My friend who is now a 'former Wadia dock owner' brought over his just-received Onkyo dock the other day, and I just had time to have a peek at the spdif output signal, and, much as I postulated it should be, with a 75ohm load, the spdif output signal was positively beautiful. Clean, no ringing, no visible harmonics, just a great looking signal. Haven't heard back from him yet on the sound quality, but I expect it to sound better than the Wadia, and will be really surprised if it doesn't.
And, yes, the unused dac portion of the BB usb chip does provide the potential opportunity for actually using that dac & adding a headphone amp. It would be a bit challenging, due to being all surface-mount, but I'm sure it's possible. I'll be surprised if Onkyo fails to bring out an 'upgrade model' soon that does exactly that.
And, yes, the unused dac portion of the BB usb chip does provide the potential opportunity for actually using that dac & adding a headphone amp. It would be a bit challenging, due to being all surface-mount, but I'm sure it's possible. I'll be surprised if Onkyo fails to bring out an 'upgrade model' soon that does exactly that.
Interesting stuff..
What most interested me: how do they get digital audio out of the iPod? If they indeed use a Ti USB DAC, does this mean that the iPod can act as a USB host, and just use the Ti DAC as a playback device? If so, do you need to do some configuration for this? As far as I know, you can let the iPod know of certain devices by putting a specific value resistor over some pins.. Maybee, this is needed to put the iPod in USB host mode?
If so, it would be very easy to make your own Ipod to SPDIF doc, just hook up a simple USB DAC with SPDIF output, and you're done.. Sounds far to easy to be true..
What most interested me: how do they get digital audio out of the iPod? If they indeed use a Ti USB DAC, does this mean that the iPod can act as a USB host, and just use the Ti DAC as a playback device? If so, do you need to do some configuration for this? As far as I know, you can let the iPod know of certain devices by putting a specific value resistor over some pins.. Maybee, this is needed to put the iPod in USB host mode?
If so, it would be very easy to make your own Ipod to SPDIF doc, just hook up a simple USB DAC with SPDIF output, and you're done.. Sounds far to easy to be true..
There are actually two spdif 'translator/driver' chips in the Onkyo, one being the USB input dac, and the other being a TI/BB DIT4096 chip that is a conventional spdif driver, albeit hi-res. I believe the USB dac is used only for the pc input, allowing the user to use the dock both as an Ipod-to-dac interface and as a pc-to-dac interface. There would be no reason for the DIT4096 if the ipod was being tapped from usb output mode. The whole reason for the Wadia to come into being was that they had gotten the license to access the proper direct digital output signals from the ipod, which now seems also the case with the Onkyo. This is, theoretically, the superior way to get a digital audio datastream out of the ipod, versus usb out.
Well, then why does the Wadia also have a USB DAC? It does not have a USB port...
I guess it's all some big marketing scam, letting it seems complicated while it's not..
Via a resistor op pin 21 and/or and maybee a serial command, the iPod is put into USB host mode, and then sends it's audio to the USB DAC. It then converts it to SPDIF.
I don't know about the DIT... There are in fact a lot of things I don't get about the Denon? Why need such a massive CPU, and even external memory...
It's sertainly a mistory worth looking into! Maybee FAA can trace the USB lines from the dock connector. Also pin 21 would be interesting.
I guess it's all some big marketing scam, letting it seems complicated while it's not..
Via a resistor op pin 21 and/or and maybee a serial command, the iPod is put into USB host mode, and then sends it's audio to the USB DAC. It then converts it to SPDIF.
I don't know about the DIT... There are in fact a lot of things I don't get about the Denon? Why need such a massive CPU, and even external memory...
It's sertainly a mistory worth looking into! Maybee FAA can trace the USB lines from the dock connector. Also pin 21 would be interesting.
Yes, i would too like to know how do apple manage to make this accessible. Sorry i'm a bit of a noob. But say it were by USB data transfer, what's to stop another person just doing an exact copy of the wadia/onkyo?
I mean does it specifically have a coding, or a chip which is only available directly from apple?
I mean does it specifically have a coding, or a chip which is only available directly from apple?
It is very difficult (read $$$$) to get the info for interfacing to the IPOD. You need to sign several non disclosure agreements and have to to a lot off legal work for example you need an attorney($$$):
Note that he/she must be a licensed attorney. The Made for iPod License is a binding legal agreement that imposes a number of significant obligations on the Licensee. It is important that these obligations are reviewed with counsel so that their impact on your organization, and its ability to comply, may be fully understood. During the enrollment process we may verify your Counsel's contact information.
This is a small part of the correspondence with Apple. In layman's language: when you leak you are broke
But there is also some info in the public domain:
1 - FireWire Ground 1
2 - FireWire Ground 1
3 - FireWire Data TPB (+)
4 - USB Data (+) 2
5 - FireWire Data TPB (−)
6 - USB Data (−) 2
7 - FireWire Data TPA (+)
8 - USB VBUS Power +5 VDC (from computer) 2
9 - FireWire Data TPA (−)
10 - Accessory Indicator 3
11 - Firewire Power +12 VDC 4
12 - Firewire Power +12 VDC 4
13 - +3.3V Power (to power iPod accessories) 5
14
15 - USB GND 6
16 - Ground 6
17
18 - Serial RxD
19 - Serial TxD
20 - Serial GND
21 - S-Video Luminance 7, Component Pr
22 - S-Video Chrominance 7, Component Y
23 - Video Out - Composite Video (for ipod colour when slideshow activated)8, Component Pb
24
25 - Line In - Left
26 - Line In - Right
27 - Line Out - Left
28 - Line Out - Right
29 - Line Out - Common Ground 9
30 - Ground 9
Note 1: Pins 1 and 2 connected on motherboard
Note 2: 4 and 6, D- and D+. Different kind of behaviour of the iPod if those pins are set to a certain state:
To force the iPod (useful for the iPod 5G) to charge in any case, when 'USB Power 5 VDC' (pin 8) is fed, pin D- must be connected to 3.3V (USB uses 3.3V for data communication, you can connect to 5V but its not as safe) through a 10kΩ resistor, and pin 4 must be connected to the Ground (for example: pin 1) with a 10kΩ resistor. 10kΩ resistor has been determined experimentally.
To force the iPod nano 2nd generation (aluminium case) to charge, you have to connect pin 6 to 5 VDC (pin 8) through a 10kΩ resistor while leaving pin 4 unconnected.
To properly charge iPod nano 2nd generation, connect pin 6 to 2.5 VDC through 10kΩ resistor, while pin 4 receives 2 VDC.
To charge your video iPod, and play at the same time, connect +12V to pin 11 (Firewire +12). Useful for car iPod players. Also when the car 12V accessory socket turns off when the ignition switch is turned off, this will turn the iPod off.
Note 3: Pin 10 connected to ground via a resistor. Different resistances indicate which accessory is connected. Known resistances/functions (ohms) are as follows:
1kΩ - iPod docking station, iPod beeps when connected
10kΩ - Takes my iPod into photo import mode
500kΩ - vava uses this for his serial-via-dock experiments. Used in Dension Ice Link Plus car interface
550kΩ - Measured value of Nike+ Receiver
1 MΩ - Belkin auto adaptor, iPod shuts down automatically when power disconnected
Note 4: Pins 11 and 12 connected on motherboard
Note 5: Pin 13 stepped up to provide +5 VDC to USB on iPod Camera Connector.
If iPod is put to sleep while Camera Connector is present, +5 VDC on USB slowly drains back to 0 VDC.
If Camera Connector is disconnected, draining power can be detected between this pin on the Camera Connector dock connector and +5 VDC on USB connector.
Used by the Honda Music Link to detect the presence of an iPod.
Note 6: Pins 15 and 16 connected on motherboard
Note 7: Newly discovered from iPod Color Dock
Note 8: Composite out uses common ground as ground
Note 9: Pins 29 and 30 are connected on motherboard
So there is a start to do some hacking. I have ordered one!
Note that he/she must be a licensed attorney. The Made for iPod License is a binding legal agreement that imposes a number of significant obligations on the Licensee. It is important that these obligations are reviewed with counsel so that their impact on your organization, and its ability to comply, may be fully understood. During the enrollment process we may verify your Counsel's contact information.
This is a small part of the correspondence with Apple. In layman's language: when you leak you are broke
But there is also some info in the public domain:
1 - FireWire Ground 1
2 - FireWire Ground 1
3 - FireWire Data TPB (+)
4 - USB Data (+) 2
5 - FireWire Data TPB (−)
6 - USB Data (−) 2
7 - FireWire Data TPA (+)
8 - USB VBUS Power +5 VDC (from computer) 2
9 - FireWire Data TPA (−)
10 - Accessory Indicator 3
11 - Firewire Power +12 VDC 4
12 - Firewire Power +12 VDC 4
13 - +3.3V Power (to power iPod accessories) 5
14
15 - USB GND 6
16 - Ground 6
17
18 - Serial RxD
19 - Serial TxD
20 - Serial GND
21 - S-Video Luminance 7, Component Pr
22 - S-Video Chrominance 7, Component Y
23 - Video Out - Composite Video (for ipod colour when slideshow activated)8, Component Pb
24
25 - Line In - Left
26 - Line In - Right
27 - Line Out - Left
28 - Line Out - Right
29 - Line Out - Common Ground 9
30 - Ground 9
Note 1: Pins 1 and 2 connected on motherboard
Note 2: 4 and 6, D- and D+. Different kind of behaviour of the iPod if those pins are set to a certain state:
To force the iPod (useful for the iPod 5G) to charge in any case, when 'USB Power 5 VDC' (pin 8) is fed, pin D- must be connected to 3.3V (USB uses 3.3V for data communication, you can connect to 5V but its not as safe) through a 10kΩ resistor, and pin 4 must be connected to the Ground (for example: pin 1) with a 10kΩ resistor. 10kΩ resistor has been determined experimentally.
To force the iPod nano 2nd generation (aluminium case) to charge, you have to connect pin 6 to 5 VDC (pin 8) through a 10kΩ resistor while leaving pin 4 unconnected.
To properly charge iPod nano 2nd generation, connect pin 6 to 2.5 VDC through 10kΩ resistor, while pin 4 receives 2 VDC.
To charge your video iPod, and play at the same time, connect +12V to pin 11 (Firewire +12). Useful for car iPod players. Also when the car 12V accessory socket turns off when the ignition switch is turned off, this will turn the iPod off.
Note 3: Pin 10 connected to ground via a resistor. Different resistances indicate which accessory is connected. Known resistances/functions (ohms) are as follows:
1kΩ - iPod docking station, iPod beeps when connected
10kΩ - Takes my iPod into photo import mode
500kΩ - vava uses this for his serial-via-dock experiments. Used in Dension Ice Link Plus car interface
550kΩ - Measured value of Nike+ Receiver
1 MΩ - Belkin auto adaptor, iPod shuts down automatically when power disconnected
Note 4: Pins 11 and 12 connected on motherboard
Note 5: Pin 13 stepped up to provide +5 VDC to USB on iPod Camera Connector.
If iPod is put to sleep while Camera Connector is present, +5 VDC on USB slowly drains back to 0 VDC.
If Camera Connector is disconnected, draining power can be detected between this pin on the Camera Connector dock connector and +5 VDC on USB connector.
Used by the Honda Music Link to detect the presence of an iPod.
Note 6: Pins 15 and 16 connected on motherboard
Note 7: Newly discovered from iPod Color Dock
Note 8: Composite out uses common ground as ground
Note 9: Pins 29 and 30 are connected on motherboard
So there is a start to do some hacking. I have ordered one!
Meaning perhaps a secret resistor value on pin 10
Who knows what kind of marketing is behind this...Maybee it even works with a 10K resistor. Photo import mode also needs USB host to work... It would be easy to measure on the Onkyo!
Hi all:
Some time ago I spent some time trying to learn how to improve the output sound quality of the iPod, so I read some stuff about it.
The iPod audio processors encapsulate the line/headphone amplification stage on chip, so very few tweaking can be done there, just directly cabling the chip line outputs to unused interface pins and building a dock with better caps and resistors on line outputs. In any case discrete improvement.
After that I discovered Wadia and Onkyo devices (this last one tempted me) and I'm quite sure that they are based on a iPod file transfer and on-device playing process, just similar that playing a song from a computer with an attached iPod using iTunes (assuming that the song is stored in the iPod, of course).
I think that the price difference is mainly due to the fact that Wadia was the first manufacturer building a device like this. Onkyo guys know how to beat Wadia: lowering the price.
I would recommend to those interested on this kind of solution (playing digitally encoded music) what I think is the best: the Logitech Squeezebox Duet. The concept is NOT the same that the Wadia and Onkyo device, but it allows you play digitally encoded music with hi-fi quality in, IMHO, a much flexible way than the Wadias and Onkyos. IN ANY CASE I don't want to state that Squeezebox is better than Wadias and Onkyos, it's just similar concept with, in my opinion, more possibilites and flexibility.
Finally if you're interested in getting more info about iPod digital processors, the Wolfson site stores all datasheets you need. Ops, the iPod 5G, which is not included on the above table, is based on the WM8971 Wolfson codec.
Regards.
Some time ago I spent some time trying to learn how to improve the output sound quality of the iPod, so I read some stuff about it.
The iPod audio processors encapsulate the line/headphone amplification stage on chip, so very few tweaking can be done there, just directly cabling the chip line outputs to unused interface pins and building a dock with better caps and resistors on line outputs. In any case discrete improvement.
After that I discovered Wadia and Onkyo devices (this last one tempted me) and I'm quite sure that they are based on a iPod file transfer and on-device playing process, just similar that playing a song from a computer with an attached iPod using iTunes (assuming that the song is stored in the iPod, of course).
I think that the price difference is mainly due to the fact that Wadia was the first manufacturer building a device like this. Onkyo guys know how to beat Wadia: lowering the price.
I would recommend to those interested on this kind of solution (playing digitally encoded music) what I think is the best: the Logitech Squeezebox Duet. The concept is NOT the same that the Wadia and Onkyo device, but it allows you play digitally encoded music with hi-fi quality in, IMHO, a much flexible way than the Wadias and Onkyos. IN ANY CASE I don't want to state that Squeezebox is better than Wadias and Onkyos, it's just similar concept with, in my opinion, more possibilites and flexibility.
Finally if you're interested in getting more info about iPod digital processors, the Wolfson site stores all datasheets you need. Ops, the iPod 5G, which is not included on the above table, is based on the WM8971 Wolfson codec.
Regards.
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Fully agree with wwence. By the photos I can't find another DAC, so I suspect device is using the pcm2704 for line output. In this case, and for getting optimum performance, this device should be considered as just a transport, not a source.
I am also very interested.
Regarding dormant pins see http://www.diyaudio.com/forums/digi...-i2s-signal-digital-output-2.html#post2087355
I am also very curious as to whether getting digital out via USB is only a matter of the right resistor (put a pot on it and start turning ).
Coupled with a GRUBdac might be a nice lowcost approach?
Any updates on the onkyo schematic or resistance on the pins of the connector?
Regarding dormant pins see http://www.diyaudio.com/forums/digi...-i2s-signal-digital-output-2.html#post2087355
I am also very curious as to whether getting digital out via USB is only a matter of the right resistor (put a pot on it and start turning
).Coupled with a GRUBdac might be a nice lowcost approach?
Any updates on the onkyo schematic or resistance on the pins of the connector?
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