How much do I need to spend to get a preamp that sounds better than no preamp?

Pistha,
I listen to cds and Tidal. I'm back to direct no pre but this time bi amped. Awesome. The AI pre adds quite a bit of bottom. 

The oppo volume control operates using 32 bit processing.

@georgehifi 
Yeah, which in a good line stage is basically insignificant. It doesn't hold a candle to the distortion generated by running a gain stage to it's limits. Getting better sound from more gain and less input signal makes perfect sense. It's really obviously, even to an unwashed rube like me. 

The best active buffer with or without gain, is going to generate distortions and noise, no matter how good it is.

Nelson Pass back that up when hes says:

" A “passive preamp” - just an input selector and a volume control.

What could be better? Hardly any noise or distortion added by these simple passive parts. No feedback, no worrying about what type of capacitors – just musical perfection.

And on his hybrid Passive/Active preamp:

" The only component in the signal path is wire and switch contacts.
At positions below 3 o’clock, the volume control functions as a precision passive attenuator using discrete resistor ladders.
Above 3 o’clock, active gain is added to the output signal in 2 decibel increments, for a maximum of 10 dB.
As a result, you SUFFER the effects of active circuitry only when additional gain is necessary."

Cheers George

Honashagen, With the L1, initially you need to set the gain control half way up (12 o clock) as recommended by the mfg and go from there. Also if you want to increase dynamics, the McCormack is not that bass heavy, certainly not Krell-like. You have two pairs of outputs on the L1, why not use one pair for an active subwoofer, just make sure it is a musical sub with tight and tuneful bass.

You mentioned components you used to own like the Crown and how you remembered you liked the presentation a lot. Let me say this, each and every time I revisited older components that I used to be fond of, I left disappointed and it turned out that what I currently have was superior. If you were to sell the upgraded McCormack and AI preamp there would be an over wehlming response from buyers as these two components are not seen for sale lately.