Although not conventional, I will be ripping all my CDs to a PC hard disk and using lossless compression (the audiophile virtues of this approach for digital deserves a fresh thread...). It will be easy to upsample to 88.2Khz using this approach.
More conventionally, I would imagine a DSP or even a PIC type device (frequencies are low, a simple interpolation algorithm can be used) between the i2s and the DAC should work (I need to read up more about the i2s spec to understand this further).
I'm wondering if the difference between a non-os DAC and one that uses the approach I suggested above will break the "magic" that non-os brings.
Regards,
Dean
More conventionally, I would imagine a DSP or even a PIC type device (frequencies are low, a simple interpolation algorithm can be used) between the i2s and the DAC should work (I need to read up more about the i2s spec to understand this further).
I'm wondering if the difference between a non-os DAC and one that uses the approach I suggested above will break the "magic" that non-os brings.
Regards,
Dean
Re: just a thought on non-os filtering...
Koinichiwa,
Yup.
The NOSDAC only gives you what is on the CD. It does not add anything. I think the whole argument is centered around the question if that which is added by the digital filter is beneficial or detrimental to the sound.
Yes, filtering is not easy, but I always argue that if your system cannot handle the energy up to around 40KHz it is deffective. If you combine the natural Sinc rolloff with even a 1st order filter you get quickly into "safe territorry".
Yes. It is the DF that "makes" the sound. I find that older, more "primitive" filters such as the SAA7220 sound better than modern types with much "longer" filters who give superior measurements.
A sample rate doubler is a Digital Filter.
I would think that it should be possible to realise a primitive 3-Tap oversampling filter either in a PIC device or even in "hardware".
Sayonara
Koinichiwa,
deandob said:
Yup.
deandob said:
The NOSDAC only gives you what is on the CD. It does not add anything. I think the whole argument is centered around the question if that which is added by the digital filter is beneficial or detrimental to the sound.
deandob said:
Yes, filtering is not easy, but I always argue that if your system cannot handle the energy up to around 40KHz it is deffective. If you combine the natural Sinc rolloff with even a 1st order filter you get quickly into "safe territorry".
deandob said:
Yes. It is the DF that "makes" the sound. I find that older, more "primitive" filters such as the SAA7220 sound better than modern types with much "longer" filters who give superior measurements.
deandob said:
A sample rate doubler is a Digital Filter.
deandob said:
I would think that it should be possible to realise a primitive 3-Tap oversampling filter either in a PIC device or even in "hardware".
Sayonara
Finally got the problem. I had a 330K resistor on the output instead of a 330R one
. That is why I had to put sooo much gain in it to get anything. Now it is playing ok, but still have to deal with this hiss (not hum) that I hear if the gain is a bit high - I am using a 15K resistor in the feedback, anything higher makes the hiss audible. This hiss is not dependent on the music volume. My guess is that the problem is on the dirty points of the cd PSU I chose to power the TDA1543 - the output pin of a 7805 as + and chassis as ground...
Miguel
. That is why I had to put sooo much gain in it to get anything. Now it is playing ok, but still have to deal with this hiss (not hum) that I hear if the gain is a bit high - I am using a 15K resistor in the feedback, anything higher makes the hiss audible. This hiss is not dependent on the music volume. My guess is that the problem is on the dirty points of the cd PSU I chose to power the TDA1543 - the output pin of a 7805 as + and chassis as ground...Miguel
Hi,
After trying several PSUs on the TDA1543 I still have the same hiss there. The chip has a I2S connection with two pins directly soldered to jumpers on the board and the third I2S pin with a shielded short wire. I am using 1k resistors at the output.
I guess that the hiss (very audible) is not coming from the psu but somewhere else. Any ideas?
Miguel
After trying several PSUs on the TDA1543 I still have the same hiss there. The chip has a I2S connection with two pins directly soldered to jumpers on the board and the third I2S pin with a shielded short wire. I am using 1k resistors at the output.
I guess that the hiss (very audible) is not coming from the psu but somewhere else. Any ideas?
Miguel
Re: Re: just a thought on non-os filtering...
Not necessarily, unless you regard the degenerate case of coefficients [... 0 0 0 1 0 0 0 ...] as a filter.
It is true, however, that in most applications a useful sample rate doubler will contain a digital filter.
Using even none-too-complex FPGAs like Spartans and lower Virtices and the right tools one could implement I2S -in, I2S-out digital filters with around 20 taps in days if one is prepared to live with simple/simplified coefficients.
A 3-tap filter is next to useless as it will have very little suppression above the original fs/2.
Kuei Yang Wang said:
Not necessarily, unless you regard the degenerate case of coefficients [... 0 0 0 1 0 0 0 ...] as a filter.
It is true, however, that in most applications a useful sample rate doubler will contain a digital filter.
Using even none-too-complex FPGAs like Spartans and lower Virtices and the right tools one could implement I2S -in, I2S-out digital filters with around 20 taps in days if one is prepared to live with simple/simplified coefficients.
A 3-tap filter is next to useless as it will have very little suppression above the original fs/2.
Re: Re: Re: just a thought on non-os filtering...
Konnichiwa,
That's not the point I'm trying to make. The suppresion of images is not the main issue (as various totally filterless non oversampling DAC's show). My main issue is the frequency domain behaviour and minimal smoothing of the waveform above 6.7KHz. A very short digital filter combined with modest analogue filter without peaking should be able to offer a nearly flat frequency domain behaviour with minimal pre- & post ringing.
Sayonara
Konnichiwa,
Werner said:
That's not the point I'm trying to make. The suppresion of images is not the main issue (as various totally filterless non oversampling DAC's show). My main issue is the frequency domain behaviour and minimal smoothing of the waveform above 6.7KHz. A very short digital filter combined with modest analogue filter without peaking should be able to offer a nearly flat frequency domain behaviour with minimal pre- & post ringing.
Sayonara
Elso Kwak wrote in post 58 of this thread:
"I had the opportunity to compare my DAC with the most expensive JK-Acoustics DAC in 't Harde.
http://www.jkacoustics.nl/DACReference.htm
Johan Ketelaar was quite perplexed that I had such a good sound from a homebrew affair. Last Friday I had on audition in my home a Arcam FMJ CD33 and a Marantz SA-17S1. The Arcam was beter on CD's than the Marantz The Arcam is Euro 2000, the Marantz Euro 2500.
My DAC had more bass but less highs than the Arcam. The Marantz had a anomaly in the bass, just did not have it under control. I decided not to buy either of them, as I preferred the sound of my own DAC/Philips CD-650. To my ears it sounds more musical more like the real thing. A week ago I attended harpsichord and clavichord concerts here in town. I don't hear the exaggerated highs at the live concert I hear from upsamplers and Hifi-ish sets. Also the volume is not that high as most Hifienthusiasts like to play, in fact volume is quite low. I concur with Kuei. Y.W. that it is all a matter of taste but I like to gauge my ears every now and then, before I loose track on the real sound."
Elso,
What DAC are you referring to?
Can you please post details of your DAC?
I listened recently to the ARCAM CD 23 (dcs Ringdac) of 2000 Euro and the ARCAM CD 82 (Wolfson dacs) of 1000 Euro.
Maybe I liked the CD 82 a bit more. It has slightly less detail, but it has a much firmer soundstage and bass-drive. All in all a very listenable dac.
However, I would prefer to build my own, so therefore I would be very interested in your solution...
Regards,
Lucas.
"I had the opportunity to compare my DAC with the most expensive JK-Acoustics DAC in 't Harde.
http://www.jkacoustics.nl/DACReference.htm
Johan Ketelaar was quite perplexed that I had such a good sound from a homebrew affair. Last Friday I had on audition in my home a Arcam FMJ CD33 and a Marantz SA-17S1. The Arcam was beter on CD's than the Marantz The Arcam is Euro 2000, the Marantz Euro 2500.
My DAC had more bass but less highs than the Arcam. The Marantz had a anomaly in the bass, just did not have it under control. I decided not to buy either of them, as I preferred the sound of my own DAC/Philips CD-650. To my ears it sounds more musical more like the real thing. A week ago I attended harpsichord and clavichord concerts here in town. I don't hear the exaggerated highs at the live concert I hear from upsamplers and Hifi-ish sets. Also the volume is not that high as most Hifienthusiasts like to play, in fact volume is quite low. I concur with Kuei. Y.W. that it is all a matter of taste but I like to gauge my ears every now and then, before I loose track on the real sound."
Elso,
What DAC are you referring to?
Can you please post details of your DAC?
I listened recently to the ARCAM CD 23 (dcs Ringdac) of 2000 Euro and the ARCAM CD 82 (Wolfson dacs) of 1000 Euro.
Maybe I liked the CD 82 a bit more. It has slightly less detail, but it has a much firmer soundstage and bass-drive. All in all a very listenable dac.
However, I would prefer to build my own, so therefore I would be very interested in your solution...
Regards,
Lucas.
KWAK-DAC
Hi Lucas,
The DAC I demonstrated in 't Harde was:
AD8561->CS8412 with Wildmonkeysects loopfilter-> ASR->TDA1543 (NON-OS)-> discrete-opamp IV->discrete outputbuffer.
I posted the powersupply (triple darlington with LM329) for the TDA1543 on this forum. The digital supply is with LT1086 and LT1033. The analog supply is with Jung like regulators (opamp driving a series pass transistor). All analog supply is referenced to one LT1021-5.
I also posted the general idea of the IV and ouput buffer including third order low-pass filter.
I am sorry, well I am not
, further schematics are NOT available.
Hi Lucas,
The DAC I demonstrated in 't Harde was:
AD8561->CS8412 with Wildmonkeysects loopfilter-> ASR->TDA1543 (NON-OS)-> discrete-opamp IV->discrete outputbuffer.
I posted the powersupply (triple darlington with LM329) for the TDA1543 on this forum. The digital supply is with LT1086 and LT1033. The analog supply is with Jung like regulators (opamp driving a series pass transistor). All analog supply is referenced to one LT1021-5.
I also posted the general idea of the IV and ouput buffer including third order low-pass filter.
I am sorry, well I am not
, further schematics are NOT available.
Hi all
I know I'm a few months late on this one but hope that someone can still help me.
I have a Philips CD624 which uses a SAA7323 bitstream dac. The onboard opamps, which for part of the low pass filter, can be bypasssed. I think it is a voltage output at this stage.
Does anyone have a design for an alternative filter arrangment to use here?
Regards
Fin
I know I'm a few months late on this one but hope that someone can still help me.
I have a Philips CD624 which uses a SAA7323 bitstream dac. The onboard opamps, which for part of the low pass filter, can be bypasssed. I think it is a voltage output at this stage.
Does anyone have a design for an alternative filter arrangment to use here?
Regards
Fin
I used many asynchronous sample rate converters as digital filters but only AD1896 (SRC4193) was suitable for Hi -End audio. This IC in synchronous mode provide very clean and detail sound (likely NPC SM5842 digital filter) despite the fact that it has passband ripple 0.015 dB against 0.00002 dB of the SM5842. The CS8420 is absolutely useless for audio because it has very hardly sound and tendency to signal dropouts.
Marantz CD And more.... Frankendiscer?
Mr. Daniel and others,
I design tube amps and simple transistor audio stuff, so I defer to those who really know their CD players. I have a Cambridge Audio D-500SE, which I seem to recall uses a Philips CDM, but mostly Sony chips after it. The output board (PS Regs, DAC, several R-C audio filters, Audio OP Amps, Digital output) was in some way defective, beautiful sound from one channel; disastrous distortion from the other. I replaced the audio IC's, it was no better. I replaced the coupling caps and other 'lytics, the problem remained the same. All this soldering despite using a temp-controlled soldering iron, and careful technique, eventually destroyed the board, as I suspect its made with 1/2 oz. copper and too thin traces, most of the redone thin copper traces lifted. I have the schematics for this Cambridge Audio unit, but for none of the other units I will mention.
I'd like to replace this board DAC/OP Amp Output board with something else, preferably something of high quality, simple or using existing "junker" boards I that I already have...
1) I have the main board and PS of an early Proton CD Player which used an early Philips CDM; two TDA-1540 DAC chips (Circa 1987?) and older OP Amps.
2) I have the main board and PS from a Marantz CD-48 which uses a TDA-1549 and JRC-4560D, plus another JRC-4560D for the headphone amp; the Cambridge Audio 500SE lacked a headphone amp and jack; the CD-48 also has a digital out, like the Cambridge Audio did.
3) Two made in China, Circa 1992 KLH Digital HA-2000 home theater units with 6 channels of TA-2020 plus a universal type DVD/CD decoder DAC board, both lasers in the players are quite dead, one might have a working optical out.
4) Two stand alone DVD/CD players KLH digital model KD-1220's which work and also have a similar universal decoding board to above unit #3.
5) Several broken Spectrasonic 7" LCD screen DVD/CD portable players, having some universal decoding DAC; and discrete audio output stages (and really small speakers).
6) One or two working UJDA720 DVD/CD-Writer drives from notebook computers.
I'm sure within the seven unit types above I can connect the signals going to the Cambridge Audio DAC chip to a circuit entering another DAC chip and get proper audio out, even if I have to switch out OP amps and / or caps to make it better.
Exactly which one to best attempt to use, that I am unsure...
Unit #5 would appear to be the most recent in manufacture only a few years old, so maybe it has the best chips inside, also the discrete audio stages may be better than OP Amps. The boards in #5 and #6 would appear to be smaller and would likely make the process easier than some of the others where the boards are about 2 to 5 times the size of the original Cambridge board. Luckily 'bout 1/3 of the Cambridge Audio unit is empty inside, so room to "grow" for a bigger board... The #3, #4, #5, #6 don't have PS Regulators on their DAC/Audio boards, I seem to recall that the Cambridge Audio board contained diodes, caps, and two or three regulators along with the DAC and audio stages.
If more info on the chips present in various devices is needed, I can rip 'em open and jot down numbers and makers.
I also have some PDF-1703/1704 chips, a DAC or two from Crystal from a few years back, LT1083, LT1084, and LT1085 pairs in various versions, as well as some LT1115, NE5532, NE5534AN, and OP-xxx OP amps somewhere.
I'd appreciate comments from all who feel qualified!
-Steven
Mr. Daniel and others,
I design tube amps and simple transistor audio stuff, so I defer to those who really know their CD players. I have a Cambridge Audio D-500SE, which I seem to recall uses a Philips CDM, but mostly Sony chips after it. The output board (PS Regs, DAC, several R-C audio filters, Audio OP Amps, Digital output) was in some way defective, beautiful sound from one channel; disastrous distortion from the other. I replaced the audio IC's, it was no better. I replaced the coupling caps and other 'lytics, the problem remained the same. All this soldering despite using a temp-controlled soldering iron, and careful technique, eventually destroyed the board, as I suspect its made with 1/2 oz. copper and too thin traces, most of the redone thin copper traces lifted. I have the schematics for this Cambridge Audio unit, but for none of the other units I will mention.
I'd like to replace this board DAC/OP Amp Output board with something else, preferably something of high quality, simple or using existing "junker" boards I that I already have...
1) I have the main board and PS of an early Proton CD Player which used an early Philips CDM; two TDA-1540 DAC chips (Circa 1987?) and older OP Amps.
2) I have the main board and PS from a Marantz CD-48 which uses a TDA-1549 and JRC-4560D, plus another JRC-4560D for the headphone amp; the Cambridge Audio 500SE lacked a headphone amp and jack; the CD-48 also has a digital out, like the Cambridge Audio did.
3) Two made in China, Circa 1992 KLH Digital HA-2000 home theater units with 6 channels of TA-2020 plus a universal type DVD/CD decoder DAC board, both lasers in the players are quite dead, one might have a working optical out.
4) Two stand alone DVD/CD players KLH digital model KD-1220's which work and also have a similar universal decoding board to above unit #3.
5) Several broken Spectrasonic 7" LCD screen DVD/CD portable players, having some universal decoding DAC; and discrete audio output stages (and really small speakers).
6) One or two working UJDA720 DVD/CD-Writer drives from notebook computers.
I'm sure within the seven unit types above I can connect the signals going to the Cambridge Audio DAC chip to a circuit entering another DAC chip and get proper audio out, even if I have to switch out OP amps and / or caps to make it better.
Exactly which one to best attempt to use, that I am unsure...
Unit #5 would appear to be the most recent in manufacture only a few years old, so maybe it has the best chips inside, also the discrete audio stages may be better than OP Amps. The boards in #5 and #6 would appear to be smaller and would likely make the process easier than some of the others where the boards are about 2 to 5 times the size of the original Cambridge board. Luckily 'bout 1/3 of the Cambridge Audio unit is empty inside, so room to "grow" for a bigger board... The #3, #4, #5, #6 don't have PS Regulators on their DAC/Audio boards, I seem to recall that the Cambridge Audio board contained diodes, caps, and two or three regulators along with the DAC and audio stages.
If more info on the chips present in various devices is needed, I can rip 'em open and jot down numbers and makers.
I also have some PDF-1703/1704 chips, a DAC or two from Crystal from a few years back, LT1083, LT1084, and LT1085 pairs in various versions, as well as some LT1115, NE5532, NE5534AN, and OP-xxx OP amps somewhere.
I'd appreciate comments from all who feel qualified!
-Steven
Peter Daniel said:
tda1549
thanks for the info
I have same dac and was looking at lukasz fikus lampizator site and he could not get this too work
did you pull the power to the internal op amp?
were you not getting dc from dac?
I would love to lose those ops and dc blocking electrolytes
did you test this with scope?
thanks
Glen
thanks for the info
I have same dac and was looking at lukasz fikus lampizator site and he could not get this too work
did you pull the power to the internal op amp?
were you not getting dc from dac?
I would love to lose those ops and dc blocking electrolytes
did you test this with scope?
thanks
Glen
I know this thread has silent for a while I just wanted to know If this works
any other gain stage after this?
thanks
Glen
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