Is the Synergy 240/3 Overkill for ZU Audio 97db efficient speakers?

0 Members and 1 Guest are viewing this topic. Read 441 times.


  • Jr. Member
  • Posts: 14
Just ordered some ZU Audio speakers today and am looking for high quality amplification for them. Due to the nature of ZU speakers and their high efficiency at 97db, I have been told they work well with even 2 watt per channel tube amps. So I was wondering if 120 watts per channel would be way too much?


  • Full Member
  • Posts: 2185
To understand what's truly overkill, we'd need to understand average SPL's at the listening position and the size / layout of your room.

With high efficiency speakers, you definitely want to focus a lot more on the quality of the amp and it's first few watts, because you'll most likely only be using a few watts the majority of the time (depending on the info above).


Unless you need our three channel amp, I would recommend our Ultravalve 35W/Ch vacuum tube amplifier for your very efficient speakers.

Ultravalve owners here on AC, please tell Avsfan more about this fantastic amplifier.



  • Full Member
  • Posts: 2905
  • Artwork that Opens and Closes
    • WGH Woodworking
A Tale of Two Amps

"It was the best of times, it was the worst of times, it was the age of wisdom, it was the age of foolishness, it was the epoch of belief, it was the epoch of incredulity, it was the season of Light, it was the season of Darkness, it was the spring of hope, it was the winter of despair, we had everything before us, we had nothing before us, we were all going direct to Heaven, we were all going direct the other way—in short, the period was so far like the present period, that some of its noisiest authorities insisted on its being received, for good or for evil, in the superlative degree of comparison only"

A member of our audiophile group has the Nola KO's (90 dB) with the Ultravalve and they sound great together, but for fun I brought my Synergy 450 over for one of our meetings. The Nola's impedance ranges from 8 ohms average / 4 ohm min. so the Synergy could have been putting out 900 watts depending on the music. Overkill? No way, the headroom was palpable.

At low volumes the sound of the two amps was very close but turn it up and the Synergy 450 had a take no prisoners lock on the bass compared to the Ultravalve. So it all depends what you listen to, how loud, and where you live. The Synergy 240 with the Zu would get you kicked out of an apartment.


  • Jr. Member
  • Posts: 14
I have Zu Omen Defs that sound FANTASTIC with the Ultravalve.  I have not heard the Synergy amp as I am a Van Alstine tube guy. I have run the Omen Defs off of Solid state but for me the magic is in the mid range and that glorious tube sound. Hard to beat the Ultravalve. And my bass is great with the Ultravalve as well. And 32 watts will give you more than enough spl’s with the Zu’s!