[Ari33]

Quote:

 
True, but MoonYeol was asking about changing internal power source (battery) from 3.7v to 5v as far as I know. While powering through USB port the voltage is being dropped by drop down circuit.
I think 5v li-ion batterries don't exist anyway, they come in multiplication of 3.7v (3.7, 7.4, 11.1v etc)

 
You're right,  there is no such thing as a 5v Li-ion battery, the Li-ion chemical reaction that takes place dictates that so the 5v Powerbanks on Ebay must have a voltage booster (.. or drop) circuit in them.
 
I wonder if the USB's 5V is dropped down though, it's strange that the bass is improved and tightened while charging if it is.
 
Edit-  Yep, from research it seems that the BH must have a voltage drop circuit because max input voltage for charging a single cell Li-ion battery must not excede 4.2V, (+- 0.055V) so this additional 0.5v must be where the better/tighter bass comes from?

 

[docentore]

Quote:

 
You're right,  there is no such thing as a 5v Li-ion battery, the Li-ion chemical reaction that takes place dictates that so the 5v Powerbanks on Ebay must have a voltage booster (.. or drop) circuit in them.
 
I wonder if the USB's 5V is dropped down though, it's strange that the bass is improved and tightened while charging if it is.
 
Edit-  Yep, from research it seems that the BH must have a voltage drop circuit because max input voltage for charging a single cell Li-ion battery must not excede 4.2V, (+- 0.055V) so this additional 0.5v must be where the better/tighter bass comes from?

Next time I will have the cover taken off I will measure voltage going into op-amps and post the results. Haven't tried using it while charging myself yet

 

[nick n]

Quote:

 
It is designed to be used while charging so a 5v input via USB should be fine. Anyone ever tried one of these li-ion powerpack with a 5v out USB connector that you get on Ebay, to see how much noise is added?

Oh why didn't I think of that before.... great idea.  Endless battery life here we go.

 

[MoonYeol]

I can check if there is any added noise. Can't be worse than the usb on my laptop anyway.

Edit: No added noise at all using:
http://viewitem.eim.ebay.se/20000mAh-Black-Portable-Powerbank-Supply-USB-Battery-Charger-UK-DISPATCH---/221266100608/item
But with my current phones and songs I'm pressed to find any real difference. It might just be placebo but I think there is some added impact and bass rumble. It would be great to know about the smallest ones. I'm pretty sure I've heard a difference when using a wall socket adapter to feed the BH. But it shouldn't be any difference since they're both putting out 5V.
Like http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=290851437444

 

[Ari33]

Quote:

Oh why didn't I think of that before.... great idea.  Endless battery life here we go.

 
That wouldn't be a great deal to me, I'd rather integrate a small voltage booster circuit pre- op amp to have full control of the input voltage and take the hit on battery life. Perhaps something like this http://www.dimensionengineering.com/products/anyvolt-micro if there was any available space inside the BH (circuit board dimensions- 33x18x9mm)
 
...or the larger (38x52x20mm) but far cheaper LM2587 voltage regulator circuit http://www.ebay.com/itm/LM2587-Volume-DC-DC-Booster-Converter-Step-up-Voltage-Regulator-/321171362490?pt=LH_DefaultDomain_0&hash=item4ac74e12ba that you could put in a small EMI shielded enclosure and 3M onto the back of the BH?

 

[Hutnicks]

Quote:

 
That wouldn't be a great deal to me, I'd rather integrate a small voltage booster circuit pre- op amp to have full control of the input voltage and take the hit on battery life. Perhaps something like this http://www.dimensionengineering.com/products/anyvolt-micro if there was any available space inside the BH (circuit board dimensions- 33x18x9mm)
 
...or the larger (38x52x20mm) but far cheaper LM2587 voltage regulator circuit http://www.ebay.com/itm/LM2587-Volume-DC-DC-Booster-Converter-Step-up-Voltage-Regulator-/321171362490?pt=LH_DefaultDomain_0&hash=item4ac74e12ba that you could put in a small EMI shielded enclosure and 3M onto the back of the BH?

I think you kind of missed the point there.
 
The anyvolt looks interesting for 20 bucks. You should be able to use a 5 volt source on that and not see any hit on battery life at all..

 

[leadbythemelody]

C&C BH2 + Ultrasone Edition 8 = Pure Magic

 

[Kamakahah]

C&C BH2 + Ultrasone Edition 8 = Pure Magic

I agree. I found one at a meet that had been abandoned by its owner. He had taken the source out for a spin.

I thought, "I'll try the RB clip+ /w BH I brought"

Then it happened... Magic lazer beams of awesomeness danced through my ears.

It was one of the meets highlights for me. I can only assume it would be even better with scaling equipment.

Nevertheless, it was pleasantly surprising to see how well the budget rig made it sing.

If the cans were cheaper, it would be my goto portable.

 

[Rayzilla]

Quote:

C&C BH2 + Ultrasone Edition 8 = Pure Magic

This was what I wanted to know. Now this is back on my radar again.
 
I have been jumping between the BH2, Aune T1 and the Audio GD NFB-11.32. Only the BH2 is portable, so they're are not exactly comparable.
 
Another question I have is how does the BH2 compare to the Fiio E17. I am using the E17 with my MB Air and it does a pretty good job for the Pro 900 and the Spirit One but I do not find it does as much for the Ed8.

 

[Ari33]

Quote:

I think you kind of missed the point there.
 
The anyvolt looks interesting for 20 bucks. You should be able to use a 5 volt source on that and not see any hit on battery life at all..

Yeah, that wouldn't be unheard of.... 

 
I guess just a Li-ion 5v external powerpack is the simplest and most cost effective, all in one solution... and you could probably change one of the resisters on its voltage booster circuit for a variable one if you really wanted to have full control over its ouput for experimenting.

 

[docentore]

I still haven't found the rest of capacitors available to buy in normal prices, so I decided to use what I have, at least to change one pair - 0.22uF. I've used Vishay/BC 0.15uF + Wima 0.068uF in parallel, giving me 230nF - close enough. They did fit but it is really tight fit.

 
Overall performance has improved after those few swaps so far but to make sure I'm going to compare fully modded amp with unmodded if I can find around here.
 
I have measured voltage with fully charged battery and compared it with voltage while connected to USB port. The difference was around 5mV. Also have compared sound with fully charged battery and USB connected to amp on its own - I can't hear the difference. I would say the better bass response is to do with battery discharging (mind that Li-Ion battery swings from fully charged to discharged from 4.2V to little bit less than 3.7V) which is 0.5V and this might cause difference in sound.
 
As for higher voltage mods etc, The 5V voltage step-up pcb would not fit inside, there is no space. I would suggest if one is brave enough to:
1. Take out battery completely.
2. Solder usb input directly to battery terminals bypassing charging circuit.
3. Connect portable power bank to miniUSB port.
This would give real and constant 5V, but I'm not bothered with doing so, I'll stick with component swap and tweaking as I think there is more potential there.
 
More to come when I will get rest of the parts!

 

[SkyBleu]

Hey guys!
 
I got my BH up for grabs if anyone is interested!
 
http://www.head-fi.org/t/675927/aus-final-price-drop-c-c-bh-portable-amp-free-shipping

 

[leadbythemelody]

I never owned or auditioned a Fiio amp before but I heard they gave a warmer sound to headphones. When you pair the Edition 8's with the BH2's the treble is slightly boosted, the midrange becomes clearer, the soundstage is increased, and the bass is significantly tighter and less muddy.  So overall, the BH2 gives the Edition 8's a faster/tighter more exciting sound with improved midrange and better soundstage while the E17 in my guess would give it a warmer sound.

 

[Rayzilla]

Thanks leadbythemelody! That sounds interesting and would work well with EDM music. I'll see if I can get a chance to test them at the local store some time soon.

 

[leadbythemelody]

Hey no problem! Happy listening!