Author Topic: Introducing ApplePi DAC -- Highest Performance Raspberry Pi DAC  (Read 2821 times)

Offline orchardaudio

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Re: Introducing ApplePi DAC -- Highest Performance Raspberry Pi DAC
« Reply #45 on: April 23, 2018, 03:37:46 PM »
Can this be used in a project to replace/emulate the Squeezebox Touch ????

You can do it, using piCorePlayer


Offline mresseguie

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Re: Introducing ApplePi DAC -- Highest Performance Raspberry Pi DAC
« Reply #47 on: April 28, 2018, 08:35:47 PM »
Now you can get and ApplePi DAC system that is completely ready to go out of the box, and includes a 7" touchscreen.

Picture:


Here is a video showing it in action:
https://youtu.be/WOCduJMGcFU

Kickstarter project link:
https://www.kickstarter.com/projects/1844799967/applepi-dac-highest-performance-raspberry-pi-dac

Hello, Leo.

I have some questions for you:

1) Is this compatible with my Mac Mini (Apple Computers)? Is this compatible with my iPhone or iPad?

2) Eventually, the touchscreen will die or malfunction (most likely before the Pi suffers indignities). Is the touchscreen user replaceable?

3) Eventually, the touchscreen maker will stop producing this unit, what options would I have if my touchscreen dies after it is no longer available?

4) If I back this product only to discover I don't like how it sounds, may I return it for a full refund?

5) Is piCorePlayer compatible with Apple Computers?

6) It appears the 'Pi' portion is open to the elements. Is there a housing to keep dust out? Is it necessary?

7) How does this DAC differ from the DAC prototypes that Tommy sent me a couple years ago? [This should be directed to Tommy, I suppose.] I ask because I did not care for
    them. If it is materially the same, I will have no interest in your product. (Sorry, but honesty is best.)

I look forward to your response.

Regards,

Michael

 
Daedalus Audio Apollos Fritz Loudspeakers LS/5-R
Gustard X20u DAC
dB Audio Labs Tranquility SE DAC w/Jupiter Caps
Don Sachs Model 2
Don Sachs Kootenay 120 KT88; Nuprime ST-10
TWL loom
PI Audio UberBUSS, DigiBUSS, Uber-MiniBUSS
PI Audio USB cable
Mac Mini

Offline orchardaudio

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Re: Introducing ApplePi DAC -- Highest Performance Raspberry Pi DAC
« Reply #48 on: April 29, 2018, 03:15:53 AM »
Michael, I send you a PM.

Offline mresseguie

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Re: Introducing ApplePi DAC -- Highest Performance Raspberry Pi DAC
« Reply #49 on: April 29, 2018, 03:19:34 AM »
Got it. Thanks!
Daedalus Audio Apollos Fritz Loudspeakers LS/5-R
Gustard X20u DAC
dB Audio Labs Tranquility SE DAC w/Jupiter Caps
Don Sachs Model 2
Don Sachs Kootenay 120 KT88; Nuprime ST-10
TWL loom
PI Audio UberBUSS, DigiBUSS, Uber-MiniBUSS
PI Audio USB cable
Mac Mini



Offline orchardaudio

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Re: Introducing ApplePi DAC -- Highest Performance Raspberry Pi DAC
« Reply #52 on: May 11, 2018, 07:52:32 AM »
Just realized I never posted the specs  :duh::
  • SNR: 128dB (A-Weighted)
  • THD+N: <0.0005% (-106dB)
  • Frequency Response: DC - 22kHz
  • Balanced Output Voltage: 5 Vrms (0dBFS)
  • Balanced Output Impedance: 200 ohms
  • Single Ended Output Voltage: 2.5 Vrms (0dBFS)
  • Single Ended Output Impedance: 100 ohms
  • Supported Sample Rates: 44.1, 48, 88.2, 96, 176.4 and 192kHz
  • Supported Bit Rates: 16-Bit and 24-Bit
  • Power Consumption: 4.5W (5V @ 0.9A)
  • Chipset: 2 Burr Brown PCM1794A - monaural mode
  • Op Amps: 6 OPA1612 - dual differential output configuration


Offline orchardaudio

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Re: Introducing ApplePi DAC -- Highest Performance Raspberry Pi DAC
« Reply #54 on: July 22, 2018, 03:49:58 PM »
Both the ApplePi DAC and Volume-Clocker are now available for purchase.

You can buy from my ebay store here:
ApplePi DAC -- https://www.ebay.com/itm/283068026346
ApplePi Volume-Clocker -- https://www.ebay.com/itm/283046502392

You can also send me an email to leo@orchardaudio.com to buy direct and save 5%.

Offline richidoo

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Re: Introducing ApplePi DAC -- Highest Performance Raspberry Pi DAC
« Reply #55 on: July 22, 2018, 05:39:23 PM »
Looks really good Leo. External HW clock great idea!

You mentioned the DACs are TI PCM1794A, nice choice. The pictures of the PCB on your kickstart page are still too small for me to read the opamps for the dual diff output stage. Can you name which output opamps you are using? It makes such a difference as I'm sure you know. Thanks
Rich

Offline orchardaudio

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Re: Introducing ApplePi DAC -- Highest Performance Raspberry Pi DAC
« Reply #56 on: July 23, 2018, 07:45:10 AM »
Looks really good Leo. External HW clock great idea!

You mentioned the DACs are TI PCM1794A, nice choice. The pictures of the PCB on your kickstart page are still too small for me to read the opamps for the dual diff output stage. Can you name which output opamps you are using? It makes such a difference as I'm sure you know. Thanks
Rich

The Op Amps are OPA1612

Offline orchardaudio

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Re: Introducing ApplePi DAC -- Highest Performance Raspberry Pi DAC
« Reply #57 on: August 02, 2018, 06:42:31 AM »
Starting to get some feedback from kickstarter backers:
Kevin:
"ApplePi DAC is an excellent DAC. Compare to the Audio Note DAC 3 I have, it has much more detail."


Offline orchardaudio

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Re: Introducing ApplePi DAC -- Highest Performance Raspberry Pi DAC
« Reply #59 on: August 19, 2018, 03:24:48 AM »
Here is a review that was just posted on diyaudio:
http://www.diyaudio.com/forums/vendor-s-bazaar/321303-applepi-dac-performance-raspberry-pi-dac-post5520363.html

I was part of the ApplePi tour and want to share my impressions of this DAC.

HARDWARE

I tested the hat with Rpi 3B, IanCanada IsolatorPi, and Allo Kali. Each board had separate power: I fed the Pi with an iFi iPower and the other three boards each got a GStew modified Jameco linear wall wart. Listening environment was a rather analytical nearfield desktop setup--a Tripath amp into some Axiom 2 way bookshelf speakers, and a humble full-range setup using another Tripath amp with Aura NS3 drivers.

First surprise: This DAC seems to be immune to PSU noise! Other DACs I have tested are all very sensitive and exhibit hum and hiss to some extent, even with an isolator board, Kali, and four separate power supplies with earthed ground rails via John Swenson Ground Tweak. Using these careful measures, I have been able to reduce noise by, say, 95% with the other DACs. But I can still hear a tiny bit near the speaker when music is stopped and I crank the volume knob to max. 

In contrast, ApplePi is silent. Even if I float the PSU grounds by unplugging my earth wires from the negative terminals...it stays silent! The other DACs would be intolerably noisy this way. I'm impressed. This could make getting good sound from a Pi a heck of a lot less hassle and expense. 

(edit: Since this test I have booted the iPower out of my setup completely, and going completely linear in combo with the IsolatorPi killed noise at the speakers almost 100% for any DAC Hat on my Pi stack )

SOFTWARE

I played music through the ApplePi with both Moode and Volumio. I was not able to get 16/44.1 files to play natively on ApplePi with Volumio, though Leo told me this works for him. It did play 24-bit files quite nicely, but everything in 16-bit I had to upsample...and IME Volumio upsampling sounds sort of lifeless. Thus, I spent most of the time playing my music collection (which is 95% Redbook FLAC) via Moode, which worked flawlessly, natively decoding all bit depths and sample rates I tried.

SOUND

One huge advantage this DAC holds over all others I have tried is the beastly 2.5V output--it just makes both of my amp/speaker combos sing, almost like having a preamp. This results in some of the best, most effortless bass control I have heard in my systems to date. I wish every source component had such gusto. In both my systems, ApplePi made my little flea-powered Tripath amps able to push significantly more air from the woofers without distortion. (Note to self: buy a real amp). IME good gain staging just makes everything downstream happier. Take note: the board gets quite hot. Leo said he has made some revisions to help dissipate heat better with the production boards. 

Entering into highly subjective territory, now. My listening impressions parallel my experience with Alex's DIAL_DAC to a great extent...the sound signature shared between the sibling Burr Brown chips is evident. Analytical and smooth at the same time--detailed without harshness. Especially with 24/192 files, transparency is excellent. 

I feel that the powerful, controlled bass and detailed treble are the most apparent and expressive parts of the music with the ApplePi. At this point I have to reveal myself as a total sucker for midrange body and warmth. Thus, the ApplePi doesn't push all my buttons...in fact, I'd say it stands in slight contrast to the meatier tonality of the TDA1387 DACs which usually sit atop my Pi stack. Which flavor you'll prefer will surely depend on the other gear in your system as well as your personal taste. 

Nice job, Leo.