[FauDrei]

Quote:

The batteryspace people will ship vis US postal service (after persuasion from me - the things I do for you guys ) so it should be a lot cheaper than $100!
 

JKeny my man!

 

[mmerrill99]

Here's what they said
 
 
Quote:

We don't use USPS to ship item due to USPS does not provide a good tracking system. However, if you still prefer to use USPS to ship then we are NOT liable for any damage/ miss shipment (no tracking information) and we will charge you $5.00 + whatever USPS shipping cost for handling this.
If this is acceptable to you, you can just place order using UPS or FedEx and then we can refund you the difference using USPS to ship to you. Please enter on the comment section - " I like to use USPS to ship and willing to accept the risk of loss or damage shipment. " Also, please send us email with your order # so we can follow up for you.

 

[punk_guy182]

Quote:

JKeny my man!

This is actually pretty cool from you JKeny!
 
I'll get the cheapest one and there will be no need for an adaptor: http://www.batteryspace.com/Smart-Charger-0.7-A-for-3.2V-1-cells-LiFePO4-Battery-Pack-100-240VAC.aspx

 

[audioengr]

 
Quote:

Same DAC SlimA was using and the next model up.  I've heard jitter added files (even spectrum) and know what you are rfering to,  this is different.  I'm sure the Jitter spectrum of the Hiface is concentrated,  it may be low overall but spikes are more audible.   I'm not evaluating it any further until I fix the design.
 
I think it is pretty conclusive thoughout this thread that Isosynchrous lin regulated powered USB is superior to USB SM powered asynchrous .   When you think about how it works it makes perfect sense.
 
 
 

 

Asynchronous versus Adaptive is one thing.  How you power it is another.
 
I have sold both Adaptive and Async converters.  My Adaptive is award-winning (Golden Ear), but I expect and know that my Async is a bit better. The technology is just better.
 
Steve N.
Empirical Audio
 

 

[audioengr]

A word of warning:  LI batteries that are low impedance can be hazardous.  If you do not use the right charger and monitor the temperature, charging current and discharge current, they can catch fire and even explode.
 
Be careful.
 
Steve N.
Empirical Audio

 

[mmerrill99]

Yes, good advice Steve - use the correct charger & you should be OK. But no need to go direct to Li batteries - why not try some NiMh first to see if there is a significant advantage to batteries over linear supply in this 5V role? 

 

[GreenLeo]

Hi Jkeny,
 
Just wonder did you try feeding an external 1.8V to the HiFace to see if it helps the SQ?  
 
Also, I notices that there are two clocks in the HiFace.  How about feeding an external PS to the other clock?  Would it improve the SQ for 24/96 files?

 

[mmerrill99]

Quote:

Hi Jkeny,
 
Just wonder did you try feeding an external 1.8V to the HiFace to see if it helps the SQ?  
 
Also, I notices that there are two clocks in the HiFace.  How about feeding an external PS to the other clock?  Would it improve the SQ for 24/96 files?

I feed the 2 clocks with one 3.3V power source - I tested with two individual PS & it made no difference in my system.
I haven't tried a 1.8V power supply as this powers the Xilinx chip LOGIC rather than any direct audio handling function - it might make a difference but I doubt it? 
 

 

[regal]

If you want to experiment with batteries on a cheapstake budget here is what I did (no guarantees),   they sell a charger and you can buy a wire leaded 18650 battery holder at digikey.
 
http://www.szwholesale.com/18650-32vrechargeable-battery1865032v-p-1139.html     - LiFePO4 Batteries
 
http://www.szwholesale.com/universal-charger-18650-16340-lion-nimh-nicd-battery-p-3241.html     -Charger

 

[regal]

Here is the 18650 battery holder from digikey.   All together my budget upgrade to the Hiface will be $25.  Surely not the quality of Jenky's mods,  but surely better than stock.  Eventually will compare to flea power.
 
http://search.digikey.com/scripts/DkSearch/dksus.dll?Cat=393250&k=18650
 
But I still need to find a female-male USB cord.   Radioshack?

 

[slim.a]

Quote:

Here is the 18650 battery holder from digikey.   All together my budget upgrade to the Hiface will be $25.  Surely not the quality of Jenky's mods,  but surely better than stock.  Eventually will compare to flea power.
 
http://search.digikey.com/scripts/DkSearch/dksus.dll?Cat=393250&k=18650
 
But I still need to find a female-male USB cord.   Radioshack?

I wonder if jkeny tried batteries before settling on his LiFePO4 batteries.

Concerning the usb cord, any usb extender should do fine. I have tried a regular Belkin one and a €20 Monster one and couldn't tell any big difference. I settled on the cheaper Belkin. I have also tried jkeny special usb cable with a 5V SMPS power supply plugged into a BADA power filter, and didn't notice much difference either with my current set-up. I haven't tried yet a 5V battery power supply (as suggested by jkeny) but it won't do the trick in my case (for convenience reasons). Even if it provided a sonic benefit over the Belkin usb extender I am currently using, I don't want to have yet another component to charge/recharge.
By the way, my computer is plugged into a separate power filter (from the rest of the equipment). So that might explain why I didn't hear a big difference when using Jkeny's special cable. But that is just a guess. I will be curious to hear other people impressions on those usb cables that allow to use external power supplies.

 

[mmerrill99]

Quote:

I wonder if jkeny tried batteries before settling on his LiFePO4 batteries.

Concerning the usb cord, any usb extender should do fine. I have tried a regular Belkin one and a €20 Monster one and couldn't tell any big difference. I settled on the cheaper Belkin. I have also tried jkeny special usb cable with a 5V SMPS power supply plugged into a BADA power filter, and didn't notice much difference either with my current set-up. I haven't tried yet a 5V battery power supply (as suggested by jkeny) but it won't do the trick in my case (for convenience reasons). Even if it provided a sonic benefit over the Belkin usb extender I am currently using, I don't want to have yet another component to charge/recharge.
By the way, my computer is plugged into a separate power filter (from the rest of the equipment). So that might explain why I didn't hear a big difference when using Jkeny's special cable. But that is just a guess. I will be curious to hear other people impressions on those usb cables that allow to use external power supplies.

I originally did this as a DIY project with the intention that others would try out different PS but it never was taken up - instead I had lots of people asking me if I would do the mods for them, etc. I have tried other batteries in the past on other devices & was never too impressed by them so that's why I wanted to give these LiFePO4 ones a shot. I was impressed by their specs - <8mohm (better than most caps); current delivery of 120Amps in in 7 sec bursts. maintaining it's voltage steady up to depletion. They sounded magnificent in this role (but also in other roles too) & I never felt the need to go experiment further. Somebody else used a different LiFePO4 (40AH battery) & was not bowled over y the sound so I don't think it's just to do with the current delivery capability but more about the internal structure & chemistry of these batteries.  
 
I guess whether you hear any improvement from feeding the modified Hiface with an external 5V depends on a) how good is your PC's 5V USB supply  b) how much better is the external 5V supply. Apart from that, I don't know if removing the power carrying line from inside the USB cable has any effect? Yes, I too will be interested to hear others experience of external 5V supplies.

 

[regal]

I edited the post above,  I didn't make it clear that the link is for LiFePO4 batteries,  I've been told that all 18650 &123A sized LIFePO4's come from the same factory,  but we really never know what goes on in China.   I figured for $25 its worth the risk.    There is also some hazmat regulation on shipping  Li batteries that aren't UL approved?  some places try to charge you an extra $25 for shipping for a 1 oz battery so watch for that.
 
One of my initial concerns with the LiFePO4 batteries I have dismissed,  after reading most datasheets is seems that most   3.3V clocks are spec'd to accept up to 4V's,  so I'm not as worried about the fact that the battery comes off the charger around 3.6V's.
 
 
 
 
Also I don't recommend attempting the mod yourself unless you understand the risks with Li batteries and you have a steady hand with a good soldering iron,  best to send to jkenky to do the mod rather than destroying your $180 Hiface.
 
 
Quote:

I wonder if jkeny tried batteries before settling on his LiFePO4 batteries.

 

 

[ccschua]

after reading all this staff, what is the recommend coaxial cable for the hiface to minimize reflection.

 

[FauDrei]

Opinions differ, but Slim had quite good experience with Oyaide DB-510...