[jamato8]

The 5002 to my ear, is the cleanest background and allows the most detail of the buf634 or 5002. I have used the 5002 stacked, though they do produce some heat. 

 

[Makiah S]

  birds of a feather haha, i too like bright, but i think its more analytical than bright, or maybe its clarity that is perceieved as bright.
 
i have the er4s/er4p and the hf2 alot of people consider those iems bright but i find them perfectly detailed and accurate. warm signature imo withholds detail in the track, and thats not my taste.
 
i have cables like the Hybrid peptide symbiote silver plated copper cable for my se535, i also have the toxic cable silver poison for my westone w4r i have the toxic silver poison pure silver interconnects... have rsa male to hirose male toxic silver poison interconnect for the amp to dac....im into anything that is going to bring out max detail.
 
and now saying that i might be perceiving all that clarity,detail,brightness,analytical sound from all that silver......but i still think the LME49990+HA5002 is hands down the best combo, maybe the muse01 or muse02 might sounds better, but those cost a penny or 2, and im not opposed to spending the money i dont care, i just havent really heard alot about those opamps and if they will yeild what i am looking for, again i have tried a ton of opamps and the lme49990 just does it for me, but everyone is different.

I see no reason to use the buffers tbh, the hm801 is very warm and likes a BRIGHT amp, that said it has a clean line out :3 best of all it all cost me $280! For my Pb2 and hiFilight Kit with lme 49990 and some other buffers, it will be here in 2 weeks!

  The 5002 to my ear, is the cleanest background and allows the most detail of the buf634 or 5002. I have used the 5002 stacked, though they do produce some heat. 

I never had any issues with background noise even on my pb1, the background is black out of the balanced out with my D2k

 

[Mooses9]

different strokes different folks, if it works for you

 

[Dopaminer]

DHL just delivered my pb2.  I`ve downloaded the pdf from ibasso; could someone here direct me to additional instructional information, like an FAQ or something?  
 
Many thanks,
 
d

 

[Mooses9]

  DHL just delivered my pb2.  I`ve downloaded the pdf from ibasso; could someone here direct me to additional instructional information, like an FAQ or something?  
 
Many thanks,
 
d

what exactly are u looking for?

 

[zilch0md]

 

 

 

[Dopaminer]

Thanks guys,
 
The basics of op-amp rolling, in general and specifically on the pb2. Those visuals are cool.  I`ll guess I`ll just start in with switching things out.  Is there some systematic way to go about it?  I`m interested in gain variations - I`ll mostly be using the amp with balanced shure se846 (9ohm and hiss like hell from the ibasso dx50 headphone out) but would also like to try my hd800s with it as well. . . 

 

[Makiah S]

  Thanks guys,
 
The basics of op-amp rolling, in general and specifically on the pb2. Those visuals are cool.  I`ll guess I`ll just start in with switching things out.  Is there some systematic way to go about it?  I`m interested in gain variations - I`ll mostly be using the amp with balanced shure se846 (9ohm and hiss like hell from the ibasso dx50 headphone out) but would also like to try my hd800s with it as well. . . 

Whoa from iems to the HD 800... let us know how that works
 
I'm going to be using mine with LME 49990 OP Amps and Dummy Buffers, gain set to low
 
it should drive all my headphones nicely! And I'm the owner of an HE 4 now, so I'm going to need every bit of current the pb2 can drive :3 my pb2 is already here, but I've yet to pick it up... should have it in hand tommorow  

 

[Mooses9]

  Whoa from iems to the HD 800... let us know how that works
 
I'm going to be using mine with LME 49990 OP Amps and Dummy Buffers, gain set to low
 
it should drive all my headphones nicely! And I'm the owner of an HE 4 now, so I'm going to need every bit of current the pb2 can drive :3 my pb2 is already here, but I've yet to pick it up... should have it in hand tommorow  

You are going to need the HA5002 Buffers and gain set on high for hd800

 

[jamato8]

The buf634 will work fine for the HD800. They have a little more power output than the HA5002, not really noticeable to me but either will work fine and to my ear the 5002 are just slightly more transparent. 

 

[Mooses9]

  The buf634 will work fine for the HD800. They have a little more power output than the HA5002, not really noticeable to me but either will work fine and to my ear the 5002 are just slightly more transparent. 

True, i would perdsonally take the transparency vs output. but thats just my opinion.
 
reason being is the added transparency plus the lme49990 = a amazing opamp setup 
 
since running the lme49990 + ha5002 i havent rolled any other opamp

 

[zilch0md]

Or for a little more warmth with the HD800:   LME49990 in I/V with Muses 02 as buffers - and the gain set as low as possible while still achieving a sufficient listening level.  
 
The lower the Gain setting that can achieve adequate volume levels, the lower your noise floor.  
 
Note:  I don't have the Muses 02 yet, but going on everything I've read, I'm pretty sure they would be a better match for the HD800, as buffers in the PB2, than the HA5002.  
 
But yes, I agree with LME49990 + HA5002 buffers, in the absence of Muses 02.  I've tried LME49990 + HA5002 with the HD800 (which is plenty loud on Low gain) and it sounds really good when the PB2 is getting a warm signal from my Bushmaster MkII DAC's analog Line Out - a slightly warm source - not as warm or dark as the iBasso DB2 Boomslang2, but with a lot more detail and just the right amount of sparkle.
 
I didn't like the DB2 Boomslang2 > PB2 for use with my LCD-2, because it was too warm and dark, so I returned it, but now that I have the HD800, I suspect the DB2 Boomslang2 > PB2 would be a good match to tame the HD800's brightness, but I'm not going to order it again to find out. 

 
As I've already said, the slightly warm Bushmaster MkII DAC > PB2 with LME49990 + HA5002 buffers is a pretty good match with the HD800, for my tastes, definitely better than when using any of my other DACs that are more neutral than the Bushmaster MkII (CEntrance LX, CEntrance DACmini CX, or Concero). 
 
Thus, I have a hunch, but haven't tested, the Muses 02 as buffers with the LME49990 in I/V might make the PB2 just about right for the HD800 when using a neutral DAC.
 
Sticking with a neutral DAC > 16V-powered PB2 with LME49990 + dummy buffers > the HD600 is also looking for warmth (in my opinion) - as could be provided perhaps with the Muses 02 as buffers , and I suspect with the HD650, it would be even better (more like my LCD-2 with a neutral DAC > 16V-powered PB2 with LME49990 + dummy buffers).
 
Note:  My comments above were made while powering the PB2 with an external XP8000 battery pack, regulated to 16V (the maximum permissible voltage for the PB2), not with the PB2's internal, 12.6V LiPo battery. This translates to better dynamics and bass control than can be had with lower swing voltages at the rails.  
 

 

 
Using the PB2's internal 12.6V battery pack, the voltage, and thus the performance, decays with use following a fresh charge, until the battery gets down to about 9V, at which point the PB2 will stop operating.
 
Using the XP8000 battery pack with an XPAL WI16 inline voltage regulator, the PB2 always sees a constant 16V, even as the external battery pack's output decays with use from 21V to 16V, when the regulator will shut down.  Thus, the PB2's optimal 16V performance remains constant, completely unaffected, as the external battery pack is consumed!
 

 
Mike
 
UPDATE:  I have to add that I have never heard an op-amp used as a buffer in the PB2, that is as clean and transparent as dummy buffers in the PB2.  I just broke out my PB2 and HD800, to validate what I've written above, and although I find the HA5002 buffers to provide the additional warmth needed by the HD800, replacing them with dummy buffers increases the transparency and detail - allowing me to hear the LME49990s without "corruption," but, of course, this reduces the current gain offered by the HA5002s - reducing total power output to the headphones - making the use of dummy buffers a better match for the HD650, for example, than for the less efficient LCD-2 or HD800.   
 
In the past, I've tried all of my meager inventory op-amps as buffers in the PB2, even using LME49990s as buffers with LME49990s in the input voltage gain stage (LME49990 x 8), but nothing beats using dummy buffers for resolution and transparency.  That's going to be the first thing on which my attentions will be focused if I ever get around to orderings some Muses 02 for use as buffers.
 
UDATED UPDATE:  All the more reason to push the PB2 with 16V power instead of 9 to 12.6V power...  Listening to the LCD-2 on LME49990 + dummy buffers with a neutral DAC right now, is sublime - just as I concluded after about three months of rolling op-amps.  (Feel free to substitute HD650 for LCD-2!)  So...  you don't necessarily need the extra power afforded by using op-amps as buffers (instead of using dummy buffers), when using a 16V supply voltage AND taking advantage of balanced output (one last piece of the puzzle) that always gives you 2x the power you'd get when using the PB2's TRS (single-ended) headphone jack.
 
There, I think I'm done with this dissertation.   

 

 

[Makiah S]

  Or for a little more warmth with the HD800:   LME49990 in I/V with Muses 02 as buffers - and the gain set as low as possible while still achieving a sufficient listening level.  
 
The lower the Gain setting that can achieve adequate volume levels, the lower your noise floor.  

Spoiler: Warning: Spoiler!

Note:  I don't have the Muses 02 yet, but going on everything I've read, I'm pretty sure they would be a better match for the HD800, as buffers in the PB2, than the HA5002.  
 
But yes, I agree with LME49990 + HA5002 buffers, in the absence of Muses 02.  I've tried LME49990 + HA5002 with the HD800 (which is plenty loud on Low gain) and it sounds really good when the PB2 is getting a warm signal from my Bushmaster MkII DAC's analog Line Out - a slightly warm source - not as warm or dark as the iBasso DB2 Boomslang2, but with a lot more detail and just the right amount of sparkle.
 
I didn't like the DB2 Boomslang2 > PB2 for use with my LCD-2, because it was too warm and dark, so I returned it, but now that I have the HD800, I suspect the DB2 Boomslang2 > PB2 would be a good match to tame the HD800's brightness, but I'm not going to order it again to find out. 

 
As I've already said, the slightly warm Bushmaster MkII DAC > PB2 with LME49990 + HA5002 buffers is a pretty good match with the HD800, for my tastes, definitely better than when using any of my other DACs that are more neutral than the Bushmaster MkII (CEntrance LX, CEntrance DACmini CX, or Concero). 
 
Thus, I have a hunch, but haven't tested, the Muses 02 as buffers with the LME49990 in I/V might make the PB2 just about right for the HD800 when using a neutral DAC.
 
Sticking with a neutral DAC > 16V-powered PB2 with LME49990 + dummy buffers > the HD600 is also looking for warmth (in my opinion) - as could be provided perhaps with the Muses 02 as buffers , and I suspect with the HD650, it would be even better (more like my LCD-2 with a neutral DAC > 16V-powered PB2 with LME49990 + dummy buffers).
 
Note:  My comments above were made while powering the PB2 with an external XP8000 battery pack, regulated to 16V (the maximum permissible voltage for the PB2), not with the PB2's internal, 12.6V LiPo battery. This translates to better dynamics and bass control than can be had with lower swing voltages at the rails.  
 

 

 
Using the PB2's internal 12.6V battery pack, the voltage, and thus the performance, decays with use following a fresh charge, until the battery gets down to about 9V, at which point the PB2 will stop operating.
 
Using the XP8000 battery pack with an XPAL WI16 inline voltage regulator, the PB2 always sees a constant 16V, even as the external battery pack's output decays with use from 21V to 16V, when the regulator will shut down.  Thus, the PB2's optimal 16V performance remains constant, completely unaffected, as the external battery pack is consumed!
 

 
Mike
 
UPDATE:  I have to add that I have never heard an op-amp used as a buffer in the PB2, that is as clean and transparent as dummy buffers in the PB2.  I just broke out my PB2 and HD800, to validate what I've written above, and although I find the HA5002 buffers to provide the additional warmth needed by the HD800, replacing them with dummy buffers increases the transparency and detail - allowing me to hear the LME49990s without "corruption," but, of course, this reduces the current gain offered by the HA5002s - reducing total power output to the headphones - making the use of dummy buffers a better match for the HD650, for example, than for the less efficient LCD-2 or HD800.   
 
In the past, I've tried all of my meager inventory op-amps as buffers in the PB2, even using LME49990s as buffers with LME49990s in the input voltage gain stage (LME49990 x 8), but nothing beats using dummy buffers for resolution and transparency.  That's going to be the first thing on which my attentions will be focused if I ever get around to orderings some Muses 02 for use as buffers.
 
UDATED UPDATE:  All the more reason to push the PB2 with 16V power instead of 9 to 12.6V power...  Listening to the LCD-2 on LME49990 + dummy buffers with a neutral DAC right now, is sublime - just as I concluded after about three months of rolling op-amps.  (Feel free to substitute HD650 for LCD-2!)  So...  you don't necessarily need the extra power afforded by using op-amps as buffers (instead of using dummy buffers), when using a 16V supply voltage AND taking advantage of balanced output (one last piece of the puzzle) that always gives you 2x the power you'd get when using the PB2's TRS (single-ended) headphone jack.
 
There, I think I'm done with this dissertation.   

 

 

Well that is going to make my Portable stack EVEN thicker but... oh well ;3 I guess I'll have to live with it and invest in bigger pockets 
 
and guys I'm not driving a HD 800, I'm diriving an HE 4, entirely different monster, in which Low Gain is best for maxium current output into the HE 4. as in Hifiman HE 4
 
I might pick that enegizer unit up here in a week or so! 
 
So where did you find the XPAL Williy WI16, I found one site in Chinnese that sold it... but without a price :\
 
And that combo unit is almost as much as the Pb2 it self <.< [or a used one] but if it's worth it. Maybe I'll sntach it up next Fall  
 
Also, the Battery pack seems like a Power Conditioner for portable gear, smart thinking, I have a conditioner sitting in between my wall and my NFB 10ES2 and it did increase over detail retentension and clarity 

 

[zilch0md]

Hi,
 
I've never heard the HE-4 and I don't know how efficient it is, but if it's as efficient as the HD600, you're not likely to hear a big improvement in bass control or dynamics, just by using 16V power - and maybe not even by using balanced output from the PB2 vs. single-ended.
 
But there's a very easy test for determining whether or not you will hear any improvements using the XP8000 + WI16 Willy Cable...  
 
Just listen to your PB2 + HE-4 while using the PB2s AC adapter.  It outputs 16V just like the XP8000 + WI16. If you decide you can hear an improvement on 16V power vs. the internal battery's 9V to 12.6V, then the XP8000 + WI16 would be the way to go for portable use.
 
See this post for more information and WI16 ordering instructions:   http://tinyurl.com/kvmjnj2
 
Mike

 

[Makiah S]

Efficiency: 86 DB
 
The HE 4 is rated at 86 DB efficeny and 32 ohms
 
It's almost has hard to drive as the HE 6... almost. And I find that all of my headphones, my D2k and W1000x and Beyer DT 880 all benifit sonically from the Balanced out of the Pb1, which is why I bought the Pb2 to get a sonic upgrade to my Pb1
 
That said, nice test! I might just save the money and not worry about it, seeing as the only time I'm really portablt, or walking with headphones on and gear in pocket is when I'm traveling and surrounded by noise. My portable set is mostly for when I'm not at home, but still sitting down in a some what quiet enviorment