> $500 integrated amp to drive JBL 530 speakers full range

I'm currently deciding between these 3 choices but am happy to consider other suggestions to drive my JBL 530 speakers full range in a medium sized room. They are 6 ohms with 86dB sensitivity. 
NAD has the Proprietary PowerDrive™ Circuit that is supposed to up the peak power to over 100 watts. Is this something that the other amps can't do as well or is it mostly marketing fluff?  
1. Emotiva mini-X a-100 Gen 2 Stereo Amplifier (50 watts) Good form factor and fit and finish are good. 
2. NAD C326bee (40 watts) The remote is a nice addition. 
3. Parasound Zamp v.3 (45 watts) I realize that it's a power amp, but the specs and brand are good. 
NAD on your list, but I'd look hard at Marantz in your budget. Marantz will be a tad warmer sounding than the NAD which might be better with the JBL. The NAD is really good but not sure on these speakers. There's a nice used Marantz PM8004 on here that would be a great integrated to consider.
Considering these 3 choices, the NAD C326bee, which is actually 50 watts. I wouldn't get to concerned about terminology, but it does have a decent power section. IMHO, it will drive your somewhat inefficient speakers better than the other two. Since the speaker is 6 ohm, it's 1 watt spec is 84.5db. I would not even consider the Zamp. Looking at its specs seem to indicate that it's power supply is just ok, not as substantial as the other two.

As with tis49 and if purchasinf new, of the 3 you list I would purchase the NAD. However, the used Marantz 8004 mentioned by adg101 might serve the JBLs better. Do you need a phono stage?
No phono needed. Yes that Marantz 8004 looks very nice. I own a Marantz 1504 5.1 receiver, but I imagine the similarities are mostly cosmetic. 
Thanks for all of the helpful responses. This is a great online community. I was about to pull the trigger on the Marantz 8004 but found a really good deal on a Brio-R. The Marantz has more power, but the Brio-R is half width so I can potentially use it on my desk with my Silverline Audio computer speakers.  
Great! Let us know how you like the Brio with both speakers.
The Brio R is a step up in clarity and detail from my Marantz 5.1 receiver. At 3:00 on the volume dial, it gets pretty warm. I guess this is to be expected as there are no vents in the steel enclosure. The JBL 530s really sing with this amp.