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Another amp that costs more than a sports car that does not offer anything close to state of the art performance.
Disappointing.
Of "state of the art"? Mine is: "a seriously mis-used and meaningless cliché used by lazy people."
So I'm getting flamed by a guy who thinks you need to spend $5K on each power chord to have a good sounding system.
Given your history of thoroughly misguided and erroneous "journalism" (which, in your case, the term is used very generously), having you slag me is a sign that I'm not wrong.
What I consider "state of the art":
• Amps that produce at least 20dB less distortion and noise than this overpriced brick
• That list, to my knowledge, has only two entries: amps by Benchmark and Devialet
• I'm confident that whatever Bruno Putzeys & Peter Lyngdorf are about to release from Purifi Audio will be way better than this cinderblock as well
• Also, all of these superior products are a fraction of the cost of this lead bar
Fremer, you are definitely that guy that would buy a Bugatti Veyron rather than an Acura NSX or purchase a $10K analog Rolex when a $400 Citizen, solar powered, digital watch keeps better time.
Based on what criteria exactly? Did you experience these amplifiers at all?
... sound quality of this amp when powered through a "Best Buy grade" Audioquest power conditioner. Surely anyone who reads - let alone writes for Stereophile - knows that he should have been using a power conditioner from Synergistic Research.
https://www.stereophile.com/content/synergistic-research-powercell-ac-conditioner-mcintosh-mc462-amp-elac-adante-speakers
Now bring on the 350W/ch Rotel RB-1590:
http://www.rotel.com/product/rb-1590
It's much lighter on both your wallet and your toes.
Rotel RB-1590 doesn't have user adjustable feed-back controls :-) .........
MF liked the way D'Agostino Momentum mono-blocks sounded ....... Momentum has similar output impedance as CH precision, when 20% feed-back is used ........ That output impedance is also close to the output impedance of darTZeel NHB-458 amp :-) ..........
CH precision is smart ....... They know that 'one size fits all' approach may not be a good idea ....... So, they provide user adjustable feed-back controls :-) ........
BTW ..... Pass labs SIT-3 ($4,000) also has somewhat similar 0.25 to 0.26 Ohm output impedance :-) ........
Yeah, I think CH has hit on an interesting feature that audiophile might like. Sort of like letting listeners choose between a range of digital filters from minimum phase to linear. Although this of course will result in more audible differences than otherwise decent digital filters at the edge of audibility.
The problem here I hope is that it does not demonize negative feedback as something "bad" (which IMO it isn't). If some people are OK with the higher harmonic distortion including elevated higher order distortions and higher output impedance (with commensurate lower dampening factor), then so be it.
But let's just make sure to frame this as a "subjective choice" rather than making it some kind of simplistic audiophile "myth" causing all kinds of companies to follow a trend of low negative feedback when there's typically no reason to...
..it's not theory but implementation that matters.
Agreed :-) ........
Wish more audiophile companies could do what CH Precision is doing less expensively :-) ........
that this amp is State of the Art in many areas of performance.
Many reviews from respected magazines with experienced reviewers can attest.
Instead the posts show misanthropic assumptions of equipment none of us have heard.
... exceed the performance of the $4K Benchmark AHB-2 (operating in bridged mode)?
and listen... Only then would you know where and how the amp compares.
The review should be insightful regarding sound quality.
Perhaps you could ask MF to compare them in a follow-up.
Or you could read the several, other reviews on the web and guess.
Or you could do none of the above, and just speculate wildly and assume everyone is lying to you.
... the CH Precision M1.1 is "State of the Art in many areas of performance."
Again, which MANY areas of performance would those be as compared to the Benchmark AHB2?
For your reference:
https://www.stereophile.com/content/benchmark-media-systems-ahb2-power-amplifier-measurements
My statement was a rebuttal of your assertion.
Read the reviews and you tell me... I already read them. lol..
... sound storage and playback via analog disc, then you must have a preference for a less flat frequency response, degraded speed accuracy and pitch stability, higher levels of distortion and worse signal-to-noise ratio, along with the presence of random impulse noises, as compared to a digital system.
In a large active system, bridgeable Benchmark AHB-2 can provide clean linear output with wide bandwidth, fully adequate for powering the tweeters. If DIY is of interest, consider the Neurochrome Modulus-686.
Below tweeter frequencies... Bandwidth is obviously constrained at lower frequencies, and class D is fully adequate, and the inefficiency of class A/B is not justified. In that range, look at ATI 5xxNC family of amplifiers which use Hypex NC500 amplifier modules.
For the subwoofer subsystem, I would suggest class H pro-grade fan cooled amplifiers, and would suggest replacing the cooling fans with suitable very quiet running Noctua fans. Class H is similar to class A/B in the output stage, with tight control provided by a large dose of negative feedback, but modulates switch mode power supply output rail voltage to follow the input signal, keeping it a little above a level that would otherwise clip the output when operating within design range. So it is much more efficient than class A/B. The downside is that bandwidth is lower than is achievable with conventional class A/B.
Horses for courses, etc.
I'm sure there are a lot of dirt poor people in 3rd world countries who could look at your possessions and your lifestyle and say the same about you. Take your "holier than thou" attitude elsewhere.
Well said ACranston
Regards,
Terry
That is among the most foolish comments yet. No one need apologize for owning this amp, or any high performance, high quality product. Should Ferrari owners apologize? Where do you draw the line? Grow up.
MF did not quite like the sound of Boulder 2150 mono-block power amps (Stereophile Class-A) ....... 2150 has very low output impedance and very high damping factor ....... 2150 also has almost 20-Bit resolution (SNR) :-) .........
... why not get a Nagra?
https://www.nagraaudio.com/product/nagra-hd-amp/
That would be a 'bravura' effect :-) .........
Both CH Precision and Nagra are located in the Swiss 'Watch Valley' :-) ..........
darTZeel is also, Swiss made :-) ........
Next MF is gonna review the latest darTZeel NHB-468 monoblock amps :-) .......
The comments section beneath many Stereophile articles are consistently hijacked by a vocal minority of judgmental, know-it alls that simply can't summon the capacity to stifle their negative rantings. I, for one, vote to turn off comments. Another one of my favorite audio review sites did it, and the world just kept on spinning. I would be surprised if Stereophile hasn't considered doing this already. I'd be interested to hear your thoughts in an "As We See It" one of these days.
..simply refuses to get into the comment section; I guess they call it a smartphone for a reason.
My android phone simply refuses to get into the comment section; I guess they call it a smartphone for a reason.
The mobile version of the Stereophile website doesn't show comments.
John Atkinson
Technical Editor, Stereophile
Idee intelligente :-) .........
First, thank you for providing the comments section.
In writing this comment, I am using a Chrome browser on Android, and the comment section becomes available by selecting the desktop site in the pull-down menu in Chrome. As you explained, the comment section is unavailable in the mobile version.
I would suggest that if anyone does not want to read the comments, then perhaps they shouldn't. They always have the option of not reading the comments, regardless which browser they might be using.
I like reading the comments, and sometimes adding my own comments.
... a pair of CH Precision M1.1 amps OR a pair of Luxman B-1000f amps - plus a BMW Z4.
https://www.stereophile.com/content/luxman-b-1000f-monoblock-power-amplifier
https://onahighernote.com/shop/stock-open-box-sales/electronics/luxman-b-1000f-monoblock-ex-demo/
http://www.luxman.co.jp/product/b-1000f
....... or, a Corvette convertible :-) .........
Invasion of the 'know-it-alls' :-) ............
May be Stereophile could come up with an 'app' for the comments section ....... So, people who don't want to read the comments, could turn off the 'app' :-) ...........
Wow!!! stunning set of measurements JA, must have a listen to this one.
Direct in to the poweramp/s with this baby, (hope you got to do this with the Halo's JA??), nothing says to me more that active preamps are obsolete and a backward sonic step when used with this dac, like these two sentences of your measurements.
JA: "
"Helios's maximum output level at 1kHz feeding 100k ohms was 16.4V with the level set to "0dB"
"The balanced output impedance was 93.5 ohms at all audio frequencies in both Loudspeaker and Headphone modes; the unbalanced output impedance was 47 ohms in both modes."
Cheers George
But then again, that price? How does that compare to everything else? Are such prices still in proportion to everything else in life? Someone who buys this, how much does he pay for a bottle of good wine? For a good coat? For an armchair? For a car? 800? 4K? 20K? 400K? Then it would be proportionate. Of course everyone has their own thing, choice (freedom), hobby and pleasure. Naturally! I just wonder.
At least with this, you'd save thousands by not having to have a preamp and be better off sonically for it.
Cheers George
I ran direct for many years from an NAD M51 using its volume control, then a D90 for another year and finally a Holo May for about 6 months before adding back a Holo Serene preamp to provide better gain-matching for my system. Not only did that addition drastically improve the sound quality it also allowed me to have proper gain matching. There are plenty of utterly transparent preamps on the market and they serve a useful purpose beyond source switching. I believed the dogma for too long that no preamp was the best preamp and I have seen the light. So have a lot of us that went all digital a long time ago and have ben using digital gain structures. The May and the Serene are designed for each other and work and sound magnificent, and much better than the May direct using a digital volume control in HQPlayer. This hobby isn't about "saving thousands" it is about getting the best sound quality -for the dollars- and that doesn't mean eliminating a useful component because it costs money. Listening isn't about theories, its about listening, with your ears, not your ideas.
If you go direct and have enough volume level for listening up to your loudest level with the quietest recording you have, then you have enough gain. (and are "gain matched")
Any more gain by adding an active preamp is not going help it sound any better "what so ever" if anything it's adding more noise and distortion.
And as far as impedance matching, the Weiss Helios D/A processors output stage is perfectly impedance matched for any poweramps input impedance.
And I repeat: "At least with this, you'd save thousands by not having to have a preamp and be better off sonically for it."
Cheers George
I want to preface my comment with sincere thanks for another well considered and well written review in combination with extensive measurements and associated commentary (a lot of work, and very well done), before continuing with some negative criticism of the component that was the subject of the review.
"...balanced and single-ended analog outputs. But on closer inspection, the Helios lacks the earlier processor's headphone jack. It can still be used with headphones, however: Using optional adapter cables ($495), the Helios can drive headphones from its balanced and unbalanced outputs." — J.Atkinson
That would seem to imply that changing output from loudspeakers to headphones requires some cable swapping, detaching the cables interconnecting the rear ports to the loudspeaker power amplifiers, and connecting an adapter cable to those rear ports to power the headphones. To me that seems like a truly shameful asnine engineering solution on a product marketed at a $22k pricepoint, a workaround that might be acceptably accomodated on some kid's entry level cheap-fi system. This should have proper headphone ports on the front panel, classic conventional 1/4 inch (6.35mm) TRS for single ended stereo headphone connection, and the newer 4.4mm Pentaconn for "balanced" (differential) stereo headphone connection, while using internal relays for the switching, and a proper control system.
I know what gain matching is. I also know how to use a network analyzer. In my system, I apply room correction filter in a convolution engine and I have insertion loss so having 6db of clean, class-A gain available without resort to digital is very helpful so I can keep well under the threshold for digital overs/clipping. You do it your way and Ill do it mine. But in my system, I know which way sounds better because I have listened.
Scintilla: "I can keep well under the threshold for digital overs/clipping" "George, I'm an EE"
http://tinyurl.com/225y6skz
JA: Even set to its highest output level, the Helios produced very low levels of harmonic distortion with full-scale data even into the punishing 600 ohm load"
Cheers George
the Swiss Army knife of digital.
After reading this review I thought that this product is a landmark in the field of modern DACs.
I can see a lot of owners feeling like pros when it comes to tailoring their sound like no other. 20 grand is a steal for what it does after considering how expensive DACs can get.
"20 grand is a steal for what it does after considering how expensive DACs can get."
Yeah, I've seen the preamp "aficionados" spend that much and more on active preamps they don't need, that are just adding more noise, colorations and distortions to the sound, that wouldn't happen if they just went direct instead.
Cheers George
It appears that a URL was not finished at this point in the text:
"After the Q Acoustics speakers had been returned, I used my content/kef-ls50-anniversary-model-loudspeaker">KEF LS50 minimonitors,"
You are welcome, and it is interesting to see that you are still using those KEFs.
Hi JA: Interested to know what preamp you used with the JC1 Halo's, as you didn't state if you did or went direct.?
Cheers George
but digital attenuators subtract information.
..are less lossy according to their creators - but lossy nevertheless especially at lower volumes. I have extensively experimented with direct-to-poweramp modern dacs and I first thought they sounded clearer.. but they just sound simpler; your mileage may vary.
They sell a preamp module purposely for that need. To assume that modern active preamp all have undesirable levels if noise, etc. is naive. Technology has come a looong way.
Benchmark is a great example. They too, like most DAC makers, feel that their digital volume control sounds worse and measures worse than their stand alone active preamps. My experience and reviews find that totally true. DCS and others would be the exception. They clearly have spent enough and designed well enough to ignore a pre.
..but I generally agree that most dacs tend to sound better when connected to a decent active preamp. Added distortion is negligible, noise less so, but dynamics and nuance compensate for both.
Going through an active preamp adds less detail, more noise, more distortions and more colorations.
Cheers George
instant swapping between direct mode and preamplification, so nothing to worry about in case of change of heart. Anyway there are also practical reasons for going preamp. First of all I use multiple sources and outputs (cd player, turntable, dac, tape, headphone amp) which render a control center sine qua non. Moreover with no preamp buffering an accidental push of a little button in the remote can turn on the dac's full output mode and blow the whole system apart.
Even at the lowest level, the amplitude error is <1.1dB, which implies very high resolution. An increase in bit depth from 16 to 24, with dithered data representing a 1kHz tone at –90dBFS, dropped the Helios's noisefloor by 33dB (fig.6). This implies a resolution between 21 and 22 bits, which is the highest I have encountered
..I read and hear much better than you do. Now get off my back. I have no time for talking to a tape loop.
Yeah right!! you hear real good.
I have read that the latest ESS ES9039MSPRO chip specifically addresses the 'IMD hump' in the past chip iteration.
What magic has Weiss wrought from a the '38 and would they see lower IMD from the new chip? Would it matter? Kudos to Weiss for creating a very special DAC.
Hilarious name even beyond 'Schiit' and released in December of 2023. Their new flagship. It even includes MQA-CD from coax and boasts a striking new design with tempered-glass fascia. The price point $1000 and measurements I've seen could be worth a listen and test. There does seem to be one note issue with DOA power after a week or two.
That being said, I would even rather the reviewers to test and listen to the new Holoaudio Cyan 2 at $1199 (or $1350 with shipping). "Equipped with R2R network and vector step resistor network at the same time. The R2R network is used for primary digital-to-analog conversion of the PCM stream, and the vector step resistor network is used for primary digital-to-analog conversion of the DSD stream."
There is support for DSD 1024x and up to PCM 1.536M (32bit). Being more at my price point for digital, I am impressed with either DAC's details.
Hi JA, what was the RMS voltage level at the output when the impulse response was captured? I would like to know if the unit was able to rise to full 0dBFS when given an impulse sample, like the Mola Mola Tambaqui.
Just a short comment on how good a digital level control can be these days. The quality depends on the quality of the D/A Converter. It should be as linear as possible and as low noise as possible. With today's high quality DACs the digital level control can yield extremely good results.
Of course dithering noise has to be applied. Dithering means adding a low level noise signal to the audio signal and then do the quantisation. Quantisation is required because the input word-length of a DAC is not high enough to accommodate for the output after the digital multiplication (i.e. the level control). As an example - if we have a 16 Bit audio signal and multiply that with a 16 Bit gain factor the result is 32 Bit long. For a 16 Bit D/A converter those 32 Bits have to be reduced to 16 Bits. This can be done by cutting them off (i.e. truncation which is bad) or by adding that dithering noise before cutting the Bits off. Dithering causes the quantisation error to become de-correlated from the audio signal and becoming pure noise.
Here are three listening examples with an 8 Bit (!) quantisation.
This example cuts off the bits after the level control to a mere 8 bits without adding dither noise:
http://www.weiss.ch/linked/digital-level-control/nodither.mp3
The quantisation distortion can be easily heard.
This example adds dither noise before the 8 bit quantisation:
www.weiss.ch/linked/digital-level-control/flatdither.mp3
Already much better. The music is undistorted, just noisy because of the 8 bit resolution. The noise is not modulated by the music.
This example adds dither using a shaped noise, i.e. a noise which has a lower level at frequencies which can be heard and higher levels and very high frequencies:
www.weiss.ch/linked/digital-level-control/shapeddither.mp3
An astonishing quality considering that the resolution is 8 bits (256 level steps).
Daniel Weiss
SQ depends on the quality of the D/A converter. Price of the product factors in heavily, I would assume.
And it doesn't depend on cost, I've seen the same ESS ES9038PRO d/a converter used in the $899usd Topping D90SE dac with stunning objective measurements.
https://tinyurl.com/22rpo5bw
And then also used in the $40,000usd Gryphon Ethos D/A processor, 44 x the price, would be interesting to do a subjective listening A/B between the two.
Cheers George
Wow!!! stunning set of measurements JA, must have a listen to this one.
Direct in to the poweramp/s with this baby, (hope you got to do this with the Halo's JA??), nothing says to me more that active preamps are obsolete and a backward sonic step when used with this dac, like these two sentences of your measurements.
JA: "
"Helios's maximum output level at 1kHz feeding 100k ohms was 16.4V with the level set to "0dB"
"The balanced output impedance was 93.5 ohms at all audio frequencies in both Loudspeaker and Headphone modes; the unbalanced output impedance was 47 ohms in both modes."
Cheers George
But then again, that price? How does that compare to everything else? Are such prices still in proportion to everything else in life? Someone who buys this, how much does he pay for a bottle of good wine? For a good coat? For an armchair? For a car? 800? 4K? 20K? 400K? Then it would be proportionate. Of course everyone has their own thing, choice (freedom), hobby and pleasure. Naturally! I just wonder.
At least with this, you'd save thousands by not having to have a preamp and be better off sonically for it.
Cheers George
I ran direct for many years from an NAD M51 using its volume control, then a D90 for another year and finally a Holo May for about 6 months before adding back a Holo Serene preamp to provide better gain-matching for my system. Not only did that addition drastically improve the sound quality it also allowed me to have proper gain matching. There are plenty of utterly transparent preamps on the market and they serve a useful purpose beyond source switching. I believed the dogma for too long that no preamp was the best preamp and I have seen the light. So have a lot of us that went all digital a long time ago and have ben using digital gain structures. The May and the Serene are designed for each other and work and sound magnificent, and much better than the May direct using a digital volume control in HQPlayer. This hobby isn't about "saving thousands" it is about getting the best sound quality -for the dollars- and that doesn't mean eliminating a useful component because it costs money. Listening isn't about theories, its about listening, with your ears, not your ideas.
If you go direct and have enough volume level for listening up to your loudest level with the quietest recording you have, then you have enough gain. (and are "gain matched")
Any more gain by adding an active preamp is not going help it sound any better "what so ever" if anything it's adding more noise and distortion.
And as far as impedance matching, the Weiss Helios D/A processors output stage is perfectly impedance matched for any poweramps input impedance.
And I repeat: "At least with this, you'd save thousands by not having to have a preamp and be better off sonically for it."
Cheers George
I want to preface my comment with sincere thanks for another well considered and well written review in combination with extensive measurements and associated commentary (a lot of work, and very well done), before continuing with some negative criticism of the component that was the subject of the review.
"...balanced and single-ended analog outputs. But on closer inspection, the Helios lacks the earlier processor's headphone jack. It can still be used with headphones, however: Using optional adapter cables ($495), the Helios can drive headphones from its balanced and unbalanced outputs." — J.Atkinson
That would seem to imply that changing output from loudspeakers to headphones requires some cable swapping, detaching the cables interconnecting the rear ports to the loudspeaker power amplifiers, and connecting an adapter cable to those rear ports to power the headphones. To me that seems like a truly shameful asnine engineering solution on a product marketed at a $22k pricepoint, a workaround that might be acceptably accomodated on some kid's entry level cheap-fi system. This should have proper headphone ports on the front panel, classic conventional 1/4 inch (6.35mm) TRS for single ended stereo headphone connection, and the newer 4.4mm Pentaconn for "balanced" (differential) stereo headphone connection, while using internal relays for the switching, and a proper control system.
I know what gain matching is. I also know how to use a network analyzer. In my system, I apply room correction filter in a convolution engine and I have insertion loss so having 6db of clean, class-A gain available without resort to digital is very helpful so I can keep well under the threshold for digital overs/clipping. You do it your way and Ill do it mine. But in my system, I know which way sounds better because I have listened.
Scintilla: "I can keep well under the threshold for digital overs/clipping" "George, I'm an EE"
http://tinyurl.com/225y6skz
JA: Even set to its highest output level, the Helios produced very low levels of harmonic distortion with full-scale data even into the punishing 600 ohm load"
Cheers George
the Swiss Army knife of digital.
After reading this review I thought that this product is a landmark in the field of modern DACs.
I can see a lot of owners feeling like pros when it comes to tailoring their sound like no other. 20 grand is a steal for what it does after considering how expensive DACs can get.
"20 grand is a steal for what it does after considering how expensive DACs can get."
Yeah, I've seen the preamp "aficionados" spend that much and more on active preamps they don't need, that are just adding more noise, colorations and distortions to the sound, that wouldn't happen if they just went direct instead.
Cheers George
It appears that a URL was not finished at this point in the text:
"After the Q Acoustics speakers had been returned, I used my content/kef-ls50-anniversary-model-loudspeaker">KEF LS50 minimonitors,"
You are welcome, and it is interesting to see that you are still using those KEFs.
Hi JA: Interested to know what preamp you used with the JC1 Halo's, as you didn't state if you did or went direct.?
Cheers George
but digital attenuators subtract information.
..are less lossy according to their creators - but lossy nevertheless especially at lower volumes. I have extensively experimented with direct-to-poweramp modern dacs and I first thought they sounded clearer.. but they just sound simpler; your mileage may vary.
They sell a preamp module purposely for that need. To assume that modern active preamp all have undesirable levels if noise, etc. is naive. Technology has come a looong way.
Benchmark is a great example. They too, like most DAC makers, feel that their digital volume control sounds worse and measures worse than their stand alone active preamps. My experience and reviews find that totally true. DCS and others would be the exception. They clearly have spent enough and designed well enough to ignore a pre.
..but I generally agree that most dacs tend to sound better when connected to a decent active preamp. Added distortion is negligible, noise less so, but dynamics and nuance compensate for both.
Going through an active preamp adds less detail, more noise, more distortions and more colorations.
Cheers George
instant swapping between direct mode and preamplification, so nothing to worry about in case of change of heart. Anyway there are also practical reasons for going preamp. First of all I use multiple sources and outputs (cd player, turntable, dac, tape, headphone amp) which render a control center sine qua non. Moreover with no preamp buffering an accidental push of a little button in the remote can turn on the dac's full output mode and blow the whole system apart.
Even at the lowest level, the amplitude error is <1.1dB, which implies very high resolution. An increase in bit depth from 16 to 24, with dithered data representing a 1kHz tone at –90dBFS, dropped the Helios's noisefloor by 33dB (fig.6). This implies a resolution between 21 and 22 bits, which is the highest I have encountered
..I read and hear much better than you do. Now get off my back. I have no time for talking to a tape loop.
Yeah right!! you hear real good.
I have read that the latest ESS ES9039MSPRO chip specifically addresses the 'IMD hump' in the past chip iteration.
What magic has Weiss wrought from a the '38 and would they see lower IMD from the new chip? Would it matter? Kudos to Weiss for creating a very special DAC.
Hilarious name even beyond 'Schiit' and released in December of 2023. Their new flagship. It even includes MQA-CD from coax and boasts a striking new design with tempered-glass fascia. The price point $1000 and measurements I've seen could be worth a listen and test. There does seem to be one note issue with DOA power after a week or two.
That being said, I would even rather the reviewers to test and listen to the new Holoaudio Cyan 2 at $1199 (or $1350 with shipping). "Equipped with R2R network and vector step resistor network at the same time. The R2R network is used for primary digital-to-analog conversion of the PCM stream, and the vector step resistor network is used for primary digital-to-analog conversion of the DSD stream."
There is support for DSD 1024x and up to PCM 1.536M (32bit). Being more at my price point for digital, I am impressed with either DAC's details.
Hi JA, what was the RMS voltage level at the output when the impulse response was captured? I would like to know if the unit was able to rise to full 0dBFS when given an impulse sample, like the Mola Mola Tambaqui.
Just a short comment on how good a digital level control can be these days. The quality depends on the quality of the D/A Converter. It should be as linear as possible and as low noise as possible. With today's high quality DACs the digital level control can yield extremely good results.
Of course dithering noise has to be applied. Dithering means adding a low level noise signal to the audio signal and then do the quantisation. Quantisation is required because the input word-length of a DAC is not high enough to accommodate for the output after the digital multiplication (i.e. the level control). As an example - if we have a 16 Bit audio signal and multiply that with a 16 Bit gain factor the result is 32 Bit long. For a 16 Bit D/A converter those 32 Bits have to be reduced to 16 Bits. This can be done by cutting them off (i.e. truncation which is bad) or by adding that dithering noise before cutting the Bits off. Dithering causes the quantisation error to become de-correlated from the audio signal and becoming pure noise.
Here are three listening examples with an 8 Bit (!) quantisation.
This example cuts off the bits after the level control to a mere 8 bits without adding dither noise:
http://www.weiss.ch/linked/digital-level-control/nodither.mp3
The quantisation distortion can be easily heard.
This example adds dither noise before the 8 bit quantisation:
www.weiss.ch/linked/digital-level-control/flatdither.mp3
Already much better. The music is undistorted, just noisy because of the 8 bit resolution. The noise is not modulated by the music.
This example adds dither using a shaped noise, i.e. a noise which has a lower level at frequencies which can be heard and higher levels and very high frequencies:
www.weiss.ch/linked/digital-level-control/shapeddither.mp3
An astonishing quality considering that the resolution is 8 bits (256 level steps).
Daniel Weiss
SQ depends on the quality of the D/A converter. Price of the product factors in heavily, I would assume.
And it doesn't depend on cost, I've seen the same ESS ES9038PRO d/a converter used in the $899usd Topping D90SE dac with stunning objective measurements.
https://tinyurl.com/22rpo5bw
And then also used in the $40,000usd Gryphon Ethos D/A processor, 44 x the price, would be interesting to do a subjective listening A/B between the two.
Cheers George
Wow!!! stunning set of measurements JA, must have a listen to this one.
Direct in to the poweramp/s with this baby, (hope you got to do this with the Halo's JA??), nothing says to me more that active preamps are obsolete and a backward sonic step when used with this dac, like these two sentences of your measurements.
JA: "
"Helios's maximum output level at 1kHz feeding 100k ohms was 16.4V with the level set to "0dB"
"The balanced output impedance was 93.5 ohms at all audio frequencies in both Loudspeaker and Headphone modes; the unbalanced output impedance was 47 ohms in both modes."
Cheers George
But then again, that price? How does that compare to everything else? Are such prices still in proportion to everything else in life? Someone who buys this, how much does he pay for a bottle of good wine? For a good coat? For an armchair? For a car? 800? 4K? 20K? 400K? Then it would be proportionate. Of course everyone has their own thing, choice (freedom), hobby and pleasure. Naturally! I just wonder.
At least with this, you'd save thousands by not having to have a preamp and be better off sonically for it.
Cheers George
I ran direct for many years from an NAD M51 using its volume control, then a D90 for another year and finally a Holo May for about 6 months before adding back a Holo Serene preamp to provide better gain-matching for my system. Not only did that addition drastically improve the sound quality it also allowed me to have proper gain matching. There are plenty of utterly transparent preamps on the market and they serve a useful purpose beyond source switching. I believed the dogma for too long that no preamp was the best preamp and I have seen the light. So have a lot of us that went all digital a long time ago and have ben using digital gain structures. The May and the Serene are designed for each other and work and sound magnificent, and much better than the May direct using a digital volume control in HQPlayer. This hobby isn't about "saving thousands" it is about getting the best sound quality -for the dollars- and that doesn't mean eliminating a useful component because it costs money. Listening isn't about theories, its about listening, with your ears, not your ideas.
If you go direct and have enough volume level for listening up to your loudest level with the quietest recording you have, then you have enough gain. (and are "gain matched")
Any more gain by adding an active preamp is not going help it sound any better "what so ever" if anything it's adding more noise and distortion.
And as far as impedance matching, the Weiss Helios D/A processors output stage is perfectly impedance matched for any poweramps input impedance.
And I repeat: "At least with this, you'd save thousands by not having to have a preamp and be better off sonically for it."
Cheers George
I want to preface my comment with sincere thanks for another well considered and well written review in combination with extensive measurements and associated commentary (a lot of work, and very well done), before continuing with some negative criticism of the component that was the subject of the review.
"...balanced and single-ended analog outputs. But on closer inspection, the Helios lacks the earlier processor's headphone jack. It can still be used with headphones, however: Using optional adapter cables ($495), the Helios can drive headphones from its balanced and unbalanced outputs." — J.Atkinson
That would seem to imply that changing output from loudspeakers to headphones requires some cable swapping, detaching the cables interconnecting the rear ports to the loudspeaker power amplifiers, and connecting an adapter cable to those rear ports to power the headphones. To me that seems like a truly shameful asnine engineering solution on a product marketed at a $22k pricepoint, a workaround that might be acceptably accomodated on some kid's entry level cheap-fi system. This should have proper headphone ports on the front panel, classic conventional 1/4 inch (6.35mm) TRS for single ended stereo headphone connection, and the newer 4.4mm Pentaconn for "balanced" (differential) stereo headphone connection, while using internal relays for the switching, and a proper control system.
I know what gain matching is. I also know how to use a network analyzer. In my system, I apply room correction filter in a convolution engine and I have insertion loss so having 6db of clean, class-A gain available without resort to digital is very helpful so I can keep well under the threshold for digital overs/clipping. You do it your way and Ill do it mine. But in my system, I know which way sounds better because I have listened.
Scintilla: "I can keep well under the threshold for digital overs/clipping" "George, I'm an EE"
http://tinyurl.com/225y6skz
JA: Even set to its highest output level, the Helios produced very low levels of harmonic distortion with full-scale data even into the punishing 600 ohm load"
Cheers George
the Swiss Army knife of digital.
After reading this review I thought that this product is a landmark in the field of modern DACs.
I can see a lot of owners feeling like pros when it comes to tailoring their sound like no other. 20 grand is a steal for what it does after considering how expensive DACs can get.
"20 grand is a steal for what it does after considering how expensive DACs can get."
Yeah, I've seen the preamp "aficionados" spend that much and more on active preamps they don't need, that are just adding more noise, colorations and distortions to the sound, that wouldn't happen if they just went direct instead.
Cheers George
It appears that a URL was not finished at this point in the text:
"After the Q Acoustics speakers had been returned, I used my content/kef-ls50-anniversary-model-loudspeaker">KEF LS50 minimonitors,"
You are welcome, and it is interesting to see that you are still using those KEFs.
Hi JA: Interested to know what preamp you used with the JC1 Halo's, as you didn't state if you did or went direct.?
Cheers George
but digital attenuators subtract information.
..are less lossy according to their creators - but lossy nevertheless especially at lower volumes. I have extensively experimented with direct-to-poweramp modern dacs and I first thought they sounded clearer.. but they just sound simpler; your mileage may vary.
They sell a preamp module purposely for that need. To assume that modern active preamp all have undesirable levels if noise, etc. is naive. Technology has come a looong way.
Benchmark is a great example. They too, like most DAC makers, feel that their digital volume control sounds worse and measures worse than their stand alone active preamps. My experience and reviews find that totally true. DCS and others would be the exception. They clearly have spent enough and designed well enough to ignore a pre.
..but I generally agree that most dacs tend to sound better when connected to a decent active preamp. Added distortion is negligible, noise less so, but dynamics and nuance compensate for both.
Going through an active preamp adds less detail, more noise, more distortions and more colorations.
Cheers George
instant swapping between direct mode and preamplification, so nothing to worry about in case of change of heart. Anyway there are also practical reasons for going preamp. First of all I use multiple sources and outputs (cd player, turntable, dac, tape, headphone amp) which render a control center sine qua non. Moreover with no preamp buffering an accidental push of a little button in the remote can turn on the dac's full output mode and blow the whole system apart.
Even at the lowest level, the amplitude error is <1.1dB, which implies very high resolution. An increase in bit depth from 16 to 24, with dithered data representing a 1kHz tone at –90dBFS, dropped the Helios's noisefloor by 33dB (fig.6). This implies a resolution between 21 and 22 bits, which is the highest I have encountered
..I read and hear much better than you do. Now get off my back. I have no time for talking to a tape loop.
Yeah right!! you hear real good.
I have read that the latest ESS ES9039MSPRO chip specifically addresses the 'IMD hump' in the past chip iteration.
What magic has Weiss wrought from a the '38 and would they see lower IMD from the new chip? Would it matter? Kudos to Weiss for creating a very special DAC.
Hilarious name even beyond 'Schiit' and released in December of 2023. Their new flagship. It even includes MQA-CD from coax and boasts a striking new design with tempered-glass fascia. The price point $1000 and measurements I've seen could be worth a listen and test. There does seem to be one note issue with DOA power after a week or two.
That being said, I would even rather the reviewers to test and listen to the new Holoaudio Cyan 2 at $1199 (or $1350 with shipping). "Equipped with R2R network and vector step resistor network at the same time. The R2R network is used for primary digital-to-analog conversion of the PCM stream, and the vector step resistor network is used for primary digital-to-analog conversion of the DSD stream."
There is support for DSD 1024x and up to PCM 1.536M (32bit). Being more at my price point for digital, I am impressed with either DAC's details.
Hi JA, what was the RMS voltage level at the output when the impulse response was captured? I would like to know if the unit was able to rise to full 0dBFS when given an impulse sample, like the Mola Mola Tambaqui.
Just a short comment on how good a digital level control can be these days. The quality depends on the quality of the D/A Converter. It should be as linear as possible and as low noise as possible. With today's high quality DACs the digital level control can yield extremely good results.
Of course dithering noise has to be applied. Dithering means adding a low level noise signal to the audio signal and then do the quantisation. Quantisation is required because the input word-length of a DAC is not high enough to accommodate for the output after the digital multiplication (i.e. the level control). As an example - if we have a 16 Bit audio signal and multiply that with a 16 Bit gain factor the result is 32 Bit long. For a 16 Bit D/A converter those 32 Bits have to be reduced to 16 Bits. This can be done by cutting them off (i.e. truncation which is bad) or by adding that dithering noise before cutting the Bits off. Dithering causes the quantisation error to become de-correlated from the audio signal and becoming pure noise.
Here are three listening examples with an 8 Bit (!) quantisation.
This example cuts off the bits after the level control to a mere 8 bits without adding dither noise:
http://www.weiss.ch/linked/digital-level-control/nodither.mp3
The quantisation distortion can be easily heard.
This example adds dither noise before the 8 bit quantisation:
www.weiss.ch/linked/digital-level-control/flatdither.mp3
Already much better. The music is undistorted, just noisy because of the 8 bit resolution. The noise is not modulated by the music.
This example adds dither using a shaped noise, i.e. a noise which has a lower level at frequencies which can be heard and higher levels and very high frequencies:
www.weiss.ch/linked/digital-level-control/shapeddither.mp3
An astonishing quality considering that the resolution is 8 bits (256 level steps).
Daniel Weiss
SQ depends on the quality of the D/A converter. Price of the product factors in heavily, I would assume.
And it doesn't depend on cost, I've seen the same ESS ES9038PRO d/a converter used in the $899usd Topping D90SE dac with stunning objective measurements.
https://tinyurl.com/22rpo5bw
And then also used in the $40,000usd Gryphon Ethos D/A processor, 44 x the price, would be interesting to do a subjective listening A/B between the two.
Cheers George
Wow!!! stunning set of measurements JA, must have a listen to this one.
Direct in to the poweramp/s with this baby, (hope you got to do this with the Halo's JA??), nothing says to me more that active preamps are obsolete and a backward sonic step when used with this dac, like these two sentences of your measurements.
JA: "
"Helios's maximum output level at 1kHz feeding 100k ohms was 16.4V with the level set to "0dB"
"The balanced output impedance was 93.5 ohms at all audio frequencies in both Loudspeaker and Headphone modes; the unbalanced output impedance was 47 ohms in both modes."
Cheers George
But then again, that price? How does that compare to everything else? Are such prices still in proportion to everything else in life? Someone who buys this, how much does he pay for a bottle of good wine? For a good coat? For an armchair? For a car? 800? 4K? 20K? 400K? Then it would be proportionate. Of course everyone has their own thing, choice (freedom), hobby and pleasure. Naturally! I just wonder.
At least with this, you'd save thousands by not having to have a preamp and be better off sonically for it.
Cheers George
I ran direct for many years from an NAD M51 using its volume control, then a D90 for another year and finally a Holo May for about 6 months before adding back a Holo Serene preamp to provide better gain-matching for my system. Not only did that addition drastically improve the sound quality it also allowed me to have proper gain matching. There are plenty of utterly transparent preamps on the market and they serve a useful purpose beyond source switching. I believed the dogma for too long that no preamp was the best preamp and I have seen the light. So have a lot of us that went all digital a long time ago and have ben using digital gain structures. The May and the Serene are designed for each other and work and sound magnificent, and much better than the May direct using a digital volume control in HQPlayer. This hobby isn't about "saving thousands" it is about getting the best sound quality -for the dollars- and that doesn't mean eliminating a useful component because it costs money. Listening isn't about theories, its about listening, with your ears, not your ideas.
If you go direct and have enough volume level for listening up to your loudest level with the quietest recording you have, then you have enough gain. (and are "gain matched")
Any more gain by adding an active preamp is not going help it sound any better "what so ever" if anything it's adding more noise and distortion.
And as far as impedance matching, the Weiss Helios D/A processors output stage is perfectly impedance matched for any poweramps input impedance.
And I repeat: "At least with this, you'd save thousands by not having to have a preamp and be better off sonically for it."
Cheers George
I want to preface my comment with sincere thanks for another well considered and well written review in combination with extensive measurements and associated commentary (a lot of work, and very well done), before continuing with some negative criticism of the component that was the subject of the review.
"...balanced and single-ended analog outputs. But on closer inspection, the Helios lacks the earlier processor's headphone jack. It can still be used with headphones, however: Using optional adapter cables ($495), the Helios can drive headphones from its balanced and unbalanced outputs." — J.Atkinson
That would seem to imply that changing output from loudspeakers to headphones requires some cable swapping, detaching the cables interconnecting the rear ports to the loudspeaker power amplifiers, and connecting an adapter cable to those rear ports to power the headphones. To me that seems like a truly shameful asnine engineering solution on a product marketed at a $22k pricepoint, a workaround that might be acceptably accomodated on some kid's entry level cheap-fi system. This should have proper headphone ports on the front panel, classic conventional 1/4 inch (6.35mm) TRS for single ended stereo headphone connection, and the newer 4.4mm Pentaconn for "balanced" (differential) stereo headphone connection, while using internal relays for the switching, and a proper control system.
I know what gain matching is. I also know how to use a network analyzer. In my system, I apply room correction filter in a convolution engine and I have insertion loss so having 6db of clean, class-A gain available without resort to digital is very helpful so I can keep well under the threshold for digital overs/clipping. You do it your way and Ill do it mine. But in my system, I know which way sounds better because I have listened.
Scintilla: "I can keep well under the threshold for digital overs/clipping" "George, I'm an EE"
http://tinyurl.com/225y6skz
JA: Even set to its highest output level, the Helios produced very low levels of harmonic distortion with full-scale data even into the punishing 600 ohm load"
Cheers George
the Swiss Army knife of digital.
After reading this review I thought that this product is a landmark in the field of modern DACs.
I can see a lot of owners feeling like pros when it comes to tailoring their sound like no other. 20 grand is a steal for what it does after considering how expensive DACs can get.
"20 grand is a steal for what it does after considering how expensive DACs can get."
Yeah, I've seen the preamp "aficionados" spend that much and more on active preamps they don't need, that are just adding more noise, colorations and distortions to the sound, that wouldn't happen if they just went direct instead.
Cheers George
It appears that a URL was not finished at this point in the text:
"After the Q Acoustics speakers had been returned, I used my content/kef-ls50-anniversary-model-loudspeaker">KEF LS50 minimonitors,"
You are welcome, and it is interesting to see that you are still using those KEFs.
Hi JA: Interested to know what preamp you used with the JC1 Halo's, as you didn't state if you did or went direct.?
Cheers George
but digital attenuators subtract information.
..are less lossy according to their creators - but lossy nevertheless especially at lower volumes. I have extensively experimented with direct-to-poweramp modern dacs and I first thought they sounded clearer.. but they just sound simpler; your mileage may vary.
They sell a preamp module purposely for that need. To assume that modern active preamp all have undesirable levels if noise, etc. is naive. Technology has come a looong way.
Benchmark is a great example. They too, like most DAC makers, feel that their digital volume control sounds worse and measures worse than their stand alone active preamps. My experience and reviews find that totally true. DCS and others would be the exception. They clearly have spent enough and designed well enough to ignore a pre.
..but I generally agree that most dacs tend to sound better when connected to a decent active preamp. Added distortion is negligible, noise less so, but dynamics and nuance compensate for both.
Going through an active preamp adds less detail, more noise, more distortions and more colorations.
Cheers George
instant swapping between direct mode and preamplification, so nothing to worry about in case of change of heart. Anyway there are also practical reasons for going preamp. First of all I use multiple sources and outputs (cd player, turntable, dac, tape, headphone amp) which render a control center sine qua non. Moreover with no preamp buffering an accidental push of a little button in the remote can turn on the dac's full output mode and blow the whole system apart.
Even at the lowest level, the amplitude error is <1.1dB, which implies very high resolution. An increase in bit depth from 16 to 24, with dithered data representing a 1kHz tone at –90dBFS, dropped the Helios's noisefloor by 33dB (fig.6). This implies a resolution between 21 and 22 bits, which is the highest I have encountered
..I read and hear much better than you do. Now get off my back. I have no time for talking to a tape loop.
Yeah right!! you hear real good.
I have read that the latest ESS ES9039MSPRO chip specifically addresses the 'IMD hump' in the past chip iteration.
What magic has Weiss wrought from a the '38 and would they see lower IMD from the new chip? Would it matter? Kudos to Weiss for creating a very special DAC.
Hilarious name even beyond 'Schiit' and released in December of 2023. Their new flagship. It even includes MQA-CD from coax and boasts a striking new design with tempered-glass fascia. The price point $1000 and measurements I've seen could be worth a listen and test. There does seem to be one note issue with DOA power after a week or two.
That being said, I would even rather the reviewers to test and listen to the new Holoaudio Cyan 2 at $1199 (or $1350 with shipping). "Equipped with R2R network and vector step resistor network at the same time. The R2R network is used for primary digital-to-analog conversion of the PCM stream, and the vector step resistor network is used for primary digital-to-analog conversion of the DSD stream."
There is support for DSD 1024x and up to PCM 1.536M (32bit). Being more at my price point for digital, I am impressed with either DAC's details.
Hi JA, what was the RMS voltage level at the output when the impulse response was captured? I would like to know if the unit was able to rise to full 0dBFS when given an impulse sample, like the Mola Mola Tambaqui.
Just a short comment on how good a digital level control can be these days. The quality depends on the quality of the D/A Converter. It should be as linear as possible and as low noise as possible. With today's high quality DACs the digital level control can yield extremely good results.
Of course dithering noise has to be applied. Dithering means adding a low level noise signal to the audio signal and then do the quantisation. Quantisation is required because the input word-length of a DAC is not high enough to accommodate for the output after the digital multiplication (i.e. the level control). As an example - if we have a 16 Bit audio signal and multiply that with a 16 Bit gain factor the result is 32 Bit long. For a 16 Bit D/A converter those 32 Bits have to be reduced to 16 Bits. This can be done by cutting them off (i.e. truncation which is bad) or by adding that dithering noise before cutting the Bits off. Dithering causes the quantisation error to become de-correlated from the audio signal and becoming pure noise.
Here are three listening examples with an 8 Bit (!) quantisation.
This example cuts off the bits after the level control to a mere 8 bits without adding dither noise:
http://www.weiss.ch/linked/digital-level-control/nodither.mp3
The quantisation distortion can be easily heard.
This example adds dither noise before the 8 bit quantisation:
www.weiss.ch/linked/digital-level-control/flatdither.mp3
Already much better. The music is undistorted, just noisy because of the 8 bit resolution. The noise is not modulated by the music.
This example adds dither using a shaped noise, i.e. a noise which has a lower level at frequencies which can be heard and higher levels and very high frequencies:
www.weiss.ch/linked/digital-level-control/shapeddither.mp3
An astonishing quality considering that the resolution is 8 bits (256 level steps).
Daniel Weiss
SQ depends on the quality of the D/A converter. Price of the product factors in heavily, I would assume.
And it doesn't depend on cost, I've seen the same ESS ES9038PRO d/a converter used in the $899usd Topping D90SE dac with stunning objective measurements.
https://tinyurl.com/22rpo5bw
And then also used in the $40,000usd Gryphon Ethos D/A processor, 44 x the price, would be interesting to do a subjective listening A/B between the two.
Cheers George