[ccschua]

Hi,
 
can you post the link of the pulse transformer and also the steps taken to replace the pulse transformer and the Hiface 50ohm BNC plug. 

 

[wushuliu]

So is it not possible/necessary to use this USB isolator recently mentioned for the Terakink X2, with the Hiface?
 
http://electronicsshop.dk/isoleret_usb.htm
 

 

[regal]

Quote:

Hi,
 
can you post the link of the pulse transformer and also the steps taken to replace the pulse transformer and the Hiface 50ohm BNC plug. 

scientificconversions.com part #SC982-04  
 
The 75 ohm BNC amphenol connector from digikey: ARF1177-ND 
 
 
Steps taken:  desolder and solder new parts in place

 

[regal]

Quote:

So is it not possible/necessary to use this USB isolator recently mentioned for the Terakink X2, with the Hiface?
 
http://electronicsshop.dk/isoleret_usb.htm
 

no not possible

 

[xdanny]

All right, I just got through ordering 2 attenuators for my BNC hiFace, one at each end of the cable.  I hope I got the right ones, they are the 10db version at the bottom of the page.  I will let everyone know once I test them.  
 
I did post my impressions of the unit that jkeny modded for me.  Here is a link to that in case anyone is interested: 
http://www.head-fi.org/forum/thread/446375/usb-24-192khz-m2tech-hiface/1440   post #1450
 
Again, thank you John (jkeny) for an excellent job!  I am really happy he agreed to do it because I do lack the knowledge yet I'm constantly drooling over these diy threads and I "hate" all you guys who really understand this stuff...

 
Cheers!

 

[regal]

Quote:

I do lack the knowledge yet I'm constantly drooling over these diy threads and I "hate" all you guys who really understand this stuff...

 
Cheers!

If you had high school physics you can understand the fundamentals, learn and apply ohms law inside and out that's 90% of it really,  the hard part is the mechanics of soldering to tiny pieces on a cheap PCB with old eyes and feeble hands.   Don't believe anyone without a Phd who claims to fully understand RFI , reflections and the like,  its an empirical science (trial and error) with the theory explaining the test results not the other way around.
 
 
On another note I found if you discharge the batteries too far and they won't take a charge you can bring them back to life by switching the charger to 4.7V for a minute or less,  then putting them back on the 3.6V charger.  I find I have to disconnect the batteries when I'm done listening otherwise they continue to have current drawn even with the USB unplugged.

 

[ccschua]

happen to mine. Within 4 weeks of listening (about 1 hour each), the battery is flat. on hindsight, I charge it to 4.7 V and I just discharge it using a 10W 10ohm resistor and within secs, it drops to 3.2V.

 

[regal]

Quote:

happen to mine. Within 4 weeks of listening (about 1 hour each), the battery is flat. on hindsight, I charge it to 4.7 V and I just discharge it using a 10W 10ohm resistor and within secs, it drops to 3.2V.

Next time just charge on 4.7V for a minute then switch to 3.6V you will get better battery life (although when we discharged them too far their life was compromised somewhat regardless.)
 

 

[keyboard]

I don't k now whether jkeny would be interested in testing the Digital Interface,I don't have a hi-face so there is no way I can compare the two.

 

[FauDrei]

In that regard I find JKeny's switch solution quite good:
 

1. When it is switched on one battery powers the clocks (slow drain), other the chip (fast drain) and the blue led is reminding you it is working.
    
2. When you switch it off - the batteries are connected in parallel and, if no charger is connected, the batteries even out - the slow drain battery "recharges" fast drain battery.
   
   This way I manage to listen for a week (2-3h per day) before recharge is needed. Of course, you have to remember to switch it off after your listening and aforementioned led comes in very useful in reminding you of that.
    
3. If charger is connected, when you switch it off the charger recharges both batteries and stops charging once both batteries are full. It is really (semi) automatic mode because you do not have to think about recharging batteries - you only have to remember to switch it off once your listening is done.
   
   This is most elegant way of dealing with battery powered hiFace, but I still prefer one "big" recharge per week instead of many "small" recharges daily. YMMV.

 
Otherwise, good to know how to revive excessively drained batteries (if/when I manage to forget to switch it off), thanks guys.

 

[regal]

Yes Jenky has a good implementation,  I bought the battery holders,  just have to remember to remove the batteries when done, I wanted to have the batteries separate from the charger just because I'm a paranoid individual and murphies law always strikes me
 
I had to put in a separate order for a dam 64 cent jam nut from digikey to hold the hiface from both sides of the case.  If you order from digikey make sure you pick up part number 1-1634816-0    so you don't pay $5 to ship a 64 cent nut that no hardware stores carry locally!

 

[Sebhelyesfarku]

What would be the simplest way to get the 4.5-5.5V range for USB from two LiFePO4 accus (2x3-3.4V = 6-6.8V)? I mean without regulators, complex PCBs, whatever. For e.g. with a simple resistor? Obviously I'm clueless about electronics

 

[ccschua]

Hi FauDrei,
 
just wonder if you have compared the modded hiface with other dedicated cd transport ?

 

[i_djoel2000]

hi, all..i heard usb input has higher jitter than coaxial/optical input. can someone tell me the audible difference of the higher/lower jitter? is this why they're building m2tech?
 
sorry for the noob question

 

[regal]

Quote:

hi, all..i heard usb input has higher jitter than coaxial/optical input. can someone tell me the audible difference of the higher/lower jitter? is this why they're building m2tech?
 
sorry for the noob question

wrong thread