDR-7506 and MacBook Pro had a grounding hum that was bothersome.

Next tried Denon D2000 > JLH 1969 Headphone Amp > TDA1387 x8 DAC > MacBook Pro. Same issue grounding hum, believe the  Denon D2000 and Sony MDR-7506 impedance is too low for the JLH 1969 Headphone Amp.

Then got Volumio working on Raspberry Pi 3.  Listening directly out of the Raspberry Pi 3 was a disappointment.

Then got Audiophonics DAC ES9023 V2 TCXO > Raspberry Pi working, gone was the grounding hum.  The sound quality was a large improvement,  not as musical as TDA1387 but a big improvement.  I miss the laid back sound of the DT770 and the TDA1387.   Next will setup Digi + Pro with TDA1387.

To do:
Set-up Digi+ Pro
Assemble Ian Fifo
Assemble 9028
   
In Order of Sound Quality (SQ)

1. WiFi > Linn Jazz > Raspberry Pi 3 > TDA1387 x8 DAC > JLH 1969 Headphone Amp > Sennheiser HD650  No grounding hum, wonderful musicality of the TDA1387.  Hard to believe the ES9028 and the Ian Fifo will sound better than this ! 
2. HD650 300ohm > JLH 1969 Headphone Amp > Audiophonics DAC ES9023 V2 TCXO > Raspberry Pi No grounding hum, not as musical as TDA1387 but grounding hum is gone 
3. HD650 300ohm > JLH 1969 Headphone Amp > TDA1387 x8 DAC > MacBook Pro Maybe it is the electricity in Mexico, but  more grounding hum than I remember   
4. DT770 250 ohm > JLH 1969 Headphone Amp > TDA1387 x8 DAC > MacBook Pro.  Sounds natural and easy, not the largest sound stage, not that large a range, great left / right separation, very musical.
5. DT770 250 ohm > JLH 1969 Headphone Amp > iFi Nano > MacBook Pro.  More digital, sharper
6. DT770 250 ohm > JLH 1969 Headphone Amp > HiFiBerry DAC+ Pro > Raspberry Pi.  Sounds small, not rich, compressed and confused, all the information is there, but not musical.