Cube Audio Nenuphar Single Driver Speaker (10 inch) TQWT Enclosure

I think the focus on DF is going overboard - circuit is more important. @213Cobra recently told me he believes the Ampzilla 2000, 2nd Edition is the best SS amp he’s heard on Zu Audio speakers which have similar driver characteristics to the Cubes. I was very surprised to hear this (and between him and I, we’ve owned/heard the SIT-1, 2, and 3, and 20+ other P/P and SET amps on them). My personal favorite amp on Zu is Quad ii Jubilees - which also use some negative feedback. I wouldn’t get too tripped up on DF being the decisive factor. Also, Srajan listens at 60db volume levels which is very unusual. For contrast, I want to hear the Tron (reboot by Daft Punk) soundtrack at 90dbs to test amp flexibility.

As far as trying the Nenuphar myself, I reached out to Jon and he was hoping to have stock at the end of the month. There are no places in SoCal to hear them, but he offers a generous 60-day return policy. I’m also looking into the Boenicke which I am hoping to demo soon.

I’m also looking into the Boenicke which I am hoping to demo soon. 

Well, you can't go wrong there. My other speakers (in my music room) were a pair of Boenicke W5se. I liked them well enough to upgrade to the W8se. Different styles but both provide a lot of quality and enjoyment. You may have a hard choice.

- Robert

Keith,
I don’t believe that anyone is going overboard in regard to the damping factor (DF) variable . The Nenuphar manufacturer himself has clearly and often discussed the inherent damping of the unique driver. He has explicitly stated the driver is purposefully designed to be used preferably with high output impedance amplifiers with little or no NFB and thus a low DF. Stephen unequivocally hears an improved sound quality with the substantial lowering of the DF of his Vinnie Rossi hybrid amplifier.

No here is disputing that low output impedance amplifiers with higher DF can sound quite well driving the Nenuphar. In fact this point has been stated in this thread on more than a few occasions . Gryphon, Bakoon and Mola Mola as a few cited examples. I believe that folks on this thread recognize that Df is just ’one’ aspect but nonetheless a relevant one.

Stephen’s recent positive experience of lowering the DF did naturally raise curiosity as to how one simple resistor could achieve this. Thanks to Stephen’s email response from Vinnie Rossi explains it for us. I and I believe most of the participants on this thread seek further education on technical matters that so obviously impact sound quality.

I don’t find Srajan Ebaen’s listening levels to be an impediment to providing meaningful reviews. BTW I’ve had limited exposure to the Swiss Boenicke and I think they sound exceptionally good.
Charles

Not to change the subject, unless it's sound quality with the Nenuphars, but I just did something that improved the SQ more than any black or silver box or cable or cartridge I've ever tried.  I changed the position of my speakers.  I know, I know, ho hum, he moved them 3 inches to the left and the heavens opened up.  Nope.  It all started when I was reading a review of the L2iSE at I believe the Capital Audio Show.  The VR was in a room with some QLN Prestige 3 speakers that were placed strangely in the room.  Then last night I read a review of those speakers (very fine ones at that) and I learned the speaker designers love to set them up catty corner, firing diagonally into the room. I'd heard of one or two  maniacal audiophiles doing this (on other forums of course) and thought it was well, you know, taking things too far.  It's awkward as hell even if you do have a dedicated room.  Especially in my relatively small parallelogram of a room (but with 14' ceilings).  Anyway, I was tired of auditioning a loaner dac and just said screw it and moved things around.  Holy Crap.  That's all I'm going to say.  Holy Crap.  
S   O   U   N   D   S   T   A   G   E    W  E  N  T    L   I   K   E     T   H   I   S.
And if I could make those letters taller, that too.  And make them three dimensionally disappear into the background, that too.  And make each one vibrate in space, that too.  And then sound richer and denser, that too.  Maybe your system already sounds like that without the speakers straddling one corner of the room.  I'm learning.

In this month's TAS (October 2020) Jonathan Valin reviewed the Børresen 05 loudspeaker. In the course of the long review he discussed sound staging.

"I’m not sure I have ever before heard clearer, tighter mono focus than that delivered by the Børresen 05s. I’m not talking about vertically “slit-like” imaging here, as if the vocalist has been turned into a narrow slice of peach pie. London’s voice, for example, is life-sized, rounded, and quasi-dimensional—not slightly one-dimensional as she would be through most cones-in-a-box or as fully 3-D as she is through the MBLs—but it is also unusually 'fixed,' solid and stable and centered right between the speakers....

"I used to wonder why Michael and Lars always widely spaced their speakers (nearly wall-to-wall) at shows, and then toed them in dramatically. (The folks at Audio Physic used to do this same thing.) But it is clear to me now that, because of their speakers’ more focused, phase-coherent release of energy and their low-reflection, low-diffusion enclosures, Borresen and Kristensen were using the space between the speakers to 'imply' greater stage width."