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The Opamp thread - Page 255

post #3811 of 4753

I just received 4x AD797BR which I've just tried in numerous positions in my Essence one.

 

I was previously running with stock op amps but with 1x 49720HA in the buffer slot and found the sound stage to be much wider, but lost a lot of bass also.

 

First I tried 1x AD797BR in the Buffer slot (Replacing the 49720HA) which overall sounded quite nice and lead me to try 1x AD797BR in the Buffer slot and 2x AD797BR in the Low Pass Filter slots. With this I found bass had returned, but sound stage was reduced slightly and more annoyingly the vocals seemed slightly veiled compared to before, like they had taken a bit of a back seat now.

 

Lastly I tried keeping the 2x AD797BR in the Low Pass Filter Slots and putting the 49720HA back in the buffer slot. Instantly I noticed that sound stage had returned and mostly I was happy with the sound, yet after further listening I noticed that vocals still sounded slightly veiled and bass is less punchy/impactful than required in certain songs. Some songs also felt very slightly 'fuzzy' sounding, like there was a bit of background noise within some parts of the music.

 

Now I've still not tried replacing the 4x I/V op amps and think that's probably what I should try next.

 

Based on the above, does anyone have any advice as to what I should try next?

post #3812 of 4753

 

Quote:
Originally Posted by Mutsu View Post
I just received 4x AD797BR which I've just tried in numerous positions in my Essence one.

I was previously running with stock op amps but with 1x 49720HA in the buffer slot and found the sound stage to be much wider, but lost a lot of bass also.

First I tried 1x AD797BR in the Buffer slot (Replacing the 49720HA) which overall sounded quite nice and lead me to try 1x AD797BR in the Buffer slot and 2x AD797BR in the Low Pass Filter slots. With this I found bass had returned, but sound stage was reduced slightly and more annoyingly the vocals seemed slightly veiled compared to before, like they had taken a bit of a back seat now.

Lastly I tried keeping the 2x AD797BR in the Low Pass Filter Slots and putting the 49720HA back in the buffer slot. Instantly I noticed that sound stage had returned and mostly I was happy with the sound, yet after further listening I noticed that vocals still sounded slightly veiled and bass is less punchy/impactful than required in certain songs. Some songs also felt very slightly 'fuzzy' sounding, like there was a bit of background noise within some parts of the music.

Now I've still not tried replacing the 4x I/V op amps and think that's probably what I should try next.

Based on the above, does anyone have any advice as to what I should try next?

Try replacing the LME49720 with LME49860NA, they are the same op-amp, but the LME49860 has a better voltage range.

 

 

post #3813 of 4753

Been tracking back to opamps I personally never really took to but that seem to get decent press. At the time I prefered the ADA4637BRZ over the 4627BRZ but Mad Max keeps refering back to the 27's so I'm going to give them a serious listen over a prolonged period and see what gives. Using 4 off in my balanced PB-2 with HA5002 buffers and have to say they are very nice. I'm not going to compare with anything at this stage, I'm just going to try and enjoy them.

 

Mad Max - I have put an envelope in todays post for you :) Do you bypass your ADA4627's? I have a few different caps here so should have something to suit if you think they benefit. I'm liking them a lot as they are!

post #3814 of 4753

 

Hi!

 

In Headphonia's review of the iBasso PB2, Mike (the article's author) wrote the following:

 

Quote:

If you want a more transparent sound and better texture on the bass areas, take out the buffer section and go with a dummy buffer.

  • No buffer – Limited current, but still good for HD650, sound is cleaner and more transparent to the actual signature of the op-amp.

 

Can anyone explain why current goes down (undesirable) but transparency goes up (desirable) when you replace the buffers with the dummy buffers that iBasso provides?  

 

How much loss of power would you guess is suffered for the sake of an increase in transparency?  (Expressed in dB or %, your choice...)  

 

Does this hold true for most amps of similar design or is this just something he is observing with the PB2?

 

Thanks!

 

Mike

 

 

post #3815 of 4753

 

Quote:
Originally Posted by Mutsu View Post

I just received 4x AD797BR which I've just tried in numerous positions in my Essence one.

 

I was previously running with stock op amps but with 1x 49720HA in the buffer slot and found the sound stage to be much wider, but lost a lot of bass also.

 

First I tried 1x AD797BR in the Buffer slot (Replacing the 49720HA) which overall sounded quite nice and lead me to try 1x AD797BR in the Buffer slot and 2x AD797BR in the Low Pass Filter slots. With this I found bass had returned, but sound stage was reduced slightly and more annoyingly the vocals seemed slightly veiled compared to before, like they had taken a bit of a back seat now.

 

Lastly I tried keeping the 2x AD797BR in the Low Pass Filter Slots and putting the 49720HA back in the buffer slot. Instantly I noticed that sound stage had returned and mostly I was happy with the sound, yet after further listening I noticed that vocals still sounded slightly veiled and bass is less punchy/impactful than required in certain songs. Some songs also felt very slightly 'fuzzy' sounding, like there was a bit of background noise within some parts of the music.

 

Now I've still not tried replacing the 4x I/V op amps and think that's probably what I should try next.

 

Based on the above, does anyone have any advice as to what I should try next?

 

BUF634 for buffer.  It's a buffer opamp, lol.  I think you will love it more than any other chip in buffer.

 

Try OPA827 in I/V.


Edited by Mad Max - 4/30/12 at 3:46pm
post #3816 of 4753

 

Quote:
Originally Posted by SpudHarris View Post

Been tracking back to opamps I personally never really took to but that seem to get decent press. At the time I prefered the ADA4637BRZ over the 4627BRZ but Mad Max keeps refering back to the 27's so I'm going to give them a serious listen over a prolonged period and see what gives. Using 4 off in my balanced PB-2 with HA5002 buffers and have to say they are very nice. I'm not going to compare with anything at this stage, I'm just going to try and enjoy them.

 

Mad Max - I have put an envelope in todays post for you :) Do you bypass your ADA4627's? I have a few different caps here so should have something to suit if you think they benefit. I'm liking them a lot as they are!

 

Because it is still my numero uno.  ADA4610-2B would take its place, but it sucks at dynamics for some reason.  C'est la vie, heh heh.

Still got some ceramic cap and a Vishay ERO MKP1837 film cap on its power supplies.  I ran out of tantalums or I would have put one on 4627.

 

 

Quote:
Originally Posted by zilch0md View Post

 

Hi!

 

In Headphonia's review of the iBasso PB2, Mike (the article's author) wrote the following:

 

 

Can anyone explain why current goes down (undesirable) but transparency goes up (desirable) when you replace the buffers with the dummy buffers that iBasso provides?  

 

How much loss of power would you guess is suffered for the sake of an increase in transparency?  (Expressed in dB or %, your choice...)  

 

Does this hold true for most amps of similar design or is this just something he is observing with the PB2?

 

Thanks!

 

Mike

 

 


Less stuff in the signal path (very desirable)?

post #3817 of 4753

 

Quote:
Originally Posted by Mad Max View Post

Less stuff in the signal path (very desirable)?

 

I'm with you, but then what's the purpose of a buffer?  Why is everyone rolling buffers in the PB2 in addition to rolling op-amps?  

 

Surely they don't want less transparency, less detail, and/or more noise, so there must be a big loss of power that goes with replacing the buffers with dummy buffers.  

 

In other words, can somebody help me understand why I don't want to just leave the dummy buffers in my PB2 permanently?

 

Thanks,

 

Mike

(Ignorant yet unwilling to ignore this mystery.) 

post #3818 of 4753

Probably also depends on how sensitive your headphones/earphones are.

So you notice this even with LCD-2?  SE530 and HD280 are very, very efficient.

post #3819 of 4753

 

Quote:
Originally Posted by Mad Max View Post

 

 

BUF634 for buffer.  It's a buffer opamp, lol.  I think you will love it more than any other chip in buffer.

 

Try OPA827 in I/V.

 

I forgot to mention my primary listening setup is through my speakers currently, would you still recommend trying the BUF634 in buffer and OPA827? Or would there be something better suited for headphones?

 

Thanks

post #3820 of 4753

Yup.  Only thing better than BUF634 in buffer is two BUF634 stacked on top of each other, lol!  But you would need to solder them together.

post #3821 of 4753

Or buy the stackable ones from ibasso.....

 

ibasso_pb2_10.jpg

post #3822 of 4753
Quote:
Originally Posted by SpudHarris View Post

 

 

That's exactly right!!

 

Personally I also like OPA602BP (CM in my EF-5), neutral but nice detail. kind of between the 49990 and LT1122. Also, I like ADA4610-2-BRZ, these are very nice indeed and great match with my musical taste (Shpongle - Younger Brother - Aes Dana - Asura - Sergio Walgood - Astropilot etc...etc...)

Perfect...i tried opa602bp n buf634 as headphones amp on protoboard lastnight..love it!!!L3000.gif

where did you buy opa602cm?/is it obsolute chips,right?any extra?

i dont try ada4610-1brz  that's much

post #3823 of 4753

qusp, (if you're still alive, lol) is it true that high speed opamps need to have their power supply high-frequency noise/junk/whatever sent to ground via high-frequency decoupling caps? That would explain a thing or two.

Edit: True

 

Oh, and 100-ohm dampening resistors before AD797's pins 2 & 3.
HURRRRRRRRR this is why we are a load of retards with overheating 797s.


Edited by Mad Max - 6/8/12 at 4:30pm
post #3824 of 4753

Hi Mad Max,

 

Quote:
Originally Posted by Mad Max View Post

Probably also depends on how sensitive your headphones/earphones are.

So you notice this even with LCD-2?  SE530 and HD280 are very, very efficient.

 

This had to be directed at me, as I own the LCD-2, SE530, and HD280, but I can't figure out what you're asking me.  confused.gif

 

I don't know what it is that you're wondering if I've noticed with the LCD-2.

 

Here's the post you followed:  http://www.head-fi.org/t/432749/the-opamp-thread/3810#post_8349405

 

Thanks!

 

Mike

post #3825 of 4753
Quote:
Originally Posted by Mad Max View Post

... this is why we are a load of retards with overheating 797s.

 

Yeah!  Tell me about it!  I'm the biggest retard of all - I don't even want to roll my opamps until I have some clue of what I'm doing...  It's my brain that's overheating.  

 

Lots of questions - no answers.   I should have bought an SR-71B with soldered-in op-amps instead of a PB2.

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