Hi, I have upgraded Denon DVD-A1 (8x pcm1704 , Alpha 24 procesosor, spdi freceiver input) a Mark levinson no360s analog IV stage is built in.
sound is much worse than Mark Levinon No360s DAC using same dac chips and same DAC IV I thought it was power suply (no360s uses discrete) so I put complete no360s DAC/IV boards to DVD-A1. to my surpise is still sounded much worse than No360s. now it was only the digital front end diferencies.
I looked deeper in the schematics of DVD-A1 and see that I2s doesn’t go from DIR to AL24 chip. instead of that it goes trought few DSP chips –DVD processor chip ES6038, and ADSPMEL322. so I connected i2s lines from DIR directly to AL24 chip and bingo- good sound at last.
I make micro small swithches near rj45 jack (denon link jack whch is perfectf or i2s input which I will add, remooved two chips to have this jack free from any conections)
now is problem with comutation. I do not want loose cd-dvd source. dvd-a1 have 3 source selector switch- DVD/Optical/Spdif I need this- WHEN DVD position is set relays are eneergized and i2s line ir connected ( or maybe is more elegant decisions) I am not familiar with micrcontrolers. How to get signal from it to relays to be energized when dvd rotaty position is set? thanks in advance.
sound is much worse than Mark Levinon No360s DAC using same dac chips and same DAC IV I thought it was power suply (no360s uses discrete) so I put complete no360s DAC/IV boards to DVD-A1. to my surpise is still sounded much worse than No360s. now it was only the digital front end diferencies.
I looked deeper in the schematics of DVD-A1 and see that I2s doesn’t go from DIR to AL24 chip. instead of that it goes trought few DSP chips –DVD processor chip ES6038, and ADSPMEL322. so I connected i2s lines from DIR directly to AL24 chip and bingo- good sound at last.
I make micro small swithches near rj45 jack (denon link jack whch is perfectf or i2s input which I will add, remooved two chips to have this jack free from any conections)
now is problem with comutation. I do not want loose cd-dvd source. dvd-a1 have 3 source selector switch- DVD/Optical/Spdif I need this- WHEN DVD position is set relays are eneergized and i2s line ir connected ( or maybe is more elegant decisions) I am not familiar with micrcontrolers. How to get signal from it to relays to be energized when dvd rotaty position is set? thanks in advance.
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If the lines you want to switch are I2S bus, its usually done with logic chips such as those used in the following devices: https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2380057.m570.l1313&_nkw=I2S+switch&_sacat=0
Basically, the chips themselves are like those found at: https://www.ti.com/logic-voltage-tr...s/digital-multiplexers-encoders/products.html
You need a mux function that is compatible with the logic families used in your equipment.
The logic chips can be driven/controlled by microcontroller I/O pins or maybe through something like an I2C bus expander chip that can provide some extra I/O pins.
e.g. https://www.ti.com/interface/i2c/general-purpose-ios-gpios/products.html
https://www.ti.com/lit/ds/symlink/pcf8574.pdf
Also, if you want to drive actual relays, you can use relay driver chips and or discrete transistors that are controlled/driven by microcontroller I/O pins.
One thing to consider when switching I2S signals is that jitter can be introduced if proper care is not taken. In some cases reclocking may be used to de-jitter I2S signals.
Not sure if that helps?
Basically, the chips themselves are like those found at: https://www.ti.com/logic-voltage-tr...s/digital-multiplexers-encoders/products.html
You need a mux function that is compatible with the logic families used in your equipment.
The logic chips can be driven/controlled by microcontroller I/O pins or maybe through something like an I2C bus expander chip that can provide some extra I/O pins.
e.g. https://www.ti.com/interface/i2c/general-purpose-ios-gpios/products.html
https://www.ti.com/lit/ds/symlink/pcf8574.pdf
Also, if you want to drive actual relays, you can use relay driver chips and or discrete transistors that are controlled/driven by microcontroller I/O pins.
One thing to consider when switching I2S signals is that jitter can be introduced if proper care is not taken. In some cases reclocking may be used to de-jitter I2S signals.
Not sure if that helps?
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Thanks Mark,really helpful. During waiting time I have redesigned my comutation to more elegant and simple "raw" way. I will use another 3 way turn button (which turn of screen and some power suplies which is not revelant for me, now it will be real pure direct as will bypass all dsp chips 
)
I will wire +12V suply at this switch and simply redistribute it to relay 1 or relay 2 or both is disabled. I find very small 12v relays (from datashhet its seems normal not solid staterelays) for this purpose -
https://www.elpro.org/gb/goodsky-st-series/30170-st-sh-112l.html
- operation time 5mS maximum
- operating frequency 30Hz
DIMENSIONS:
length 12.6 mm
width 7.8 mm
height 10 mm
now questions is how to implement this -
1)are using smallest relay is best or better use bigger (mabe less interference with coil?)
2) better use 5V or 12V?
2) I can simply feed them via LM7812 (do not limit any current?) just ON/OFF suply of voltage ?
3) beter disconect GND or 12V on relay when not working?
there is 74HCU04AF just before alpha 24 filter processinng chip.
) I will wire +12V suply at this switch and simply redistribute it to relay 1 or relay 2 or both is disabled. I find very small 12v relays (from datashhet its seems normal not solid staterelays) for this purpose -
https://www.elpro.org/gb/goodsky-st-series/30170-st-sh-112l.html
- operation time 5mS maximum
- operating frequency 30Hz
DIMENSIONS:
length 12.6 mm
width 7.8 mm
height 10 mm
now questions is how to implement this -
1)are using smallest relay is best or better use bigger (mabe less interference with coil?)
2) better use 5V or 12V?
2) I can simply feed them via LM7812 (do not limit any current?) just ON/OFF suply of voltage ?
3) beter disconect GND or 12V on relay when not working?
there is 74HCU04AF just before alpha 24 filter processinng chip.
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The relays you linked to have a minimum switching current of 2mA. Sometimes the contacts in a relay don't conduct well until enough current is run through them after the contacts are closed. If you want to use relays maybe consider Panasonic or Omron low-signal miniature relays with gold and or palladium contacts. Maybe something like this: https://www.mouser.com/datasheet/2/315/Panasonic_03172022_TX_Relays-2934354.pdf
For 12v relays you could use an integrated driver chip such as NUD3160: https://www.onsemi.com/pdf/datasheet/nud3160-d.pdf
For lower coil voltages maybe a transistor and some associated components would offer less voltage drop.
For 12v relays you could use an integrated driver chip such as NUD3160: https://www.onsemi.com/pdf/datasheet/nud3160-d.pdf
For lower coil voltages maybe a transistor and some associated components would offer less voltage drop.
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Thanks Mark, I will look in to these (but i have ordered that small ones) I would like to avoid relays drivers, so to be sure - technicaly speaking nothing prevents from runing relays with "raw" 12v suply diceonecting and conecting them by open /close circuit. I used that way in my car without any issues.
there is no PMD100 inside. digital filtering is done via AL24 PLus(capable of 192khz) and HDCD decoding done with DSP, I believe(unless al24Plus have integrated HDCD decoder)
but i have DVD-5000 which is similar a it older machine and have selectable PMD100/ AL24 filter HDCD materials goes trougth PMD100 and the rest via AL24. it was easy task to comapre it when fed via usb-spdif playing HDCD file( I have HDCD decoder plugin in foobar 2000): as soon as I decreaeed digital volume from 100% to 99% its switched from PMD100 to AL24 ( HDCD led goes off, Al24 led goes in and relay adjusnting HDCD/non HDCD levels clicks)
so in real time adjunsting swound from 100 to 99% it is posible AB testing.I have found AL24 superior to PMD100. after AL24 PMD 100 sounds rounded, mellow,lumpy and without real sharp edged resolution.
Main reason why I started this I2s swithing is that DVD-A1 are capable of 24 bit 192khz (internal DVD-audio CD) and 24bit 96khz external ( even spdif receiver are capable of 192khz) when using external spdif only 44 and 48khz works, as soon as I switched to 88khz or 96khz sreens shows locked to frequency output relays clicks and very loud white noise with some excerps of music apears. i have tested many usb/spdif converters , usb wires- nothing helped. it seems there is some internal failure of selecting clocks or firmaware upgrade needed (which is impossibel to get after 20 years) so I put straight i2s Righ justified to Al24 PLus and it worked like a charm with 32khz/44.1khz, 48khz,88.2khz, 96khz and 192kHz.
DVD-5000 was impressive build unit (19kg, 4xpcm1704, AL24, PMD100) but very medciore performance) after upgrade (see pics it realy changed)
DVD-A1(also 19kg, 8x pcm1704, Al25 plus) was better sounding as stock but there is hughe performance wall between those units and Mark Levinson and Wadia units I have, considerng they are same build quality (Denons are build even nicer than Wadia)
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D'oh. I've read too many data-sheets and, as you deduced, confused the 9000 and the 5000. That's a nice looking output stage on the 5000. Is that a current-mirror-fed diamond buffer on the output of the I/V?
I run 16 relays off a 5VDC rail in a line-level stereo attenuator, no problem with electrical noise/interference when switching the coils from the "B+" and still operational after ten-plus years. Your circuit appears to be carrying a control signal, so I'd think any conveniently-interfaced relay would work, providing it doesn't load the line too much. The data sheet will give you a coil-resistance, which will give you the relay's current draw, which should be enough to actuate the relay at its rated voltage. Apologies in advance if this a simplistic answer.
I run 16 relays off a 5VDC rail in a line-level stereo attenuator, no problem with electrical noise/interference when switching the coils from the "B+" and still operational after ten-plus years. Your circuit appears to be carrying a control signal, so I'd think any conveniently-interfaced relay would work, providing it doesn't load the line too much. The data sheet will give you a coil-resistance, which will give you the relay's current draw, which should be enough to actuate the relay at its rated voltage. Apologies in advance if this a simplistic answer.
