Hello all! I realize this is a huge ask and will require some time to help me as I'm not well versed in the digital realm. If you can help. But, Are only interested in helping for a fee. Contact me and maybe we can work out some compensation for your time!
I have a car audio head unit and DSP. It's a rare F#1 model by Alpine. They work as a pair with proprietary connections. The head unit connects with the DSP via "ion bus" and IEEE 1394. It was a very expensive combo in it's day. It has 8 PCM1704U-K DACs.
CD PCM is transmitted via Ionbus. DVD Audio is transmitted via IEEE 1394/Firewire. It does have an analog input.
I would like to repurpose this for my home system. I need to add a SPDIF. I would also like to replace the analog input with a E1DA Cosmos ADC for my Phono input.
I would also like to upgrade the clocks and anything else you can recommend to improve the sound quality. Perhaps changing the I/V stage in the output circuits. I've seen a few people here liking the sound of (IIRC) AD797 NNFB with the PCM1704. I have 2 of the DSPs kicking around. So, I can afford the time to upgrade the audio circuitry over some time.
I'm wondering if the best route for the spdif input would be to disable the internal ADC and insert the spdif signal. Digital listening is my priority and I would think interfacing that signal directly into the DSP itself would provide the best sound quality as the Ionbus cable is probably 20ft long and I would think the PCM signal in the head unit is converted to Ionbus and then back to PCM in the DSP.
I'm wondering if I can use a higher sample rate if I interface with the DVD-A section (IEEE 1394). Or, If there's any way to confirm that I could simply use a firewire interface for the
If I remove the disc transport (It's having trouble loading anyways). I can place the E1DA ADC inside the radio. So, That would be my preferred route to take.
My experience is mostly with amplifiers. So, My knowledge of digital signals is almost 0.
Wish list summary:
#1- Digital SPDIF Input (Preferrably in the DSP. But, The head unit also appears to have 2 SPDIF. 1 from the tuner and 1 from the transport. Maybe this is the easiest?)
#2- Interface With External ADC (ED1A Cosmos. It appears to have I2S/I2C and SPDIF output)
#3- Clock Upgrades (Both the head unit and the DSP seem to have multiple clocks. Which should I upgrade? And is it as simple as replacing them with an OCXO clock of the same frequency?)
#4- Output Section Upgrades.
#5- Possible Use Of Existing Firewire Port
I will attach a few pages of the different schematics with descriptions below. I really appreciate the help!
Edit. I'm uploading the files in PDF format. I tried to convert them (via Adobe) to images for ease of viewing. But, They don't have enough resolution to zoom in. If someone can recommend a converter that retains full resolution to make the images more convenient to view for the forum members. Please let me know!
I have a car audio head unit and DSP. It's a rare F#1 model by Alpine. They work as a pair with proprietary connections. The head unit connects with the DSP via "ion bus" and IEEE 1394. It was a very expensive combo in it's day. It has 8 PCM1704U-K DACs.
CD PCM is transmitted via Ionbus. DVD Audio is transmitted via IEEE 1394/Firewire. It does have an analog input.
I would like to repurpose this for my home system. I need to add a SPDIF. I would also like to replace the analog input with a E1DA Cosmos ADC for my Phono input.
I would also like to upgrade the clocks and anything else you can recommend to improve the sound quality. Perhaps changing the I/V stage in the output circuits. I've seen a few people here liking the sound of (IIRC) AD797 NNFB with the PCM1704. I have 2 of the DSPs kicking around. So, I can afford the time to upgrade the audio circuitry over some time.
I'm wondering if the best route for the spdif input would be to disable the internal ADC and insert the spdif signal. Digital listening is my priority and I would think interfacing that signal directly into the DSP itself would provide the best sound quality as the Ionbus cable is probably 20ft long and I would think the PCM signal in the head unit is converted to Ionbus and then back to PCM in the DSP.
I'm wondering if I can use a higher sample rate if I interface with the DVD-A section (IEEE 1394). Or, If there's any way to confirm that I could simply use a firewire interface for the
If I remove the disc transport (It's having trouble loading anyways). I can place the E1DA ADC inside the radio. So, That would be my preferred route to take.
My experience is mostly with amplifiers. So, My knowledge of digital signals is almost 0.
Wish list summary:
#1- Digital SPDIF Input (Preferrably in the DSP. But, The head unit also appears to have 2 SPDIF. 1 from the tuner and 1 from the transport. Maybe this is the easiest?)
#2- Interface With External ADC (ED1A Cosmos. It appears to have I2S/I2C and SPDIF output)
#3- Clock Upgrades (Both the head unit and the DSP seem to have multiple clocks. Which should I upgrade? And is it as simple as replacing them with an OCXO clock of the same frequency?)
#4- Output Section Upgrades.
#5- Possible Use Of Existing Firewire Port
I will attach a few pages of the different schematics with descriptions below. I really appreciate the help!
Edit. I'm uploading the files in PDF format. I tried to convert them (via Adobe) to images for ease of viewing. But, They don't have enough resolution to zoom in. If someone can recommend a converter that retains full resolution to make the images more convenient to view for the forum members. Please let me know!
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Here is the ADC section of the DSP.
Can I simply disable the PCM1802 and connect a spdif (or possibly a USB audio) interface to the MCK,LRCK,BCK,Data? If so. What kind of interface do I need?
Can I simply disable the PCM1802 and connect a spdif (or possibly a USB audio) interface to the MCK,LRCK,BCK,Data? If so. What kind of interface do I need?
Here is the main decoder section of the DSP. It has a SPDIF input and MCK,LRCK etc input and output. Could I possibly interface directly with this to bypass all of the endless clocks and clock buffers from all the other sources and input boards? Is this I2S or I2C?
Here is a block diagram of the DSP. I am not using any of the multichannel inputs. I'm wondering if I'd get a cleaner digital signal by bypassing all of the switching and multichannel interfaces.
Here is the PCM1704U-K output section. Wondering if its worth changing the I/V to a NNFB AD797 or something different. Or, Should I just upgrade the current circuit with low ppm resistors and PP/Mica caps?
This is the firewire section of the DSP. I'm wondering if I can use a usb firewire interface to connect to it. Or, If I can interface the SPDIF with it. As I'm assuming it's capable of a much higher bitrate than the PCM section. (24bit/192k)
Here is the digital interface inside the head unit.
It appears IC703 is the digital source switcher. Can I possibly just send the Spdif from the Cosmos ADC directly to this? Or, Will I get a much better signal by using I2S/I2C?
It appears IC703 is the digital source switcher. Can I possibly just send the Spdif from the Cosmos ADC directly to this? Or, Will I get a much better signal by using I2S/I2C?
Here is the decoder inside the head unit.
It appears to have Spdif input as well as LRCK,BCK,Audio Data.
I also see a clock here. Should I update this clock?
It appears to have Spdif input as well as LRCK,BCK,Audio Data.
I also see a clock here. Should I update this clock?
If anyone would like copies of the complete service manuals for the DVI-9990 and PXI-H990. I can send them. They are too large to upload here.
Also. Does anyone have any resources to learn more about I2S/I2C/SPDIF etc?
Thank you!
Also. Does anyone have any resources to learn more about I2S/I2C/SPDIF etc?
Thank you!
Looking at those schematics and done a quick read up
https://www.caraudionow.com/alpine-status-f1-hi-res-stereo-explained/
(1) The clocks on the system are integrated to a master clock to reduce jitter. I don't know what you'd gain.
(2) The head unit controller runs fimware ( or at least some logic ). Even if you were able to hack into the SPDIF... how would you select it or configure the system to process it?
(3) Is the system voiced to the speakers and car? How would it sound with other speakers in a different environment?
I believe this to be an All In One System.
https://www.caraudionow.com/alpine-status-f1-hi-res-stereo-explained/
(1) The clocks on the system are integrated to a master clock to reduce jitter. I don't know what you'd gain.
(2) The head unit controller runs fimware ( or at least some logic ). Even if you were able to hack into the SPDIF... how would you select it or configure the system to process it?
(3) Is the system voiced to the speakers and car? How would it sound with other speakers in a different environment?
I believe this to be an All In One System.
If it would be difficult to hack completely. I could leave a cd in the transport in and simply replace the spdif output from the transport?
It does have the analog input in the DSP. I could disable the PCM1802 and interface with those digital signals could I not? Then, All source switching and functionality would be retained?
I've seen a few people over the years replace the analog input with a digital input. Unfortunately I can't track down the people that did the work!
Also. Thanks for finding the explanation. I haven't come across this information before! This is the new F#1 system. Mine is the previous generation from 04/05(ish).
It does have the analog input in the DSP. I could disable the PCM1802 and interface with those digital signals could I not? Then, All source switching and functionality would be retained?
I've seen a few people over the years replace the analog input with a digital input. Unfortunately I can't track down the people that did the work!
Also. Thanks for finding the explanation. I haven't come across this information before! This is the new F#1 system. Mine is the previous generation from 04/05(ish).
Might be easier to start with it the way it is... plug your phono preamp into the analog input and move from there.
Otherwise if you want to convert the analog to S/PDIF it sounds like your digitizing the analog signal twice... once in the external ADC and whatever else is being done internally.
Anyhow, looking at the schematics I see a lot of integration into large scale integrated silicon (ASIC). The schematics are not sufficient to understand what it's doing.
Otherwise if you want to convert the analog to S/PDIF it sounds like your digitizing the analog signal twice... once in the external ADC and whatever else is being done internally.
Anyhow, looking at the schematics I see a lot of integration into large scale integrated silicon (ASIC). The schematics are not sufficient to understand what it's doing.
I need a digital input. The transport is failing and I primarily listen to digital via streaming. I could use an external DAC. But, It seems redundant and wasteful of such a well designed DSP with 24bit/192khz to go from an external DAC to an old *** ADC that was just meant as an AUX input.
Is the MCK,LRCK,BCK,Data from the PCM1802 chip not all I need to interface with? I know it's possible. As others have done it? Would I not only need a SPDIF to I2S adapter? I was told that's what the others used.
Or, Could I not just send the external spdif signal into the output of the transport? and replace the existing analog input ADC with the I2S signal from the E1DA ADC?
I have the complete schematics for both units if that helps. I just can't upload them
Is the MCK,LRCK,BCK,Data from the PCM1802 chip not all I need to interface with? I know it's possible. As others have done it? Would I not only need a SPDIF to I2S adapter? I was told that's what the others used.
Or, Could I not just send the external spdif signal into the output of the transport? and replace the existing analog input ADC with the I2S signal from the E1DA ADC?
I have the complete schematics for both units if that helps. I just can't upload them
Sorry, I can't help. I do firmware. When I look at those schematics, my first reaction is to look for the Programmer's Manual.
I've programmed multimedia, S/PDIF included, but always with a Programmer's Manual.
Good luck.
I've programmed multimedia, S/PDIF included, but always with a Programmer's Manual.
Good luck.