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

Most everyone knows that the McCormack amps have high enough input gain that allow passive preamps to drive this amp and as a result sound spectacular.

I am familiar with your Audible illusions L1 preamp and I liked it a great deal. It was said to be the same linestage used in their more expensive model the Audible Illusions 3 which may be debatable however It may not be to your liking nor the ideal companion for your McCormack DNA-1. Several years ago when I owned a DNA-1 with a Revision A the best sounding tube preamp to my ears was the VTL 2.5, and everybody else in the household that had a high appreciation for great sound agreed.

+1 PHD.
As this tested McCormack shows, absolutely no need for an active preamp, when most sources are >2v or more out, and this McCormack only needs 828mV in for full output wattage. 

Stereophile: " Input impedance at 1kHz was a calculated 99.5k ohms, consistent with the manufacturer's specification of 100k ohms. The DNA-1's gain was very high, this gain ratio corresponds to a decibel gain of 32.4dB, implying an input sensitivity of 828mV for full 150w output."


Cheers George

I  did buy an axiom passive preamp. Although it is very good it lacks in bass and warmth for me.  I'm using the audible Illusions again.