[privilege15]

No surprise PB2 is capable of a lot. Unfortunately it is so underestimated and becoming forgotten. I sold all my other amplifiers leaving only this one and not planning to change it. It's much more powerful out of balanced port than even it's neighbour P5 with external power supply. In fact, since it is no longer manufactured and almost disappeared from the shelves I almost bought a second PB2 recently just in case my current one will get broken but my new money sink into DIY multicopters stopped me from buying it.

 

[zilch0md]

^ It's nice to see someone so passionate about audio exhibiting an interest in other hobbies.  I'm sure a lot of us are that way, but it's hard to tell, reading these threads.  

 

[HiFlight]

Absolutely great work!!!! The PB2 is a great amp that was overlooked in favor of the boutique stuff.

 

[zilch0md]

You've been a faithful and very helpful advocate of iBasso's gear for a long time, Ron. I very much appreciate your enthusiasm and generosity, especially in my early days of rolling op-amps.  
 
Thanks!
 
Mike

 

[FallenAngel]

 

 
Seeing that photo made me think : at what point of upgrade-itis do you just say "maybe I should get a different amplifier"

 

[zilch0md]

^ I feel so silly now. What was I thinking?

 

[Makiah S]

^ I feel so silly now. What was I thinking?

no no, you get another amp when iBasso makes a pb3 xD 
 
I still love mine! 

 

[zilch0md]

I've added Edna SILMIC II 35V 10uF caps to DIP8 extenders that I can insert or remove from beneath the Burson V5s, at will.  
 
(This was the idea of Head-Fi member "pelopidas" on the Opamp Thread - soldering the caps to the extenders instead of to the op-amps themselves.)
 

 
 

 

 

 
Improved dynamics!  
 
I can't believe there was room for improvement, but now I understand why Burson has a web page describing this mod and why so many people like it.
 
(YMMV depending on how your amp's power supply is designed.)
 
This was my second attempt at soldering anything other than power cables.  My first attempt was a disaster  

  
 
It helps to wear two pair of reading glasses and use lots of Scotch Tape.  Doh!  

 
Mike

 

[privilege15]

Why are you doing this to me? Lol

 

[zilch0md]

Good one!  

 
I'm always chasing someone else, so you might as well do the same!  
 

 
At least this is an affordable experiment (compared to the many audio components I've bought that didn't pan out.)
 
Start by just trying the caps soldered to extenders for insertion beneath whatever op-amps you're currently using.
 
http://www.ebay.com/itm/10-PCs-ELNA-SILMIC-II-10uF-35V-ELECTROLYTIC-CAPACITORS-NEW-/191772894800
 
http://www.ebay.com/itm/8-Pin-Round-DIP-Socket-For-DIP8-Package-Pack-of-5-/300922720329
 

 

 
 

    <--- Top-down view
 
 
Note:  The photos above show the DIP8 socket upside-down, on its back.  So pay attention to where the notch is when looking at this diagram, immediately above.
 
For single op-amps, you use different pins:
 
<--- Top-down view
 
 
I'm really a novice at soldering, but I managed to do it.  

 
Mike

 

[WhiskeyJacks]

I really wish the Burson V5's were not so tall and large, I would love to use them in my PB2 when I would get the money for them, currently I am using 4x LM49710  opamp and the dummy buffers. Pairing this with the iBasso DX90 and the Oppo PM-3 has been a delight thus far.

 

[zilch0md]

^  I hear you!  I'm having a difficult time even getting a quote from a water jet cutting service to precisely cut two rectangular holes in the spare lid of my PB2.  They want nothing to do with it, saying, "You only want one of them done?  The job is too small.  We're booked."  
 

 
Three different local companies here in the Dallas area have turned me down - they won't even give me a quote with my having said, "Give me a crazy number. You might be surprised what I'm willing to pay." 
 
So now I'm looking for an "old-school" machinist who thinks he can drill and cut without messing it up.  I know I don't have the skill, so I'm not about to attempt it myself.
 
No lid means it's not transportable.  Ugggh!    
 
But man, does it sound great!
 
Mike

 

[Makiah S]

  Good one!  

 
I'm always chasing someone else, so you might as well do the same!  
 

 
At least this is an affordable experiment (compared to the many audio components I've bought that didn't pan out.)
 
Start by just trying the caps soldered to extenders for insertion beneath whatever op-amps you're currently using.
 
http://www.ebay.com/itm/10-PCs-ELNA-SILMIC-II-10uF-35V-ELECTROLYTIC-CAPACITORS-NEW-/191772894800
 
http://www.ebay.com/itm/8-Pin-Round-DIP-Socket-For-DIP8-Package-Pack-of-5-/300922720329
 

 

 
 

    <--- Top-down view
 
 
Note:  The photos above show the DIP8 socket upside-down, on its back.  So pay attention to where the notch is when looking at this diagram, immediately above.
 
For single op-amps, you use different pins:
 
<--- Top-down view
 
 
I'm really a novice at soldering, but I managed to do it.  

 
Mike

I'm wondering how that would sound, with the LME 49990 Op amps, having the addition of the capcitors

 

[zilch0md]

Hi Mshenay,
 
Somehow, I overlooked your post, above.  I've never tried the caps with the LME49990, and unfortunately, I've just spent about six hours wearing out my ears with testing the Sparkos SS3602 Duals vs. the Burson V5 Duals, in my PB2, so I will have to test the LME49990s with and without caps, some other day.  
 
Meanwhile, for the sake of the guys on the Gustard H10 thread, where many of them use the Burson V5s that have been melting left and right, here's a link to my post discussing the SS3602 with the PB2:
 
http://www.head-fi.org/t/735828/gustard-h10-high-current-discrete-class-a-output-stage-headphone-amplifier/5040#post_12629394
 

 
Mike

 

[Lohb]

Hi, guys looks like this thread just sprung to life after I finally picked up a PB2.
 
Following Zilch0md's advice before,I picked up the xpal battery pack with LPS 16 volts plug and already have a set of 4 Burson V5i new generation opamps coincidentally that I was going to use elsewhere.
I'll have to get the Hirose connector from ebay and make everything balanced.
 
I wish the gain switches were on the outside as I'd really wanted to share it between IEMs and my LCD 2.1s and Fostex planars. But if I only use it with planars fair enough.
From all that has been written about this amp (desktop class but transportable), they should NEVER have discontinued it, but taken it to a sleeker V2 unit design....tut tut !!

 
 
Does anyone know if it takes a single-end DAC input and makes it fully balanced end-to-end like the RSA F-35 ?