[ROBSCIX]

How does it sound?

 

[12Bass]

This is an AD8397 in my Gina24's headphone circuit, replacing SSM2135. A number of bypass capacitors were used, two 2200 µF on the rails (+/- 12V), two 22 µF and two 0.01 µF on pins 4 and 8, plus one 0.01 µF across.

The circuit looks messy largely because it has been modified too many times and traces have lifted, plus the AD8397 required some circuit changes in order to make things stable/reliable. That and my careless soldering....

The Gina's headphone output with the AD8397 is clearer and more punchy sounding than with the original chip, which sounded sort of small and lifeless. Other mods are an OPA2211A in place of NJM2068 on the PCI card, along with shorted output capacitors, meaning that the output is DC coupled. This is my main source/headphone amp, used for driving my K702s.

 

[12Bass]

Quote:

Originally Posted by ROBSCIX /img/forum/go_quote.gif How does it sound?

If you're referring to THS4052, I made some comments here: http://www.head-fi.org/forums/f6/opa...ml#post6116238

 

[ROBSCIX]

Quote:

Originally Posted by 12Bass /img/forum/go_quote.gif If you're referring to THS4052, I made some comments here: http://www.head-fi.org/forums/f6/opa...ml#post6116238

Yes, already seen that. Early morning with no Coffee

 

[leeperry]

humm, U87 vocals and violins sound miles better on the OPA2132P than on the OPA827

they sound more "holographic", warmer, livelier...involving, emotional. Clinical and low distortion is not always the best choice IMHO for euphonic listening

PS: as Kingwa puts it "I ever use OPA2132 at some years ago, it sound very good."

 

[ROBSCIX]

Quote:

Originally Posted by 12Bass /img/forum/go_quote.gif This is an AD8397 in my Gina24's headphone circuit, replacing SSM2135. A number of bypass capacitors were used, two 2200 µF on the rails (+/- 12V), two 22 µF and two 0.01 µF on pins 4 and 8, plus one 0.01 µF across. The circuit looks messy largely because it has been modified too many times and traces have lifted, plus the AD8397 required some circuit changes in order to make things stable/reliable. That and my careless soldering.... The Gina's headphone output with the AD8397 is clearer and more punchy sounding than with the original chip, which sounded sort of small and lifeless. Other mods are an OPA2211A in place of NJM2068 on the PCI card, along with shorted output capacitors, meaning that the output is DC coupled. This is my main source/headphone amp, used for driving my K702s.

If your planning on doing more work to this output, maybe go with a SOIC to DIP8 adapter and you could just install DIP8 modules. This would prevent all the soldering etc when trying out various units. Brown dog has a model that would work->LINK
Solder down the SOIC side and solder in a DIP8 socket. They are kind of big but may be something you might want to check out.

 

[12Bass]

Thanks ROBSCIX.

Actually, I'm pretty happy with the AD8397.... can't think of another chip which would be better for this application (driving low impedance headphones). Also don't like the idea of adding more mechanical connections from a reliability/stability perspective. The intention behind this particular circuit was to fabricate a reliable, good sounding, headphone output, not to mess around with op amps.... I have other circuits for that....

 

[igor0203]

I've got OPA827 today for testing. Will report when I'll install them. Currently I have LT1364 which I found to be the best so far.

Here is schematic of amp I'm using

http://www.shrani.si/f/2C/OV/1hAqJ18...0schematic.pdf

 

[ROBSCIX]

Quote:

Originally Posted by 12Bass /img/forum/go_quote.gif Thanks ROBSCIX. Actually, I'm pretty happy with the AD8397.... can't think of another chip which would be better for this application (driving low impedance headphones). Also don't like the idea of adding more mechanical connections from a reliability/stability perspective. The intention behind this particular circuit was to fabricate a reliable, good sounding, headphone output, not to mess around with op amps.... I have other circuits for that....

Sure, just a suggestion. Figured it might be easier then re-soldering new opamps in there. However, as you said, your not changing this one now.
Just a thought.

 

[leeperry]

ouhhhh, Kingwa sure knows his business..will try Moon later today, but Earth is quite impressive so far

photos available here: http://www.head-fi.org/forums/6120046-post76.html

 

[ROBSCIX]

Yes. This is why they are suggested by many people around here.

 

[leeperry]

woohah...soundstage is just CRAZY in movies and lives concerts w/ the Earth...talking about SS w/o having heard discrete op-amps is like trying to explain music to a deaf-born person, it makes that much of a difference!

it's totally 3D, your brain can do his work at measuring delays and calculating distances in a totally natural way...full 180 degrees SS FTW!

 

[leeperry]

ahhh OPA-Moon sounds exactly like its RMAA measurements look, distorted to death

it feels like going from a top rate home CD player to a crappy FM car radio...major waste of $$$

 

[ROBSCIX]

The moon sounds great but like many opamps is not compatible with every circuit.
Perhaps, simply asking questions and reading may have helped. If you had of asked anybody their opinion I would have told you the Moon can be unstable in many circuits. I am sure others would have mentioned it also...

 

[12Bass]

Just looking at the photos, it is hard to imagine that running a bunch of long wires from a discrete op amp to a DIP socket can be helping performance any.... all sorts of inductance, RF pickup, and an open invitation for oscillation there.

Just curious, leeperry, have you done any quasi-scientific testing, perhaps having a friend swap op amps so that you don't know which ones you are listening to? Expectation can have a huge impact on auditory perception.