What amp are you using with your Zu Essences?

In fact my previous statement is correct.

Having had 3 pairs of Definition (6 ohm) here with an Atma-Sphere S-30 for over 2,000 hours of critical listening I'm quite sure of my conclusion.

The only instance in which the S-30 worked properly was on 1 pair of Definitions that had a 30 ohm load option. The bottom end performance was extremely poor using the 6 ohm taps. I suspect the Omen Defs (6 ohm) would perform similiarly.

I did not use the M-60 or MA-1 models so no opinion with them is offered.

Thank you.

Audiofeil's comment about OTLs and ZUs is incorrect. There don't seem to be any OTLs that will not drive the 6 ohm ZUs quite well.

I had the Essence and they were paired with a Melody I2A3. I bought it based on Zu's recommendations and found it to be a nice pairing, and there was never a question of not enough power.

FirstWatt J2, M2 and F5 are terrific as are my 25wpc EL84 class A push/pull monos. My 8wpc Yamamoto A-09S or Woo Model 5 work very well too (both 300B) but I personally prefer the 25-watt transistor amps for their better low-level resolution, grippiness in the bass and lower noise.

Having owned every Zu speaker (except Superfly), most on multiple occasions, I'd opine that virtually any amp will work ok.

That being said there are better matches than others. My recommendation after thousands of hours would be to stay away from Class D amps with every Zu speaker. In general they seem to suck the warmth and polish out of Definition, Essence, Druid, Tone,Presence, and my newly arrived Omen Defs.

Most other topologies work quite well and sound terrific; pay particular attention to the speaker's impedance. For example, OTL amps are not ideal with the Omen Defs (6 ohm) whereas Class A solid state is magnificent. The best amp with the Omen Defs so far, to my ears, is the Pass XA30.5.

Alternatively, Presence and Druid with their 16 and 12 ohm impedances, work extremely well with OTL.

Class D amps can be wonderful with the proper speaker but to my liking, Zu is not high on that list.

However, at the end of the day, if you like what you hear go for it. Afterall, your money.

Dealer disclaimer

I have a pair of Essence and have just transitioned to tubes from solid state-- actually, I'm still in transition as I won't have my pre until the third week of February.

Current setup:

Zu Essence

Manley 300B SE/PP monoblocks (11 wpc SET; 24wpc PP); SET at 0-2dB negative feedback; PP at 1-3 dB negative feedback.

Sony ES receiver serving as a temporary pre-- being replaced with a Manley 300B pre.

Sony HAR-D1000 cd

Zu Libtech speaker cable
Zu Gede interconnects to the amps
Zebra Cables custom interconnects from CD to pre
Zu Mother power cords

11 wpc in SET mode plays LOUD in my room 12*16*8. The sound is exceptionally liquid, dynamic, and three-dimensional. This should improve dramatically when I use a better pre, but it's pretty fantastic now.

I have also paired the Essence with the Sony ES Receiver, a Cambridge 340A integrated, and a Rega Elicit integrated. Best sound was obviously the Elicit, but the 340A put in a strong showing.

Some points about the Essence with tubes: the top-end is very balanced and well integrated with the FRD. The impedance of the ribbon tweeter seems to interact with the tube amp to shelve the response down slightly to better intergrate with the rest of the frequency spectrum. Bass is full and weighty. In-room response is in the high 20's in my room.

Some points about the Essence with solid-state: the 340A (roughly 40wpc) has more than enough power to be speedy and exceptionally dynamic. The Elicit has a little more headroom, but the difference in power and drive is not noticeable. The 340A is slightly more punchy at the expense of smoothness, lack of grain, and the flow of the Elcit. Overall, an amp with the characteristics of the Elicit is a better match in the solid-state world. Placement can be tricky with solid-state as I found the treble response to be a little "hot". I don't want to overstate this as it was easy to deal with, but others (in the Zu camp) have different opinions on the magnitude of this issue. I found it easy to compensate for this by using different interconnects and speaker cables (annealed copper) from Zebra cables. This smoothed the response nicely. In addition, experimenting with toe-in so that the tweeter outputs cross behind the listening position on the midpoint of the rear wall smoothed this.

Overall, 11 SET wpc really lights up the Essence in my room. A small but noticeable difference from 24 PP wpc-- better grip in the bass, slightly more dynamic, slightly less liquid.

PMB