Amp matching with high sensitivity speakers

I hate to extrapolate, but my experience with lower output amps (35, 70, 80, 150 watt) with JBL 4367s (94db/hybrid with 15" woofers) was not good. Sure, they will play loud, but the bass is soft, creating great discontinuity between the horn's and woofer's respective frequency range. Obviously there are speakers without crossovers that sound fantastic with tiny amps. One is Voxativ's Zeth at 95db. I have come to the conclusion that the sensitivity is not the beginning and end of amplifier output choice.     

Sounds like I have some options for amps for these speakers, which is what I was hoping for. I will say things don’t sound of out whack with my 300 watt Levinson, which many would consider over kill for these speakers but it’s what I have right now. 

Would going with an all tube system introduce more hum or blackground noise with high sensitivity speakers? I have a tube pre and phono and curious about that. Or, would a high watt amp like my Levinson contribute to background noise as well? 

 

There’s no problem driving them with your 300 Watt amp, just be careful with the volume control. Again, your ears will bleed before the speakers are in danger.

I have 96 dB / 2.83V Tannoys, and I’ve definitely noticed that noise floor is something to be mindful of. Any power amp by itself, whether tube or SS, should not render audible hiss or hum. The problem is that the amp’s gain will magnify your preamp’s noise floor (from active circuity after the volume control). So the more gain your amp has, the lower you need the preamp’s noise floor to be. Active preamps with a higher gain tend to have higher noise floor, unless their signal-to-noise ratio is also higher. Tube preamps with high gains (> 14dB) are usually asking for trouble. I can really hear the noise floor of many preamps in my system.

The ARC Reference 6 has an extremely high signal to noise ratio, so despite its relatively high 14dB gain, it’s dead quiet in my system. Most other tube preamps, I can hear varying degrees of hiss noise with the volume at 0 (not muted).

In modern times, a SS amp will have higher gain in order to facilitate tapping into a very high power rating (you need a lot of gain to push out say 400+ Watts). However, a lot of the lower powered tubes amps will have a surprisingly high gain because using a 12ax7 V1 tube was popular, and analog sources of that era had low output levels so the extra gain was welcomed (for example: the Eico HF-87 tube amp required a meager 0.38V input to produce full rated power of 35 Watts!). So even when you go to lower power tube amps, it may have similar gain to your much more powerful SS amp. This means you should be very careful if you’re selecting a tube preamp to pair with it, or you will hear its hissssss noise!

Thanks @Mulveling for the explanation! That could explain some hum concerns I experience when moving interconnects and components in and out. The gain for the Levinson is 26db. The gain from my Audible Illusions L3A is 30dB which seems quite a bit more than you recommend. I have a Herron preamp with two gain options: one at around 14 and the other at about 8dB. I’m going to move the Herron back in to see how everything reacts. Today I installed a Cardas blue sky phono interconnect to replace the stock one in my table and a hum is there when I turn up Tyne volume a bit. I wish there was a book or similar to find out more about all this electronic component matching you detail.