iBasso PB-2 Pelican fully balanced portable, DB-2 Dac . . HiFlight recommended op amps page 16. .
Jan 27, 2011 at 10:25 AM Post #136 of 1,604
Good George, i'm glad you got something out of it. some might say I made a lot of noise without really saying anything and truth be told that was kinda the point. you may well find you prefer copper in the end depending on how your system turns out.
 
anyway back to this rather intriguing headamp, I would be all over this if I didnt already have a portable balanced rig.
 
Jan 27, 2011 at 10:34 AM Post #137 of 1,604
Qusp, I appreciate your thoughts on the topic.  I understand much better of what you mean now.  Since this is off track, I will not continue the discussion here any more but suffice it to say that I did not regurgitate stuffs that are passed around here on the forum.  I think I have spent enough money to experiment and to know what I am talking about.  For instance, I have the TWag silver cable and the ALO chain Mail UPOCC copper cable for my JH13 in the same system, and I know they sounded differently.  I have the SAA Voice for my HD800 and I know it altered the sibiliance character of the phone.  I have used from generic cable to Black Dragon (GS1000), Silver Dragon, Cardas cable (HD600), Transparent cable, ALO Chain mail (LCD2) and so on.  I just want you to know that I have personal experience on cable when I talk about them.  But I do appreciate your thoughts, and actually I agree with a few aspect of them.
 
Jan 27, 2011 at 1:23 PM Post #138 of 1,604
not all was directed at you personally; I was not labeling you with every example in my post, I was just saying that such generalizations contribute to noobs picking up what I deem falsehoods as defacto standards and 'fact'; as a result system synergy is often overlooked when I feel it is the most important aspect of the lot.
 
so enough of the sidebar, I almost feel like buying one of these so I can make a cool 6 wire interconnect for it :wink: 
 
Jan 27, 2011 at 3:35 PM Post #140 of 1,604


Quote:
Does anyone have any more impressions of the PB2 compared to the PB1?

I am still forming my opinion and I want the PB2 to get some time on it both for burning it in and listening impressions. One thing I can say is that it goes deeper in the bass, sustains the note better and still keeps the sound well articulated. The upper bass does not smear into lower midrange area and the amp is well extended. It can also power my HE-6, which is amazing with the volume control anywhere from 1 to 3 o'clock and no clipping or distortion even on bass heavy music. On other headphones on high gain I am around 9 to 10o'clock and with all the power the PB2 has, any other phone is easy to drive (that I own). 
 
Jan 27, 2011 at 4:00 PM Post #141 of 1,604
 
Quote:
I am still forming my opinion and I want the PB2 to get some time on it both for burning it in and listening impressions. One thing I can say is that it goes deeper in the bass, sustains the note better and still keeps the sound well articulated. The upper bass does not smear into lower midrange area and the amp is well extended.


Does the extent of the improvement vary depending on what headphones you're using? In other words, is the improvement more noticeable on some of your phones than others? I'm most interested in the difference it makes with the HD650.
 
Jan 27, 2011 at 4:24 PM Post #142 of 1,604


Quote:
 
Quote:
I am still forming my opinion and I want the PB2 to get some time on it both for burning it in and listening impressions. One thing I can say is that it goes deeper in the bass, sustains the note better and still keeps the sound well articulated. The upper bass does not smear into lower midrange area and the amp is well extended.


Does the extent of the improvement vary depending on what headphones you're using? In other words, is the improvement more noticeable on some of your phones than others? I'm most interested in the difference it makes with the HD650.

I will try it with them and get back. 
 
edit:
 
Yes, in a very good way the HD650's go low and are extremely well controlled. I like the drum on the start of Hotel California, Hell Freezes Over. The bass can just truncate or in the right system, go low and resonate. It sounds excellent with the PB2 and the 650's, lower and a better trailing bass note, it is not truncated at all. 
 
Jan 27, 2011 at 10:52 PM Post #143 of 1,604


 
Quote:
 I was just saying that such generalizations contribute to noobs picking up what I deem falsehoods as defacto standards and 'fact'; as a result system synergy is often overlooked when I feel it is the most important aspect of the lot.

 
Hehehe, Qusp, isn't that is how noobs learn?  By spending a lot of money?  Why are we robbing them of that valuable experience of being a noob?  
biggrin.gif
   Besides, I really think cable believers are the ones that really knows the limitation of cable, because they/we tried so hard to spend the money and make cable do what we want them to do.  But we all knows there is only so much cable can do to the sound.  And you are right System Synergy is important and there is no disagreement from me.  Thnaks for pointing that out.

 
 
Jan 28, 2011 at 2:54 AM Post #144 of 1,604

I take it then that with the PB1 and the HD650's the bass was truncated at the same passage?
Quote:
Yes, in a very good way the HD650's go low and are extremely well controlled. I like the drum on the start of Hotel California, Hell Freezes Over. The bass can just truncate or in the right system, go low and resonate. It sounds excellent with the PB2 and the 650's, lower and a better trailing bass note, it is not truncated at all. 

 
Jan 28, 2011 at 2:56 AM Post #145 of 1,604
Jam, could you comment on the difference in the bass department between the SR71b, D6 and PB2 using the LCD2 as reference?  Which one has the most bass?  Which of these has the best bass definition, tightness, punchiness, quickness etc. Thanks
 
Jan 28, 2011 at 4:53 AM Post #146 of 1,604


Quote:
I take it then that with the PB1 and the HD650's the bass was truncated at the same passage?
Quote:
Yes, in a very good way the HD650's go low and are extremely well controlled. I like the drum on the start of Hotel California, Hell Freezes Over. The bass can just truncate or in the right system, go low and resonate. It sounds excellent with the PB2 and the 650's, lower and a better trailing bass note, it is not truncated at all. 

To a degree, yes, the PB1 is a little truncated in direct comparison. It doesn't go as deep or sustain the bass note as long or with as much authority, on the same passage. 
 
 


Quote:
Jam, could you comment on the difference in the bass department between the SR71b, D6 and PB2 using the LCD2 as reference?  Which one has the most bass?  Which of these has the best bass definition, tightness, punchiness, quickness etc. Thanks


That will take a while as I am still getting used to everything and take it very serious when I make statements. If someone says, wow, this guy said it does this and then buys something because of that and I didn't evaluate carefully enough or listen long enough, I feel bad. I don't enjoy that feeling and never want to lead Anyone astray. 
 
---------------------
 
On another note, I modified my DB1 because somehow I blew one op amp. I put a socket in the DB1 and changed the caps out for Black Gate (rare now) 47uf HiQ 6.3 volt. I am sure I still have some in storage back in Tucson Arizona (BG's) but have no idea when I will see those. Yes the Black Gates have a positive impact but the DB1 needs more time now to form the caps. 
 
 
 
Jan 28, 2011 at 10:02 AM Post #147 of 1,604
Thanks, Jam, take your time.
 
Jan 28, 2011 at 11:56 AM Post #148 of 1,604
I have spent considerable time evaluating different opamp combinations in the PB2 and below are some of the top contenders so far along with a few comments.  I used both BUF634 singly, 2X and 2X Hi-C (not recommended due to high battery drain) and AD797 as buffers.  The 797's were more "polite" with a warmer SQ but, IMO, did not control the bass as tightly as BUF634.  They also ran a bit warm to the touch.
 
Most of my evaluations were with 2X stacked BUF634 non-Hi-C.  Phones used were Sony Z1000, driven from the SE output, as these are tonally very accurate and present both instrumental timbres and vocals in a very realistic manner.
Gain was set to mid position.  A variety of instrumental, vocal and acoustic musical genres were used in the trials.   The opamps below were the best sounding of the many different ones that I tried. 
 
AD743.  Single-channel: Well-balanced, accurate, but now almost impossible to source.
LT1678 Class A. Dual-channel: Overall, my favorite for accuracy, imaging and 3-dimensional soundstage. 
OPA1642  Dual-channel: Just behind the 1678 in my ranking, not quite as analytical. 
LME49990 Single-channel: Very transparent, accurate, taut bass.  Can be a bit on the dry and bright side.
OPA606  Single-channel: Favorite of iBasso.  Warm, analog sound.  Lacks that extra bit of 3-dimensional depth.
TLE2142 Dual-channel:  Similar to OPA606 but with a bit more depth.  If you liked the D10 Topkit, you will like this. 
AD797 Single-channel: Can be used as either L/R or buffer.  Warmish tube-like SQ.  (included in rolling kit)
LT1358 Nice all-around SQ.  Well-balanced,  a bit narrower soundstage reminiscent of crossfeed. 
 
I do have several more combinations to try, and hopefully, I will be able to source the adapters to use the HA5002 buffer. 
 
Jan 29, 2011 at 1:18 AM Post #149 of 1,604
Wow, Ron, can you really tell the difference between those opamps and their characteristics?  That's amazing.  Looking forward to more impressions.  Great job.
 
Jan 29, 2011 at 2:32 AM Post #150 of 1,604
He can.
 

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