Manley Chinook with (very) low output MC ZYX?

@johnss Can you answer the question above about the opamp upgrade?  Do we change out all 3?

Thanks Johnss!

Do I need to desolder the existing opamps?  I can do it, but I just want to know what I'm getting into.

@soundermn 

Here is a cheaper solution that sparkos labs with strong specs.  Some say specs don't matter so much with op amps.  I have no idea and will let my ears be the judge. 

http://www.doukaudio.com/dual-discrete-op-amp-hifi-audio-preamp-operational-amplifier-opamp-replace-...

Correction--they BB's were $10 ea.  I got them here:

https://reverb.com/item/15240397-1pcs-burr-brown-opa2134pa-opa2134-dual-hifi-audio-opamp-new-ic

@soundermn 

Yes, I did do it.  I bought Burr Browns with some really great specs.  I wanted to first try them as opposed to some super custom ones due to expense.  The BBs were about $15 for two. 

I used dual op amps because that is what I think is in there to begin with.  I did the 2 in the amp stage, I didn't do the third one in the power section of the amp.  

I heard a mild improvement (not a big change) in further noise reduction.  There could be other changes that I just didn't take notice of because the surface noise (already quiet with the Chinook) improved a bit.  That was easily detectable because I know what noise to expect on certain records from playing them many times before.  

This wasn't a huge improvement but worthwhile and cost effective.  I'd be curious to try what Johnss recommended--the sparkos labs op amps.  But they aren't cheap.  

The one thing I can say about the Chinook is that it's going nowhere in my system.  I cannot imagine how much I'd have to spend to upgrade.  It's a wonderful preamp.  I'm really attached to it unlike other pieces of equipment. 

Exactly soundermn!  I also wonder if the Herron would be great yet just different. Since I'm in love with the Chinook it's staying.  

The Chinook is the single best piece of gear I've ever bought, including speakers, tube amps, etc.  Why?  Because it elevated the overall vinyl game into liquid tube honey sound.  It's that good. 

@johnss ,  So after a year of using the Burr Brown 2134 opamps in the Chinook, I bit the bullet and bought the Sparkos Labs SS3602.  

The Burr Browns provided a subtly nice improvement--mostly a lowered noise floor from what I could tell.  

The Sparkos labs are better than the Burr Browns and the stock opamps in the Manley.  They sound so smooth and clean.  Highly recommended.  Not cheap, but worth it.