Berning ZH270 Synergy

Budrew,
Prior to getting my Merlins, I used the Berning with Quad ESL63USA monitors. I've never heard that speaker sound better than with the Berning.
IMHO, the Berning isn't made to mate with anything in particular, it's just that if you bother to get such an amp, you want to pair it with a speaker transparent enough to let the Berning's strengths shine through. The Merlins are one of the few that pull this off.
The Berning has enough power to drive many speakers, and with variable feedback, the sound can be tailored to personal taste.
I think I'd have to spend quite a bit more to find anything that would satisfy me as much as the Berning does...
Cheers,
Spencer

Budrew,

I've listened to a pair of ZH270's powering Salon's and Merlins for extended, multiple listening sessions. To say I'm impressed is a serious understatement. While I have not listened as extensively to other highly regarded amps I will say without hesitation that if I owned one it would be my last amp. I can't imagine many speakers not responding favorably to it. It's that good.

As a Berning owner, I can say that few amps can match Berning amps.

However, an amp is only a part of the package, and must be paired to speakers that will match it electrically, as well as sonically.

The ZH270 has an output impedance of 1.8 ohms with normal feedback, and higher with less feedback(switchable). Therefore, choosing speakers with a "tube friendly" impedance curve, staying above 4 ohms at all frequencies would be preferred. If you desire to select less feedback, then a speaker with even higher impedance at all frequencies would be desired. For best damping factor and less strain on the amp, I'd suggest using a speaker with a nominal 8 ohm impedance, that doesn't "swing" into low impedance dips, especially at lower frequencies. Even though this ZOTL has remarkable properties for an OTL, you have to observe proper system matching to get the best from it.

I believe that Sonus Faber also voices some of their speakers with the Berning ZH270. Saw it in the factory tour article in a past Sterophile.

Budrew,
I have the ZH270 matched with Piega P10's-the older grand piano black, not the newer aluminum models. The Piegas are rated at 89 db sensitivity and are a 4 ohm load, and I use them in a 17x14 room. I had some trepidation when I ordered it about it not having enough power,etc, but with the 30 day money back trial period I figured it was worth a try.
It was the best decision i ever made. It is a beautiful matchup. I get the best out of the Piega's ribbons, and the Berning is so good at both frequnecy extremes, it has no problem with the Piega's two 8 1/2 inch Vifa cones, and it provides exceptional dynamics. Plus, you get the flexibility of three feedback settings to tailor the degree of control the amp has over the drivers and the resulting sound.
I loved the sound running my sources direct into the Berning so much, but i am a lazy guy and needed a remote volume control. I ended up with a Placette Passive Linestage, also available on a 30 day trial, to go with the Berning. It preserved the Berning sound, improved the detail and soundstage with no loss of dynamics, and allows me to control source and volume via remote.
I am in sonic bliss. i heartily recommend the Berning under the parameters described above. It is a remarkable product, as is the Placette. I hope this is useful to you.
Flemguy