CS4398 has a multi bit modulator, PCM 19794 data sheet don't give any info.
Are these S-D type DACs?
Are these S-D type DACs?
Perhaps your datasheet reading skills are slipping after being complimented on them 😀 This comes from the PCM1794 datasheet, page 24. Yes both are S-D type.
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Yes CS4398 is SD type and a good one too. Before I started working with other DACs I had a CS4397 DAC I enjoyed a lot. Strange thing is the CS4397 datasheet mentions DEM (Dynamic Element Matching). Both CS4397 and CS4398 sound very good with transformers at the output so completely passive sym-asym conversion.
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I take the view that a DAC that needs a trafo on its output to get it sounding decent quite simply isn't a DAC designed with the downstream analog stage in mind. Its a DAC designed in isolation that offloads the heavy lifting onto the implementer.
It seems only S-D type DAC available. Better to dance with it.
ADUM4160 USB isolator is available RMB118.
ADUM4160 + Async USB DAC, low jitter choice.
HIFI360 may best in cost and performance. Depends on how good the upsampler is.
Today I switched to non-verbal mode. So its difficult to comprehend words.
ADUM4160 USB isolator is available RMB118.
ADUM4160 + Async USB DAC, low jitter choice.
HIFI360 may best in cost and performance. Depends on how good the upsampler is.
Today I switched to non-verbal mode. So its difficult to comprehend words.
Or it is a DAC chip that sounds better with a passive output (no opamps) like most DAC chips do if they can drive transformers. So I strongly disagree with this view as my experiences are from working for years with transformers. I have had a few CS4397 DACs and they just sound better without opamp stage. Some even used these DAC chips without transformers or opamps by just connecting the + output via a cap to the RCA connector. I dislike this method as the output voltage is lower, there will be no filtering at all and the chip won't reach its specifications as it does not have a symmetric output without a reason. The DAC chips I use now are not able to drive transformers otherwise I would have used transformers again.
Output transformers: the simplest and most elegant output stage of all with the bonus that it filters RF and offers galvanic isolation.... No feedback, no power supply needed, no offset etc. etc.
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If external opamps are detrimental to the sound then there's no reason to believe internal ones are any better. Most probably internal ones (being fabricated on a digital CMOS process) are worse. So if passive output stages sound best, DACs with no on-board active stages are the obvious choice. Bye bye CS4397/8 on that basis.
You can debate as much as you want but you should simply try transformers. Any DAC chip that can be used passive/transformers sounds just better.There is a saying here that "believing should be done in church"😉
AFAIK CS4387/8 have no opamps in them but even if they do I would not dismiss them for that reason. I know them and they're OK. And not every opamp is the same. These chips sound better with transformers/passive output stages and it is possible to use them passive. Tell me which other DAC chips can ? (I know WM8740/1 can because I also used those with transformers). There are better DAC chips available but I had a good time listening to these CS types years ago.
Discussion about this leads nowhere. There are quite some forum members that have CS4398 DACs and really like them so the chip at least does something good.
AFAIK CS4387/8 have no opamps in them but even if they do I would not dismiss them for that reason. I know them and they're OK. And not every opamp is the same. These chips sound better with transformers/passive output stages and it is possible to use them passive. Tell me which other DAC chips can ? (I know WM8740/1 can because I also used those with transformers). There are better DAC chips available but I had a good time listening to these CS types years ago.
Discussion about this leads nowhere. There are quite some forum members that have CS4398 DACs and really like them so the chip at least does something good.
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I'm not against trafos but I prefer to find a way around them as they're heavy, bulky and expensive. If I couldn't get acceptable sound without resorting to them, then of course they'd be a reasonable choice.
In other words: good 🙂
Output transformers can be quite small but the rule (unfortunately) is : the bigger the better.
After having played a bit with the device and having written an operation manual in english I notice a kind of bug. Sometimes the device comes in a unstable situation after being powered up. Display stays gray (no text) and backlight is also either on or off intermittently and the blue power on LED stays off. Also the red LED from the SD slot glows dommed. It seems one of the regs is suffering from latch up. After being a few minutes without power switching it on again solves the problem. They will look into this, it could be my specific unit exhibiting this behavior.
Abraxalito, did you notice muting is done with a relay ?
Abraxalito, did you notice muting is done with a relay ?
I haven't noticed any power-up probs on my unit. Yes, I have noticed two relays doing muting of the outputs.
After all your talk of trafos I'm now curious to see if I can implement some kind of electronic trafo in place of the filter they're using, which incidentally is much simpler than the ones recommended by CS. I've ripped out all the passives in the differential-SE stage and will bodge up a stage with better CMRR. I just noticed LM6172 has enviable CMRR in the audio band. I've also torn up most of the power supply as that's not being implemented too majestically. They have though made an attempt at star grounding, so all is not lost. I'd really like to see the CS4398 give its best shot then compare that with my multibit DAC 🙂
After all your talk of trafos I'm now curious to see if I can implement some kind of electronic trafo in place of the filter they're using, which incidentally is much simpler than the ones recommended by CS. I've ripped out all the passives in the differential-SE stage and will bodge up a stage with better CMRR. I just noticed LM6172 has enviable CMRR in the audio band. I've also torn up most of the power supply as that's not being implemented too majestically. They have though made an attempt at star grounding, so all is not lost. I'd really like to see the CS4398 give its best shot then compare that with my multibit DAC 🙂
I've spent that past 3 days doing the modding to the analog output filter and PSUs. The upshot is the tonality is much improved - flute sounds more flute-like and female voices have lost almost all their razor-sharp edginess. Still though the dynamics are flattened compared to multibit - impact on drums is softened. So I figure the CS4398 is a reasonable performer but its not winning any prizes up against my multibit designs. I confess I've done nothing to sort out the clocking to the DAC, which is fed from the VS1053b so probably has not inconsequential jitter.
If anyone wants more details about the mods, please shout 🙂
If anyone wants more details about the mods, please shout 🙂
Given the apparent absence of interest here, I've begun another thread about modding this player over at WBF where at least one person has indicated he's interested so far -
Digital source for frugal-philes
Digital source for frugal-philes
There seems no much members interest in this subject. So I follow your posts there.
Strange conclusions. Not many people here have this player as it is meant to be sold on the chinese market only. So there will be members reading but not giving comments as they don't have one (yet).
For instance I will be going the low jitter way but feel no obligation to post pics etc. Still I read what others do to this player.
For instance I will be going the low jitter way but feel no obligation to post pics etc. Still I read what others do to this player.
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