[spookanide]

I'm trying to replicate this. I have a PC running JRiver MC connected to USB and a QP2R connected to optical. I can switch between the two by cycling the inputs with no effect on volume. In what way does the volume 'not work properly' when you do this?

Ok I should have specified what actually happens. After turning on my PS3, the optical input seems to work fine and the samplerate locks into 44.1 fine. However, no audio is being played until I cycle the power. Have you tried turning on your optical device after the 400i?

 

[esauseesaw]

Ok I should have specified what actually happens. After turning on my PS3, the optical input seems to work fine and the samplerate locks into 44.1 fine. However, no audio is being played until I cycle the power. Have you tried turning on your optical device after the 400i?

I've just tried this..

QP2R off (no optical signal present)
jRiver MC play back with 'USB' selected
Turn on QP2R
Press 'input', switch to 'OPT' selected
Audio is immediately present on pressing play.

Perhaps it depends on the optical source but as long as there is sync/lock it does suggest the CMA400i is seeing the signal. I could try something other than QP2R.

 

[spookanide]

Yeah it's nothing major in my book. I can flick that switch real quick. My other DAC didn't have this bug though so it's not completely a source issue.

 

[JohnIgel]

I purchased this SE to Balanced adapter just to experiment:

https://www.amazon.com/Sukira-Balan...=1517768220&sr=8-17&keywords=balanced+adapter

There is a small difference when plugging into the adapter using the 2.5mm output vs using the Unbalanced output. The difference is subtle, but there is a little more space around instruments, a slightly bigger stage. I think it's worth the small investment for the adapter.

 

[SomeGuyDude]

I don't think an adapter actually works, does it? Doesn't the entire cable need to be balanced in order to have the wires fully separated? Wouldn't that just split it down at the adapter level?

 

[JohnIgel]

I'm not sure how it works on the cable side, but the unit itself is fully balanced to the balanced outputs. I was a little skeptical that I would be able to detect a difference, but although subtle, it is a small improvement.
Has anyone else tried the 2.5mm balanced output into SE headphones/IEMs?

 

[davehutch]

I'm not sure how it works on the cable side, but the unit itself is fully balanced to the balanced outputs. I was a little skeptical that I would be able to detect a difference, but although subtle, it is a small improvement.
Has anyone else tried the 2.5mm balanced output into SE headphones/IEMs?

The idea is that each driver has it's own earth or 'return' path, rather than sharing one. An adaptor would mean the drivers still share the same earth down the existing cable which is still single ended. You'd need a complete cable to run your headphones balanced.

 

[JohnIgel]

The idea is that each driver has it's own earth or 'return' path, rather than sharing one. An adaptor would mean the drivers still share the same earth down the existing cable which is still single ended. You'd need a complete cable to run your headphones balanced.

Hi Dave,

I have a 4-pin balanced cable and a SE cable for my Oppo PM-2 headphones, which I previously reported made a palpable difference in the sound quality when switching between the two cables and outputs. The experiment here is trying to see if there is any difference in sound quality when using SE cable connected to either the 2.5mm balanced output or the 6.35mm unbalanced output. I tried this out using the Periodic Audio Beryllium IEMs and I could hear a subtle difference. I believe the balanced amp circuit makes a difference when listening to the CMI400i unit. Give it a try and let me know what you find.

-John

 

[davehutch]

Yes, you may well find there is an improvement by using an amp’s balanced circuitry, that’s something to do with it being able to supply twice the voltage swing. I must confess I don’t understand it fully.
I was just replying to your comment ‘I don’t know how it works on the cable side’.
I don’t have a balanced amp so I can’t try it out I’m afraid

 

[Satcher]

I have the CMA400i and I use the balanced 2.5mm output with the Vega and Andromeda IEMs with 2 custom balanced mmcx cables with the 2.5mm connector (purchased off of ebay). Before, I used the default 3.5mm litz ALO Audio cables and thought I was satisfied with them... until I heard the custom cables off of the balanced 2.5mm output on the 400i. Some things I observed was that I could move the knob on the amp less with the balanced output for louder volume and elements of the songs I love listening to sounded fuller/livelier via the balanaced output (things like bass on the Andros felt more pronounced and the Vegas were even more hard hitting, mids/highs for both were much more engaging as well). Can't really say the soundstage felt expanded to me, but I find myself feeling completely enthralled with my IEMs now compared to before which felt just okayish out of the 3.5mm unbalanced output.

Just my two cents. I had a CMA600i previously which sounded lovely with the HD800 and HD800 S (I had both) and I used the balanced output for those two off of that amp.

 

[BunnyNamedCraig]

I have the CMA400i and I use the balanced 2.5mm output with the Vega and Andromeda IEMs with 2 custom balanced mmcx cables with the 2.5mm connector (purchased off of ebay). Before, I used the default 3.5mm litz ALO Audio cables and thought I was satisfied with them... until I heard the custom cables off of the balanced 2.5mm output on the 400i. Some things I observed was that I could move the knob on the amp less with the balanced output for louder volume and elements of the songs I love listening to sounded fuller/livelier via the balanaced output (things like bass on the Andros felt more pronounced and the Vegas were even more hard hitting, mids/highs for both were much more engaging as well). Can't really say the soundstage felt expanded to me, but I find myself feeling completely enthralled with my IEMs now compared to before which felt just okayish out of the 3.5mm unbalanced output.

Just my two cents. I had a CMA600i previously which sounded lovely with the HD800 and HD800 S (I had both) and I used the balanced output for those two off of that amp.

Right!? The story goes that the creator of Questyle was not happy with the headphone amps that came out around the time of the HD800 (his personal headphone at the time) so he created his own amp for it. That current mode technology in the 600/400i is what has been passed down through the original amp he built. He said the amps at the time made the HD800 sound too harsh and he wanted to remedy that. I think he totally hit the nail on the head. Glad your enjoying both!

 

[kundica]

I have the CMA400i and I use the balanced 2.5mm output with the Vega and Andromeda IEMs with 2 custom balanced mmcx cables with the 2.5mm connector (purchased off of ebay). Before, I used the default 3.5mm litz ALO Audio cables and thought I was satisfied with them... until I heard the custom cables off of the balanced 2.5mm output on the 400i. Some things I observed was that I could move the knob on the amp less with the balanced output for louder volume and elements of the songs I love listening to sounded fuller/livelier via the balanaced output (things like bass on the Andros felt more pronounced and the Vegas were even more hard hitting, mids/highs for both were much more engaging as well). Can't really say the soundstage felt expanded to me, but I find myself feeling completely enthralled with my IEMs now compared to before which felt just okayish out of the 3.5mm unbalanced output.

Just my two cents. I had a CMA600i previously which sounded lovely with the HD800 and HD800 S (I had both) and I used the balanced output for those two off of that amp.

Do you get any hiss with the Andros? I'm considering the 400i but it needs to be silent with sensitive IEMs.

 

[Satcher]

Do you get any hiss with the Andros? I'm considering the 400i but it needs to be silent with sensitive IEMs.

Unfortunately, no, it is not dead silent (there is some hiss I can hear with the Andros). The Vegas are quiet however.

 

[TSAVAlan]

Unfortunately, no, it is not dead silent (there is some hiss I can hear with the Andros). The Vegas are quiet however.

On low gain? Not hearing hiss with my UE18+ but UE aren't especially sensitive ciems.

 

[kundica]

Unfortunately, no, it is not dead silent (there is some hiss I can hear with the Andros). The Vegas are quiet however.

Bummer. Thanks for the info.