Audio-gd Digital Interface
May 18, 2012 at 5:32 AM Post #2,852 of 4,156

fourwed

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I want to share my comparison of different power sources on DI and their differences with Audiophilleo 2.
 
Equipments:
1. NFB-10SE (Filter: 5; Gain: Low), RCA coaxial input changed to Canare BNC.
    I think the DI's BNC is better than its RCA, it sounds clearer although it is said to be the same.
 
2. DI-V1 (No upscaling)
 
3. HD650 (with DIY balanced Neutrik jack)
 
4. USB isolator (No brand)
     It must be powered by an external power supply, battery powered is the best and different power packs have different sounds.
     The power is directly feeded from the external power supply without regulation.
 
5. Audiophilleo 2 (Thanks to my friend, David)
 
Power sources:
1.1000mah unprotected 7.4V lithium polymer battery
 
2. Linear power (8.4V, ripple noise < 0.5mVRMS.)
    This power supply is for mobile phone maintenance. It is a cheap Chinese brand and the spec might not be accurate.
    However, I believe it is better than an average one.
 
Player:
Battery powered Lenovo Notebook, foobar v1.1.11, Windows 7, WASAPI
 
My comments:
If the DI is lithium powered, it is very bright, clear, bass well definited and the soundstage is large. However, the vocal seems to be moved to the both sides instead of the center which might be becasue of the larger soundstage. Upscaling makes it too bright and unbearable, especially string sounds. Even without upscaling, I feel fatigue after 2-hour listening because the sound is sharp.
 
If I add a battery powered isolator to it, it will be less bright and others are more or less the same. The vocal moves back to the center. DI sounds the best with it and I do think it is 60%-70% of Audiophilleo 2.
 
The linear power supply is not as good as lithium battery, although it is definitely better than USB powered. It sounds not as clear as lithium battery.
 
Audiophilleo 2 stills shines, it is more musical and smooth. It is even better if I add a battery powered isolator. However, it carries a too hefty price tag.
 
 
 
My DI with lithium battery

 
BNC to BNC adaptor

 
Linear power supply

 
Isolator with 5V directly feed from battery
\
 
2 different power packs for the isolator

 
Compare with AP2

 
May 18, 2012 at 7:42 AM Post #2,854 of 4,156

kr0gg

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there's something wrong...
you must be kidding about DI being bright
 
1) it is considered the darkest sounding usb-spdif converter of them all.
2) even with my W1000X i don't get any fatique
3) i dont' get how HD650 can sound bright. i've borrowed them a month ago and they are really dark.
 
on the opposite - it is AP2 which is often considered too bright and that is the usual reason why people get rid of it.
 
May 18, 2012 at 12:13 PM Post #2,855 of 4,156

fourwed

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Quote:
Nice! What's the ripple spec of that PSU? It should be stated in its user manual.
 
Does your USB isolator use linear voltage regulators? This matters quite a bit as well.


Do you mean ripple noise? it stated <= 0.5mV RMS.
 
My isolator itself should be powered from the USB port, the connected device (DI) is powered directly from the power packs (5V). The isolator has a power input like Olimex isolator and it claims that it is a linear voltage regulator. You could feed an 5V to 9V to it to power the connected device but I think it is inferior than the power packs.
 
Quote:
there's something wrong...
you must be kidding about DI being bright
 
1) it is considered the darkest sounding usb-spdif converter of them all.
2) even with my W1000X i don't get any fatique
3) i dont' get how HD650 can sound bright. i've borrowed them a month ago and they are really dark.
 
on the opposite - it is AP2 which is often considered too bright and that is the usual reason why people get rid of it.

 
Obviously I am not an audiophile. It is just my opinions and all are comparatively.
 
Please correct me if I am wrong about "Bright". According to Headfonia,
 
               9. What do you mean by “bright”? (i.e a bright sounding headphone)
                   Bright refers to a headphone with a lot of treble presence.
 
I called it "Bright" because I notice the treble becomes more apparent and sharper, the warmth and muddy sounding are gone.
 
HD650 is one of the dark and warm headphone and I agree. Before I buy mine, I searched the Internet and there should be two versions of it. The later version that I own was not as dark as the first version.
 
I still remembered that I went to a local shop and compared the DT990, DT880 and HD650 in order to buy one. I think the DT990 and DT880 is more bright, exciting, clearer and thin sounding. I finally bought HD650. The HD650 was muddy in my FUN + Earth OPAMP. It becomes clearer and bright with my NFB-10SE. More so after I converted it and plug in the balanced output.
 
DI is also dark and warm by default. In order to make it less dark, I use the DI's BNC connector and modded my 10SE to BNC connector too. Coaxial connection in audio should be 75ohm but DI's RCA might not be 75ohm (confirmed by Kingwa). Most RCA cable, adapter and connector are not 75ohm because it is not designed for coaxial connection. I copy the AP2 theory and use the BNC-to-BNC adaptor to connect them.
 
Oh, I suddenly remember that I don't know whether my BNC-to-BNC adaptor is 50ohm or 75ohm, they look the same, might be the comparison are all wrong
 
When I upscale my DI to 96K, DI sounds more clear and little brighter. My comparison was started with the upscaled DI, but its sound with lithium battery powered was way too bright. Therefore, I redo my comparisons with the upscaling OFF.
 
AP2 is definitely brighter than original DI in my opinion. Bright and fatigue is subjective too.
 
May 18, 2012 at 6:55 PM Post #2,856 of 4,156

leeperry

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Talking about I2S output from the DI-V2, I guess it'd make the most sense to cannibalize a cat6a cable? http://www.cableorganizer.com/articles/cat5-cat5e-cat6.htm
 
Quote:
Category 6 is the most advanced and provides the best performance. Just like Cat 5 and Cat 5e, Category 6 cable is typically made up of four twisted pairs of copper wire, but its capabilities far exceed those of other cable types because of one particular structural difference: a longitudinal separator. This separator isolates each of the four pairs of twisted wire from the others, which reduces crosstalk, allows for faster data transfer, and gives Category 6 cable twice the bandwidth of Cat 5

 
http://en.wikipedia.org/wiki/Category_6_cable#Category_6a
 
Quote:
Category 6a performs at improved specifications, in particular in the area of alien crosstalk as compared to Cat 6 UTP, which exhibited high alien noise in high frequencies.

 
I sure ain't seeking any alien noise 
 
My DAC has a mini-din5 connector for I2S, so I'll cut the cable as short as possible, solder the right connector et voilà ))
 
May 19, 2012 at 1:18 AM Post #2,857 of 4,156

LosNir

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Me too, I think I'll use this patch cable - http://bit.ly/JXvM9d
 
May 19, 2012 at 4:08 AM Post #2,858 of 4,156

kr0gg

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i was thinking about using this cable:
http://www.musicdirect.com/p-58121-audioquest-rje-cinnamon-ethernet-cable.aspx
 
but the i2s lines are in a different order in my DAC :frowning2:
so i guess i'll either have to try to resolder the i2s module on the DI or i'll be forced to cut the cable.
 
haven't ordered it yet, though.
another problem is that i2s cables are recommended to be not longer than 10cm
 
May 19, 2012 at 5:06 AM Post #2,859 of 4,156

drez

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I would say length should be as short as possible and that should be the number one priority IMO.
 
A good idea might be to buy the Audioquest cable and then cut it to length and share the cost with someone else using I2S.  Reterminating the cable will also save you from having to reconfigure the hookup wires in the DI.  You could also go all the way and do DIY and be able to chose the conductor but I don't know of any 28AWG good quality silver wire with teflon insulation.  I have some 28 AWG silver with cotton insulation but I don't think this will maintain as even wire separation as plastic dielectrics.  But then again cotton has a lower dielectric loss, so who knows which will be better.  I still have to try this silver wire in a USB cable to see how it compares to 28AWG stranded OCC copper in PET dielectric.
 
EDIT: I think I spotted some 28 AWG OCC silver in PET dielectric, just from google search with those terms.
 
May 19, 2012 at 5:33 AM Post #2,860 of 4,156

fourwed

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Quote:
I've been experimenting with USB cable design and it seams that I might have beaten Monoprice after all. I still need some more listening to be conclusive.
 
After building cast cables using Canare DA202. I decided to try them as USB as well. One needs 2 runs since they are twisted pairs. One run for the Data + and -, and another for V+ and Ground (or -). Shield connects to connector shield.
 
So far I've built 2 1 meter USB cables, one using the DA202 which is a low capacitance 110 ohm AES/EBU digital cable, but also sounds great as an analog XLR or cast cable. The impedance is slightly higher than recommended, but that doesn't seem to be an issue. And another using Canare L-2E5 microphone cable. This is a miniature of the L-2T2S which is a 88 ohm cable (its impedance being within to the USB 2.0 cable specification of 90 ohms with a 15% tolerance - not sure how critical this is since 15% is quite a wide range). I've tested them both with a hard drive and speeds look like USB 2.0 (sorry, can't be more scientific than that). I also plan to have another USB cable built using L-2T2S.
 
They both sound very good! I'm waiting for a little more break-in to start a shoot out. Probably early next week.

 
JulienM, I am thinking to DIY a USB cable. Can't wait for your result.
 
It is easy to find Canare cables here.
 
May 20, 2012 at 5:32 PM Post #2,861 of 4,156

JulienM

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JulienM, I am thinking to DIY a USB cable. Can't wait for your result.

It is easy to find Canare cables here.


Subjective impressions are very positive so far... Tomorrow I should start to compare their sound... I run some speed test with my hard drive, and they all perform just as well as a Monoprice USB cable for data transfers. At least it looks like I got the USB 2.0 specs right...
 
May 21, 2012 at 5:37 AM Post #2,864 of 4,156

LosNir

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Also important not to get too caught up by cable voodoo!
(Speaks the guy who impulsively bought Wireworld 2M USB cable)

JulienM, where did you get the usb plugs and the canare cable? I could only find the usb plug on DoubleHelix but shipping is $40!

Anyone got shipment email for the DI-V2 yet?


On May 16:

Dear Nir,
Yes, we plan to shipping at next week.
Kingwa
 
May 21, 2012 at 11:35 AM Post #2,865 of 4,156

modaudio

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Quote:
I want to share my comparison of different power sources on DI and their differences with Audiophilleo 2.
 
Equipments:
1. NFB-10SE (Filter: 5; Gain: Low), RCA coaxial input changed to Canare BNC.
    I think the DI's BNC is better than its RCA, it sounds clearer although it is said to be the same.
 
2. DI-V1 (No upscaling)
 
3. HD650 (with DIY balanced Neutrik jack)
 
4. USB isolator (No brand)
     It must be powered by an external power supply, battery powered is the best and different power packs have different sounds.
     The power is directly feeded from the external power supply without regulation.
 
5. Audiophilleo 2 (Thanks to my friend, David)
 
Power sources:
1.1000mah unprotected 7.4V lithium polymer battery
 
2. Linear power (8.4V, ripple noise < 0.5mVRMS.)
    This power supply is for mobile phone maintenance. It is a cheap Chinese brand and the spec might not be accurate.
    However, I believe it is better than an average one.
 
Player:
Battery powered Lenovo Notebook, foobar v1.1.11, Windows 7, WASAPI
 
My comments:
If the DI is lithium powered, it is very bright, clear, bass well definited and the soundstage is large. However, the vocal seems to be moved to the both sides instead of the center which might be becasue of the larger soundstage. Upscaling makes it too bright and unbearable, especially string sounds. Even without upscaling, I feel fatigue after 2-hour listening because the sound is sharp.
 
If I add a battery powered isolator to it, it will be less bright and others are more or less the same. The vocal moves back to the center. DI sounds the best with it and I do think it is 60%-70% of Audiophilleo 2.
 
The linear power supply is not as good as lithium battery, although it is definitely better than USB powered. It sounds not as clear as lithium battery.
 
Audiophilleo 2 stills shines, it is more musical and smooth. It is even better if I add a battery powered isolator. However, it carries a too hefty price tag.
 
 
 
My DI with lithium battery

 
BNC to BNC adaptor

 
Linear power supply

 
Isolator with 5V directly feed from battery
\
 
2 different power packs for the isolator

 
Compare with AP2

 
good work with the battery, but have u measured the battery output, if I am  not wrong, is the worst type of power supply! is meant for charging
 
the last time I measure a sanyo eneloop portable battery charger, without oscilloscope, just a multimeter, the voltage fluctuations is crazy!
 

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