[razzz42]

  I'd clean up that awful flux mess.
Flux can become conductive sometimes and cause shorts and problems.  Cleaning it up might even be the solution to your issue.

That is non-conductive cement holding the ceramic caps in place. I am wondering if changing the stock op-amps (the caps are jumped across some of the op-amps legs) to a more recent design that newer op-amps wouldn't need the caps at all??

 

[Mad Max]

  That is non-conductive cement holding the ceramic caps in place. I am wondering if changing the stock op-amps (the caps are jumped across some of the op-amps legs) to a more recent design that newer op-amps wouldn't need the caps at all??

 
Just make sure they aren't opamps with tremendous bandwidth as the circuit is designed for low-speed opamps.

 

[UnknownAX]

The opa2107 and ad823 should work fine in a unity gain circuit that's using jrc4556 and opa2134, shouldn't they? I can't find any problems comparing their datasheets. (Except that the 2107 will need a higher supply voltage but that isn't a problem.

I'm also unsure about buying the opamps from eBay/China, but I don't really have any options. What puts me off though, is that every opa2107 seems to have different markings and most of them don't have the "gap" that indicates with way the opamp is placed. I thought it isn't worth it to fake any "cheap" opamps, but....
The 2107's cost like 2.5€ which seems a little too low. I'd prefer an US seller but none of them has the opamps I want.

 

[razzz42]

The opa2107 and ad823 should work fine in a unity gain circuit that's using jrc4556 and opa2134, shouldn't they? I can't find any problems comparing their datasheets. (Except that the 2107 will need a higher supply voltage but that isn't a problem.

I'm also unsure about buying the opamps from eBay/China, but I don't really have any options. What puts me off though, is that every opa2107 seems to have different markings and most of them don't have the "gap" that indicates with way the opamp is placed. I thought it isn't worth it to fake any "cheap" opamps, but....
The 2107's cost like 2.5€ which seems a little too low. I'd prefer an US seller but none of them has the opamps I wan

Looks like current/update packaging for the OPA2107AP, no half moon indent, just an indented circle.
 
Mouser has them, kinda expensive. Here
 
eBay has the newer and older packaging. Here and Here For about $3.50 or $8.25 apiece, what could possibly go wrong? China is not totally backwards anymore, I never had any problems other than shipping times maxs 2 weeks tops but when I can I prefer Hong Kong based sellers.
 
Seems in retail settings or mass manufacturing products, you can work with and get away with swapping out most any opamp for another.

 

[tan1415]

Is an op-amp an amplifier?
I always thought opamps works like a pre amp(minus dac) in stereo. Just color the sound.
But to really power the sound you will need a power amplifier.

Asking this question because of a motherboard the gigabyte g1 sniper b5.
It has interchangeble op amps and a headphone amp. But if I read the information correctly, they are not connected.
The op amp plays from rear jack.
The headphone amp from front jack.

 

[zilch0md]

Those LT1028ACN8s sound tempting for use as buffers, but I've had my sights set on the Muses 02 for a long time and now, Mouser.com has them in stock, so I've finally ordered a pair of them.  
 
With tax and shipping it came to $166.87 for two opamps. Ouch!  I bought the Schiit Vali for less than that.
 
But I must find out what they sound like!
 

 

[blasjw]

  Those LT1028ACN8s sound tempting for use as buffers, but I've had my sights set on the Muses 02 for a long time and now, Mouser.com has them in stock, so I've finally ordered a pair of them.  
 
With tax and shipping it came to $166.87 for two opamps. Ouch!  I bought the Schiit Vali for less than that.
 
But I must find out what they sound like!
 

 
Ouch!  Too bad NJR doesn't offer samples.  

 

 

[SpudHarris]

Those LT1028ACN8s sound tempting for use as buffers, but I've had my sights set on the Muses 02 for a long time and now, Mouser.com has them in stock, so I've finally ordered a pair of them.  

With tax and shipping it came to $166.87 for two opamps. Ouch!  I bought the Schiit Vali for less than that.

But I must find out what they sound like!

Mike, I've invested in another 01 and 02 so will have a pair of each to try in the PB2 soon. I really rate the PB2, I can't wait to try the Muses in it....

I was listening with balanced LCD3 last, the PB2/DB2 sounds BIG, HUGE in fact with a quad of AD743's and stacked buffers. With eyes closed you would be forgiven for thinking it was a decent desktop rig costing at least twice it's retail. It punches way above it's weight. Probably the best bang for buck ever.

 

[zilch0md]

Oh no! I need to buy more op-amps? Noooooooo....!



LOL

When you get the 2nd Muses 02, please tell me what you think of LME49990 in I/V with Muses 02 as buffers - to the HD800. That's what I'm dying to try and would really like your opinion.



Mike

 

[SpudHarris]

Will do pal. Never really thought of using them as buffers but will give it a go. What are you expecting buddy Audio Nirvana per chance?

 

[zilch0md]

LOL Nigel!
 
Yes, I'm hoping for exactly that!  

 
Actually, it's about my last shot at finding a solid state amp that will justify keeping the HD800, without spending a lot of money.
 
Keeping this as brief as possible...
 
I bought the HD800 without having any particular amp in mind, but I knew that it has a reputation of being finicky.
 
Even after burn-in, I didn't like the HD800 with anything I own, nor anything I've borrowed - all solid state - except for finding it "tolerable" with my TBI Audio MG3 > TBI resistor network that imposes 15.8 dB attenuation to kill hiss from excessive gain in the MG3.  For me, the problem has been not enough bass and too much treble, but I love the detail, imaging and sound stage of the HD800.  It's like a girl with a beautiful face and crooked teeth.  I want to take my HD800 to the orthodontist!
 
So, several people suggested I try the Schiit Vali hybrid amp > HD800 and as of this writing, the Vali is the best HD800 solution I've heard for handling any type of recording (without spending a ton of money on a proper tube amp and going OCD with rolling tubes) - but, I've come to realize that the Vali is intrinsically noisy and puts a bit of a sheen on everything, even though I really like the FR it yields with the HD800, and even the detail it preserves.
 
Then I got the Beresford Bushmaster MkII DAC/amp (which is known for being warm and having great bass), where I liked it not quite as much, so I tried feeding the Bushmaster MkII analog out to the TBI MG3 > resistor network > HD800, which was getting real close to being ideal, until I got some HD650 and realized just how little bass I was hearing in the HD800, even still, and...  how much dynamics and even resolution were being lost with the attenuated TBI MG3. 
 
Going back to using the Bushmaster MkII DAC + amp directly into the HD800, I've resorted to creating an HD800-specific playlist - with recordings that don't demand much bass performance, nor have anything shrill happening in the treble.  These recordings, like solo guitar, or guitar + vocal, or pretty much anything acoustic - when played through the Bushmaster MkII - directly into the HD800 really show off both the Bushmaster and the HD800, with no ill effects.
 
My last hope, short of buying an Eddy Current or Cavalli tube amp (and I'm not even interested in something more affordable like the Woo WA6SE, as I've heard that they color the sound to "fix" the HD800 while also degrading some of the resolution), is to make my iBasso PB2 as warm as possible - it's the only amp I can tweak in this way.  The goal is to "fix" what's wrong with the HD800, without degrading what's right.
 
I've found that I can pretty much emulate the sound of the Bushmaster MkII's amp section by equipping the PB2 with OPA1612s in I/V and dummy buffers, so that gives me more power than the Bushmaster MkII's amp section outputs, but I want treble warmth and more bottom-end energy, with as little impact as possible to the micro-details and separation that are rendered so nicely by the Bushmaster MkII > HD800. 
 
Just from reading, I have a hunch that I will get closer to what I'm looking for, if not Audio Nirvanna, with this chain:
 
Resonessence Concero (as USB-to-SPDIF converter) > Bushmaster MkII analog out (bypassing its amp) > iBasso PB2 equipped with LME49990 in I/V and Muses 02 as buffers > balanced out to HD800.
 
Of course, I'll probably be rolling some other combinations, as well, including Muses 02 in I/V with dummy buffers and OPA1612 in I/V with Muses 02 as buffers...
 
I can't believe I'm about to start rolling opamps again after keeping a lid on the PB2 for so many months...
 

 
Which all begs the question... "What's your favorite rig for use with your HD800 (PB2 or otherwise)?"
 
Thanks!
 
Mike

 

[SpudHarris]

LOL Nigel!

Which all begs the question... "What's your favorite rig for use with your HD800 (PB2 or otherwise)?"

Thanks!

Mike

Oh man, I'm not going to help matters.... I use the Icon HP8 with the HD800's. I'm told many people find synergies but I think unless you have a boutique stash of tubes you may struggle to find the ideal sound. I started collecting 6SN7 tubes ages ago when I bought a WA6. I kept most tubes as I thought I may get back into them again one day and most of my collection were as rare as hens teeth.

I will definitely check out the combination you desire and report back but I don't have a balanced cable for the HD800 so YMMV.

You aren't rolling aimlessly now, you have got to the fine tuning stage. I hope that you find what you are looking for as the HD800 is a truly superb phone and you will regret it if you let it go. I bought mine used (here on Head-Fi) and the guy I bought it of kicked himself and bought them again within a month

Take care - Nigel

 

[zilch0md]

Thanks Nigel!  I knew you had some tube gear, but I was hoping you had a favorite PB2 configuration for the HD800, too.  

 
Your sngle-ended HD800 cables should sound pretty much the same on the PB2, except for running half the power, so don't worry about that.  I already had a balanced Toxic Cables Silver Poison for HD800, purchased used, for use with my MG3 speaker amp + resistor network.  The Silver Poison is terminated with a 4-Pin XLR, so I've ordered the CB11 adapter from iBasso to adapt the PB2's Hirose connector to 4-Pin XLR.  
 
I hear you about not selling the HD800.  It has some very special traits, but they come with negative traits, as well (with most amps).  I bought mine new for only $890 during a 30-minute window of opportunity at Amazon this past December 19th. Since then, because of the HD800, I've bought balanced cables, the Schiit Vali, and now the Muses 02 (x2) and CB11 - all because of the HD800 - trying to keep the wallet as closed as possible while "fixing" the HD800, but something tells me I'm going to end up buying one of every solid state amp that's allegedly good for the HD800 (i.e. Matrix M-Stage, Violectric V200, etc.) before I cave in and get a >$1k tube amp.  I really don't want to go to tubes, though.  There comes a point where I'd be better off just selling the HD800, as I get plenty of enjoyment from my much less finicky LCD-2, but I would be haunted by the inability to enjoy its detail, separation, and sound stage.  
 
If you want, just wait for me to try the LME49990 + Muses 02 as buffers.  If that, or some other combination, works well with the HD800, I'll come running for your second opinion.  

 
Thanks,
 
Mike

 

[zilch0md]

A post I made to the PB2 thread regarding how Mouser.com packaged and shipped my Muses02 (x2):
 
http://www.head-fi.org/t/528149/ibasso-pb-2-pelican-fully-balanced-portable-db-2-dac-hiflight-recommended-op-amps-page-16/1050#post_10280548

 

[ClieOS]

  A post I made to the PB2 thread regarding how Mouser.com packaged and shipped my Muses02 (x2):
 
http://www.head-fi.org/t/528149/ibasso-pb-2-pelican-fully-balanced-portable-db-2-dac-hiflight-recommended-op-amps-page-16/1050#post_10280548

 
I received mine in similar (plastic bag) package as well, but from akizukidenshi.com (MUSES official distributor in Japan). I don't think those pretty boxes from Audiotrak has anything to do with MUSES directly. It is probably just a nice box Audiotrak happens to have at their hand.