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?

I never tried the opamp in the power supply, just the two on the input circuit. but having said that, the third may make a difference too.

The other area on the Chinook that really benefits the sonics and reduced noise is replacing the load resistors (vertical board at the rear of the unit) with vishay bulk foils.

Hope that helps

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.

@jbhiller you did end up replacing the opamps, right?  What did it do for your Chinook?  I think they are just plug-ins, so should be easy.  Did you use the single or dual op amps?  Would you do it again?

@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.