The Objective DAC is Here!

[kanwar]

Great buy Thad....

 

[Thad E Ginathom]

Having spent a few months dreaming of various options more than ten times the price, I really think it is a great buy.

the extra dosh spent on the original enclosure seems worth it

It is a nice box, although many here have said that it is overpriced. Actually, I think JDS will even "personalise" their product boxes with a print to order. Apart from having nothing in particular to have printed, I did not want to affect the resale value, this being an experimental buy that could have ended up in the For-Sale forum if it hadn't suited me.

What I appreciate is that people have the choice, and that a good DAC can be had at a lesser price with just a little work. Also, of course, for many the DIYing is all part of the fun.

 

[maniac_2004]

How does one connect various outputs to this dac ? There is only an USB input so does one have to take a RCA->usb connector ? What about phones like iphone and also 3.5 mm jacks ?

Regds

 

[Thad E Ginathom]

This is purely a USB DAC. It has one USB Digital Input and one Analogue Line Out.

There are two ready-built versions available.

-- One has 3.5mm-jack line out;

-- the other has 3.5mm-jack and RCA line out. One can use either but not both at once.

If someone needs a DAC to take central place in the hifi stack, with numerous inputs, then this is certainly not the DAC for them. This is simply a USB DAC for computer or laptop, or any USB device that is able to not only feed data to it but also power it.

 

[maniac_2004]

If someone needs a DAC to take central place in the hifi stack, with numerous inputs, then this is certainly not the DAC for them. This is simply a USB DAC for computer or laptop, or any USB device that is able to not only feed data to it but also power it.

So will the o2 odac combo from jds labs be a better buy. What are your views on it ? Also does the power constraint mean that it will have to be powered thru a computer usb data connection ?

 

[Thad E Ginathom]

So will the o2 odac combo from jds labs be a better buy.

If you want to listen with headphones. It won't do anything else for you.

Also does the power constraint mean that it will have to be powered thru a computer usb data connection ?

Or a powered USB hub, which means you could connect phones that have USB digital audio out. But USB is the only way to power the ODAC.

The ODAC is a simple product: it does just one thing. It is designed to prove a concept: that a reference-quality DAC can be made at low cost and without many of the "boutique" features that some insist are necessary to achieve that level of performance. That is in my words: the full story is much more, and, if interested, you would have to get it from NwAvGuy's blog.

I guess there are two reasons for buying an ODAC...

1. You want an excellent, simple USB DAC at a low price.
2. NwAvGuy's thoughts and design philosophy interest you, and you want to check it out for yourself.

Of course, one can buy for both reasons! As hifi-spending prices go, it is cheap enough to buy it for the second reason alone, especially if DIYing the enclosure.

 

[BLASTO]

I borrowed an ODAC from Sajjad and tested it with my ATH-M50 for headphone out and my hifi setup for RCA output.

Felt like I have heard everything.

 

[Thad E Ginathom]

my ATH-M50 for headphone out

Was it an ODAC/O2 DAC/AMP combo?

I actually wish I'd bought one of those, even though I have other HP-Amp plans

 

[BLASTO]

Was it an ODAC/O2 DAC/AMP combo?

I actually wish I'd bought one of those, even though I have other HP-Amp plans

It is only ODAC with RCA and HP out.
The volume control is through windows.

Clips after about 50% volume. But that is good enough volume for most cases.

 

[Thad E Ginathom]

Hmmm... ODAC does not have a headphone out. It has a 3.5mm line out and optional RCA line out if you buy that model.

Interesting that you are successfully running headphones direct from that. I admit that it has occurred to me to try, but I do not know enough about the elctronics to be sure that there would be no risk to either hp or ODAC.

ps... this is from the ODAC instructions:

Note: Do not connect headphones directly to the ODAC, The ODAC is a line-output device which absolutely requires connection to an external amplifier

You can find the instructions on JDS Labs' site, but I'll try to get back here with the link. ...Here it is: ODAC Instructions PDF It is the ODAC instructions, even though it says O2 in the URL.


.

 

[BLASTO]

Ordered mine and it is on the way..

Wonder what this thread is doing in the DIY section, A thread in the DAC section will spread the word.

I for one, completely missed it as I have no intensions of anything DIY until I chanced upon a borrowed unit.

This DAC is cheap enough to order one just for the kick and most will most definitely do.

 

[BLASTO]

Sorry, no pics of amazing DIY, because I went the lazy route and bought the ready-boxed (with RCA sockets) version from JDS Labs.

Ahem.. Cough cough. Same pinch.. couch..

 

[Thad E Ginathom]

The opening posters bought the board and made their own boxes. This, I suppose, the thread ended up in DIY.

Yes: it is cheap enough to try, although I'm not certain that I would have paid UK100 (about) if I had not already known some of the story from NwAvGuys blog. I bought a hundred quid's worth of philosophy as much as a hundred quid's worth of DAC :lol:

 

[haisaikat]

Does anyone have any idea around whether having ODAC fed from a a powered USB hub instead of PC USB ports directly will improve the sound?

Vaunix: Rugged, 4 port USB hub for audio, rf, microwave, ATE

http://jplay.eu/forum/computer-audio/clean-usb-out-of-pc/

 

[Thad E Ginathom]

I think you should please try it and let us know

On thing that I have noticed s a certain "sensitivity." I don't know for sure where it lies, but sometimes, when I turn on my powered speakers, they draw enough current to blank the monitor for a second or two. Never enough to reboot the computer, but sometimes I find that the Jack (Linux) audio setup has forgotten about the USB DAC and I have to restart it.

I'd been thinking to change around some plugs/sockets so that the speakers are not drawing on the same UPS (although the UPS convenience will be lost). A powered hub might be a good alternative.

However, presently the Firewire interface is back in action, as I don't find my probably-faulty Bravo Ocean HP amp good for all music, and the ODAC is waiting for its time to come again.

 

[s_sachin]

sometimes I find that the Jack (Linux) audio setup has forgotten about the USB DAC and I have to restart it.

.

I experience this as well where on system boot jack changes the interface assignment .. Earlier hw1 is odac USB and now its hw3. So need to change in jack setup and restart jack. Hope there is a fix for this.

 

[Thad E Ginathom]

Another Jack user? Great!

Earlier hw1 is odac USB and now its hw3...

This is a different problem, and is to do with the fact that your system is assigning device numbers as it finds stuff, and it does not find stuff in the same order on every boot.

I can't give proper instructions for fixing this, but it has to do with using names rather that numbers. Yes, there is a fix for it: I'm fairly certain you can find the information on the linuxmusicians forum.

This is how I see my device listed:

$ aplay -l
...
...
card 2: DAC [UAC1 DAC], device 0: USB Audio [USB Audio]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
$
$

This is how I configure Jack (in the KXStudio cadence tool):

hw:DAC,0 [USB Audio]

offtopic PS... Why do you use Jack? I feel that it is over-the-top and initially hard to understand and configure for music playback. The original reason that I got involved with it is that it has to be used for firewire devices. After that, I started to experiment with EQ to compensate for hearing loss, and, especially with the KXStudio tools, "wiring" stuff together with jack soon becomes intuitive.

 

[s_sachin]

OT again..

Actually I installed the build from AudioPhile Linux | Quality audio on Linux and followed instructions. There is a fluxbox session and they recommend deadbeef player with jack as output for bit perfect sound To me it sounds better than foobar.

 

[captrajesh]

I was keen to hear the ODAC perform as part of a "real hifi" and, also, to see how it compares to other DACs, and how the owners of those DACs hear it. First to be arranged was a visit to Capt Rajesh, where we put it between a laptop (just plain WinXP) and his massive Dared tube amp, feeding sound into his Cadence speakers. The comparison was with his AP DAC. We listened to a variety of music from quite-heavy 60s prog rock, through vocal/acoustic to quite-heavy Western classical orchestral.

There was far less difference than I expected. I am keen on the AP kit that I have heard, it has a really lovely sound, but I thought that, quality aside, the AP might be voiced towards a warmer tone, and that, should the ODAC be as transparent as it is meant to be, there might be a noticeable contrast. That was not the case. We felt that we could perhaps detect a little more depth and/or dynamic range with the AP, but, again, signal levels differed, and we made no more than a very subjective attempt with the volume knob to equalise them. I felt the tests were complimentary to both DACs. If the ODAC is transparent then so is the AP; if the AP is musical, then so is the ODAC.

Immediately after this post, Thad sent me a PM and I wanted to supplement it at leisure but I've gotten busy with some office stuff and some touring and then somehow it got out of my mind.

Yes, prima facie as Thad has put it, ODAC appeared to be a fantastic little piece of equipment. There are differences though, some glaring and some subtle.

First the glaring difference; the output from the ODAC is far less than that of the AP.

Now for the subtle differences; The macro dynamics and the depth of field of the music was better in the AP DAC. Also, to my ears, the LF content from the ODAC was on the lighter side in comparison. This is not exactly surprising because of the elaborate power supplies available in the AP DAC with one transformer for each section when compared to the power to the entire circuit of the ODAC coming through the USB cord.

Of course as Thad rightly put it, approximation sought to be achieved by using the volume control may not be the right way to make a head to head comparison. May be we should do the level matching accurately using a decibel meter sometime. What say Thad?

 

[Thad E Ginathom]

Sure. Do you have such a thing?

I use apps on the android phone, but people talk about something crazy like .1dB tolerance for blind tests. Heck, I hope I got that wrong! I'm sure it is not consciously audible difference.

It'd be interesting to know in absolute terms, but, again, I'm ignorant of the test method. I think it involves playing a known tone and measuring the current at the line out. I don't like to stick meter probes when I don't know what I'm doing . Wait... you're more of an electronics guy... Or Kiranps earns his living with that kind of thing...