Sorry, but I cannot recall where I bought the RCAs. I just had a few gold plated ones in my electronics parts box. They may even be lowly Radio Shack jacks!
I don't plan to use the RCA line-outs very often though, so they will get extremely minimal use. I only installed them in case I want to listen to the ODAC through another amp (for instance, I was A-B'ing the ODAC vs. the Bifrost with a tube-rolled Lyr amplifier.
I would like to have the O2 and the ODAC in the same case. I would also like a 6.3mm headphones output on the back (preferably on the back, on the front is OK). I would also like the option to add a pair of RCA connectors to the back (if possible) and bypass the ODAC. Say, if I have another DAC at the moment. I could skip this but it would be nice to have.
Also... Is it possible to move ALL connections to the back of the case and only have the volume knob and on/off switch on the front? I know that might cause problems with the front panel and/or back panel but I'm not afraid to drill my own holes if it's possible and maybe produce my own panels (but in wood).
Also... Is it possible to move ALL connections to the back of the case and only have the volume knob and on/off switch on the front? I know that might cause problems with the front panel and/or back panel but I'm not afraid to drill my own holes if it's possible and maybe produce my own panels (but in wood).
Dear Stefan, you have a big fault in your guide on how to connect the O2 to the ODAC.
http://www.headnhifi.com/components/com_jshopping/files/demo_products/How_To_O2_ODAC.pdf
In the last picture at page three you have shown that the black wires go to the upper holes and the white to the lower ones. This is reversed and if you do it like the way in the guide you'll en up with mono sound because so have I.
Looking at this picture here
It show the right way of doing it. If you want I can supply you with a new picture for your guide if you're not okay with "stealing" it from NwAvGuy's blog.
http://www.headnhifi.com/components/com_jshopping/files/demo_products/How_To_O2_ODAC.pdf
In the last picture at page three you have shown that the black wires go to the upper holes and the white to the lower ones. This is reversed and if you do it like the way in the guide you'll en up with mono sound because so have I.
Looking at this picture here
It show the right way of doing it. If you want I can supply you with a new picture for your guide if you're not okay with "stealing" it from NwAvGuy's blog.
Dear Stefan, you have a big fault in your guide on how to connect the O2 to the ODAC.
http://www.headnhifi.com/components/com_jshopping/files/demo_products/How_To_O2_ODAC.pdf
In the last picture at page three you have shown that the black wires go to the upper holes and the white to the lower ones. This is reversed and if you do it like the way in the guide you'll en up with mono sound because so have I.
Looking at this picture here
It show the right way of doing it. If you want I can supply you with a new picture for your guide if you're not okay with "stealing" it from NwAvGuy's blog.
Hi, thanks for pointing this out. I took the guide offline and will correct it.
Thanks, Stefan
Hi Stefan, have you noticed a long mute on the ODAC? I think Foobar closes the USB connection when you change tracks manually and the ODAC then mutes. To me the mute time is too long and I loose a couple of notes when the new track starts.
Have you seen any reference to changing the time constant of the mute circuit? I think you need to change C120 to something a lot smaller than 1uF. Maybe we need to ask the elusive NWAVGUY.
Steve
Have you seen any reference to changing the time constant of the mute circuit? I think you need to change C120 to something a lot smaller than 1uF. Maybe we need to ask the elusive NWAVGUY.
Steve
Hi Stefan, have you noticed a long mute on the ODAC? I think Foobar closes the USB connection when you change tracks manually and the ODAC then mutes. To me the mute time is too long and I loose a couple of notes when the new track starts.
Have you seen any reference to changing the time constant of the mute circuit? I think you need to change C120 to something a lot smaller than 1uF. Maybe we need to ask the elusive NWAVGUY.
Steve
hi DoktorSteve,
do you experience this behaviour only with your first track or every track you play? I do not use foobar and never had this kind of issue. might be some buffer settings in foobar itself that cause the delay?
I have not heared from NwAvGuy for a couple of weeks now, hope he is OK. Maybe George as can comment on your query...
Stefan
Member
Joined 2009
phase performance
I believe this issue was mentioned on NwAvGuy's blog somewhere but I'd like to bring it up again and get more opinions. There is a significant phase wrap at 2kHz. I'm not going to argue whether it's audible or not since I just got the ODAC and so far I like it.
I guess I'm more interested in what is it caused by and whether it's possible to be fixed in later revisions.
I measured the ODAC with my very old Creative Audigy 2 ZS sound card. Both produce extremely linear frequency response. The TDH measurement is dominated by the sound card's noisy input so it does not represent actual performance. There is a 360 degree phase wrap at 2kHz on the ODAC output. The ODAC was also 8dB more quiet but I compensated for that to make the measurement more comparable.
Green = Audigy2 OUT -8dB -----> Audigy2 IN
Red = ODAC OUT -----> Audigy2 IN
I believe this issue was mentioned on NwAvGuy's blog somewhere but I'd like to bring it up again and get more opinions. There is a significant phase wrap at 2kHz. I'm not going to argue whether it's audible or not since I just got the ODAC and so far I like it.
I guess I'm more interested in what is it caused by and whether it's possible to be fixed in later revisions.
I measured the ODAC with my very old Creative Audigy 2 ZS sound card. Both produce extremely linear frequency response. The TDH measurement is dominated by the sound card's noisy input so it does not represent actual performance. There is a 360 degree phase wrap at 2kHz on the ODAC output. The ODAC was also 8dB more quiet but I compensated for that to make the measurement more comparable.
Green = Audigy2 OUT -8dB -----> Audigy2 IN
Red = ODAC OUT -----> Audigy2 IN
Hi Stefan,
it looks like the pad under C120 has been reworked - I guess the DACs were a bit quiet with the mute pin tied to ground ! I changed C120 to 3.3uF but I don't think it reduced the mute time. I saw another design using 2.2uF so I wonder if 22uF is not correct in the schematic.
The mute is only a problem with Foobar 2000. I can see the music appear in the graphic display then the sound starts. 2.2uF and 110k would give a time constant around 0.25s which seems about right. I may just bypass the 110k with 10k and see if that makes a difference.
Steve
it looks like the pad under C120 has been reworked - I guess the DACs were a bit quiet with the mute pin tied to ground ! I changed C120 to 3.3uF but I don't think it reduced the mute time. I saw another design using 2.2uF so I wonder if 22uF is not correct in the schematic.
The mute is only a problem with Foobar 2000. I can see the music appear in the graphic display then the sound starts. 2.2uF and 110k would give a time constant around 0.25s which seems about right. I may just bypass the 110k with 10k and see if that makes a difference.
Steve
Yes, the card was too quiet with the mute pin shorted to ground.
The values selected for the RC were to minimize the 'power on' pop. (RC time constant to release the mute ) This pin has no effect on inter-track muting.
George Boudreau
Yoyodyne Consulting.
The values selected for the RC were to minimize the 'power on' pop. (RC time constant to release the mute ) This pin has no effect on inter-track muting.
George Boudreau
Yoyodyne Consulting.
George, can you update the schematics for new revision please?
I'd like to fix it on my first-batch ODAC. Thanks.
I'd like to fix it on my first-batch ODAC. Thanks.
Thanks for the reply George.
To be honest I had never even connected the odac with the O2 powered up before so I don't know what the power up click was like. Now I get 3 slight clicks when I do this. I can't find the cap I took off so I will have to live with it!
The inter track muting is still a bit of a mystery then:
I only get it with the ODAC not with the internal soundcard or my UCA222.
I get it with both Foobar and Media Player but it may be more noticable with Foobar.
The normal transition from the end of one track to the start of the next is no problem - only the manual selection of the new track.
To be honest I had never even connected the odac with the O2 powered up before so I don't know what the power up click was like. Now I get 3 slight clicks when I do this. I can't find the cap I took off so I will have to live with it!
The inter track muting is still a bit of a mystery then:
I only get it with the ODAC not with the internal soundcard or my UCA222.
I get it with both Foobar and Media Player but it may be more noticable with Foobar.
The normal transition from the end of one track to the start of the next is no problem - only the manual selection of the new track.
Miero, I think there is no new revision. The change I made was due to a misunderstanding. I think the error in the tracking was in the second batch and was fixed before release - it would have been pretty obvious as there would be no sound!
You are correct. The pad for the cap C120 'grew' into a stitching via and shorted to mute pin. This was a screw-up on the pcb manufacturers side but it required we 'hand adjust' the pad to clear the via.
I'm wondering why the Cbyp cap on the MIC5205-3.6YM5 (pin 4) was omitted? Does it run better without it? Or would it improve noise to add it?
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