Belles 21A with Auricap

Is there any type of number or letter designation to indicate that the Belles 21A has the cap up grade?

I am looking for a good preamp to match my Mark Levinson ML 333. Currently I am using a Audio Research SP-6 -C

I want a wide deep soundstage. Any suggestions and if you have something for sale let me know.
Krell KRC, KSL-2 Belles or something similar.
Thanks Pete
take the top off and see if the caps say auricap.
The 21A with auricaps will have big large yellow auricaps when you take the top off. You can see them through the vents as well with the cover on. I have a 21A with auricaps that will eventually be sold as I upgrade my system but it will be the last thing upgraded as it is such a wonderful line stage. I have auditioned several amps and pre-amps over the last few months and though I have lusted after a few amps, VTL MB-185 highest on the list, I have never really found something that really outshines the little 21A. So don't wait for mine until next year sometime. The thing that I am most after is musicality, soundstage and imaging.