[Anaxilus]

The ODAC can change signature depending on the quality of power being supplied.  Nothing new, it's been discussed already.

 

[adydula]

Its not the ODAC changing the sound.....a circuit is designed to do things, in this case to convert digital bits to an analog signal.
 
The circuit needs DC power....clean DC power...provide that and there is no real issue.
 
I have several USB dacs and  5 pcs that I have played with and the changes u imply are so insignificant and there are many more aspects that are important.
 
The ODAC is not cold or warm as shown in blind testing and measuremnents...it does what it does...Digital to Analog conversion...and comparisions with other DACS do show differences...but usually with the source and or the headphone types themselves.
 
Everyone seems to be lookng for the magic sauce that will work with their headpones and their music...with the O2 amp and ODAC you at least have the part of the music reproduction chain that is transparent and constant...and most likely what you think your hearing as cold or warm...is coming from the source, or the transducers or cans themselves..and your brain, mood, having a cold, or sinus or ear infection and hundreds of other "human" things...
 
This is why measurements are important that are done correctly and reflect what could reall affect the reproduction of the source....all the rest is subject to dicussion, debate and argument.
 
Dont take this the wrong way...not starting a flame war etc...there are other well designed pieces of gear, amps and dacs that do very well etc....its just that we have a very well desgined low cost pairing here that is setting the audio world on its ear over simpicity, cost and what it "does not do"..
 
And isnt that what we really want???? os is it??
 
All the best
Alex

 

[sling5s]

How would the Dacport as amp/dac combo compare to O2+ODAC
I know it comes down to power and sound signature but anything else? 

 

[tdockweiler]

I think i've gotten this ODAC issue fixed. You know what's funny?
Thanks to this ODAC i've discovered 3 issues with my setup that i've corrected.
 
First, it turns out that the ODAC needs a ton of power from a USB port or so it seems. This probably would not work on my laptop without a powered usb hub.
 
Next, at one point I had plugged my amp into my $40 Belkin Surge Protector with filters. My first reaction was something like "Ah Hah! There's my nice and full mids".
Only awhile later did I realize it was bloating the bass slightly with my DJ100 and HD-580. Even the soundstage seemed smaller. Since the Q701 is not super bassy, it's sound wasn't changed as much it seems.
I guess the DJ100 with ODAC is good to analyze any power issues

 
Some guy wrote a review of the Micro Amp and said that you shouldn't connect it to a surge protector with filtering because it robs it of power. I just laughed at that. I'm eating my words now.
 
Next, most of my albums sounds OK, but something sounded really off. My impression was like that the mids varied too much. They were often very good and full and then the bad stuff sounds dramatically worse than they should. It felt as if the mids were super thin on this stuff and the treble was slightly too much. The treble itself seemed OK on most good music.
 
On my HRT MSII I used Medium Gain with my amp. Sounded perfect. One reason I did this is that there was an article on Headfonia claiming low gain is generally best blah blah blah. I figured since I'm getting to the 40% volume mark with the Micro Amp that medium gain would be perfectly OK, just like on my HRT MSII. I switched back and forth and didn't hear any difference at all.
 
At random I switched to high gain and left it there. There was this voice at first telling me to NOT DO IT because at high gain on my Q701 I need to set the volume at 8-10%!!!! If I accidentally bumped it to volume my ears might blow up.
 
I have no clue why it sounds better. On my HRT MSII medium gain is perfect. Why the difference with the ODAC? My one idea is that maybe the Micro Amp limits the power to 1.21 gigawatts at Medium Gain. Maybe the Q701 needs about 5 Gigawatts. Here's where it gets even worse..I was doing A/B comparisons with the E10 and the E10 sounded absolutely PERFECT on medium with the Q701! What the heck?
 
So previously I felt that bad songs were thinner that they normally should be. It seriously felt like I was listening to the Q701 with bad recordings, but with the DT-880. It felt like the Q701 was too thin and trebly, but only with the bad stuff. It was such a huge distraction. I mean the Q701 isn't this thin and sounding this way on any other dead neutral gear. Again, most warm recordings or good material sounded perfect usually. Maybe a slight extra amount of treble. It did feel that the sound was more fatiguing than it should be with bad recordings.
 
So right now my harsh/fatiguing/bad tracks are still bad, but made to be not quite as bad. It looks like on High Gain the mids really fill in and the Q701 is back to it's old self (like medium gain on the HRT!!). The treble is now perfectly smooth mostly and even some of the fatiguing stuff isn't so bad and quite listenable. Of course you still know it's bad, but doesn't stick out as much now. So basically due to the slightly thinner mids, my brain is what made me think there was more treble. The Q701 with the bad stuff just sounded so much like my Koss A/250 and a DT-880 in the mids! Yet on a very good song it could be like say the HD-600.
 
It's finally sounding like a normal Q701 should. The way i've ALWAYS heard it, but even better. It just didn't make sense why my Q701 would sound slightly off like this.
 
Last night before bed this setup was sounding so amazing I didn't want to sleep!
 
The ODAC now doesn't seem TOO REVEALING at all. It doesn't make my Q701 cold and analytical. I'm soooooo glad about this. I was thinking (and hoping) that no DAC could do that to the Q701 and I guess I was right.
 
BTW I do find it better than the HRT MSII by far. The HRT MSII doesn't actually sound that much warmer IMO. Just slightly. In comparison to the ODAC, the HRT MSII has a much smaller soundstage.
 
Again, the differences in how I heard this previously and now are not super huge. What i'm going to do is give it 3-5 days and then go back and check my earlier impressions. I will edit them if needed if anything is different. I plan on doing an ODAC review in a week. You wouldn't believe what a nightmare this has been! Sounding a lot more musical now

Even with the garbage tracks! Nope..the ODAC doesn't suddenly rob my precious Q701 of it's natural warmth (a lot of the time it's in the recording too obviously). Just make sure it has a TON of power or something. Still annoying have to use high gain at 8% volume when medium is fine on any other DAC!! I can't explain this one.

 

[adydula]

I have a O2+ Odac with LCD2's....works very very well...
 
A person recently asked this same type of question:
 
recently purchased Audeze LCD-2 revision 2 the specs are;
• Impedance: 60 Ohms, nominal
• Maximum diaphragm excursion: 2.5mm p-p
• Efficiency: 91 dB/1mW
• Maximum output: 133dB, 15W

How would the o2 cope with that? What is its power output in Watts to this headphone? how loud will it drive the LCD-2 in decibels, loud enough? I ask as I have purchased your amp and plan to use it with the LCD-2.

I have a friend electronics engineer and he was saying from a rough quick estimate in his head, that to drive the LCD-2 to full power you would need roughly 400wrms (into 8 ohms) to drive it to full power! Mind you max output of the LCD-2 is a crazy 133db. That's a large full size speaker amp heh.

So will the o2 suffice?

REPLY:
 
There are many happy LCD-2 users using the O2. It has power to spare to drive the LCD-2 to hearing damaging levels and beyond. Your engineer friend needs either read my More Power article or start using the correct LOG button on his calculator. He's very wrong.

The LCD-2 hits 110 dB with about 1 volt of input. Peaks of 110 dB are considered plenty loud by most people (hearing damage starts past 85 dB). 110 dB is standing on a sidewalk next to a jack hammer tearing up concrete.

Even if you plan for 115 dB peaks, which is extremely loud, you only need about 1.7 Vrms which is 0.048 watts. The O2 can provide 5+ Vrms which is good for 124 dB SPL with the LCD-2. And that's running from battery power.

If you really wanted to push the headphones to 133 dB you would need 14 Vrms which is 3.2 watts not 400 watts.
 
But, long story short, even at an ear splitting 124 dB SPL that's a peak voltage of 7 volts. Ohms law gives a peak current of 7/60 = 117 mA. The O2 has a peak current capability of 200 mA per channel--nearly twice what's required.

Current with the LCD-2 is where many headphone amps will fall on their face--especially OTL tube amps, Cmoys, and anything using a typical wimpy virtual ground or 3 channel design.
 
Alex

 

[chrislangley4253]

Quote:

I think i've gotten this ODAC issue fixed. You know what's funny?
Thanks to this ODAC i've discovered 3 issues with my setup that i've corrected.
 
First, it turns out that the ODAC needs a ton of power from a USB port or so it seems. This probably would not work on my laptop without a powered usb hub.
 
Next, at one point I had plugged my amp into my $40 Belkin Surge Protector with filters. My first reaction was something like "Ah Hah! There's my nice and full mids".
Only awhile later did I realize it was bloating the bass slightly with my DJ100 and HD-580. Even the soundstage seemed smaller. Since the Q701 is not super bassy, it's sound wasn't changed as much it seems.
I guess the DJ100 with ODAC is good to analyze any power issues

 
Some guy wrote a review of the Micro Amp and said that you shouldn't connect it to a surge protector with filtering because it robs it of power. I just laughed at that. I'm eating my words now.
 
Next, most of my albums sounds OK, but something sounded really off. My impression was like that the mids varied too much. They were often very good and full and then the bad stuff sounds dramatically worse than they should. It felt as if the mids were super thin on this stuff and the treble was slightly too much. The treble itself seemed OK on most good music.
 
On my HRT MSII I used Medium Gain with my amp. Sounded perfect. One reason I did this is that there was an article on Headfonia claiming low gain is generally best blah blah blah. I figured since I'm getting to the 40% volume mark with the Micro Amp that medium gain would be perfectly OK, just like on my HRT MSII. I switched back and forth and didn't hear any difference at all.
 
At random I switched to high gain and left it there. There was this voice at first telling me to NOT DO IT because at high gain on my Q701 I need to set the volume at 8-10%!!!! If I accidentally bumped it to volume my ears might blow up.
 
I have no clue why it sounds better. On my HRT MSII medium gain is perfect. Why the difference with the ODAC? My one idea is that maybe the Micro Amp limits the power to 1.21 gigawatts at Medium Gain. Maybe the Q701 needs about 5 Gigawatts. Here's where it gets even worse..I was doing A/B comparisons with the E10 and the E10 sounded absolutely PERFECT on medium with the Q701! What the heck?
 
So previously I felt that bad songs were thinner that they normally should be. It seriously felt like I was listening to the Q701 with bad recordings, but with the DT-880. It felt like the Q701 was too thin and trebly, but only with the bad stuff. It was such a huge distraction. I mean the Q701 isn't this thin and sounding this way on any other dead neutral gear. Again, most warm recordings or good material sounded perfect usually. Maybe a slight extra amount of treble. It did feel that the sound was more fatiguing than it should be with bad recordings.
 
So right now my harsh/fatiguing/bad tracks are still bad, but made to be not quite as bad. It looks like on High Gain the mids really fill in and the Q701 is back to it's old self (like medium gain on the HRT!!). The treble is now perfectly smooth mostly and even some of the fatiguing stuff isn't so bad and quite listenable. Of course you still know it's bad, but doesn't stick out as much now. So basically due to the slightly thinner mids, my brain is what made me think there was more treble. The Q701 with the bad stuff just sounded so much like my Koss A/250 and a DT-880 in the mids! Yet on a very good song it could be like say the HD-600.
 
It's finally sounding like a normal Q701 should. The way i've ALWAYS heard it, but even better. It just didn't make sense why my Q701 would sound slightly off like this.
 
Last night before bed this setup was sounding so amazing I didn't want to sleep!
 
The ODAC now doesn't seem TOO REVEALING at all. It doesn't make my Q701 cold and analytical. I'm soooooo glad about this. I was thinking (and hoping) that no DAC could do that to the Q701 and I guess I was right.
 
BTW I do find it better than the HRT MSII by far. The HRT MSII doesn't actually sound that much warmer IMO. Just slightly. In comparison to the ODAC, the HRT MSII has a much smaller soundstage.
 
Again, the differences in how I heard this previously and now are not super huge. What i'm going to do is give it 3-5 days and then go back and check my earlier impressions. I will edit them if needed if anything is different. I plan on doing an ODAC review in a week. You wouldn't believe what a nightmare this has been! Sounding a lot more musical now

Even with the garbage tracks! Nope..the ODAC doesn't suddenly rob my precious Q701 of it's natural warmth (a lot of the time it's in the recording too obviously). Just make sure it has a TON of power or something. Still annoying have to use high gain at 8% volume when medium is fine on any other DAC!! I can't explain this one.

 
 
tdock, I really think you need to try another amp that isn't the micro amp. Really, really. Something like an O2
 
Quote:

I have a O2+ Odac with LCD2's....works very very well...
 
A person recently asked this same type of question:
 
recently purchased Audeze LCD-2 revision 2 the specs are;
• Impedance: 60 Ohms, nominal
• Maximum diaphragm excursion: 2.5mm p-p
• Efficiency: 91 dB/1mW
• Maximum output: 133dB, 15W

How would the o2 cope with that? What is its power output in Watts to this headphone? how loud will it drive the LCD-2 in decibels, loud enough? I ask as I have purchased your amp and plan to use it with the LCD-2.

I have a friend electronics engineer and he was saying from a rough quick estimate in his head, that to drive the LCD-2 to full power you would need roughly 400wrms (into 8 ohms) to drive it to full power! Mind you max output of the LCD-2 is a crazy 133db. That's a large full size speaker amp heh.

So will the o2 suffice?

REPLY:
 
There are many happy LCD-2 users using the O2. It has power to spare to drive the LCD-2 to hearing damaging levels and beyond. Your engineer friend needs either read my More Power article or start using the correct LOG button on his calculator. He's very wrong.

The LCD-2 hits 110 dB with about 1 volt of input. Peaks of 110 dB are considered plenty loud by most people (hearing damage starts past 85 dB). 110 dB is standing on a sidewalk next to a jack hammer tearing up concrete.

Even if you plan for 115 dB peaks, which is extremely loud, you only need about 1.7 Vrms which is 0.048 watts. The O2 can provide 5+ Vrms which is good for 124 dB SPL with the LCD-2. And that's running from battery power.

If you really wanted to push the headphones to 133 dB you would need 14 Vrms which is 3.2 watts not 400 watts.
 
But, long story short, even at an ear splitting 124 dB SPL that's a peak voltage of 7 volts. Ohms law gives a peak current of 7/60 = 117 mA. The O2 has a peak current capability of 200 mA per channel--nearly twice what's required.

Current with the LCD-2 is where many headphone amps will fall on their face--especially OTL tube amps, Cmoys, and anything using a typical wimpy virtual ground or 3 channel design.
 
Alex

careful calling that article "yours"

 

[adydula]

Hello....I never said it was mine.....
 
But the post was a real one....and the facts are the facts....
 
If you have LCD2's and really want to know if this amp will drive the cans...well sir they can...
 
There is no hidden agenda here.....the amp and dac are really a great simple eleant design and work very very well..
 
All the best
Alex

 

[tdockweiler]

Quote:

 
 
tdock, I really think you need to try another amp that isn't the micro amp. Really, really. Something like an O2
 
careful calling that article "yours"

 
Why? It's the best amp i've found under $400. It's a full desktop amp and pretty powerful. Better than the Asgard I previously had, E9 and the WA22. I'm really convinced it's pretty transparent and this is after using it for maybe 2 years now.
For the life of me I can't hear any major coloration of it's own unless I have bad hearing. Unlike the Asgard it plays well with both the Sennheiser and AKG stuff (unless a colored DAC craps up the sound).
 
I did however try the ODAC with the E9. Doesn't work with my Total Airhead or probably an E11 of course. I don't have any need for any more expensive amps. I was considering the M-Stage, but that'll probably be a side-grade (or downgrade) and not so good with the Sennheiser stuff.
 
O2 is on my radar. I'll probably sell my E9 and get one. I want to compare it to my Micro. Doubt I can hear any difference and that's a good thing. Micro's not going anywhere though. It'll be nice to have another amp for upstairs.
 
I actually would rather upgrade my Micro's power supply instead of getting an O2

 

[khaos974]

Quote:

The ODAC can change signature depending on the quality of power being supplied.  Nothing new, it's been discussed already.

 
A lot of laptops (or even regular mother boards) don't have USB ports according to specs.

 

[Anaxilus]

Quote:

 
A lot of laptops (or even regular mother boards) don't have USB ports according to specs.

 
Ain't that the truth.  

 

[chrislangley4253]

Quote:

 
Why? It's the best amp i've found under $400. It's a full desktop amp and pretty powerful. Better than the Asgard I previously had, E9 and the WA22. I'm really convinced it's pretty transparent and this is after using it for maybe 2 years now.
For the life of me I can't hear any major coloration of it's own unless I have bad hearing. Unlike the Asgard it plays well with both the Sennheiser and AKG stuff (unless a colored DAC craps up the sound).
 
I did however try the ODAC with the E9. Doesn't work with my Total Airhead or probably an E11 of course. I don't have any need for any more expensive amps. I was considering the M-Stage, but that'll probably be a side-grade (or downgrade) and not so good with the Sennheiser stuff.
 
O2 is on my radar. I'll probably sell my E9 and get one. I want to compare it to my Micro. Doubt I can hear any difference and that's a good thing. Micro's not going anywhere though. It'll be nice to have another amp for upstairs.
 
I actually would rather upgrade my Micro's power supply instead of getting an O2

 

Well, in all honesty I have NOT heard it myself.. I was considering buying one though, I did a lot of research. From what I gathered the amp IS better than the DAC, however neither are that great.

Now, that is someone else's opinion, I'm just passing it along. You might not hear a difference, if you don't, no harm done. 

FWIW, I consider the M-stage and the O2 both transparent and indistinguishable from each other when I am blind folded.

 

[adydula]

What???
 
Laptops and motherboards without USB ports???
 
I am in the pc business, development etc...and have built hundreds of pc over the last 20 + yrs...and the majority of them have USB ports.
 
Are u referring to a usb hub?? or the USB port?
 
USB has been around for years now....1.0, 2.0 and 3.0....
 
I just find that statment strange??/
 
Alex

 

[stv014]

Quote:

Originally Posted by adydula /img/forum/go_quote.gif
 
Laptops and motherboards without USB ports???

 
khaos974 was referring to USB ports that fully meet the specifications (particularly those related to the +5 V power supply).

 

[adydula]

Ok fine...thats better....
 
I just build a HTPC that has USB 2.0 and USB 3.0 ports...
 
I have my dac plugged into the 3.0 port and nothing else....the spec on 3.0 has increased the total power available etc..
 
The best way to really be sure is to measure the DC voltage under load with your 'Dac' or appliance under load etc..
 
Which is something I have wanted to do...I have a ODAC in a box and dont want to re-open that one, but I have a second one
on its way I will measure the voltage and current draw and report back at the end of the week..
 
I have lots of PC's avail but due to me being an employee in the business I cant really comment about dev specs etc except to say
that the USB org specs are in the design criteria as with many mainstream pc manufacturers/sellars.
 
That said its good to understand the current draw of your dac and what your source can suply etc...
 
Alex

 

[MattTCG]

So is it better to plug the odac into a usb3.0 port...guessing that it might support a better power spec??