Home > DIY HiFi, USB AUDIO > Apple Airport Express USB Audio Output Mod

Apple Airport Express USB Audio Output Mod

The Airport Express is Stereophile 2014 recommended component [link]:

Apple AirPort Express: $99 $$$ ✩
While the Airport Express works only with iTunes v4.6 or later (running on both PCs and Macs), is limited to 16-bit data, and functions only at a 44.1kHz sample rate, the combination of iTunes and the Airport Express offered an easy way to pipe CD-quality music around the entire home. “The beauty of this unassuming component,” said JA, “is its S/PDIF data output, which allows the Airport Express to assume a respectable role in a true high-end audio system.” However, its lack of an internal clock can lead to the first couple of seconds of songs being missed with DACs that are slow to lift their mutes.

Its performance can be enhanced several notches if the I2S digital output can be tapped.

I have been contemplating modding the Airport Express since at least 2009 [link], but never got around doing it.

Now, adding an additional “Airplay” input to the audio system is a desirable option, especially for an “iOS household” like mine. With multiple built-in switchable inputs available in the Sabre-32 DACs which are easily implementable under software control [link], there is even no need for an external switching device.

Certainly no modding is necessary since the AE already has a Toslink output. But for diyers, there is always something to mod 🙂

I2S Output?

For this model of AE, tapping into the I2S signals is not feasible since it is based on the PCM2705 which only supports SPDIF output. (for I2S output, you would need a different PCM chip (PCM2706 or PCM2707) or use a newer version of Airport Express that uses an I2S based DAC such as the second and third generation AE (the first generation “N” and second generation “N”. The original was 802.11 “G”).

Best Model for Audio?

Reports seem to indicate that the original AE is probably the best one to use for audio and for modding…

The original Apple Airport Express was introduced in 2004. According to Wikipedia,

The original version (M9470LL/A, model A1084) was introduced by Apple on June 7, 2004, and includes an analog–optical audio mini-jack output, a USB port for remote printing or charging the iPod (iPod Shuffle only), and a single Ethernet port. The USB port cannot be used to connect a hard disk or other storage device.

The original AE (“G” version as in 802.11g) seems to have the “best” audio performance of all the AE models.

1- Tests published at CA shows that the “First Gen N” version (the follow-on version to the “G” version) has better audio than the current “Second Gen N” version of AE [link]

…To make a long story short, yes, the AE First Gen will have a lower jitter and better sound with your outboard DAC, than the AE Second Gen. An outboard DAC can only suppress incoming jitter, but can never remove.

2- The “G” version in turn has better audio performance than the “First Gen N” version of AE:

I have both a wireless G model & a wireless N model. My DacMagic frequently lost lock when used with the N but is rock solid with the G. At the time I was struggling with this issue, forums and such indicated that the jitter in the N model was much higher than the G…

OPENING THE AIRPORT EXPRESS

For reference here is the “original” Airport Express take-apart post: [link]

The two halves of the Airport Express are bonded together with some kind of crazy glue. The only option is to cut it apart. But rather than brute force, I preferred an approach with some finesse…:

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Several passes were required in order to gauge the appropriate depth and avoid cutting into any internal components. In particular the power supply wires are butting against the casing.

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DSC03445

The case can still be used after cutting the the case apart. Apple is a master in industrial design. We’ll try to save the case.

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Inside the Airport Express.

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Certainly a cleaner approach than what iFixit did 🙂 [link]

ifixit

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The switching supply was made by Samsung in their China Dongguan factory (Dongguan is about an hour drive from ShenZhen). Nowadays, Samsung is likely not building “low-end” components anymore…

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THE AUDIO BOARD

The AE is partitioned into two parts: the network board and the audio board. The audio board is a daughter card that plugs into the network board.

Removing the RF shield:

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Removing the audio board:

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The audio board in detail. Even for a simple DAC implementation such as this, the board is a 4-layer PCB.

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The PCM2705 USB DAC

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pcm2705Circuit

NETWORK BOARD

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DSC03449  DSC03450

That is a lot of electronics in a $99 package!

COMPARING WITH OTHER AE

Here is the 2nd Generation (also knows as the first generation “N”) AE. This version connects to the on-board DAC chip with I2S

1GN-2 1GN-1

The DAC chip used in the second generation AE is the CS4344 (the 10-pin chip in the photo below)

aeinside-001

Here is the 3rd generation AE (current generation) courtesy of Rogue Amoeba

SOME EXPERIMENTS

Functionality without the audio board

I tried powered up the AE without the audio board in place. It turned out that the networking capabilities of the device work fine, but its Airplay capabilities were disabled. Seems the AE performs a power-on self-test and disables the Airplay capability if it finds the audio section not functioning.

PS Wiring

According to iFixit, [link] the 3.3v and 5v supply wires are as follows:

  • Black wires: ground. All three should be connected to the two ground wires from the power supplies.
  • Red wire (middle): 5V, 0.7A power input.
  • Orange wires (two on the right): 3.3V, 1.21A power input.

Functionality without the 5V supply

I removed the red wire from the connector to test whether the device would operate without 5V. (If this is the case, then replacing the power supply would be easier since we would only have to worry about a single supply -the newer AE only require 3.3v for operation)

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Result:

The network part of AE works without the 5V supply. Now, lets see if putting back the audio board will enable Airplay… Airplay does not work without the 5V supply.

WHAT TO MOD?

Power supply replacement

The standard mod has been the power supply mod, replacing the switching dual supply with a linear dual supply.  It is the most popular mod on the AE. In fact, there are commercial versions Apple Express with vastly enhanced power supplies such as La Rosita Alphas:

LRalpha

LRAlpha2

…and the Micromega Streamer products:

MicromegaInside2

MicromegaInside

MicromegaOutside

Notice the unique design of the Micromega: the antenna of the AE extends outside of the case for better reception (I suppose if you totally enclose the AE the WIFI reception would be very poor)

“MONSTER MOD”

I found this project in the Vietnam AV Network. The user replaced the clock, power supplies, and output capacitors, plus a isolation transformer in the spdif output [link]

AEMonsterMod

USB AUDIO OUTPUT MOD

I have not seen another reference to this mod. So I think it is the first 🙂

What if we can take the USB output, and feed it to an external USB interface? We can then try different devices such as the PCM2706 with both SPDIF and I2S output, or the TENOR TE7022 with similar capabilities. We can add isolation.  Isolating the USB will greatly clean up the digital signal and isolate the more sensitive audio part from any digital noise in the AE, including noise generated by the network/wifi chips and related parts.

No need to replace the original PS?

Since we tapping into the USB Audio stream, a purely digital signal, there may be not much to gain in replacing the original PS, especially since we can later add a USB isolator for full isolation. In addition, being a communication device, we can be assured that the designers have done their work in ensuring no (at least unrecoverable) errors in the digital domain.

Undoubtedly, a PS mod would benefit the analog performance and even perhaps the conversion to digital audio, but for this mod, I think am going to leave the original PS in place.

Looking closely to the input power connector, we can see that the designers have taken good care in filtering out the noise from the switching supply. Aside from the EMI shield covering the components, we find that the power lines and ground are further isolated with ferrites:

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Tapping to the USB lines

The USB data from the AE audio board is “readily available”. There are 4 vias where the the 4 USB signals can be tapped:

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We can even leverage the built-in USB connector by first cutting the existing lines (which are only good for connecting to a printer) and tapping the USB signal from the Audio board. 5V and GND are already there, so only two wires are needed:

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Here is the mod. I tried to move the wires away from any active circuitry.  Zero cost and completely and easily reversible.

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Cut the original signals to the USB connector (which we won’t use anymore since this is for printer sharing)

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The metal shield covers everything including the USB wires

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TESTING THE MOD

I used the iBasso D2 USB Portable DAC/AMP to test my mod. The USB interface is the PCM2706 and connects to the Wolfson WM8740 DAC. The PCM 2706 is part of the PCM 270x family, so it should work…

Results:

Airplay complains that there are no speaker connected to the AE. The device is just too smart. It senses if there is a plug in the output connector and prevents Airplay from connecting if there is nothing plugged in… No problem. Use any mini-plug into the output port.

Now Airport connects, I first try to to connect a portable speaker to ensure that everything is in working order. I get sound in the speaker…So far so good.

Now I connect the iBasso into the USB port of the AE… Nothing… The iBasso has a “link” LED and it is not lit. No connection to the iBasso…

OK, perhaps I need to reboot the AE with the iBasso connected… Reboot… Airplay does not show up in iTunes… This AE is just too smart. I figure that since there are two USB interfaces connected, the AE can’t figure out what is going on (there is no handshake/link to any of the two DAC chips) then the self test fails and the AE does export itself as a functional device…

Back to bench.

I theorize that the firmware in the AE is looking to one USB DAC to link up with. I would make sense to turn off the on-board DAC chip and allow a single device to hang off the “USB port”.

Pin 7 is the VDD (digital power) for the PCM2705. We can just lift the pin.

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I didn’t even have to use the soldering iron. Just an exacto knife and a bit of pressure. There is also analog power, but I won’t bother lifting those.

Result: Yes! it works.  After booting up the AE with the iBasso connected, immediately the link LED lights up. Airplay shows up in iTunes… Play a song… Ahhh… Music!

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UPDATE (July, 2015)

SAVIAUDIO SA9023/SA9027

Recently, low cost DACs and USB-I2S interfaces have been implementing with a new device: The SaviAudio SA9023/SA9027 [link]. No device driver is needed under Windows implying that it is compatible with USB 1.1 sound, the same as the PCM 2706 of the Airport Express.

The Teradak is a USB-I2S board using the SA9023. The chip is advertised to have jitter <100 psec. [link]

teradak-1

sa9023Jitter

The HifimeDIY Sabre USB DAC has been updated with the SA9023 [link]. According to the specifications, no driver is required for Windows.

  • Supports 32khz, 44.1khz, 48khz, 88.2khz, 96khz and 16 and 24 bits
  • Works in USB Adaptive Isochronous mode (same as PCM2706)

hifimediySA9023-1

The SA9023 USB interface chip can also be implemented as “Asynchronous mode” [link]

Notice a second 27MHz clock in addition to the 12 MHz clock. I am not sure if this configuration would work with the modded Airport Express.

HifimediyAsynchSA9023

The all digital amplifier SMSL Q5 uses the SA9027 for USB input. Since there is a single clock near the USB circuitry (upper right corner), it would be safe to assume that it is operating in Adaptive mode.

The SA9027 adds 32-bit support

smslQ5Front

SMSLQ5

I had a chance to try this device with the modded Airport Express. Sadly, it is not compatible. I does not recognize this device when connected to the USB port. I have not have a chance to try the SA9023 USB.

  1. July 21, 2013 at 09:57

    Great work on the USB mod, have you tried with it with other dacs?

    • BlgGear
      August 12, 2013 at 18:27

      I think it would only work with a TE7022-based DAC aside from PCM270X-based DACs. I tried a CM6631 USB interface (which is supposed to work with USB1.1) but it did not work.

  2. Sam Wishpot
    August 30, 2013 at 04:25

    Great post, very intrepid mod. Would love to output audio to the AE USB.

  3. BlgGear
    August 30, 2013 at 05:26

    Thank you very much. it was a fun mod

  4. November 1, 2013 at 03:06

    Wow man, that’s just awesome dude!
    And yes, it works with pcm2707 too.

  5. Jamie
    November 27, 2013 at 23:35

    Cool post!! One question I had half way though you talk about the 2nd Generation (also knows as the first generation “N”) Am trying to get the wiring spec on the 6 black wires that feed from the power pack in the ae and plug into the main bored if you can’t sheed any light I would be most thankful

    • BlgGear
      December 5, 2013 at 21:10

      Try measuring the voltage. In my AE. 3 of the wires are ground wires. The other ones are either 5V or 3.3V

  6. Anonymous
    January 1, 2014 at 22:45

    hi, great mod. is the sound better than through the optical out ? thank’s

    • BlgGear
      January 23, 2014 at 22:00

      Have not done the comparison. This gives you an option to isolate the USB (with a USB isolator chip) and then connect to a USB 1.1 compatible interface

      • January 24, 2014 at 00:54

        It don’t see how it would sound better per sé.

        I don’t know how the Airplay audio protocol works but I think, even if it actually re-creates the original clock by some buffering mechanism, jitter will still be introduced by the USB isochronous audio transfer because I doubt the Broadcom processor sends packages on exact intervals since it has to be responsive in performing other tasks simultaneously.

        Apart from being a really cool mod as such, I think the core benefit would is to replace the USB audio receiver with one that outputs I2S. This lets you connect an I2S DAC design of your own choosing, possibly with a linear PSU.

        If you’re just plan on pulling out S/PDIF (optical or otherwise) from your replacement USB, then I’d say it’s pretty pointless – you’d probably be back pretty much where you started.

        Just my five cents, could be wrong though.

      • BlgGear
        January 24, 2014 at 16:34

        You are right. However, the embedded OS in the Airport could be a real time OS (I don’t know). The advantages I can see are:

        – (As you said) use a PCM2707 which has I2S outputs
        – Use a USB isolator to eliminate potential noise from the Airport and switching supplies (the device is limited to 48KHz sample rate, so a USB isolator would work fine)
        – Try other USB 1.1 compatible interfaces (such as the Tenor and even the XMOS with the proper firmware -have not tried either yet)
        – And as you said, it is a cool mod 🙂

  7. January 24, 2014 at 18:39

    BlgGear :
    – And as you said, it is a cool mod

    Certainly so, the only tricky part for me was lifting the Vdd leg of the PCM2705. I find it very odd to incorporate USB audio as an inter-board audio interface but turned out a golden nugget for brilliant people like you to find.

    Btw, I’ve also found CM108 to work well for I2S output.

    • BlgGear
      January 25, 2014 at 16:30

      Yeah, it is very odd to have USB for interboard audio interface. Maybe it was easiest to implement the USB audio protocol rather than getting I2S out of those Broadcomm chips at that time. Thanks for the tip on the CM108.

  8. Signo
    January 31, 2014 at 11:21

    Anonymous :
    hi, great mod. is the sound better than through the optical out ? thank’s

    Did you get some tests?
    I have AE A1088. I read that the 1st generation N A1264 is better for digital out removing the original power supply. So do I keep A1088 making your usb mod or buy an A1264 changing the power supply and good optical cable?
    Thank you for your mod!!

    • BlgGear
      January 31, 2014 at 18:08

      Have not done comparison. But with the USB mod, you can use a different interface and get I2S output. Overwhelmingly people prefer I2S over optical if the wires can be kept short.
      My recommendation is to do my mod (it is free :-)). You can get a PCM2706 or PCM2707 with I2S output from eBay for like $15

  9. Taz
    March 25, 2014 at 10:28

    Hi! Tried this mod and have a couple of questions.

    1. If the Vdd leg of the PCM2705 is lifted, should I still be able to get (analogue) out of the 3.5mm jack? I’m getting sound with a headphone amp hooked up with a regular 3.5mm audio cable.

    2. Airplay to the Airport Express is working, but no sound when connected by USB to an ODAC, which is a Sabre ES 9012 with TE7022 I think? Incompatibility or could I have stuffed something up?

    Thanks!
    Taz.

    • BlgGear
      March 26, 2014 at 05:37

      1- If you still get analog sound that means the DAC is still working. Check again and see if you indeed lifted the VDD leg of the PCM2705. (Measure the voltage of the VDD leg)
      2- If #1 is true (that the DAC is still working), it will not recognize a second DAC.

      • xnoodlesx
        April 7, 2014 at 01:34

        I had the same experience as Taz. I had to lift pin 10 (Vbus) in addition to pin 7 (VDD) in order for the AE to not see it (onboard PCM2705) on the bus. After that, it recognized my externally connected PCM2706. The funny thing is that pin 7 was still showing 3.3Volts lifted and it was definitely disconnected. This has been the case on the 2 that i’ve modified.

      • BlgGear
        April 8, 2014 at 01:24

        Thanks for sharing your experience. I am almost definitely sure that I only lifted one pin in my version.

    • Giovanni pignoni
      September 23, 2015 at 09:34

      Hi Taz, where you finally able to use the Odac whit your airport?
      Thanks

  10. Yardbeatles
    May 15, 2014 at 05:38

    I would love to see a redo of this based on the latest (3rd gen) airport express. Could possibly get USB 2 and use an asynchronous USB DAC to really make it shine… Possible?

    • Anonymous
      May 15, 2014 at 07:48

      The newer models don’t use USB Audio internally so it’s not possible or at least would require a whole different approach than in this h/w hack.

      • BlgGear
        June 9, 2014 at 21:30

        The latest ones connect directly to DACs through I2S. You may be able to tap the I2S and feed an external DAC

  11. Dan
    September 21, 2014 at 22:21

    Great use of an airport express. I am starting on this now. My 2nd generation board has all black wires coming off the power supply to the mother board. I think that I have it correct, that with the USB and audio inputs on top, with the black power supply connector to the left, and the wires coming out of the plug leading up, from left to right, the leads would be 3.3v, 3.3v, 5v, ground, ground, ground. Could you confirm this? Thanks!

    • BlgGear
      September 21, 2014 at 23:50

      Can you measure the values? You could disconnect the power wires from the other half and measure the voltages.

  12. November 17, 2014 at 19:25

    Let me see if I understand this correctly: If I get a first model Airport Express, do your mod and connect it to my Hegel HD11 that’s based on the TE7022 (that’s what my Mac says when I connect the DAC directly) i can improve the sound quality because that setup has a lower jitter value – or is the jitter value not improved by that setup?

  13. December 31, 2014 at 04:11

    I would like to install one of these puppies into my car, this way I could plug the AUX in and have anyone play music through the AIRPLAY feature.. I’ve been searching for a way tap into the cigarette lighter outlet possible from the back so it would all be tucked away. If anyone can point me in the right direction I would be more than grateful.

    Thanks for sharing

  14. January 22, 2015 at 13:33

    I found this information very useful. Using this and information from other sites, I have been able to replace the faulty power supply of my early model airport express from EBay and get it working. I used a spare apple iPad 2Amp charger for the 5V supply I then used a low dropout regulator from Maplin for the 3.3V supply. This utterly basic system seemed to work at first. The AE powered up but I found it would not retain settings. I figured that the extra current required to write to memory was causing a voltage drop. This is probably because the regulator is very close to its minimum dropout voltage 5-3.3=1.7 and the reg needs 1.5V to work correctly. I wired a 470uF electrolytic across the 5V pins of the regulator and added a heat sink extracted from a very old computer PSU as the regulator was a bit warm. I have left this running for some days now and it seems to perform OK.
    I have never had lots of money to spend on audio, I used to listen to LPs played on my trusty Garrard SP25 mark II with rumble, wow, flutter, and crackles that would cause modern audiophiles to reach for medication so I think the sound from this setup is amazing.
    I have two questions.
    I currently have the AE connected to my Kenwood amp. With this setup I find I have to turn the Kenwood treble almost full on. If I listen directly to the AE output with headphones the top is there. There is also no missing treble when I connect my. LG soundbar optically. Should I improve the PSU filtering, or is this loss of treble due to impedance mismatch do you think?
    Eventually I would like to switch my amplifier on and off when the airplay option is selected from my iPad/computer. I note that the optical output is switched on when the airport is selected, but this is disabled when the audio plug is connected. Any suggestions on which pin on the DAC indicates if it is selected?

    • BlgGear
      January 23, 2015 at 04:54

      There should not be impedance mismatch between the analog output of the AE and your aux input of your receiver. Try another input like “tape”?
      When you say “I note that the optical output is switched on when the airport is selected, but this is disabled when the audio plug is connected.” do you mean disabled in the control panel or does the toslink red light turns off?. I seem to remember that the jack is “smart enough” to determine what kind of plug is plugged in and turn the toslink on/off.

      • Anonymous
        January 23, 2015 at 18:12

        Yes i will try an alternative input when I can get at the back of the amp when no-one happens to be watching TV! LOL
        The toslink red light turns off as you push an audio plug in. This happens before the plug is fully inserted – it looks like there is some sort of switch contact which is pushed aside on insertion. With nothing plugged in the led is visible and comes on when the airplay icon for the airport express is selected and vice versa. It should not be difficult to arrange a circuit to detect this led and use it to switch a relay to switch the amp. Although I think there must be better ways to do this.
        I have been studying the specs of the DAC chip at-

        Click to access pcm2707.pdf

        After reading it several times I have learned a lot, but it is not clear if there is a way to detect if the chip has detected data and/or how it knows to turn the toslink led on when the AE is selected from my iPad. Pin 27 not SSPND looks like a possibility. What do you think?
        I will do some experiments regarding this as soon as I get time.
        Thanks BigGear

      • BlgGear
        January 23, 2015 at 19:03

        Do you have a pcm2707? I have a pcm 2705

      • Deepthought
        January 23, 2015 at 22:09

        PCM2705

  15. Deepthought
    January 23, 2015 at 18:17

    Ooops – not sure why I just posted as anon
    Deepthought

  16. Deepthought
    January 23, 2015 at 22:13

    I think the datasheet shows both – correct me if I’m wrong?

  17. Rza
    May 18, 2015 at 00:00

    With this usb mod would you be able to plug in an iDevice and play audio through the sync cable? Would it charge the device as well?

    • BlgGear
      June 15, 2015 at 19:48

      No. Seems it would connect to a USB 1.1 Audio DAC device only (maybe only to the PCM USB DAC chips)

  18. July 21, 2015 at 17:53

    Somebody try AE(+ mod) with M2Tech HiFace DAC on PCM5102A?

    • BlgGear
      July 22, 2015 at 02:12

      The AE usb (modded to use the usb port) cannot support the M2Tech DAC. It seems to only support the PCM270x family of dacs…

      • July 22, 2015 at 15:46

        Ok. Thnks.
        I think, since time of your mod you test many DAC.
        Which model you can recommend for home?
        Which model you can recommend for car(better if PS will be 12V)?

      • BlgGear
        July 24, 2015 at 04:30

        I don’t have experience with using a DAC in a car. But the environment is very noisy so I don’t think it matters. The power may be quite polluted too. For home use, I all depends on your budget, I choose the ones here because they are a good value for the money and are diy. If it for listening only (without the “value” of building/modding it), then anyone would do. They all sound very good.

  19. July 24, 2015 at 14:42

    I right understood, that I can use any of:
    – iBasso D2 (Wolfson WM8740 DAC Chip + TI PCM2706);
    – iBasso D2+ (Wolfson WM8740 DAC Chip + TI PCM2706);
    – iBasso D4 Mamba (Dual Wolfson WM8740 DAC Chip + TI PCM2706),
    right?

    • BlgGear
      July 25, 2015 at 18:23

      Yes, the modded AE would work with those… My original aim was to get I2S output. The built-in DAC in the AE is the PCM2704 and that device model does not have I2S output. With the USB mod, I can connect to a PCM2706 or PCM2707 and those devices have I2S output.

  20. July 26, 2015 at 05:37

    You got I2S output. Which plans next? Which device you will connect to this by I2S?

    • BlgGear
      July 27, 2015 at 05:04

      No plans at this moment, but can be used with any I2S DACs. The best candidate is one that can reclock the I2S signal such as the Soekris DAC or you can use an external reclocker such as Ian’s I2S reclocker before the DAC.

  21. Giovanni Pignoni
    September 22, 2015 at 20:29

    Sorry to bother on such an old tread, I have an old airport and I was thinking about modifying it to use it whit a matrix m-stage usb headphone amp.
    Do you think there is a chance it will work? It is based on TAS1020B control cip witch would be is. 1.0 and 1.1 compatible and pcm PCM1793 dac?
    Thanks for the help

    • BlgGear
      September 23, 2015 at 03:25

      I have not tested it, but I would guess it would not work. I did try another USB 1.1 compatible USB DAC interface and it did not work. (Saviaudio SA9023 I believe was the part)

      • Giovanni Pignoni
        September 23, 2015 at 08:11

        Thanks for the quick answer!
        I’ll try and report here 🙂

      • Giovanni Pignoni
        September 23, 2015 at 17:23

        hi again
        I just modded my Airport, and as you predicted it doesn’t work whit the matrix m-stage, it works with another usb headphone amplifier I have, the musical fidelity V8 too bad this one has a dac that is just crap 🙂 (i do not know the chip inside tis though).

        connected to the matrix m-stage I get a strange behavior: the airport just doesn’t work, i mean the light (on the airport) flash once when you connect it to the power line and then nothing else, it seems like its’ going in a protection mode and will not turn on

        can someone suggest an usb dac in the 100€ range that would work, odac would be fantastic, anyone tried it?

        thanks
        giovanni

      • BlgGear
        September 23, 2015 at 18:02

        Should work. The MF uses a PCM270x similar to wha is inside the AE

      • Giovanni Pignoni
        September 23, 2015 at 18:15

        sorry for my bad english, i generated some confusion.

        I tried the modded airport with the matrix and it doesn’t work (the airpot do not even torn on completely)

        then I tried it whit the Musical fidelity and it does work (but the dac in the musical fidelity has a a very low output and i do not get enough volume out to drive most of my headphones)

        then i ask for another dac that would work, is the old odac suitable ? the one whit TE7022 ?

        thanks
        giovanni

      • BlgGear
        September 24, 2015 at 05:32

        Your English is fine. My response was too short. I was referring to the fact that the Musical Fidelity would surely work because the USB interface/DAC is the PCM270x which is the same chip inside the airport express. I have not tried the Tenor TE7022.

      • Giovanni Pignoni
        September 24, 2015 at 10:02

        thanks, i’ll report as i experiment further 🙂

        giovanni

  22. August 19, 2017 at 13:50

    My boyfriends trying to learn more on this topic. You deserve a hug right now. You saved me a lot of hassle just now.

  23. August 25, 2017 at 03:14

    I wants to be a master in this subject someday. I really love your writing style. Keep it up! You could survive a Zombie apocalypse. Very nice blogs.

  24. Marc NL
    April 13, 2020 at 23:15

    Hi BlgGear, thanks for the write-up! I managed to turn a bricked Airport into a USB sound card using the pinout in one of your images. One small thing: the 5V input is actually the via a little bit up and to the left of the via you labeled 5V. Either way, I had fun, thanks!

  25. orrpan
  26. LescureJP
    July 14, 2020 at 18:47

    Hello, question about HD music transfer, if the USB of AE is open instead of PC2705, 24/96 kbHz possible with the AE?

  27. Anonymous
    May 6, 2024 at 09:29

    After reading it several times I have learned a lot Audio,
    I will do some experiments regarding this as soon as I get time.

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