Amp change/upgrade for JBL4367 (94dB 2Way with Horn tweeter & 15" woofer)

Thanks. I don’t quite understand the advantage of say: 30 W class A vs a 250W class A/B. Isn’t the class A/B has the advantage of both ? Example:Pass Int 250 don’t leave class A till 15 W and has all the extra class A/B reserve up to 500 W into 4 ohms! Why would a 30 W class A be a better choice over the 250 W A/B???

A few comments:

1)  Power-  For these speakers, at a 12 foot listening distance, 10 watts gives 99 db, 25 watts 103 db, 100 watts 109 db, and 200 watts 112 db.  The OP said he mostly listens at lower levels, where 10 watts would be more than sufficient, but if he wants to turn it up, perhaps to listen to an orchestra at live levels, 200 watts will keep him from clipping at the peaks. 

2)   Totally personal, but for me of the three amps, it is a no brainer, Pass Labs.  I always found them wonderfully transparent.  I liked older Mark Levinson, but they lost me when their Proceed and 331-333 amps started dying early.  McIntosh has never done a thing for me, always providing adequate power, but sounding lifeless.  To me they are the B&W of electronics.  

3)  I would be tempted to try tubes with your system.  Perhaps something like the Rogue Pharoah integrated with a tube preamps section and solid state amp section.  

One thing to keep in mind with Class A amps, high biased Class-B, and tube amps; they all put out a lot of heat and use a good amount of energy.  They make nice room heaters in the winter, but depending on your room, could sweat you out in the summer.  

I own the 4365's and i have found that the JBL's love current. I've tried them with EL34 40w mono blocks, 400w Class D and 50w Class A and the best they've sounded is with the ASR Emitter. 

In most rooms a 60 watt tube amp would do nicely on a speaker like that.

i have found that the JBL's love current.

If you drive this speaker with a 100 watts, because its 6 ohms the current will be slightly less than 4.1 amps. It won't matter what sort of amp is driving the speaker - tube, transistor or class D, the current will be the same.

I think that you should try tubes! The best tubes amps I have ever heard at a resonable cost are the Atma-sphere OTLs. You will need a preamp of which many are available on Audiogon or as new. Atma-sphere also makes a less expensive preamp which I have yet to hear. I owned a Pass Labs 30.8 and found it not to be transparent and to have a definite house sound which didnt impress me when compared with OTLs, other much more expensive SS equipment as well as some other tube amps. Newer Levinson is to be avoided and I am not a fan of McIntosh gear but I havent heard the newer iterations from this company. I also would steer you away from some of less expensive tube amps from Rogue and Schiit.