I have a stupid question and I have searched both here and the other place.
If I want to use the PMD100 with I2S inputs, the datasheet says I should use a D Flipflop preceeded by an inverter (Fig.3). But someone at the other placed said that the D Flipflop in the datasheet was supposed to be falling edge triggered (though I do not see the inverting circle at the clk of the flipflop), and hence he used a 74xx74 for the flilflop, but without the inverter.
Quote :
"Found the problem, WS is inverted, but not delayed. When i copied the AN on the I2S adaptiation i did not pay enough attention to it. The used FF is rising edge (GAL), but the drawn FF must be falling edge ...."
I am confused -- the datasheet is incorrect ?
Thx,
Patrick
If I want to use the PMD100 with I2S inputs, the datasheet says I should use a D Flipflop preceeded by an inverter (Fig.3). But someone at the other placed said that the D Flipflop in the datasheet was supposed to be falling edge triggered (though I do not see the inverting circle at the clk of the flipflop), and hence he used a 74xx74 for the flilflop, but without the inverter.
Quote :
"Found the problem, WS is inverted, but not delayed. When i copied the AN on the I2S adaptiation i did not pay enough attention to it. The used FF is rising edge (GAL), but the drawn FF must be falling edge ...."
I am confused -- the datasheet is incorrect ?
Thx,
Patrick
"Gain and Scale" PMD100 datasheet No.14 page
Hi! HDCD reserchers,
Now I am using PCM1704 DAC and ES9008S DAC with no digital attenuation. Because I want use fullscale of D/A converter, I don't like digital attenuator.
In case of PMD100, if we choice -6dB attenuation with digital domain, this is unpleasant, usualy we diyers choice analog gainscaling. We don't use digital gain scaling.
But please see "Gain and Scale infomation" on PMD100 datasheet No.14 page.
http://www.teddigital.com/PMD100.pdf
PMI said.... " PMD100 set attenuation 1dB for protect overshoot. "
How do you think about this "-1dB attenuation".
Hi! HDCD reserchers,
Now I am using PCM1704 DAC and ES9008S DAC with no digital attenuation. Because I want use fullscale of D/A converter, I don't like digital attenuator.
In case of PMD100, if we choice -6dB attenuation with digital domain, this is unpleasant, usualy we diyers choice analog gainscaling. We don't use digital gain scaling.
But please see "Gain and Scale infomation" on PMD100 datasheet No.14 page.
http://www.teddigital.com/PMD100.pdf
PMI said.... " PMD100 set attenuation 1dB for protect overshoot. "
How do you think about this "-1dB attenuation".
Switching off HDCD processing
You guys are well versed in the HDCD chip, I have a question I have a Classe CDP10 which has the HDCD PDM200 chip in it I also have the the circuit diagram for it, would it be possiible maybe with a switch on the back to be able to switch off the HDCD processing on the fly and have standard Red Book even while playing a HDCD CD? the reason for this is to show a/b comparisons between Red Book and HDCD at our Audio meetings using the same disc. It uses the CS8420 and two PCM1738's
Cheers George
You guys are well versed in the HDCD chip, I have a question I have a Classe CDP10 which has the HDCD PDM200 chip in it I also have the the circuit diagram for it, would it be possiible maybe with a switch on the back to be able to switch off the HDCD processing on the fly and have standard Red Book even while playing a HDCD CD? the reason for this is to show a/b comparisons between Red Book and HDCD at our Audio meetings using the same disc. It uses the CS8420 and two PCM1738's
Cheers George
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Hi George
I don't think it would be real easy to do. I don't know that much about the Classe CDP.
It could be done with a programmable logic chip. If you really wanted to, you could intercept the LRCK, Data and bit clock before it gets to the HDCD chip. Manipulate the LSB, bit 16, of every sample by inverting it or generating random dither. That would destroy the HDCD code.
Another real problem with that is it would affect the volume because the output of the digital filter is affected by the presence or not of HDCD code. It would make it hard to do a true A-B test. Volume immediately affects the perception in an A-B test, and it's important to match volumes when doing an A-B test.
I don't think it would be real easy to do. I don't know that much about the Classe CDP.
It could be done with a programmable logic chip. If you really wanted to, you could intercept the LRCK, Data and bit clock before it gets to the HDCD chip. Manipulate the LSB, bit 16, of every sample by inverting it or generating random dither. That would destroy the HDCD code.
Another real problem with that is it would affect the volume because the output of the digital filter is affected by the presence or not of HDCD code. It would make it hard to do a true A-B test. Volume immediately affects the perception in an A-B test, and it's important to match volumes when doing an A-B test.
That is some very good speculation. In my decoder project I have designed in the switch to turn off the scale feature, which violates the license that HDCD made the manufacturers sign.
I have come to the conclusion that it is not necessary at all to have the scale on. That observation could possibly be construed as supporting that cynical rumour, Sy
I have come to the conclusion that it is not necessary at all to have the scale on. That observation could possibly be construed as supporting that cynical rumour, Sy
Another thought!!!
I take it your HDCD box goes between transport and dac?
Rossl I have another CD transport +dac a Wadia WT2000S transport that has AT&T out and SPIDF out. the Wadia X64.4 dac has 2 x AT&T in and 2 x SPIDF in all switchable. If your HDCD box was on one of the SPIDF and the AT&T was connected straight from transport to dac then I could switch between the two.
Would the benifits of HDCD with your box go through the Wadia dac unimpeded or would the Wadia dac make it back into Red Book again.
As you can tell I know nothing of how HDCD works or what part of the digital chain it can be taped into.
Cheers George
I take it your HDCD box goes between transport and dac?
Rossl I have another CD transport +dac a Wadia WT2000S transport that has AT&T out and SPIDF out. the Wadia X64.4 dac has 2 x AT&T in and 2 x SPIDF in all switchable. If your HDCD box was on one of the SPIDF and the AT&T was connected straight from transport to dac then I could switch between the two.
Would the benifits of HDCD with your box go through the Wadia dac unimpeded or would the Wadia dac make it back into Red Book again.
As you can tell I know nothing of how HDCD works or what part of the digital chain it can be taped into.
Cheers George
HDCD and fs converter in CS8420
Hi! georgehifi, I'm nagaesan of Japanese HDCD fan.
I thought about various methods to jump by an HDCD function.
If CS8420(with fs-conv) and PCM1738, you are always jump HDCD function.
Because when music data pass threw CS8420's inside fs-converter circuit, it will disappear HDCD hidden-code.
So, if you would like to use PCM1738's HDCD function,please choice CS8416 or 8414.
When you playback "Red Book" and "HDCD" S/PDIF signal, the data of decorded by digital signal interface IC itself is the same but if HDCD equipments do not detect HDCD hidden code when reciving "Red Book" S/PDIF signal, the reproduction volume level of this HDCD equipment must set -6dB by a HDCD standard book.
Many HDCD models are attenuated with digital domain(My TPC's DAC1.5), but sometimes using analog attenuater(the one is Madrigal's DAC unit).
I think you would like to not using these attenuater, because you want using full-scale of DAC-IC when playback "Red Book" S/PDIF data. But analog attenuated models are no problem.
And if you 'd like to use with digital domain, please set pull-UP "gain-scaling pin"
My DAC1.5 HDCD DAC unit has gain-scaling pin switch.
Note!
Many people bring it into question this "-6dB digital ATT", but please learn PMD200 is always working "-1dB digital ATT" It is used so that square wave does not clip it.
Hi! georgehifi, I'm nagaesan of Japanese HDCD fan.
I thought about various methods to jump by an HDCD function.
If CS8420(with fs-conv) and PCM1738, you are always jump HDCD function.
Because when music data pass threw CS8420's inside fs-converter circuit, it will disappear HDCD hidden-code.
So, if you would like to use PCM1738's HDCD function,please choice CS8416 or 8414.
When you playback "Red Book" and "HDCD" S/PDIF signal, the data of decorded by digital signal interface IC itself is the same but if HDCD equipments do not detect HDCD hidden code when reciving "Red Book" S/PDIF signal, the reproduction volume level of this HDCD equipment must set -6dB by a HDCD standard book.
Many HDCD models are attenuated with digital domain(My TPC's DAC1.5), but sometimes using analog attenuater(the one is Madrigal's DAC unit).
I think you would like to not using these attenuater, because you want using full-scale of DAC-IC when playback "Red Book" S/PDIF data. But analog attenuated models are no problem.
And if you 'd like to use with digital domain, please set pull-UP "gain-scaling pin"
My DAC1.5 HDCD DAC unit has gain-scaling pin switch.
Note!
Many people bring it into question this "-6dB digital ATT", but please learn PMD200 is always working "-1dB digital ATT" It is used so that square wave does not clip it.
Absolutely.
Yes. From your description, with your Wadias, you could set up a system with transport -> DAC with one connection and switchable to another connection of transport -> HDCD box -> DAC
It would be cool test. It would still be necessary to adjust the volume with every switch.
My HDCD box converts all CDs to 88K, 24 bit, and unless the Wadia DAC can't receive 88K-24 bit, it would be an excellent test setup.
HDCD decoded to 88-24 will never "go back" to redbook
A Redbook CD converted to 88-24 by the PMD doesn't offer much over sending 44-16 to the DAC. It won't make much difference to a hi-end DAC.
Shame I don't think it can do 88K, I have a feeling the Wadia only does 64.4 re last sentence in the attachment.
On the front panel it has 3 lock lights 32, 44.1 & 48
The Wadia transport locks the 44.1 light when wired with the AT&T glass link or the SPIDF coax.
Cheers George
On the front panel it has 3 lock lights 32, 44.1 & 48
The Wadia transport locks the 44.1 light when wired with the AT&T glass link or the SPIDF coax.
Cheers George
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Hi Ross
Whether you can play 4 wave files and record output from your HDCD decoder?
(link to files: dir )
play/record: S/PDIF-out on PC -> HDCD decoder -> S/PDIF-in on PC
It is possible to play to S/PDIF-out without any change by AC3Filter or Spdifer (see AC3Filter.net )
decoding: 44.1kHz/16bit -> 88,2kHz/24bit
Please, pack resulting files to flac and share them
Thnx
Vick
p.s. sorry for my poor english
Whether you can play 4 wave files and record output from your HDCD decoder?
(link to files: dir )
play/record: S/PDIF-out on PC -> HDCD decoder -> S/PDIF-in on PC
It is possible to play to S/PDIF-out without any change by AC3Filter or Spdifer (see AC3Filter.net )
decoding: 44.1kHz/16bit -> 88,2kHz/24bit
Please, pack resulting files to flac and share them
Thnx
Vick
p.s. sorry for my poor english
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