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iBasso PB-2 Pelican fully balanced portable, DB-2 Dac . . HiFlight recommended op amps page 16. . - Page 72

post #1066 of 1128
Quote:
Originally Posted by zilch0md View Post

I'd say it doesn't matter, given that I can't think of a single headphone that has three wires going to each transducer!

I'm sure that fellow is right so far as how to wire 3-pin XLR connectors between a balanced DAC and a fully balanced amp, for example, but eventually, you've got to get down to only two conductors per channel - for headphones or speakers. So, for most people, it's OK to call a four-wire headphone cable "balanced," while a 3-conductor headphone cable is called "single-ended" (or "unbalanced").

Try http://toxic-cables.co.uk - he won't get tripped up in semantics. :-)



Mike

Thanks Mike.

I went to Frank at Toxic Cables and now have just received a beautiful looking balanced cable. No question that it is a work of Art.

Time to try it out to see if it sounds as good as it looks.
post #1067 of 1128

Congratulations!  Yes, Frank does fine work.

 

:beerchug:

post #1068 of 1128
If I use the PB2 in the single ended mode, rather than balanced, can I get away with fitting only two single OPamps rather than four?

If so, into which sockets would I put them.

Thanks
post #1069 of 1128
Quote:
Originally Posted by highfell View Post

If I use the PB2 in the single ended mode, rather than balanced, can I get away with fitting only two single OPamps rather than four?

If so, into which sockets would I put them.

Thanks

I always use in single mode with 2 buffer and 2 single TO-99 opa637
post #1070 of 1128
Quote:
Originally Posted by pitsel View Post


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

That surely can't be how the OPAMPS are installed right? My OPAMPS are installed as below

post #1071 of 1128
Quote:
Originally Posted by pitsel View Post

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

Cool. Thanks. I can try my 2x OPA627s
post #1072 of 1128
Quote:
Originally Posted by spurxiii View Post
 

That surely can't be how the OPAMPS are installed right? My OPAMPS are installed as below

 

You are using duals in L/R with singles as buffers.  But if you're using the TRS jack for single-ended cables, you could pull the first and third buffer op-amps (counting from left to right in your photo) and you wouldn't hear any difference.

 

Pitsel's photo is proof that using the PB2 single-ended gives us only half the power of going balanced with this design - but its still two-channel stereo, even with half as many op-amps.


Edited by zilch0md - 3/24/14 at 3:40am
post #1073 of 1128
Quote:
Originally Posted by zilch0md View Post
 

 

You are using duals in L/R with singles as buffers.  But if you're using the TRS jack for single-ended cables, you could pull the first and third buffer op-amps (counting from left to right in your photo) and you wouldn't hear any difference.

 

Pitsel's photo is proof that using the PB2 single-ended gives us only half the power of going balanced with this design - but its still two-channel stereo, even with half as many op-amps.

Thanks Mike!

post #1074 of 1128
Quote:
Originally Posted by spurxiii View Post
 

Thanks Mike!

 

You're welcome,

 

Those look like HA5002 as buffers, but what are those duals you're using?

 

Mike

post #1075 of 1128
Yes Mike they are the HA5002 buffers. Those duals are LME49860 which is from the topkit in Aug last year
post #1076 of 1128
Quote:
Originally Posted by highfell View Post

Cool. Thanks. I can try my 2x OPA627s

But they will have to wait my newly arrived 2x Muses 01 redface.gif



post #1077 of 1128

Joy!

 

It seems I'm hopelessly addicted to dummy buffers (at the expense of additional current) but, depending on your headphones, you might find you can better hear what the Muses01 brings to the table, at least for a little while, if you go "bufferless."  

 

This is analogous to something I once read at the forums of CoffeeGeek.com (paraphrasing):  If you really want to know what your non-dairy creamer is doing to the flavor of your coffee, just fill your mug with hot water - not coffee, then add the usual amount of creamer and drink up. Keep doing this until you find one that doesn't taste nasty. And by the way, good luck with that!

 

I have yet to find an op-amp that is as transparent as a dummy buffer. That's actually a gross understatement, given that a dummy buffer is nothing more than conductors, but the transparency is just as obvious to my ears as the understatement is to my eyes.  Even my best-sounding buffer (the HA5002) has a slight veil, best heard with something like the HD800 and a really noise-free DAC, like the Beresford Bushmaster MkII.

 

Lastly, just running the PB2 balanced out instead of single-ended gives me plenty of power (from two duals or four singles) for my LCD-2 or HD800.  With the LCD-2, I typically run the volume knob somewhere between 9 and 11 o'clock, but let me be the first to say that I'm probably forfeiting some dynamics and bass control by running dummy buffers, as the planar magnetics prefer power (volts * amps) that comes from amperage (via buffers) rather than from voltage (via the op-amps in L/R).  

 

And in truth, the LCD-2 is not ultra resolving, so I can tolerate the "veil" of the HA5002 when using the LCD-2, but I try to keep the lid closed on my PB2 - to protect my sanity from the incessant rolling of op-amps. I could easily get into pulling the HA5002 in and out, in and out, with the changing of headphones.  

 

It's all I can do to keep the lid closed.  As yet, I haven't resorted to putting Loctite Red on the case screws... 

 

Loctite Threadlocker Red 271

 

Mike

(Currently running 2x Muses02 with dummy buffers, after several months using 4x LME49990 with dummy buffers).  


Edited by zilch0md - 3/25/14 at 4:29am
post #1078 of 1128
Quote:
Originally Posted by zilch0md View Post

Joy!

It seems I'm hopelessly addicted to dummy buffers (at the expense of additional current) but, depending on your headphones, you might find you can better hear what the Muses01 brings to the table, at least for a little while, if you go "bufferless."  

This is analogous to something I once read at the forums of CoffeeGeek.com (paraphrasing):  If you really want to know what your non-dairy creamer is doing to the flavor of your coffee, just fill your mug with hot water - not coffee, then add the usual amount of creamer and drink up. Keep doing this until you find one that doesn't taste nasty. And by the way, good luck with that!

I have yet to find an op-amp that is as transparent as a dummy buffer. That's actually a gross understatement, given that a dummy buffer is nothing more than conductors, but the transparency is just as obvious to my ears as the understatement is to my eyes.  Even my best-sounding buffer (the HA5002) has a slight veil, best heard with something like the HD800 and a really noise-free DAC, like the Beresford Bushmaster MkII.

Lastly, just running the PB2 balanced out instead of single-ended gives me plenty of power (from two duals or four singles) for my LCD-2 or HD800.  With the LCD-2, I typically run the volume knob somewhere between 9 and 11 o'clock, but let me be the first to say that I'm probably forfeiting some dynamics and bass control by running dummy buffers, as the planar magnetics prefer power (volts * amps) that comes from amperage (via buffers) rather than from voltage (via the op-amps in L/R).  

And in truth, the LCD-2 is not ultra resolving, so I can tolerate the "veil" of the HA5002 when using the LCD-2, but I try to keep the lid closed on my PB2 - to protect my sanity from the incessant rolling of op-amps. I could easily get into pulling the HA5002 in and out, in and out, with the changing of headphones.  

It's all I can do to keep the lid closed.  As yet, I haven't resorted to putting Loctite Red on the case screws... 


Mike
(Currently running 2x Muses02 with dummy buffers, after several months using 4x LME49990 with dummy buffers).  

Good idea. I will try replacing with dummy buffers.

Silly question - if you have no buffers at all what happens ???
post #1079 of 1128

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

post #1080 of 1128
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

Download the PB2 "manual" at the bottom of this page

http://ibasso.com/en/products/show.asp?ID=70

Don't the chips have markings on them to identify them? And then read this thread, there are some more details about the Topflight kits
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