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Topic: "Good looking" ODAC/Objective? (Read 12889 times) previous topic - next topic
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"Good looking" ODAC/Objective?

Hello, new member here. As with many posters that I have read from on this forum, I came here after feeling way too greasy with snake oil from the 'audiophile' sites, and googling my way here via NwAvGuy's blog.

I hope to get some advice from you, much more knowledgable than me about these technical issues, and help me cut through the marketing speak.

Currently, I'm listening to my music and movies through my PC. I'm quite happy with the Realtek audio output of my Asus P8P67 - when I chose this board I paid attention to a good implementation, as in low noise and distortion. I'm using a Sennheiser HD595, and am looking at a Sennheiser HD700 or Beyer T90 or AKG701 next. Some of these might be needing some extra power, not sure. That made me look into an external DAC/amp combo, since I'll be changing systems soon and I may no longer have the luxury selecting a board with good sound. I'd like a solution I can use for many years to come.

I'd like to hear the sound as it was meant, and thus keep the coloring an amp or DAC adds to a minimum. That got me to the ODAC/Objective and NwAvGuy's blog. This looks like what I want except for some 'details' that really irk me (I'm a pretty fussy guy in some regards, unfortunately). Those are mainly how the device looks - exteral power brick/wall wart, cables all cluttering the front, and a tiny design that looks like I need pincers to change the volume (I have big hands). It would't hurt to have it look a bit nice too, since it will sit right next to me on my desk all the time of day.

So my first question: is someone offering the ODAC/Objective design in an integrated powersupply variant, in a decent case?

Sofar I have not found such a thing, so I looked around for alternatives. This turned out to be very hard. Too much blabbing, not enough facts. I can't even find out the headphone output impedance of most devices I found.

So my second request for help would be - which of the following would adhere best to the ODAC/Objective adage of being just a gain on a wire? And if you know, could you tell me how much the headphone output impedance is?

I'm looking at the Marantz HD-DAC1, Pioneer U-05, Teac Ai101, Teac UD301, Sony UDA1 (although this seems to have the headphone out as an afterthought), Onkyo CR-N765, Denon PMA-50 and the Asus Essence One series. Any alternatives you might suggest are also welcome - I have no preference for brands.

Thanks for putting up with me!


Re: "Good looking" ODAC/Objective?

Reply #1
NwAvGuy reviewed a number of other DACs, some of which were quite good even in comparison to his.  Have you looked through those?

However, I should note that the headphones you list are all moderate impedance and relatively high sensitivity, making an amp as capable as the O2 somewhat less important. 

Re: "Good looking" ODAC/Objective?

Reply #2
I read a few of them, but they're pretty old and not all can still even be found. In fact, even the ODAC/Objective is hard to find, just a few dealers have it and may take time to ship. The custom version for instance at least had the power input at the back (though it still used the external brick) but this is no longer for sale it seems. He has not posted on his blog for over 4 years, unfortunately.

Yes, the headphones listed are not that fussy, but I do need an external device, as I explained. And I'd like it to be future proof.

Re: "Good looking" ODAC/Objective?

Reply #3
If I didn't already own a Benchmark DAC, here's what I might own:

http://emotiva.com/products/dacs/electronics/dacs/stealth-dc-1

Looks like a nice versatile unit which can be used as a regular preamplifier too. I am lazy and enjoy being able to select from a number of different digital sources at the push of a button.

ODAC and O2 are great but I prefer O2 with 2x 9V batteries onboard, because I discovered that if one powers down a battery-less O2 at the power strip, it emits a whopping pulse of DC. At the time, I had powered speakers connected: That was interesting.


Re: "Good looking" ODAC/Objective?

Reply #5
Thanks for the Stealth SP-1 link, looks like another alternative. Does it sound neutral?

Re: "Good looking" ODAC/Objective?

Reply #6
Thanks for the Stealth SP-1 link ... Does it sound neutral?

Specs say that at 44.1K sample rate and 16 bit word length it has:
20 Hz -20 kHz flat to wtihin +/- 0.1 dB
0.00033% THD or less
95 dB signal to noise ratio.

I think that qualifies as a "Yes".

No hard numbers for output impedance except for "Very low output impedance and a flat, load invariant frequency response".

Re: "Good looking" ODAC/Objective?

Reply #7
I found a French website that did a review of the Pioneer U-05 and Marantz HD-DAC1, with some measurements. I can't say if they did those properly, but here are the results.
Test settings
sampling mode 24bit 48kHz
testing chain external loopback
20Hz-20kHz filter ON
Normalize amplitude ON
level change -0.4dB/-0.4dB
mono mode off
calibration signal 1000 Hz
polarity correct/correct

Pioneer U-05
Freq response from 40Hz to 15kHz in dB: +0.03, -0.24
Noise level dB(A): -116.1
Dynamic Range dB(A): 115.9
THD, %: 0.00007
THD + Noise, dB(A): -93.5
IMD + Noise, %: 0.0019
Stereo crosstalk, dB: -104.0
IMD at 10 kH, %: 0.016

Marantz HD-DAC1
Freq response from 40Hz to 15kHz in dB: +0.09, -0.24
Noise level dB(A): -96.9
Dynamic Range dB(A): 96.9
THD, %: 0.016
THD + Noise, dB(A): -73.6
IMD + Noise, %: 0.219
Stereo crosstalk, dB: -76.9
IMD at 10 kH, %: 0.0086

How do these look? I kind of expect Marantz not to sound neutral, but I'm not familiar enough with these measurments to tell. Also, the stereo crosstalk is a factor important for how good a soundstage is formed, right? So is the Marantz poor in this regard?

The website is www.audiovideohd.fr

EDIT: dropping the Emotiva. No dealers or support whatsoever here, and having to pay taxes on re-import in case of repairs is for me a showstopper. I need something that can be purchased/returned if necessary/repaired locally. The list I have in my first post has those brands. But please don't let that deter you from suggesting others.

Re: "Good looking" ODAC/Objective?

Reply #8
How do these look? I kind of expect Marantz not to sound neutral, but I'm not familiar enough with these measurments to tell. Also, the stereo crosstalk is a factor important for how good a soundstage is formed, right? So is the Marantz poor in this regard?
Better than about -20dB (and -76dB is stratospherically better than -20dB) is easy to measure but extremely difficult to hear in normal loudspeaker listening. Much easier to detect with headphones and signals in a single channel, but not if you use a digital crossfeed. :-)

No harm in being better, but it's helpful to understand what's audible and what isn't / what matters and what doesn't.

There is harm if some other quantity that wasn't measured is audibly problematic on the one with "better" measurements. I'm not saying for one minute that this is the case here; I have no idea.

Cheers,
David.

Re: "Good looking" ODAC/Objective?

Reply #9
None of the reported test results should make an audible difference between the Pioneer and the Marantz. I am a bit surprised, however, that the Marantz seems to be significantly worse that what should be easily achievable using modern electronics.

Re: "Good looking" ODAC/Objective?

Reply #10
Thanks! The Marantz isn't top of my list anyway (these are the headphone amp results, DAC mode was even worse) because of the tacky plastic sides. Putting fake wood on a device kinda makes me wonder how fake the rest is too. I know that's no reason to diss the Marantz, measured results are all that counts, but from a marketing/design point of view, it seems kind of a stupid thing to do. Just use real wood.

Re: "Good looking" ODAC/Objective?

Reply #11
OK, found another French site with similar measurements of the Teac UD-301.

Test settings
sampling mode 24bit 48kHz
testing chain external loopback
20Hz-20kHz filter OFF (which is different from the Pioneer/Marantz tests)
Normalize amplitude ON
level change -0.0dB/-0.1dB
mono mode off
calibration signal 1000 Hz
polarity correct/correct

Teac UD-301
Freq response from 40Hz to 15kHz in dB: +0.01, -0.19
Noise level dB(A): -109.1
Dynamic Range dB(A): 108.9
THD, %: 0.0004
THD + Noise, dB(A): -100.6
IMD + Noise, %: 0.0018
Stereo crosstalk, dB: -105.1
IMD at 10 kH, %: 0.024

If I learned a little from your comments, this looks good. However, they use one different setting (see red text). Does this make the results comparable or would the results be much different with the filter ON? And these results may be for the DAC output, I can't tell for sure if these are valid for the headphone output, unfortunately.

Also, they rate the Teac (www.hdfever.fr) down because of a serious quality issue on the USB input:
Rien qu’en prenant les mesures coaxiale > RCA les relevés de bruit et gamme dynamique indiquent jusqu’à 25-30 dB de différence, 10 dB sur la diaphonie, une distorsion décuplée, etc. C’est colossal.

What this translates to is that they measured on the coax input, and the measurments of the USB input showed a 25-30dB worse dynamic range, 10dB worse on stereo crosstalk and a doubled distortion value etc.

Is such a thing really possible? USB is digital after all, so the problem would be on the Teac internals. But at this level, is this more likely a defective sample, or do such things actually happen to 'big name brands' like Teac?


Re: "Good looking" ODAC/Objective?

Reply #13
I have a O2/ODAC stack from massdrop.  Their version was assembled in China (hence the cheaper price).  The options available through massdrop meant all the connections (except the headphone jack) are in the back so it's pretty clean looking from the front (the "desktop" version).  The power supply is external but I think that's desirable from an interference perspective.  The volume knob is a good size and had some resistance so minute adjustments are easy.  It has a rubber o-ring to enhance grip.

I did have to send my first O2 Amp back due to a problem with one of the channels losing power but it was replaced quickly within days with a good unit.  I drive everything from IEMs to the 250 ohm version of the Beyerdynamics DT-990 to Sennheiser HD-800.  For gain, I ended up with 1.0x and 3.3x combination.  With ODAC as the source, 6.5x was way too much power.  (my original was 2.5x/6.5x unit and the replacement unit was 1.0x/3.3x). 

There was some discussion in the massdrop forum about the quality of the units vs JDS Labs or Mayflower but not having dealt with those companies' products, I can't say much there.  I do believe warranty service and tech support in general is much better with them.  Also there were some talk regarding the included wall warts being "under spec" but I haven't experienced any issues.  Others have upgraded to "up to spec" power supplies but no difference in sound were reported. 

Good hunting.

Re: "Good looking" ODAC/Objective?

Reply #14
Is such a thing really possible? USB is digital after all, so the problem would be on the Teac internals. But at this level, is this more likely a defective sample, or do such things actually happen to 'big name brands' like Teac?

USB is digital but the amplifiers and other components are still analog.  Sounds like they screwed something up and didn't properly isolate the USB lines from the analog parts. 

Re: "Good looking" ODAC/Objective?

Reply #15
What this translates to is that they measured on the coax input, and the measurments of the USB input showed a 25-30dB worse dynamic range, 10dB worse on stereo crosstalk and a doubled distortion value etc.
Ground loop maybe.
Also, it is useful to remember about RMAA flaws: http://nwavguy.blogspot.ru/2011/02/rightmark-audio-analyzer-rmaa.html

Re: "Good looking" ODAC/Objective?

Reply #16
Output impedance specs are conspicuously absent: I'd think that could potentially make the biggest audible difference for a headphone amplifier.

Teac: Yes, sounds like a possible ground loop issue, had this happen with an HP notebook computer + cheap USB DAC: If both were grounded, noise floor would rise dramatically, but if I ran the computer from battery power, all was well. I'm thinking the degraded crosstalk and distortion performance would still be far below audibility if we're talking 0.0008% and -95.1 dB respectively.

Re: "Good looking" ODAC/Objective?

Reply #17
4season, I can't find the output impedance on any of the listed devices. That is, the headphone output, the other outputs often do get their impedance listed. It's very frustrating.

As for the ground loop issue, I take it this is still a problem with the Teac? As saratoga mentioned, they should design it so that the USB is separated between device and PC? Or is this something that can happen to any device depending on the circumstances and I need a galvanic isolator 'inbetween' gadget to solve this?

I'm striking the Onkyo and Denon from my list. I simply cannot find any real data on them, just "audiophile poetry" that doubles as a review. Pity, because the Denon really had the features I needed and I could use it standing on its side. The Onkyo had a lot of kit I don't need (CD drive, network radio). Both did get the standard reviews at the usual places, but no-one seemed interested to look at the headphone output, so I'm guessing these devices weren't intended for headphone use to begin with.

Re: "Good looking" ODAC/Objective?

Reply #18
Filter off may be NOS mode like with the 501 http://archimago.blogspot.de/2013/05/measurements-teac-ud-501-pcm-performance.html

Wombat, is this site reliable? He seems to know what he's talking about, and relies on measurments. The reason I'm confirming is that he puts the Asus below the Teac. The Teac having some problems as described (though it's the UD-301) and a few remarks I found on Head-Fi (I think, don't remember the place, I should have bookmarked it) where they complained about the build quality of the new much more expensive 503 - cold solder points and such, really unacceptable in this price range - my confidence in Teac as a brand is somewhat shaken.

That would mean the Teac and the Asus would be striken from my list. Damn.

Re: "Good looking" ODAC/Objective?

Reply #19
Wombat, is this site reliable? He seems to know what he's talking about, and relies on measurments.
He does his best but has no multi thousand $ measuring equipment. The units he tests he usualy uses himself and nothing is sponsored. I like his approach.
Is troll-adiposity coming from feederism?
With 24bit music you can listen to silence much louder!

Re: "Good looking" ODAC/Objective?

Reply #20
I've been reading his tests for a couple of hours now, he does seem to be quite down to earth. A valuable resource, thanks for sharing it!

The Teac does get good results and he seems to like it. However he does mention the headphone amp is not very powerful and some headphones like the AKG Q701 would have troubles. This is interesting for me, because  100mW 32Ohm does not really mean anything to me, is it powerful or weak? Now I have a reference.

What power level should I be looking for as a minimum, so that I don't have to worry about future headphones? Would 180mW/32Ohm be enough, or would you really need the whopping 800mW/32Ohm of the Marantz?

Re: "Good looking" ODAC/Objective?

Reply #21
180 mW into 32 ohms is 2.4 volts, which is pretty respectable.  I doubt you'd want something higher unless you were planning to buy some really unusual headphones. 

Re: "Good looking" ODAC/Objective?

Reply #22
Correction, my mistake, the Marantz is 2x400mW. The Pioneer is 2x180mW. Just in case anyone's wondering.

Thanks all for your help! I learned a lot, and through a proces of elimination am left with the Pioneer U-05.

I struck the Denon, Onkyo and Sony because I could not find much on them as far as the headphone output is concerned. And the Sony turns out has a fan at the back.

The Teac UD-301 did not look pretty on the inside. Cable bridges on boards, looked like it was thrown in the case, transformer unshielded, and a USB issue, possible ground loop. The UD-501 is more expensive, looks better built, and did get a good review from Archimago, but shares the somewhat underpowered headphone output of the UD-301. And overall, I do keep finding people having reliability issues with these devices (having to send them in for repair or exchange). Really a pity, I liked the look of the Teac case design.

Archimago had some issues with the Asus Essence One, and considering the price is the same as other devices, I decided to delist this one too.

I really wanted to like the Marantz, great look, some interesting features, but the tacky plastic side panels, the reported annoying clicking noise when it loses sync (apparently between every track) and again some reliability problems (hum) reported in the thread on Head-Fi made me want to avoid this one too.

So I'm left with the Pioneer. It gets good reviews, if you can find them. It's not a popular device it seems, relatively hard to find. But it has all the boxes ticked of features I need and good measurements. It also does not cost a lot.

However, I'm still a bit unsatisfied. I didn't 'choose' the Pioneer, I came by it because of a lack of other options. I've fired off an email to Emotiva, inquiring about a close by dealer, maybe they have one after all, can't hurt to ask.

If anyone has other suitable alternatives in mind, price range around 500-700 USD or less, please let me know!

Re: "Good looking" ODAC/Objective?

Reply #23
One more question about the Pioneer. Since I could not find anything about headphone output impedance (same for the Emotiva, why is everyone hiding this information?), I looked up the technical data on the used opamps for the Pioneer's headphone amp section. They used the OPA2134, which NwAvGuy tested as being okay, but a bit overpriced for its performance.

In the specsheet I find this:
Output Impedance,
Closed-Loop f = 10 kHz 0.01Ω
Open-Loop f = 10 kHz 10Ω

Is this information of any use? Or would a manufacturer actually add resistors or other components to increase impedance?
Which of these values is the correct one to designate to the output, open or closed loop (so I can compare to other devices)?

Re: "Good looking" ODAC/Objective?

Reply #24
Pioneer U-05
I'm left with the Pioneer.
If anyone has other suitable alternatives in mind, price range around 500-700 USD or less, please let me know!
Isn't Pioneer out of 700 USD range? $965 on amazon.com.
For €672,27 (what is ~$760) you can get Violectric V100 with USB input 24/96 - http://lake-people.de/produktdetails/HPA_V100.html

If integrated powersupply unit wasn't mandatory, you'd have more choices and lesser prices.