I have a SONY CDP-750, which has CXD1125 as RF, CXD1088 AS DF, and TDA1541 as DAC. I have modded it into the non-oversampling mode. It works. But the output level (both phone and RCA jack). Any suggeston?
BTW, such modding is also works with CDP-207es, CDP-950, CDP-333esd. if you want the modding, I will tell you.
BTW, such modding is also works with CDP-207es, CDP-950, CDP-333esd. if you want the modding, I will tell you.
I recently bypassed DF in CDP102, 502ES and 502ESII, very easy and no problem, muting still works..
The operation was a success but the patient died.
Did you bypass the CXD1088 by simply connecting the output of the CXD1125 to the input of the TDA1541 ?
Did you bypass the CXD1088 by simply connecting the output of the CXD1125 to the input of the TDA1541 ?
Re: The operation was a success but the patient died.
NO. The out lines of CXD1125 to CXD1088 were cut, CXD1088 to TDA1541 too.
To put CXD1125 into 1FS mode (non-oversampling), the pin 56 was set to low, and 57 to high.
rfbrw said:
NO. The out lines of CXD1125 to CXD1088 were cut, CXD1088 to TDA1541 too.
To put CXD1125 into 1FS mode (non-oversampling), the pin 56 was set to low, and 57 to high.
In short the CXD1125 is connected directly to the TDA1541. This is not good.Not good at all.
The input to the CXD1088 is in the Sony format. Fixed 24 bits per channel per L/R frame with LSB justified data. LRCLK is high for the left channel, low for the right.
The TDA1541 is in the I2S format. Minimum of 16bits per channel
per L/R frame with data MSB justified to the second bitcell after a transition of LRCLK. LRCLK is low for left channel and high for the right.
In effect you are turning the sign bit and the 8 MSB's into the 9 LSB's effectively leaving you with 9bit data. To make matters worse the the sign bits are now always low meaning you have halved your signal. A low output sounds about right.
To correct this you need to invert LRCLK and delay it by 7 bits.
One more thing. You say you have put the CXD1125 into 1Fs mode suggesting it was previously oversampling. In that case, what was the CXD1088 doing?
The input to the CXD1088 is in the Sony format. Fixed 24 bits per channel per L/R frame with LSB justified data. LRCLK is high for the left channel, low for the right.
The TDA1541 is in the I2S format. Minimum of 16bits per channel
per L/R frame with data MSB justified to the second bitcell after a transition of LRCLK. LRCLK is low for left channel and high for the right.
In effect you are turning the sign bit and the 8 MSB's into the 9 LSB's effectively leaving you with 9bit data. To make matters worse the the sign bits are now always low meaning you have halved your signal. A low output sounds about right.
To correct this you need to invert LRCLK and delay it by 7 bits.
One more thing. You say you have put the CXD1125 into 1Fs mode suggesting it was previously oversampling. In that case, what was the CXD1088 doing?
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I can't read this place any longer.................ciao, y'all.
Call me when all the NOSsers fall off the edge of the world.
Jcoko
Call me when all the NOSsers fall off the edge of the world.
Jcoko
rfbrw said:
Thanks rfbrw. I can answer your question.
The CXD1125 outputs 2FS signal to CDX1088, and CXD1088 outputs 4FS. CXD1088 also does digital filtering.
CXD1125, pin 56 "H", 57 "L", 2FS;
pin 56 "L", 57 "H", 1FS.
(CXD1135 too!)
1125 can precisely allow 2FS, to not use int DF ?
Then it is possible to make 2õ DAC, similar
http://www.tnt-audio.com/clinica/convertusdecdig_e.html
and to refuse from SP-dif
Then it is possible to make 2õ DAC, similar
http://www.tnt-audio.com/clinica/convertusdecdig_e.html
and to refuse from SP-dif
Hi GYCAO ,
To move to non-OS , I am looking into the CXD1125 working, have only a Japanese datasheet, but I see that pins 56 and 57 are non-descriptive (55=MD1, 56=MD2, 57=MD3).
BUT, I have found a clue:
79 = DCK and it mentions DF in 176 or 88 kHz
80 = LRCK and it mentions DF in 88 or 44 kHz
So definitely there is some upsampling capability in the CXD1125!
Question 1: to GYCAO : Can I have a 88 Khz output into the DAC chip PCM56 (semi)directly? (I am following up Bernard's suggestions, involves inserting an inverter in the LRCK to connect the L channel LE). My player has as second stage a CXD2551 upsampler/DF that I'll take out of the loop.
Why: if there is a double sample rate, the first 'reflections' will not start at 25 kHz but at a higher frequency, if I understood discussions from a few years back. So this has an advantage as long as we do not have the digital filter.
Question 2: Does a double oversampled stream need another passive filter after or part of the I/V?.
albert
There is no output at 88 kHz without creating interpolated samples and that would be a 2x DF which also would need an analog filter.
Sure you didn't disturb any SMD parts along the way? I did that messing with a Marantz TDA1541 player and had a reduced sound level on one channel.
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