| Tieftoener |
I just got confirmation from TI that my SRC4192's are shipped and on the way to my door :) Woo hoo!!! :) Anybody got a preliminary design worked out yet??? ;)
Just wanted to give a heads up to those that were waiting on backorder also for their samples...
l8erg8er |
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| AD1865 |
| IMHO, The AD1896 sounds smooth but no bass strength, and with no sensation, becaue the data is completly changed! It's garbage.So I don't think the SRC4192/3 can give us an better sound than without it, although its spec is very good. |
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| tiroth |
| I have some boards for AD1896/AD1853 that would work, but there is some kind of clicking in the left channel. Very annoying. I am wondering if is because I used very early stock AD1896, I know there have been some problems with those. |
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| AD1865 |
| quote: | Originally posted by tiroth
I have some boards for AD1896/AD1853 that would work, but there is some kind of clicking in the left channel. Very annoying. I am wondering if is because I used very early stock AD1896, I know there have been some problems with those. |
My DAC DIR1703+AD1896+AD1852 runs well,but the sound is
very "atony" and lack bass.Check the circuit diagram if some sets
wrong. |
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| tiroth |
| Do you use slave-mode output? |
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| AD1865 |
I only use 96KHz sample rate,the slave mode is hard to
use,and the THD of AD1853/2 in 192KHz is worse. |
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| Brian Brown |
| quote: | Originally posted by tiroth
I have some boards for AD1896/AD1853 that would work, but there is some kind of clicking in the left channel. Very annoying. I am wondering if is because I used very early stock AD1896, I know there have been some problems with those. |
Make sure that the /RESET timing is being correctly met. /RESET must be held low while the rest of the AD1896 powers up, or problems such as clicking may occur.
Brian.:cubist: |
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| Brian Brown |
I haven't found the AD1896 to make any change in tonal balance. In my setup, the strength and general character of the bass is the same as without the AD1896.
Brian.:cubist: |
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| AD1865 |
| quote: | Originally posted by Brian Brown
I haven't found the AD1896 to make any change in tonal balance. In my setup, the strength and general character of the bass is the same as without the AD1896. |
Which D/A do you use? My DAC with AD1852 can easily been
heard that the bass have no wallop. Although I use AD811 as
buffer. |
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| tiroth |
I'll have to check ~RESET out Brian--thanks. First time anyone had heard of a similar problem!
I use a global reset, for DIR, ASRC, and DAC (from a reset generator). The PSU is stabilized by that point, but since DIR and ASRC are simultaneously reset the input clocks are not active when ~RESET goes high. Do you really think this could be the reason? |
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| AD1865 |
My reset circuit use 1u Cap and 20k Res, DIR1703 and AD1896 and AD1852 use separate reset. All of it can reset well.
If one of chips can't reset well ,the problem will come forth.
DIR1703 need 10ms,AD1896 only need 0.2ms,AD1853/2 need 15ns,so if you use DIR1703,check the reset time is enough. |
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| Brian Brown |
| quote: | Originally posted by AD1865
Which D/A do you use? My DAC with AD1852 can easily been
heard that the bass have no wallop. Although I use AD811 as
buffer. |
I'm using mine with a digital amplifier.
See:
http://www.diyaudio.com/forums/show...&threadid=22741
At the present, I can switch back and forth between S/PDIF without ASRC, and MUXIT w/ AD1896 ASRC. There isn't any change in volume or tonal balance.
Have you tried bypassing the AD1896? My suspicion is that some other part of your signal chain may be causing the lack of bass.
One place to check is the quality of the analog power supply to your DAC and output buffer opamps. If this supply isn't good and solid it might be causing the bass weakness.
Regards,
Brian.:cubist: |
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| Brian Brown |
| quote: | Originally posted by tiroth
I'll have to check ~RESET out Brian--thanks. First time anyone had heard of a similar problem!
I use a global reset, for DIR, ASRC, and DAC (from a reset generator). The PSU is stabilized by that point, but since DIR and ASRC are simultaneously reset the input clocks are not active when ~RESET goes high. Do you really think this could be the reason? |
It sounds like what you've got for /RESET is correct. hmm...
In my setup with the MuxIt data link, all of the source inputs to the ASRC (including BCLK and LRCLK) are pulled low when the audio source is turned off or if the CAT5 MuxIt cable is unplugged. The ASRC is not in reset when these events occur. I can do a live plug-in of the MuxIt cable and the ASRC resynch's and goes to work.
Another thought...
I'm not quite sure what you meant by 'input clocks'.
I'm using the ASRC in slave mode for both the input and output ports. I have a separate 30MHz oscillator for the internal ASRC logic. This oscillator is up and running before /RESET is released. This is important.
Is your MCLK for the ASRC running before /RESET is released?
Brian.:cubist: |
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| AD1865 |
It's good work.OHIM, I think these is no use to convert DSD to PCM. DSD sounds better.
I didn't use AD1896's standby,all the BCLK,LRCLK,DATA,SCLK are connected to DIR1703's. Compared by my solid earphone amplifier and K501 , these is some difference in bass without AD1896. And the mediant isn't reality,although you can hear more "details" which is produced by AD1896, but I don't like the sound.You can see now less and less HI-END corporation use sample rate converters.They prefer much more complex FIFO and DDS to reduce jitter to sample rate converter(Mark Levinson and so on), because it sounds bad.Audio Note even reject the digital filter for reducing"digital" distortion. |
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| tiroth |
Brian,
Thanks for your input. I am also using slave mode in and out and my MCK is running when the reset is generated. I'll give a manual reset a try tonight.
AD1865,
Can you try enabling the bypass mode in your design? That would be one easy way to know for sure. |
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| AD1865 |
| I have compared AD1896 bypassing and 4 switchs bypassing. The sound is different. I think AD1896's bypass is useless,because I can't hear any difference.But if use switchs to bypass you can hear more real sound. |
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| tiroth |
It sounds to me then that the problem is not AD1896. Bypass mode simply spits the input signal out at the output.
Maybe it is a signal integrity issue with the routing of the AD1896 outputs. (=> jitter) |
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| AD1865 |
The datasheet of sample rate converter deceived us!See SRC4192 datasheet.The FFT of 1KHz tone is good, but 20KHz is much worse(44.1 to 96KHz), so you can't see the figure of FFT of 20KHz tone (44.1 to 192KHz) in datasheet.If it's 30KHz,the FFT will worse than 20KHz,if......
The high frequence distortion will modulate and bring big
distortion in audio frequence which we may heard.So the SRC
is only garbage to us. |
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| tiroth |
Brian,
My AD1896 issue is not reset-related. I broke out the AD1896 reset line and held reset low for 1s before bringing it high, after the reciever clocks were active. No change. Thanks anyway. |
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| tiroth |
| AD1865, at 20kHz the worst distortion shown is -144dB! In other modes the distortion is below -160dB. This is so much better than even the best DACs that I find it hard to believe that you will get intermodulation products that aren't swamped by other distortions. |
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| Brian Brown |
| quote: | Originally posted by tiroth
My AD1896 issue is not reset-related. I broke out the AD1896 reset line and held reset low for 1s before bringing it high, after the reciever clocks were active. No change. Thanks anyway. |
I'm running out of ideas. It might be time to try another / newer AD1896 or SRC4192.
Brian.:cubist: |
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| Brian Brown |
AD1865:
I agree with your premise that the ultimate approach is to avoid ASRCs altogether. An ideal system would be designed so that there is a single low jitter clock by the DAC, distributed to the sources, with the data buffered and reclocked near the DAC.
On the other hand, that approach isn't always practical for DIY when modifying existing commercial units. ASRC certainly offer a high level of convenience when interfacing between varying devices.
Especially being a newer technology, the spec. sheets for these devices probably are missing some characteristics that affect the sound quality. The specs. that are published, however, I find to be quite impressive.
Convenience and specifications aside, my subjective impression of the AD1896 has been entirely favorable. In some cases, I've heard little or no improvement. In others (especially upsampling 44.1KHz CDs) I've been very surprised at the level of improvement in clarity and detail that I hear. This seems particularly true of softer sounds and at higher frequencies. A common thing I've noticed on many recordings has been the ability to hear the breathing of a vocalist or wind player where it had been completely masked before. I haven't found a technical explanation that fully explains why this occurs. The best idea I've been able to come up with is that some recordings have information that is statistically dithered below the word size and sample rate that an ASRC is somehow able to recover. Jitter attenuation offered by these devices has been stated. The change in the low-pass output filter allowed by the higher sampling rate could also be a factor.
I have yet to find a case where the AD1896 caused something to sound subjectively worse. I also haven't found any case where the AD1896 made any change to the imaging, depth, or tonal balance of the sound. I wouldn't be surprised to find that another person, or perhaps a different sound system might find the AD1896 to have certain sonic deficiencies, but I do have to take exception to the notion that the AD1896 sounds like garbage.
I suspect that most of the people on this thread, like myself, are new to ASRC devices. At this point our main concern is simply getting experience with them and also making comparisons to different devices as they become available.
My experience so far has been very rewarding.
Regards,
Brian.:cubist: |
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| AD1865 |
Brian Brown:
If you have compared the pictuer to its magnified picture you will see the magnified picture can't recover the original details which the first picture havn't. The SRC can't recover more than input inf.I believe AD1896 is garbage because it broken the original sound not only it sounds bad.Someone maybe like the
smooth and more "detail" sound,but i don't. If you hear AN dac you will know what oranginal sound replayed is.But if you like AD1896's sound,of course you can use it.
I will make a new DAC with PCM1704,PCM63, AD1865, DIR1703, CS8414 and so on. I prefer R-2R DAC becuae the sound
is more real,the density of the sound is the best.I also will use
SRC4192.
regards,
markamp |
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| takashi |
YES, THE bypass function in ad1896 is meaningless! i can hear any different! and the LRCLK and BCK are the same freq as up sampled.
and have you all tried src4192? can it do the "bypass" function? |
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| takashi |
| sorry, it is "i can not hear any different" |
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| AD1865 |
| I will try it next month. |
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| nFORCE |
all,
I tested the SRC4192, it is a great device, listen more detail than before.
Which device I use?
I simple put it on to replace the Ad1896 in Philips DVD-963SA.
PS: The original 963SA is using AD1895.
My SRC4192 is not the sample from TI, I bought 20pcs from TI through the distributor.
Regards,
nFORCE |
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| tiroth |
| I think there are some stringent requirements for the bypass function to operate. i.e. the output clocks must be syncronous to the input clocks. In output master mode I assume this means the ratio must be set appropriately via MCLK and MMODE_X. In most cases this will not be possible, but if your design is flexible enough you can try it. |
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