The Opamp thread

[headphoned]

In that case you can try the LT1364, LT1057ACN8, OPA2132P and the TL052CP (or ACP), then choose yourself

 

[buz]

Or you could try your luck with the ones already soldered to adapters on sold ebay...

 

[leeperry]

yes, clearly the cardas eutectic solder is a godsend! the usual 60/40 stuff takes forever to melt..
 
anyways:
 
more bass than 1363/1028, would you believe that? SS is also even better than 1363...there used to be some very harsh/edgy upper mids when I first tried it, but either my brain got used to them or they magically "burned in"?

 
http://www.diyaudio.com/forums/digital-source/105512-ad845-drop.html#post1273080
 

 The 845 is more shouting, unforgiving, and it sounds if there is some more distortion at the higher frequenties

 
it still seems less colored than 1363, and one of my current test songs is "Boards of Canada - Twoism\01. Sixtyniner.flac"...this track kinda lacks dynamics when the breakbeat shows up in the intro on the 1363, I've heard it far more overwhelming...and it's back w/ a vengeance on 845, which would appear to be a close cousin of 797...besides KN is its highest grade, and it's only available as DIP8.
 
You know you're obsessed about opamps when you solder them at midnight and try them at 3AM...I'm currently listening to ADA4627-1, and I've also put together some LT1360CS8...

 

[Sebhelyesfarku]

Quote:

You know you're obsessed about opamps when you solder them at midnight and try them at 3AM...

 
But you can quit anytime you want, no?

 

[leeperry]

 But you can quit anytime you want, no?

I'll have to, I really don't like ADA4627-1A...some sort of OPA827? it's got BB written all over it

 
that "plasticky" sound I really hate...LT1360 is a sub-par LT1363, and AD845 has that nasty distortion in the upper mids/ trebles...it does wonders on 70's music(like a "perfect" tube!), but it makes classical music very harsh and unrefined

 
so far nothing beats LT1363 to my ears

 

[Mad Max]

Quitting is blasphemy.

 
ADI and the like will not stop developing more opamps over time.
Perhaps a vacation might not be a bad idea for leeperry. =P

 

[leeperry]

hehe, well 1363 doesn't have a high PSRR so it does need a very clean environment, but its pros have been extensively documented before: http://www.head-fi.org/forum/thread/89813/lt1363-opamp

 

[Spacehead]

detailed but smooth sounding chip ADA4898-1 
maybe little lifeless
now on my PPA v2. listened to it all night

 

[SpudHarris]

Just got 2 x OPA637AM's (TO-99) for use in my Fi-Quest. They arrived with 2 x Nichicon caps (Audio KT 33/50 (M) if that means anything at all to you guys. I've not yet got into bypassing etc yet but assume this is what they are for.
 
Can someone clarify where I would use them, there is one for each opamp. I'd have a stab at +in & -in (pins 2-3) but I'd be guessing........
 
Like to get into this at some point so this could be a good place to start, any help would be greatly appreciated

 

[leeperry]

one thing really not clear to me is that 1028A was making static
pops when my bathroom neon turned off or my fridge turned on...and
this doesn't happen whatsoever on OPA2604/AD845/LT1363, so much for PSRR?! maybe coz 1028 is a negative feedback opamp?
 
my HD2 soundcard was also making nasty pops in the very same situations..the mysteries of audio

 

[ROBSCIX]

Quote:

Just got 2 x OPA637AM's (TO-99) for use in my Fi-Quest. They arrived with 2 x Nichicon caps (Audio KT 33/50 (M) if that means anything at all to you guys. I've not yet got into bypassing etc yet but assume this is what they are for.
 
Can someone clarify where I would use them, there is one for each opamp. I'd have a stab at +in & -in (pins 2-3) but I'd be guessing........
 
Like to get into this at some point so this could be a good place to start, any help would be greatly appreciated

 
You can use them for various tasks but the circuit needs gains of 5 or better as the OPA637 is not internally compensated.
I have a set of OPA637SM and they sound great but can only be used in certain circuits.
 

 

[Spacehead]

OPA637AU works well in my PPA v2 with gain of 51K/15K = 4.4X 
 
It sounds pretty nice too. Details aren't as clear as they are with ADA4627-1 though, but almost. 

 

[SpudHarris]

Quote:

 
You can use them for various tasks but the circuit needs gains of 5 or better as the OPA637 is not internally compensated.
I have a set of OPA637SM and they sound great but can only be used in certain circuits.
 

Thanks Rob,
 
yeah been using the BP in my Fi-Quest for a while on and off it has a adjustable gain switch which has to be on the highest setting to use them. What do you think the electrolyics that came with them were for?

 

 

[K3cT]

I doubt it's for bypassing. Ceramic or film is more suitable for this since it comes in very low values and the footprint is small.

 

[SpudHarris]

These are tiny. Small as the BG NX's used for imod LODs.....
 
I'm flattered that they sent them, just wouldn't mind knowing what for? I have sent an e-mail but no response yet so thought I'd ask the people in the know
 
Wonder if I'll tell any difference between the OPA637BP's and AM's? There is a difference between the OPA2111KP and AM's so I'm hopefull....