>>You need 40-50W minimum.<<
I recently had another experience that undermines any notion of a hard-and-fast rule about minimum power requirements for Zu speakers. Again, for the record, while I understand the enthusiasm some people, including Sean Casey and Adam DeCaria, have for the sound of 2w 45 SET amps (they've brought a Yamamoto to my own systems to try to convince me of it's viability as a match), flea power isn't sufficient for me. Some people will be thrilled with sub-ten-watts amplifiers on 101 db/w/m Zu speakers. However, I use 25w SET on both my Zu systems, 845 in one case and 300B PSET in another, in an open plan house where rooms aren't fully bounded. One room is 20' x 14' x 8.5'. The other is 22' x 12' x 10'.
I recently had a chance to buy a pair of NOS Quad II Jubilee mono block tube amps. The Quad II is, I've long maintained, the most SET-like push-pull tube amp. It's also only marginally more powerful than classic SET single tube designs at 15w each -- less than the big glass 845s and any number of PSET configurations. I don't need this pair of Quads; I just bought them because I wanted to own them.
The Quad II becomes marginal into low impedance speakers, but it's still quite viable into the 6ohms Zu Definition. Into 12ohms (Druid) and 16ohms (Soul) it's in its sweet spot, and a sweet spot it is. I heard a pair of Quad II on Druids a few years back, in passing, but not with a chance to listen closely. I put the current reissue as well as rehabbed originals on my list of recommended amps for Druids and Presence, particularly. But now Ive been able to listen for days on end and not only are these amps tonally beautiful, revealing and convincing but they are more than sufficient dynamically on Druids -- and by extension, Superfly. I will make a point of hearing them on Superfly soon, but I already know the answer, given my familiarity with the similarities, differences and assets between Druid 4-08 and Supefly, and the Quad II behavior into 16 ohms.
Designed in the early 1950s for it's 1953 debut, the Quad II represents Peter Walker's sense of innovation and responsibility against the backdrop of a still-struggling Britain in recovery from WWII. It's a simple circuit that wastes nothing in terms of resources. The amp was designed to be affordable in a nation still oriented to scarcity, built into a maximally-efficient packaging footprint requiring minimal sheet metal and parts. But nothing was skimped in the critical transformers.
Sure, today's legacy-informed Quad company has added 40w and 80w updates to the classic Quad II topology, bringing Tim DeParavicini to the task of improving on Peter Walker's elemental design from nearly 60 years ago. And of course they offer an excellent reissue of the original Quad II which is affordable by modern high-end standards.
I normally consider 15w below my satisfaction point for amplification with Zu speakers, but the Quad II upends that bias. Even a highly-dynamic Blu-Ray soundtrack isn't too much for it, in a room of my dimensions noted.
Phil
I recently had another experience that undermines any notion of a hard-and-fast rule about minimum power requirements for Zu speakers. Again, for the record, while I understand the enthusiasm some people, including Sean Casey and Adam DeCaria, have for the sound of 2w 45 SET amps (they've brought a Yamamoto to my own systems to try to convince me of it's viability as a match), flea power isn't sufficient for me. Some people will be thrilled with sub-ten-watts amplifiers on 101 db/w/m Zu speakers. However, I use 25w SET on both my Zu systems, 845 in one case and 300B PSET in another, in an open plan house where rooms aren't fully bounded. One room is 20' x 14' x 8.5'. The other is 22' x 12' x 10'.
I recently had a chance to buy a pair of NOS Quad II Jubilee mono block tube amps. The Quad II is, I've long maintained, the most SET-like push-pull tube amp. It's also only marginally more powerful than classic SET single tube designs at 15w each -- less than the big glass 845s and any number of PSET configurations. I don't need this pair of Quads; I just bought them because I wanted to own them.
The Quad II becomes marginal into low impedance speakers, but it's still quite viable into the 6ohms Zu Definition. Into 12ohms (Druid) and 16ohms (Soul) it's in its sweet spot, and a sweet spot it is. I heard a pair of Quad II on Druids a few years back, in passing, but not with a chance to listen closely. I put the current reissue as well as rehabbed originals on my list of recommended amps for Druids and Presence, particularly. But now Ive been able to listen for days on end and not only are these amps tonally beautiful, revealing and convincing but they are more than sufficient dynamically on Druids -- and by extension, Superfly. I will make a point of hearing them on Superfly soon, but I already know the answer, given my familiarity with the similarities, differences and assets between Druid 4-08 and Supefly, and the Quad II behavior into 16 ohms.
Designed in the early 1950s for it's 1953 debut, the Quad II represents Peter Walker's sense of innovation and responsibility against the backdrop of a still-struggling Britain in recovery from WWII. It's a simple circuit that wastes nothing in terms of resources. The amp was designed to be affordable in a nation still oriented to scarcity, built into a maximally-efficient packaging footprint requiring minimal sheet metal and parts. But nothing was skimped in the critical transformers.
Sure, today's legacy-informed Quad company has added 40w and 80w updates to the classic Quad II topology, bringing Tim DeParavicini to the task of improving on Peter Walker's elemental design from nearly 60 years ago. And of course they offer an excellent reissue of the original Quad II which is affordable by modern high-end standards.
I normally consider 15w below my satisfaction point for amplification with Zu speakers, but the Quad II upends that bias. Even a highly-dynamic Blu-Ray soundtrack isn't too much for it, in a room of my dimensions noted.
Phil