The Opamp thread

[K3cT]

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AD8597?? Never used this...... Any good?

I like it as it sounds like a "funner" AD797.

 
 

 

[ROBSCIX]

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And after all that.................. It doesn't fit inside my Fi-Quest anyhow. You gotta laugh

 
And the OCD continues on the DIY cable thread also. Yes, Leeperry I'm talkin' to you hehe.....

 Where do we put a stop to our search for the perfect sound??

Can you use an extension cable?  Not ideal but it may work.  Why would you ever want to stop looking for your personal "perfect" sound?
 

 

[SpudHarris]

Quote:

I like it as it sounds like a "funner" AD797.

 

 
Well I like the sound of that for sure. I usually get my opamps from Farnell but they are only showing US stock (£16 delivery charge).
 
Anyone have a couple of them to trade??? I have a few different opamps here. Failing that I'll buy if anyone has any spare, pleeeeeeeeeease. I need another fix and a funner AD797 sounds like just the job

 

 

[Apocalypsee]

I would like to ask, can the LT1364 runs from single positive voltage, or higher positive voltage than negative one? Because I felt that ~5V on this opamp don't do it any justice and I think higher voltage would definitely make it sound better, any thought? Planning to feed it through single +17V linear PSU and see how does it sound

 

[ROBSCIX]

@Spudharris, are you losing your love for the OPA2111AM's?

 

[SpudHarris]

Haha, funny you should ask that.......
 
I have been using OPA637AM's in my Fi-Quest Headphone amp. It's set up with 4 stacked BUF634's and has an option of 2 or 4 channel mode. Unfortunately with the 637's (which are astoundingly good) I can't use with low impedance phone and even with my 600ohm DT880's I can't use high current mode 
 
I've swapped back to the OPA2111AM which suits all my phones and is IMHO not a million miles from the OPA637 in terms of SQ, also the high current mode which can be used with this chip adds a little more to the SQ.
 
So no still lovin' the OPA2111AM What about you? 

 

[ROBSCIX]

Yes, still a great amp.  I sent one to a buddy also and he started using it in his sources.

 

[SpudHarris]

I assume I'm not on my own by saying this...... Every once in a while everything is just soooooooooooooo right you could listen forever
 
Last night whilst desparately trying once again to love my DT880/600's I swapped out the OPA637's in my Fi-Quest and dropped in some AD797BRZ's (been a while since I've tried these) and Oh my God everything just clicked and the hairs on my neck stood on end many time during the evening.
 
I paid quite a lot of money for the DT880's as the manufaktur route was the only way I could get the 600ohm version. I had to wait a long time for them to be made so the expectation was high especially since I've been following the appreciation thread. When they got here a couple of weeks back I was slightly dissapointed that they didn't set me alight immediately and I've been trying to love them every night since. Well thanks to the AD797's I can honestly say I'm in love..........
 
Is there a higher grade AD797 than BRZ? I can get these from a reputable seller are they a higher grade? Anyone know?
 
Cheers
 
Nigel

 

[leeperry]

BN is no higher grade than BRZ...it's not lead free that's all. Did you roll LT1363CS8? this is the true king of PRaT to my ears...but its PSRR is low so it needs a clean PSU and at least ±12V to really sing

 

[SpudHarris]

I have those but, no i haven't tried them in the Fi-Quest. Cheers for that, tomorrow is LT1363 day

 

[leeperry]

You can literally hear the very high speed of LT1363CS8, and the sound is very percussive...especially the low end bass

 

[morfic]

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You can literally hear the very high speed of LT1363CS8, and the sound is very percussive...especially the low end bass

You HEAR the SPEED of the OPAMP? Seriously? What does speed sound like?

 

[leeperry]

You HEAR the SPEED of the OPAMP? Seriously? What does speed sound like?

 
It picks up every minute detail slower opamps only wish they could present you with, this guy tried to put it in words: http://www.head-fi.org/forum/thread/89813/lt1363-opamp#post_1042510
 
When I roll slower opamps, I'm usually bored after a few mins....w/ LT1363 my phone is the bottleneck, w/ slower opamps they are the bottleneck

 

[morfic]

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It picks up every minute detail slower opamps only wish they could present you with, this guy tried to put it in words: http://www.head-fi.org/forum/thread/89813/lt1363-opamp#post_1042510
 
When I roll slower opamps, I'm usually bored after a few mins....w/ LT1363 my phone is the bottleneck, w/ slower opamps they are the bottleneck

 
Where does "fast" start? OPA627?
 
About the LT1363: have you checked your DC offset lately? I don't know what you use it in, so if you are not so lucky, it might pass you on a little present.
Compare input bias current of something sane like the LME49710 (55MHz is still fast for you, no?) with that of the LT1363.
 
Point i am trying to make is not every opamp is a good match for a circuit that was not made for it.
 
If the 55MHz of the LME49710 is not fast enough for you, then you surely are a LM6171 candidate.
 
 

 

[leeperry]

my DAC has decoupling caps, I get a steady 0.3mVDC from the LT1363(used as PCM1793 LPF).
 
well, it's not about Gain-Bandwidth, it's about Slew Rate....1000V/µs on the 1363