The volume control is built into the chip and can't be bypassed anyways. It's a very good volume control, and the noise floor is very low on that DAC. So you wont have any audible sound degregation by doing this.
Chinese DAC shames a few heavy hitters
- Thread starter nc42acc
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The volume control is built into the chip and can't be bypassed anyways. It's a very good volume control, and the noise floor is very low on that DAC. So you wont have any audible sound degregation by doing this.
Mike,
What settings do you think we should be running on this DAC (keeping stock for now)?
Thanks,
B
What settings do you think we should be running on this DAC (keeping stock for now)?
Thanks,
B
I would use the auto clock mode for sure. And as far as filter, that would be your call, because they are for tuning to subjective taste.
Thanks a lot Blizzard !!
I will continue to run it for burning and try to make comments on my listening impressions for sure.
For now i don't think i will go for an upgrade, but what the HK dealer and Ric Schultz are proposing is very interesting, even i'm not sure to understand eveything
.PS : sorry if my english is not always that good, i'm a french audiophile.
Thanks a lot Blizzard !!
I will continue to run it for burning and try to make comments on my listening impressions for sure.
For now i don't think i will go for an upgrade, but what the HK dealer and Ric Schultz are proposing is very interesting, even i'm not sure to understand eveything
PS : sorry if my english is not always that good, i'm a french audiophile.
No problem. Just sit tight, let it burn in, and enjoy. Keep your eye on this thread, as any beneficial mod will be clearly explained once we have details.
This has been confirmed to be false information. They didn't even knew the company existed when I asked.
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Hi guys,
I took some pictures of the DAC inside. There are some modifications from the promos pictures (maybe a first production batch). Some components have a different color, a capacitor has been replaced by a couple of capacitors, and also holes on the lid (also on the bottom).
I took some pictures of the DAC inside. There are some modifications from the promos pictures (maybe a first production batch). Some components have a different color, a capacitor has been replaced by a couple of capacitors, and also holes on the lid (also on the bottom).
I'd like also to talk with you about clock mode.
Here is what is written in the manual :
Master Clock Mode
Under the several years of research and development, DAC-X20 features with “Master
Clock Mode” special function. It makes ES9018 reach hi-end hi-fi performance when
proper master clock is chosen. There are two options, “Auto” and “Normal”, in this
clock function. When “Auto” option is selected, DAC-X20 will enter into an adaptive
master clock mode. A more accurate clock will be obtained by a set of high performance
- 24 -
PLLs (phase-locked loop), and it will then be fed to the ES9018 DAC. Because the signal clock and the master clock are not the conventional asynchronous mode, the digital interpolation filter inside ES9018 will no longer produce a weak timing error (jitter),
and the digital signal will be more accurately recovered. When selecting “Normal”
option, the clock mode becomes to the normal mode, which is the official ES9018
asynchronous mode.
*Under the “Auto” mode, the quality of the master clock of DAC-X20 will be more or less depended by the quality of the superior clock. This mode is recommended to be used only for the clock of the front-end audio equipment in good condition.
Until now i was listening only in Auto mode.And reading that i told myself that maybe the clock of my source (optimized Mac Mini) is not so good as the DAC clock (i don't know, really).
Then i switched in normal mode but i have an issue in this mode : my DAC is my central piece of my Hifi and TV system, so my TV is connected to my DAC using optical cable. In normal mode, with my TV, the DAC is always switching between LOCK and UNLOCK, so the sound is stopping, restarting and so on... It looks like my TV signal is not locked correctly in this mode. I try changing the cable and the issure remains. In Auto mode no issue.
With my MAC no problem.
In this mode i would have thought the clock would be independant from the quality of the source...
Do you have an idea ? Me no
Thanks for your help.
Here is what is written in the manual :
Master Clock Mode
Under the several years of research and development, DAC-X20 features with “Master
Clock Mode” special function. It makes ES9018 reach hi-end hi-fi performance when
proper master clock is chosen. There are two options, “Auto” and “Normal”, in this
clock function. When “Auto” option is selected, DAC-X20 will enter into an adaptive
master clock mode. A more accurate clock will be obtained by a set of high performance
- 24 -
PLLs (phase-locked loop), and it will then be fed to the ES9018 DAC. Because the signal clock and the master clock are not the conventional asynchronous mode, the digital interpolation filter inside ES9018 will no longer produce a weak timing error (jitter),
and the digital signal will be more accurately recovered. When selecting “Normal”
option, the clock mode becomes to the normal mode, which is the official ES9018
asynchronous mode.
*Under the “Auto” mode, the quality of the master clock of DAC-X20 will be more or less depended by the quality of the superior clock. This mode is recommended to be used only for the clock of the front-end audio equipment in good condition.
Until now i was listening only in Auto mode.And reading that i told myself that maybe the clock of my source (optimized Mac Mini) is not so good as the DAC clock (i don't know, really).
Then i switched in normal mode but i have an issue in this mode : my DAC is my central piece of my Hifi and TV system, so my TV is connected to my DAC using optical cable. In normal mode, with my TV, the DAC is always switching between LOCK and UNLOCK, so the sound is stopping, restarting and so on... It looks like my TV signal is not locked correctly in this mode. I try changing the cable and the issure remains
. In Auto mode no issue.With my MAC no problem.
In this mode i would have thought the clock would be independant from the quality of the source...
Do you have an idea ? Me no
Thanks for your help.
Seems like a bug to me. It says that in normal mode it lets 9018 be in charge of async conversion so it should not be an issue.
Hi guys,
I took some pictures of the DAC inside. There are some modifications from the promos pictures (maybe a first production batch). Some components have a different color, a capacitor has been replaced by a couple of capacitors, and also holes on the lid (also on the bottom).
Wow looks impressive to me!
I'd like also to talk with you about clock mode.
Here is what is written in the manual :
Master Clock Mode
Under the several years of research and development, DAC-X20 features with “Master
Clock Mode” special function. It makes ES9018 reach hi-end hi-fi performance when
proper master clock is chosen. There are two options, “Auto” and “Normal”, in this
clock function. When “Auto” option is selected, DAC-X20 will enter into an adaptive
master clock mode. A more accurate clock will be obtained by a set of high performance
- 24 -
PLLs (phase-locked loop), and it will then be fed to the ES9018 DAC. Because the signal clock and the master clock are not the conventional asynchronous mode, the digital interpolation filter inside ES9018 will no longer produce a weak timing error (jitter),
and the digital signal will be more accurately recovered. When selecting “Normal”
option, the clock mode becomes to the normal mode, which is the official ES9018
asynchronous mode.
*Under the “Auto” mode, the quality of the master clock of DAC-X20 will be more or less depended by the quality of the superior clock. This mode is recommended to be used only for the clock of the front-end audio equipment in good condition.
Until now i was listening only in Auto mode.And reading that i told myself that maybe the clock of my source (optimized Mac Mini) is not so good as the DAC clock (i don't know, really).
Then i switched in normal mode but i have an issue in this mode : my DAC is my central piece of my Hifi and TV system, so my TV is connected to my DAC using optical cable. In normal mode, with my TV, the DAC is always switching between LOCK and UNLOCK, so the sound is stopping, restarting and so on... It looks like my TV signal is not locked correctly in this mode. I try changing the cable and the issure remains
With my MAC no problem.
In this mode i would have thought the clock would be independant from the quality of the source...
Do you have an idea ? Me no
Thanks for your help.
I would just keep it on the mode that works smooth with your TV. The auto mode is supposed to be better anyways. It uses the same trick as the Resonessence mirus in order to get the best out of the internal Async in the Sabre chips.
Gustard X20 in da house. Puts out a whooping 3.3 volts in the normal mode and almost 6V in the plus +6db mode and clips a zero vu signal on the +12db mode. Even the +6db mode has enough juice to drive any amp....never use the +12db mode. The phase invert switch does nothing. I will email the distributor and see if there is a fix. Nice to have a phase switch.
The I-V op amp is the ADA4898-1. Not much on the sonics of this opamp except for this one persons evaluation on the headfi forum a few years ago:
"Finally mounted 2 x ADA4898-1 on a BrownDog adapter. From a quick audition, this part sounds a bit more "in your face" than the OPA827/OPA211 family. Perhaps not as dynamic? A little less detail and spacial information compared to the TI parts. Not bad sounding, though. Draws a lot of current (16 mA) and gets quite warm to the touch. Not sure, but could be unstable in this circuit, even though there is PSU bypassing and 10 pF in the feedback loops for each channel. For bipolar input, I prefer OPA211/1611."
After the I-V converter op amp it appears the signal goes through another op amp....the OPA1632 differential amp. After that it goes to a very complex discrete buffer for each phase then out. So it looks like the "completely discrete output stage" is actually two op amps in series and then a complex discrete buffer. Wow! is thing going to be transformed using either a single discrete I-V converter per phase or my zero feedback single fet buffer per phase (going to try this first since this first customer has 99db speakers and one volt would be enough to drive the amp direct). If the plus 6db function is in the digital domain then you could possibly get 2 volts from my buffer per phase and even 4 volts per phase with the +12db mode....we shall see.
The bolts on the transformers are indeed magnetic so need to be changed to brass as well as the trannies elevated off the chassis on thin wood. The AC input is long and complex....will shorten mucho.
I will burn in for a few days and then give a quick listen and then start to mod. Next week should be having some serious fun with this thing! Stay tuned!
The I-V op amp is the ADA4898-1. Not much on the sonics of this opamp except for this one persons evaluation on the headfi forum a few years ago:
"Finally mounted 2 x ADA4898-1 on a BrownDog adapter. From a quick audition, this part sounds a bit more "in your face" than the OPA827/OPA211 family. Perhaps not as dynamic? A little less detail and spacial information compared to the TI parts. Not bad sounding, though. Draws a lot of current (16 mA) and gets quite warm to the touch. Not sure, but could be unstable in this circuit, even though there is PSU bypassing and 10 pF in the feedback loops for each channel. For bipolar input, I prefer OPA211/1611."
After the I-V converter op amp it appears the signal goes through another op amp....the OPA1632 differential amp. After that it goes to a very complex discrete buffer for each phase then out. So it looks like the "completely discrete output stage" is actually two op amps in series and then a complex discrete buffer. Wow! is thing going to be transformed using either a single discrete I-V converter per phase or my zero feedback single fet buffer per phase (going to try this first since this first customer has 99db speakers and one volt would be enough to drive the amp direct). If the plus 6db function is in the digital domain then you could possibly get 2 volts from my buffer per phase and even 4 volts per phase with the +12db mode....we shall see.
The bolts on the transformers are indeed magnetic so need to be changed to brass as well as the trannies elevated off the chassis on thin wood. The AC input is long and complex....will shorten mucho.
I will burn in for a few days and then give a quick listen and then start to mod. Next week should be having some serious fun with this thing! Stay tuned!
Sounds cool! Yeah you should let it completely burn in and get a solid listening impression of it stock before too many mods. Seems pretty tweaked out even in stock form. The ADA4898-1 is a pretty expensive opamp compared to what many use in DAC's this price range. And it's only for the I-V converter stage! Try popping a sonic imagery labs 992 in it's place:
http://www.sonicimagerylabs.com/products/Model992DiscreteOpAmp-Ticha.html
It can sink or source 30mA in pure class A. That should make a huge difference on it's own.
If you have not done many mods then you think that mucho burn in is more important than mods.......not so. You can take a completely non burned in thang and mod the crap out of it and every mod will make the same difference that it makes with a "completely burned in unit". I have been modding CD players since they first came out in the mid 80s (and making my own DACs since the mid 90s).....this is my experience. Burn in is real.....but not necessary to tweak something.
Yes, the Sonic Imagery op amp (or other great discrete circuit) could be used as I-V conversion and then directly out.....no other circuitry whatsoever....this is the whole point....removing all unnecessary components. Why would 3 stages of circuitry on the output of a DAC chip be "pretty tweaked out"? All that unnecessary stuff is wrecking the sound, one great stage is all you need! I don't care how expensive an integrated circuit op amp is.....it will never sound as good as a discrete circuit. And they have 2 op amps in there....and a ton of parts in the discrete output stage. Removing all that stuff and using better regulators on the output stage will bring a serious improvement to this DAC. Just changing the I-V converters to discrete will not do it! You need to get rid of all the extra junk on the output. Less is more!
Yes, the Sonic Imagery op amp (or other great discrete circuit) could be used as I-V conversion and then directly out.....no other circuitry whatsoever....this is the whole point....removing all unnecessary components. Why would 3 stages of circuitry on the output of a DAC chip be "pretty tweaked out"? All that unnecessary stuff is wrecking the sound, one great stage is all you need! I don't care how expensive an integrated circuit op amp is.....it will never sound as good as a discrete circuit. And they have 2 op amps in there....and a ton of parts in the discrete output stage. Removing all that stuff and using better regulators on the output stage will bring a serious improvement to this DAC. Just changing the I-V converters to discrete will not do it! You need to get rid of all the extra junk on the output. Less is more!
Well lets see if you can make it better! Then offer it with warranty and see if anyone will buy it.
You are correct, if you turn it off and back on after switching the phase it does its magic.....very silly, having to turn it off and one each time you want to change phase. Will this turning off effect the sound? Where did you find this out?
Hi Ric,
nice you have the X20. I'm really looking forward the tweak you will purpose and the results ! I'm also very curious about your feeling on this DAC.
For the phase switch, it's described in the manual. You can find it here : http://yun.baidu.com/s/1jH1SCg2. Download it, first part is only in chinese, but the second part is in english and easily readable.
I have a friend who taught me that source equipment is not always in correct phase so whenever I put a new piece in the system I test it with a polarity checker. When I tested it, I was getting same results as you - no change. I decided to turn it off and on and voila, it worked.
Rick I find my X20 sensitive to AC power cables. Let me know if you experience this as well as you listen and analyze your X20. Thanks.
