iBasso PB-2 Pelican fully balanced portable, DB-2 Dac . . HiFlight recommended op amps page 16. .
Mar 26, 2014 at 8:22 AM Post #1,082 of 1,604
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Hi Turboman808,


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:

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.

:)
 
Mar 26, 2014 at 9:20 AM Post #1,083 of 1,604

pitsel

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

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
 
Mar 27, 2014 at 8:31 PM Post #1,085 of 1,604

HiFlight

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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!!!
 
Apr 10, 2014 at 7:59 PM Post #1,086 of 1,604

Makiah S

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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 >.>
 
Apr 11, 2014 at 4:46 AM Post #1,087 of 1,604

SpudHarris

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  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....
 
Apr 11, 2014 at 1:00 PM Post #1,088 of 1,604

Makiah S

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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
 
Apr 11, 2014 at 8:04 PM Post #1,089 of 1,604

HiFlight

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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.
 
Apr 11, 2014 at 9:25 PM Post #1,090 of 1,604

Makiah S

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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!
 
Apr 12, 2014 at 9:24 AM Post #1,091 of 1,604

HiFlight

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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!
 
Apr 14, 2014 at 12:34 AM Post #1,092 of 1,604

Lohb

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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.
 
Apr 14, 2014 at 1:09 AM Post #1,093 of 1,604

Uchiya

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  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.
 

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