Halide Design DAC HD D/A converter Associated Equipment

Sidebar 2: Associated Equipment

Analog Sources: Linn Sondek LP12 turntable with Lingo power supply, Linn Ekos tonearm, Linn Arkiv B phono cartridge.
Digital Sources: Ayre Acoustics C-5xeMP & DX-5 universal players; Apple 2.7GHz i7 Mac mini laptop running OS10.7, iTunes 10, Pure Music 1.86; Shuttle PC with Lynx AES16 soundcard & dual-core AMD Athlon processor running Windows 7, Foobar 2000, Adobe Audition 3.0; Musical Fidelity V-DAC II, Benchmark DAC1, Logitech Transporter, Mark Levinson No.30.6 D/A converters; Ayre Acoustics QA-9 USB A/D converter.
Preamplification: Liberty B2B-1 phono preamplifier, Classé CP-800 preamplifier.
Power Amplifiers: Classé CT-M600, Lamm M1.2 Reference (both monoblocks).
Loudspeakers: BBC LS3/5a, Emotiva X-REF XRT-5.2, PSB Imagine Mini.
Cables: Digital: DH Labs Silver Sonic. AES/EBU: AudioQuest Coffee, Belkin Gold USB. FireWire: AudioQuest FireWire 400 (prototype). Interconnect (balanced): AudioQuest Wild. Speaker: QED. AC: XLO Reference 3, manufacturers' own.
Accessories: Target TT-5 equipment racks; Ayre Acoustics Myrtle Blocks; ASC Tube Traps, RPG Abffusor panels; Shunyata Research Dark Field cable elevators; Audio Power Industries 116 Mk.II & PE-1, APC S-15 AC line conditioners (computers, hard drive). AC power comes from two dedicated 20A circuits, each just 6' from breaker box.—John Atkinson

Company Info
Halide Design
(858) 224-3551
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Sumflow's picture
Computer Audio

 

The Halide allows easy connecting to computers, but your review does not address the Halide HD’s inability to control the volume from the computer without derogating the sound.

John Atkinson's picture
Re: Computer Audio

Quote:
your review does not address the Halide HD’s inability to control the volume from the computer without derogating the sound.

if you are feeding the Halide's output to your preamplifier, you don't need to adjust the DAC HD's volume with the computer, so your criticism is moot. If you are feeding the Halide drectly to a power amplifier or headphone amplifier without a volume control, then you can use the volume control in Pure Music, which is very much more transparent than the system volume control. But I don't recommend this set-up, as any reset of the system might result in full-level sound being fed to your speakers.

John Atkinson

Editor, Stereophile

Sumflow's picture
Computer Audio

 

And what about all the other uses of a computers volume control, doesn’t everything go through the Dac?

deckeda's picture
Short answer: No

Long answer:
The computer and/or software player is setup to send audio to the external DAC; the "rest" of the computer still sends audio to the computer's internal system.

The goal is for the computer becomes a dedicated component. Quit the music player and the computer acts like it always has.

Et Quelle's picture
Swallow

With all the things you here about quality of good components weighing more, it surprising the review of the Halide compared to Musical Fidelity. I would treat it more as an accessory if I were in and out of town. Hey a lot of guys are trying to fill up our shelves on our entertainment center. [Hiding real prices from our wives?] The cover to the book matters. Good Citizen Swallow is a neat low energy track to test a component though. I really got into into it.

John Atkinson's picture
Re: Swallow

Quote:
it surprising the review of the Halide compared to Musical Fidelity.

I don't see why. Both products are intended to do exactly the same thing: take the bits from an audio file, convert them to analog, and send the signal to a line preamplifier. The Halide DAC HD turns a PC into a genuine high-end source at an affordable price.

Quote:
Good Citizen Swallow is a neat low energy track to test a component though. I really got into into it.

The "Lofty Fake Anagram" album was one of the first LPs I bought 40 years ago that sounded better as I improved my system.

John Atkinson

Editor, Stereophile

dalethorn's picture
These new mini-DACs

Having recently acquired a FiiO E17, an HRT iStreamer, HRT Headstreamer, Audioengine D1 and Audioquest Dragonfly, I learned about some of the features and sound quality differences of these items. Since the Dragonfly was nearly twice the price of the Headstreamer, I expected it to sound much better, but it doesn't. It may be better, but not anywhere near the difference between it and the lower fidelity FiiO E17 and iStreamer.

Since the latter 3 DACs I noted all sound similar in quality, I wouldn't expect the DAC-HD to sound a lot better. There does seem to be a glut of these mini-DACs coming on the market now, which may be due to widespread availability of the key components. An interesting and useful feature of many or most of these mini-DACs is the ability to drive average hi-fi headphones directly at satisfactory volume, and while the manufacturers are careful to not refer to that feature as a 'headphone amp', it begs that comparison.

And that utility to drive hi-fi headphones raises the volume control issue as one other person noted here. I've read the FAQs, many reviews, and discussed the volume issues with some audiophiles, but it's still not very clear who or what is doing the volume attenuation at all times. Despite some of the DAC makers' claims about 'repurposing' a system volume control, it just seems to me that volume must be part of the digital data that goes to the DAC from the computer, and so the DAC's output volume would somehow be set according to the data bits from the computer that describe a volume setting. At the very least, a more precise description of that process by the manufacturers would clear things up. A 'for example' text (which is just an example, not intended to be an actual description) might read like this: "The computer music player senses its volume setting and the system volume setting and internally decides which is applicable (or combines both), and then sends that setting as part of the data stream going to the USB port, via the specified or default output device. It is up to the device on the USB port to act on that setting or ignore it altogether."

John Atkinson's picture
Re: These new mini-DACs

Quote:
An interesting and useful feature of many or most of these mini-DACs is the ability to drive average hi-fi headphones directly at satisfactory volume, and while the manufacturers are careful to not refer to that feature as a 'headphone amp', it begs that comparison.

The engineering requirements for a true headphone amplifier and a DAC that is intended to drive a line-level input are different. So if a manufacturer refrains from claiming that their mini-DAC is also a headphone amp, I feel that should be respected.

Quote:
And that utility to drive hi-fi headphones raises the volume control issue as one other person noted here. I've read the FAQs, many reviews, and discussed the volume issues with some audiophiles, but it's still not very clear who or what is doing the volume attenuation at all times.

If the system volume control is set to the maximum, then the bits sent to the DAC are the bits in the file, which is the optimal situation - no loss of resolution. The Halide DAC HD doesn't have any volume control; the AudioQuest DragonFly (reviewed in our October issue) has an analog-domain volume control, allowing it to be used as a headphone amp without loss of resolution. The same is true for the CEntrance DACPort.

If you want to use the Halide as a headphone amp, then you can either use the system volume control, which will degrade sound quality, or use the high-precision software volume control provided by something like Pure Music, which does a lot better at preserving sound quality. But the real solution is _not_ to use the Halide as a headphone amp - controlling the volume with the computer eliminates the sound quality advantage it has over less-expensive products like the DragonFly.

John Atkinson

Editor, Stereophile

dalethorn's picture
Good clarification

That fills in a few blanks, thank you.

deckeda's picture
A few more blanks filled in, perhaps.

it just seems to me that volume must be part of the digital data that goes to the DAC from the computer, and so the DAC's output volume would somehow be set according to the data bits from the computer that describe a volume setting.

If we consider that a digital level of 0db is the maximum, full distortionless output, that figure is represented by such things as iTunes' maximum volume setting and other software players maximum volume settings. This reference is taken from classic VU meters which display 0 as the max and a few positive integers "beyond" that as the permissible headroom analog recording can sometimes afford. Digital of course can't do that.

Since a digital recording has a relative volume level when created, that becomes the basis or reference for its noise level for whatever resolution was used to create it.

Say you have a 16-bit file played "normally"---fully. Your software player's volume control is maxed. Remember, doing so doesn't "amplify" anything; the volume control is out of the circuit if you will and all 16 bits arrive at the DAC. 

Now lower the volume in iTunes, Pure Music, foobar2000---doesn't matter. You've just reduced the number of bits delivered to the DAC because that's the only way the software CAN reduce the relative volume of a given file.

Whenever you lose bits, you gotta dither (add sophisticated noise) to mask the effects of the lost bits, which by themselves would likely be worse.

iTunes now dithers-I think-but it won't be as sophisticated as the dithering Pure Music and some others can apply. Pure Music even says that if you want to use its most sophisticated dither you need a more recent Mac --- applying good dither on the fly, i.e. while the file is playing, doesn't come free and you need CPU cycles.

Analog volume controls have their own problems of course but traditionally are more benign. That's why you leave your software's volume maxed (think of it as delivering "line level" to your amp) and control volume as you always have, at your amp. The output levels from one DAC's analog out to the next likely isn't too great, just as it isn't likely too different from one CD player to the next.

The Dragonfly and Headstreamer, both being headphone-oriented but with an audiophile conscience, include digitally-controlled analog volume control. Something on the computer (music player app?) retains its volume control interface but instead of delivering a lower relative volume to the DAC delivers full volume and invokes an analog volume within the Dragonfly/Headstreamer hardware. Don't ask me how any of that works.

Sumflow's picture
No effect

Quote:
deckeda :> Quit the music player and the computer acts like it always has.
The Dac only acts on the music player.  It has no effect on MOG, Pandora, Netflix, Hulu, Google phone or any other audio source.  Even thou everything has to pass through Halide HD to get from the USB to the pre-amp?

dalethorn's picture
DAC -vs- MOG and other services

When we say the DAC acts only on the music player, is that because the music player has selected a specific driver or sound processor to send its output to the DAC, whereas the rest of the system isn't calling that same driver/sound processor for its output for the other services?

deckeda's picture
correct

Only dedicated music players will provide the ability to "link up" with an external DAC. A web browser or Spotify app for example has no understanding of what an external DAC is ...

The other way to do it (i.e., send everything through the external DAC) would be to setup the computer OS' audio out to use the DAC by default. And you still would need to setup the software player to use it (which is no big deal.)

Sumflow's picture
Numbers

Quote:
deckeda :> Quit the music player and the computer acts like it always has.
When we go audio out of a computer with an optical cable, isn't that just numbers out?

deckeda's picture
Nope.

Optical connectors and cable such as TOSLink has a physical/mechanical advantage of being immune to electrical interference and other issues like capacitance, voltage loss etc.

What it gains are disadvanatges in suspectibility to other physical attributes such as getting pinched (!) and whatever else challenges light transmission. And it still has a physical length limitation before it begins to lose connectivity with whatever's next in the chain.

The practical issues however, are that for a given DAC that accepts both optical and electrical inputs, one may be more susectible to jitter than the other, or react with a given cable more than the other, leading to performace differences between the two inputs. Numbers ain't numbers.

There are also often resolution differences. Some DACS or computer cards will limit their TOSLink to 24/96. Others may put that limitation on their digital coax port but not the TOSLink. And so on.

And all of that assumes the computer is delivering "perfect numbers" out, which it may not if it's RAM-starved, the storage HD is being asked to do two things at once, the CPU is overburdened trying to decode a lossless file while playing and doing something else, etc.

JadenKrosis's picture
Volume control?

I have the Halide DAC HD in my computer audio system and I`m not clear on this discussion regarding volume control. I turn everything on and listen to music and as far as I know there are no issues with volume.

Mind you I am a newbie to this so for all I know I`m listening to half a system.........

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