O2 AMP + ODAC - Page 61

Quote:

Originally Posted by Ren19 

I just recieved my O2+Odac combo and i'm wondering if its normal that the computer volume control affect the volume of my amp.

That's the way it works for me. Windows modifies the source audio data to reduce the volume and transmits the result, digitally, over USB to the ODAC. (It may be possible to override this behavior but I've never tried.)

Thanks for the replies,

I have noticed something else:  when there is no sound playing trough the O2/Odac i can put the volume to the maximum with the low 2.5x gain and i wont hear a single noise coming out of my headphones. But when i open a music program or when my computer sees that a sound is about to be played i can hear noise. (I believe the noise is still there when the song is playing)

Is there any fix for that?

Also it is major when i put the 6x gain on it, it sounds like i'm in the middle of a rain forest...

Thanks.

Quote:

Originally Posted by Ren19 

Thanks for the replies,

 

I have noticed something else:  when there is no sound playing trough the O2/Odac i can put the volume to the maximum with the low 2.5x gain and i wont hear a single noise coming out of my headphones. But when i open a music program or when my computer sees that a sound is about to be played i can hear noise. (I believe the noise is still there when the song is playing)

 

Is there any fix for that?

 

Also it is major when i put the 6x gain on it, it sounds like i'm in the middle of a rain forest...

 

Thanks.

Interesting... You definitely have something going on here. Try unplugging the o2, and anything else you can think of moving around, maybe moving the odac to a different usb port. The o2 and odac are dead silent, you shouldn't be hearing a noise like that. Someone else will probably chime in with better troubleshooting advice.

I played music on Mac and the noise problem dissapeared. I looked at what could be the problem on Windows and i think it could be because my version of windows is "Not Genuine". On startup, there is a pop-up saying that "Windows Update" and other things may not work because my version is not genuine anymore. So i suspect that this could be the cause even though windows seemed to have installed all the required drivers on first usb plugging.

Could this be caused by something else?

Quote:

Originally Posted by Ren19 

I played music on Mac and the noise problem dissapeared. I looked at what could be the problem on Windows and i think it could be because my version of windows is "Not Genuine". On startup, there is a pop-up saying that "Windows Update" and other things may not work because my version is not genuine anymore. So i suspect that this could be the cause even though windows seemed to have installed all the required drivers on first usb plugging.

 

Could this be caused by something else?

I don't think that is your problem.. Also, I'll send you a few links to help you fix that authentication problem of yours.

Maybe the Windows audio output format is set to 16 bits ?

Quote:

Originally Posted by stv014 

Maybe the Windows audio output format is set to 16 bits ?

There's no reason why it should behave like that even if set to 16bit..

Quote:

Originally Posted by stv014 

Maybe the Windows audio output format is set to 16 bits ?

My problem is fixed and this was exactly the cause.

Thanks everyone.

Quote:

Originally Posted by adamlr 

Quote:

Originally Posted by Stratok 

I have not yet received it I thought to dig up some info beforehand. Sig DJ has 115db sensitivity i think.

98db is the sensitivety of the signature pro. i was wrong.

 

i cant seem to find the sesitivity of the the signature djs... on the ultrasone site, part of the specs say "SPL: 115 dB", is that sensitivity? sensitivity rating is usually given together with "@ 1kHz 1mW" or something of the sort...

 

either way, ill be glad to hear how they fair with *2.5 gain, especially if their sensitivity is 115db, which would make them even more sensitive than the m-100.

 

 

 

anyone here with ~32ohm impedance and ~103db sensitivity cans? if so, is *2.5 gain too much for them, are do you still get manageable volume control without channel imbalance?

Does the M-100 count? You mentioned it earlier. 2.5x gain is too much (I have the 2.5x/1.0x installed).

With my K 701 I have the volume on my computer set to ~60% and the O2 at ~8 o'clock at 1.0x gain.

Speaking of all of this, can anyone explain the source vs amp volume control thing? I used to have the source at low volume, O2 on max until I read otherwise. It doesn't make much sense to me. If I need to adjust the volume, wouldn't it be easier to have amp set at max volume, source at a comfortable loud volume, then just reduce the amp volume from there? That way you don't have to worry about any channel imbalance problems, nor having the amp constantly at a "low" volume and adjusting everything again for different headphones (M-100 for example). Not to mention having the Windows boot-up sound blast at full volume every time you boot because you leave the volume on the source (computer) at max. With the other way I used to have it, I would just swap headphones, lower amp volume accordingly, not worry about channel imbalance at all. Can't get much simpler than that.

Quote:

Originally Posted by miceblue 

Does the M-100 count? You mentioned it earlier. 2.5x gain is too much (I have the 2.5x/1.0x installed).

 

With my K 701 I have the volume on my computer set to ~60% and the O2 at ~8 o'clock at 1.0x gain.

 

Speaking of all of this, can anyone explain the source vs amp volume control thing? I used to have the source at low volume, O2 on max until I read otherwise. It doesn't make much sense to me. If I need to adjust the volume, wouldn't it be easier to have amp set at max volume, source at a comfortable loud volume, then just reduce the amp volume from there? That way you don't have to worry about any channel imbalance problems, nor having the amp constantly at a "low" volume and adjusting everything again for different headphones (M-100 for example). Not to mention having the Windows boot-up sound blast at full volume every time you boot because you leave the volume on the source (computer) at max. With the other way I used to have it, I would just swap headphones, lower amp volume accordingly, not worry about channel imbalance at all. Can't get much simpler than that.

yes it counts! thats the one im talking about! maybe i will "go for the snip"... ill wait and see if i do go for the m-100 first, if i do, ill see how they fair with the *2.5 gain. worst comes the worst, ill send an email to john and ask for some guidance... 

while were on the subject, how do i take the volume knob off? i want to open up the O2 and take the batteries out and i cant seem to figure out how to take the knob off, which i assume is necessary.

and as for the second part of your post, im given to understand that for maximum fidelity, you want to control volume with your amp, not your source. having your source on 100% will deliver the maximum quality, and if its on less, you could be delivering like, 12 bits of digital audio to your amp, as opposed to 16 bits, if the volume was at 100%. granted, i have no idea if this is true, even if it is, i dont know how audible the difference will be and ofcourse, im in no way an authority on these issues.

Quote:

Originally Posted by adamlr 

while were on the subject, how do i take the volume knob off? i want to open up the O2 and take the batteries out and i cant seem to figure out how to take the knob off, which i assume is necessary.

Just take the front plate off and the whole board should slide out easily (If your O2 build is like the JDS Labs one). No need to remove the knob.

That's the same impression that I got from reading other posts about this subject. If you have a 16 bit dac and your files are 16bit, lowering the volume in windows lower your dynamic range / quality of the output. You want to control the volume via the amp. The other bit that I gleemed from this is that if you set the dac to 24 bit and your audio files are 16 bit, you can lower the volume in windows up to a point w/o effecting dynamic range since the dac will take the 16 bit file and upconvert it to 24 and fill in the missing 8bit with just 0s so you can change the volume in windows and all you're losing is 8bits worth of 0s.

Quote:

Originally Posted by adamlr 

yes it counts! thats the one im talking about! maybe i will "go for the snip"... ill wait and see if i do go for the m-100 first, if i do, ill see how they fair with the *2.5 gain. worst comes the worst, ill send an email to john and ask for some guidance... 

while were on the subject, how do i take the volume knob off? i want to open up the O2 and take the batteries out and i cant seem to figure out how to take the knob off, which i assume is necessary.

 

 

and as for the second part of your post, im given to understand that for maximum fidelity, you want to control volume with your amp, not your source. having your source on 100% will deliver the maximum quality, and if its on less, you could be delivering like, 12 bits of digital audio to your amp, as opposed to 16 bits, if the volume was at 100%. granted, i have no idea if this is true, even if it is, i dont know how audible the difference will be and ofcourse, im in no way an authority on these issues.

Not sure if JDS uses a set screw or just a press fit knob, but either way should be simple enough.  If it's a press fit just pull it off, if a set screw loosen the screw and it'll fall off.

Quote:

Originally Posted by adamlr 

while were on the subject, how do i take the volume knob off? i want to open up the O2 and take the batteries out and i cant seem to figure out how to take the knob off, which i assume is necessary.

There's a set screw on the volume knob. IIRC, all you need is a tiny allen wrench.

Quote:

Originally Posted by MrEleventy 

 

 

Just take the front plate off and the whole board should slide out easily (If your O2 build is like the JDS Labs one). No need to remove the knob.

couldnt seem to take the front panel off together with the knob, im pretty sure i need to remove it first

Quote:

Originally Posted by shadow419 

Not sure if JDS uses a set screw or just a press fit knob, but either way should be simple enough.  If it's a press fit just pull it off, if a set screw loosen the screw and it'll fall off.

Quote:

Originally Posted by HamilcarBarca 

 

There's a set screw on the volume knob. IIRC, all you need is a tiny allen wrench.

yep, looks like an allen key is what i need. thank you very much