Head-Fi.org › Forums › Equipment Forums › Portable Headphone Amps › iBasso PB-2 Pelican fully balanced portable, DB-2 Dac . . HiFlight recommended op amps page 16. .
New Posts  All Forums:Forum Nav:

iBasso PB-2 Pelican fully balanced portable, DB-2 Dac . . HiFlight recommended op amps page 16. . - Page 73

post #1081 of 1128
Quote:
Originally Posted by highfell View Post

Good idea. I will try replacing with dummy buffers.

Silly question - if you have no buffers at all what happens ???

Silence. :-)
post #1082 of 1128
Hi Turboman808,

Quote:
Originally Posted by turboman808 View Post

Hey Guys.  I just got the hiflightaudio kit yesterday and I really don't have a clue what I am doing.  I use my amp with my alpha dogs and hifiman headphones.  I also should have a DB2 coming in pretty soon.  Plan to run everything balanced.  

Anyways I see pictures of different things, I see hiflight pictures but they all look different.  Mine came with 4 chips with diodes on them. I put all those in the second row from the jumpers.  I then put 2 of the larger chips in near the jumpers.  I didn't like the way the first set seems to be breaking up in the highs.  I think it had white paint on them.  I then put in the set with red paint and it sounds much better.  

I can take a picture tonight but I would really like to just set this up and leave it alone.  Any advice would be much appreciated.  Thanks Nate

The first thing to do is to identify all the op-amps in your possession so that you can take notes and share comments with others and receive opinions from others. Then, remove the top four screws from your PB2 case, remove the lid, plug in the cables and headphones of choice, and start listening and rolling, listening and rolling. :-)

If you have single-ended cables, you can speed up the rolling process by using half as many op-amps, like pitsel does:
Quote:
Originally Posted by pitsel View Post

I always use in single mode with 2 buffer and 2 single TO-99 opa637

If you want to skip all that trial and error, go with the opinions of others by telling us which op-amps you have.

:-)
post #1083 of 1128
If you have single-ended cables, you can speed up the rolling process by using half as many op-amps, like pitsel does:
Quote:
Originally Posted by pitsel View Post

I always use in single mode with 2 buffer and 2 single TO-99 opa637

If you want to skip all that trial and error, go with the opinions of others by telling us which op-amps you have.

:-)[/quote]

Hi,
For single-ended cables, ^ ^ with standard BUF634 and "Single" op-amps OPA637



And below same for single-ended cable, with Dummy buffer and "Dual" LME49720HA, i more prefer than opa637


Thanks
post #1084 of 1128

Thanks I will have to take some pictures and write down what they are tonight.  

post #1085 of 1128
Perhaps I can add a bit of clarification here.... buffers are primarily current devices rather than voltage devices, so by bypassing them, one will lose some output power, but this will likely be a non-issue unless attempting to drive extremely challenging phones or listening to music with a very wide dynamic range, such as some hi-rez files. More importantly, buffers function as impedance-matching devices. When bypassing them, some phones will sound just fine while others will have the frequency balance affected to some degree or another.

Regardless of what type of buffers are used, they will add their own signature to that of the L/R opamp(s) which can be either a positive or a negative, depending on your personal preferences.

Topkits include more than one set of L/R opamps to enable the user to optimally match their musical tastes as well as find the best synergy between the amp and a particular set of phones.

As far as choosing a "best" combination, TRUST YOUR EARS!!!
Edited by HiFlight - 3/27/14 at 5:33pm
post #1086 of 1128

SO guys I have a bit of an issue, and a question for you all?

 

My pb2 has a White Battery inside of it, not a HUGE blue one and I've also got a capcitor Sitting atop of the Blue sodder joints that lead into it's soddered in with a right angle plug

 

more importantly, I've been having some issues with my left channel, first of all the CB11 that I got died on me, it wsn't running the left channel at all, now I've got a new adaptor and all is well except that... if I bump the amp [which I don't often do] I get a click or a pop on my left channel :/

 

what is that, should I be worried? Do I need to purchase a new pb2 at some point to avoid this one dieing q.q, should I find my Warrenty card, which may now be expired since I got it second hand >.> lot's o questions I have

 

also I found a FREAKING hair inside my amp... which I didn't know was there, I removed it. But I am worried that it may have lead to the death of my last adapter and it my have been the cuase that developed this left channel clicking due to movement from the amp

 

IF I tap on the chassis I get some MAJOR Mirconphonics and the left channel again goes super silent... what the heck <.< this is a freaking SOLID state device, and why does the internals of mine not look like what you guys have pictures of up there q.q

 

yea if I thunk it to hard no left channel... if I thunk it with just ONE finger, the left channel comes back... what the heck >.>


Edited by Mshenay - 4/10/14 at 5:00pm
post #1087 of 1128
Quote:
Originally Posted by Mshenay View Post
 

SO guys I have a bit of an issue, and a question for you all?

 

My pb2 has a White Battery inside of it, not a HUGE blue one and I've also got a capcitor Sitting atop of the Blue sodder joints that lead into it's soddered in with a right angle plug

 

more importantly, I've been having some issues with my left channel, first of all the CB11 that I got died on me, it wsn't running the left channel at all, now I've got a new adaptor and all is well except that... if I bump the amp [which I don't often do] I get a click or a pop on my left channel :/

 

what is that, should I be worried? Do I need to purchase a new pb2 at some point to avoid this one dieing q.q, should I find my Warrenty card, which may now be expired since I got it second hand >.> lot's o questions I have

 

also I found a FREAKING hair inside my amp... which I didn't know was there, I removed it. But I am worried that it may have lead to the death of my last adapter and it my have been the cuase that developed this left channel clicking due to movement from the amp

 

IF I tap on the chassis I get some MAJOR Mirconphonics and the left channel again goes super silent... what the heck <.< this is a freaking SOLID state device, and why does the internals of mine not look like what you guys have pictures of up there q.q

 

yea if I thunk it to hard no left channel... if I thunk it with just ONE finger, the left channel comes back... what the heck >.>

 

My first thought would be to ensure your OpAmps are sat correctly in the sockets. Post a pic if you think yours is different....

post #1088 of 1128
Quote:
Originally Posted by SpudHarris View Post
 

 

My first thought would be to ensure your OpAmps are sat correctly in the sockets. Post a pic if you think yours is different....

they are and have been I can check again

post #1089 of 1128
Quote:
Originally Posted by Mshenay View Post

they are and have been I can check again

Sounds to me like a cracked/incomplete solder joint on one of the opamps. NEVER insert them by pushing down on top of the opamp. Press gently around the edges of the adapter. The SOIC solder joints are very small and very fragile.

I would try changing L/R opamps one at a time. Doesn't matter at this point if they are all the same, you are just looking to find the one that is faulty.
post #1090 of 1128
ewww thanks for tellin me that... I used tweesers today on the tops... super gently! but actually one of the pins was slighty bent. Ive never removed thr op amps or buffers before but i reseated them all today straightend the pin with a tweezer. took me 2 painful mins

but everythings all clear now. I appreciate u respobding. Ive got a quad of lme 49990s. If the problem appears again n reseating the doesnt fix it ill buy new op amps first

but removeing n reinsrting all 8 op m buffers solved the noise issues!
post #1091 of 1128
Quote:
Originally Posted by Mshenay View Post

ewww thanks for tellin me that... I used tweesers today on the tops... super gently! but actually one of the pins was slighty bent. Ive never removed thr op amps or buffers before but i reseated them all today straightend the pin with a tweezer. took me 2 painful mins

but everythings all clear now. I appreciate u respobding. Ive got a quad of lme 49990s. If the problem appears again n reseating the doesnt fix it ill buy new op amps first

but removeing n reinsrting all 8 op m buffers solved the noise issues!

Glad to have been able to help!
post #1092 of 1128

Anyone know how this compares to RSA F35 in stock form and with any other upgrade kits in it (LME49990 etc) ?

...and is it a compromise to use it as your main desktop amp as well @ about $400 inc. upgrade chips/shipping ?

I'll be running it off a Bushmaster Mk2 downstream.


Edited by Lohb - 4/13/14 at 10:01pm
post #1093 of 1128
Quote:
Originally Posted by Lohb View Post
 

Anyone know how this compares to RSA F35 in stock form and with any other upgrade kits in it (LME49990 etc) ?

...and is it a compromise to use it as your main desktop amp as well @ about $400 inc. upgrade chips/shipping ?

I'll be running it off a Bushmaster Mk2 downstream.

Something like an Asgard2 would better serve you if you're using it purely as a desktop amp.

post #1094 of 1128
Quote:
Originally Posted by Uchiya View Post
 

Something like an Asgard2 would better serve you if you're using it purely as a desktop amp.


Thanks, was looking to share mobile and desktop....more money for more cans !

post #1095 of 1128
Quote:
Originally Posted by Lohb View Post
 


Thanks, was looking to share mobile and desktop....more money for more cans !

There are limitations to what portable amps can do, nice as they are.  If you hear your cans on a desktop setup and can live with the compromise in sound from a portable amp, go for it.

New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Portable Headphone Amps
Head-Fi.org › Forums › Equipment Forums › Portable Headphone Amps › iBasso PB-2 Pelican fully balanced portable, DB-2 Dac . . HiFlight recommended op amps page 16. .