JC3+ With Kleos SL?

Davey, You cannot be sure that your "gain" problem centers around the gain of your phono stage (65db per your report) and the output of your cartridge (0.25mV).  The subjective impression of gain also depends upon the input sensitivity and gain of your linestage (if you drive a linestage via your phono stage) and the input sensitivity of your amplifier(s), assuming other evidence that the amplifier/speaker match is copacetic.  On paper, a cartridge with a real output of 0.25mV driving a phono stage with 65db of gain should be fine.  I am currently using an Audio Technica ART7 (less than 0.2mV output) into a Manley Steelhead set at 65db for gain.  The Manley output stage adds no further gain, and there is absolutely no sense of strain or noise due to stress.  (The Manley drives a pair of Beveridge direct drive amplifiers which have a solid state input stage; I do not know the input sensitivity, but obviously it's adequate.)

By the way, for the purposes of discussion, at least, it's best to separate "distortion" from "noise", I think.  Your lumping of noise and distortion is not wrong but maybe a little confusing.  Noise of the kind you describe is accounted for by the "signal to noise ratio" specification, which is usually stated separately from harmonic or IM distortion measurements.

So let me quote Lyra and then I have a question.  They say, "Most users (and phono stages) will benefit from the regular Kleos with much higher output and considerably more energy; resulting in a much better signal-to-noise ratio."  

The energy part is interesting.  Are the lower output carts less dynamic?  The fact that they say higher output and more output in reference to the regular Kleos begs the question.

Enjoying the discussion:-)

@lewm. The interaction with my preamp and amp were not an issue, the preamp I utilized at the time had no problem with a cartridge that was spec’d at 0.35mv. I agree there are several issues that can crop up that affect the outcome of the pairing, but IME it isn’t wise to push the gear to the max, just because we can.
I think the warning, and that’s the way I read it, that Rob posts above from Lyra is there for a very good reason. I totally respect that they put that out there, as so many other ultra low output cartridge manufacturers, like Ortofon as an example, don’t bother.
Unfortunately, on paper is rarely going to tell you the whole story...on paper my 0.25 mV cartridge should have worked, which is why I bought it...in reality...not so much!

I repeat: Driving a phono stage capable of 65 dB of gain with a cartridge that puts out 0.25mV under standard conditions is not per se “stress”-ful. I don’t suggest that you didn’t hear what you heard. I do think maybe there was some unknown factor that affected your results. In general, I agree with you that ideally you want all components to operate within their comfort zone. Or maybe you were picking up RF, etc. There are many possibilities.

Ok, here’s my question for the OP and lewm.Why do you think that Lyra and the distributor both recommend a phono stage with at least 65db of gain, vs one that has 64db of gain? Could it be that they know something that lewm doesn’t?