Manley Chinook with (very) low output MC ZYX?

I agree that Vishay nude resistors (I don't know about "VSRS";  I do know about nude TX2575, which can be ordered on-line) will be superior to the stock phono load resistors in the Manley phono stages.  The TX2575 are superior to just about any resistor ever.  However, on the subject of the op amps, was there ever an audible "noise floor" to begin with?  I find the Steelhead to be intrinsically very quiet even at full volume.  Further, in most cases where there is an op amp used as servo, the device is bypassed by a capacitor or two, just for that reason to render the op amp inaudible.  When or if the op amp is intrusive, one cure is to increase the value of the bypass capacitor(s).  But I don't hear it, assuming the Steelhead, like the Chinook apparently, uses op amps as servo.  Finally, the Steelhead is so full of parts that I am loathe to get in there with my soldering iron, except to change the phono load resistors, and in my case to change the output stage, since that part of the circuit is quite accessible.  A lot can be achieved with a little effort on the output stages.

Thanks, JT. FWIW,  I think Evanna goes by “Ms”, not Mrs. Sometimes we swap out parts just because it gives a feeling of control. But without a schematic and the proper knowledge, it’s a crap shoot. Manley won’t give out schematics even to professional repair businesses;, not that there’s anything wrong with that. It actually makes sense from their point of view.

Sorry, instead of RPMs, I refer to Op Amps.  I was messaging by voice and Siri screwed up Op Amps into RPMs.

 Where are the RPMs in the circuit of the Chinook?. So far as I know, my steelhead uses discrete transistors plus triodes throughout the audio circuitry. So I am wondering what is going on with op amps in the Chinook. Perhaps they only serve for the relays and switching apparatus when you change settings. In which case I would not expect them to have much effect on sound. Thanks for any insights.

tre, I am getting a bit confused here.  I gather now that your cartridge drives a Chinook which in turn drives a Bryston linestage with an additional 15db of gain after the phono gain.  You've got gain to spare, even if your Chinook itself only supplies 60db max.  I am using the Steelhead as a full function preamplifier, so that the total phono gain in my system is whatever I set on the Steelhead.  At the max of 65db, I have ample gain with the AT ART7.  You've got 10db more gain than I do at your disposal. Of course, keep in mind that the input sensitivity of your amplifiers and the efficiency of your speakers also play a vital role in determining how much gain you need.
Now for my area of confusion: Did you say that you are using the balanced inputs on your Bryston?  But the Chinook is single-ended, so how does that help, unless the Bryston has a circuit or a transformer at its line input that converts the SE to balanced?  If the system were true balanced, using the balanced mode will result in less noise, not more noise.  But as it is, I don't know if you'll have any benefit from the balanced inputs.

I own a Steelhead; I use it at 65db setting with an AT ART7, which has about the same output as a low output ZYX. You will have no problem. Moreover, I like my low output ZYX UNIverse a bit more than the ART7.