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


Hello all.
I'm using an Audible Illusions L1 preamp and I think my system sounds better when I remove it from the signal path. Oppo BD105 directly to SMC Audio DNA1 Gold power amp. I have read that there is level of quality you need to hit before there will be an improvement in sound. I can't seem to find what that level is. Any ideas?
Thanks in advance,
Ben
honashagen
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To me the real benefit of a good active preamp is better dynamics, increased soundstage dimensions, better imaging, and (if tube based) having the ability to match tube choices that best mate with the speakers.

It was mentioned earlier in this thread, but +1 for LTA MZ2 preamp.  It does all of the above running dead quiet.  Its price and simple looks makes many think its a toy, but smile all the way to bank. 

" Like so many things he's designed, it's a quirky component with a  narrow appeal ". I honestly cannot believe this has been said. NP has shared with the diy community most of his designs, which were all labors of love, not to make a dime. Give me, and everyone else a break !
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Maximum Gain 10 dB
Freq. Response +0, -1 dB @ 10 Hz and 100 kHz
Distortion < .1 % THD
Hm. We can do that with 1Hz to 400Khz, distortion at 0.01%. And that's with no feedback. And all tube, balanced.