toetapaudio
Thanks for the recommendation. Just ordered them--they are certainly a better resistor than the one I'm using (which Vinnie probably suggested since we didn't know whether it would work). We'll see if they make a difference.
david_ten
This is heresy! But I'm going to try it--even the part about putting my VR on the Townsend platform, although I think it is too light for the weight load range of the platform springs. Have to check.
When I first put the Nenuphars on the platforms I noticed a big change to the sound. Sometimes one is lead to believe that means a change all for the better, which is obviously not always the case. We'll see. Thanks for passing on what you found.
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A couple of setup changes that might be of interest....
I had an audio friend visit this past weekend. He has broad experience listening to and problem solving for his audio clients, primarily for analog and speaker setups in systems that reach into the stratosphere.
After spending two evenings listening to my system, his primary recommendation was to remove the Nenuphars from the Townshend Platforms.
This relates to @onhwy61 's question regarding driver vs. cabinet contribution and also to @charles1dad 's response to onhwy61 (both posts from a previous page).
For transmission line designs, my friend finds the floor and room interface and their relationship and interaction with the driver critical to sound quality.
The results were spectacular. Even he was surprised by the degree of difference. As he put it, greater than a component upgrade.
The speakers were positioned the same as when on the platforms. They remain on Eden Sound Spikes. They are on a suspended hardwood floor.
After he left, I decided to use the Townshend Platforms for my 2A3 mono blocks. I removed the GAIA footers from the amps and the Timbernation Maple block with brass spikes and Herbie's isolation pucks.
I had to remove the bottom plate on each amp since the screw heads extend beyond the wood chassis. The reason for doing this was to have a completely flat amplifier surface when on the Townshend metal platform. The Townshend Platform has a center perforation; airflow is preserved.
To my ears, removing the Nenuphars from the platforms resulted in a two step gain. The amps on the platforms a three-quarter step gain. Combined synergy, a three step gain. Significant; an understatement.
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Opinion Poll
Hi all, I'm new to audiogon and new to this post.
It's been a very enjoyable read so far if not a little long winded and time consuming, but can now feel proud to have finally managed to make it through to the end.
Just wondering if those that have actually listened to both the Nenuphar 10 inch and 8 inch could give there preference just to see which one is ultimately the preferred choice. |
Nenuphar journey, part 3.
Now that the Nens were broken in, it was time to try different amplifiers. I had been using the LTA Z10 integrated. It sounded fine but lacked enthusiasm, a certain jump factor. Time to explore my FirstWatt collection.
First up was the J2, which actually exceeded my expectations. It sounded clearer than the Z10. The bass was fine, but the soundstage only average. Perhaps a pre would expand the soundstage. PRaT was good, restoring the jump factor. All in all, a decent match, so if you have a J2 don't throw it away. :-)
To be continued.... |
Series vs. parallel.
If the only link between the amp the speaker is through the resistor and then to the cable, then it would be in series.
If the resistor makes a looping connection in addition to the regular cable connection, then it would be in parallel.
It is still not clear to me which Vinnie suggested.
Robert |
Stephen, might be worth looking at Dueland cast graphite resistors. Attach to high quality male and female banana preferably by crimped connections if possible or crimp to spade at amplifier end.
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Yes in series. Cal, good analogy and explanation.
Charles |
@stephendunn Thanks for the additional information regarding resistor setup, much appreciated.
That would actually be a series connection. In parallel circuits, electricity is flowing through two independent circuits. If either is cut, the other circuit will be still be conducting electricity (think modern Christmas lights where breaks in the circuit, i.e. a burned out bulb, don't cut out the whole stand). Alternatively, in a series circuit, each component is an integral part of the circuit and if it breaks, no electricity flows (i.e, old Christmas light strands where every bulb needed to be tested to find the fault).
In this case your amp is producing electricity and the positive & negative wires complete that circuit and allow it to flow through the speaker. If the resistor were connected in parallel to that circuit, it would be connected to both the positive and negative terminals of the amp (or speaker). Cut one leg of the resistor and the full speaker circuit is still connected to both terminals, electricity flows, and the music continues. Instead, you've got it connected in series with the speaker circuit. Cut one leg of the resistor and it breaks the circuit and there's no connection/electricity/music. |
Robert,
The resistors were connected between the positive output of the amp and positive speaker cable connector. So I wound one end around the WBT positive terminal of the VR and the other end I wound around the banana plug of the speaker cable. When I asked Vinnie if he suggested soldering the connection to the banana plug, which is probably not a good idea considering possible damage or visual marring of the banana plug he replied:
"It might be a good idea to make that resistor connection better. Maybe a male banana on one end (to the L2) and female banana jack on the other end (to your speaker cable)."
As to your question about whether the resistors are in series or parallel, I am not technical enough to answer, although my guess is since there is only one resister per channel they are definitely not in series.
BTW I checked out your room. Beautiful space and great set up. Despite the height of your ceiling, I think you'll be surprised how the Nenuphars will fill the space. When I went to this catty corner speaker set up I was shocked how much more height there was to the soundstage. Listening to Cohen Live In London my room took on the dimensions of that enormous hall where the concert took place. I thought this was strange considering the ceiling height (14') hadn't changed from my previous set up with speakers 3' out from the long wall.
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Speaking of the resistor solution, Stephen, could you elucidate more? Were they across the terminals? Were they at the amp or the speaker? Are they in series or parallel?
TIA,
Robert |
General comment for those not active in this thread: the designers of Cube Audio's Nenuphar (and variants) have routinely shown their work paired with low watt (45 and 2A3) SET amplifiers.
Peter Breuninger, of AVShowrooms, fell under the spell of the Nenuphar Minis driven by the Tektron 45/50 SET amp. Just another recent example of the exceptional synergy of the Nenuphar(s) with low watt amps. |
@debjit_g If you are still looking at amps, and a 2A3 is still an option... My Found-Music 2A3 drives the Nenuphars with ease. I top out at 90dB averages when I choose to crank the music. We have had it up over 100dB averages for a couple of audio buddies who prefer their music really loud. Above 90dB levels, my untreated room asserts itself as an unwelcome actor. [Note: by average, I mean the average over the recording (including peaks)] My usual (and normal) listening levels are in the low 70dB range with averaged peaks in mid to high 80 (spikes into the 90s); recording dependant, of course. Room is 19 ft by 26 ft. I am hoping that the 2A3 can power the Cube’s to a comfortable listening level when the listening position is 8-9ft from the speaker. Not all 2A3s are created equal. I encourage you to reach out to @charles1dad and others qualified to address build quality. |
@stephendunn Congratulations on your success with the Vinnie Rossi integrated and resistor solution. |
@cal3713 +1 Btw, I just wanted to say how exemplary this thread is. Just pure, helpful, experience sharing and education. It's really a pleasure, thanks. |
Initially I had my Cubes pointed straight ahead but have found they do sound better with a slight toe-in. Haven't tried corner placement because of furniture constraints.
Boenickes and Cubes are quite different animals but share something that I find attractive. It might be called flow or a more natural sound. I don't care for speakers that "push" music at me. |
The Raido/Børresen in shows always have a wider placement configuration very close to the side wall with aggressive toe-in towards the listening position. Maybe they don't care for the sidewall reflection based on how the speaker is designed. I am still playing to the positioning with the Nenuphars and experimented a little with the toe-in and I find aggressive toe-in make the sound too bright and sharp for my taste. Currently they are toed in about 5-10degree. How much toe-in do you guys have ? Between, anyone using a pair of subs with the Cube ?
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I have never heard a Boenicke apart from the youtube videos and I liked what I heard. Its interesting that folks who are interested in Cube are also also interested in them as I am. I would be highly interested in a comparison between the two though I am not sure if this would be the right thread. The amp requirements for the Cube and Boenicke are on the opposite end of the spectrum.
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This week Jeff Day at Positive Feedback has a review of the Pass XP-12 preamp. He starts by writing:
"I have been looking forward to telling you about the Pass Labs XP-12 line-level preamplifier, as I've found the XP-12 to make for an excellent match to the Pass Labs XA25 Class A stereo amplifier as well the First Watt SIT-3 single-ended stereo amplifier which are my current benchmarks for relatively affordable, lower-powered (25 watts and 18 watts, respectively) high-performance, solid-state stereo power amplifiers." |
@stephendunn I also have my system set up on a room corner (see my system pictures). Forced by the room in my case, but it works really well. Eliminates the usual side wall reflection issues and allows for a deep space between the speakers as if they were pulled out much further into the room. I much prefer it to the long wall setups I've been forced into in the past. |
@toetapaudio No pressure, but I personally think a pros/cons list would be useful here too. Seems relevant given that this thread is more of a place (one of the only ones) to generally get information about the cube audio experience... |
@keithr not wanting to go off on a tangent here so if you care to PM me regarding my thoughts of pros and cons of Boenicke vs Cube please feel free. We are dealers for both brands in the U.K.
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Nenuphar journey, part 2.
My new Nenuphar Mini Monitors sounded alright after setup, but as my mother used to say, they "didn't send me anyplace I couldn't get back from." Break-in time. As they were I my living room I couldn't just crank them up and let them play 24 hours a day. I took awhile; the sound improved after about 50 hours, and the magic happened at 95 hours.
Now it was time to match the speakers with electronics. I decided to concentrate on amplifiers, adding a preamp later. I had two DACs available, one with volume control and one without, so I started with the direct from DAC to amp configuration. The DAC used was the MSB IV. Then it was on to explore my passel of FirstWatt amps, all designed by Nelson Pass and one even built by the master himself.
To be continued.... |
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." |
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.
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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 |
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 |
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.
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rwpollock
Look forward to hearing more!
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charles1dad & others
According to Vinnie's email below the resistor changed the output impedance of the amp to 1 ohm and did not change the speakers' impedance. Since the stated output impedance of the L2iSE is 0.1ohm the resistor increased the output impedance by 10 times (about the limit of my math skills). After adding the resistor I did not notice having to increase volume levels, for what's that worth. Except that it sounded much better at low volumes, as mentioned before.
Hi Steve,
Glad it worked!
Can you fix a typo? It should say 1-ohm resistor (not 100 ohm)
And I meant to say that your damping factor is now 8 (not 80) - sorry!
Speaker impedance / amp output impedance = damping factor. So 8 ohm / 1 ohm = 8 Enjoy it, and thanks for sharing it!
Vinnie
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It's a rainy morning here in Wisconsin so I thought I'd write some about my Nenuphar journey. Two or three years ago I decided to build a system around high efficiency speakers in order to see what people were talking about. I ended up with the Teresonic Magus monitors and the LTA Z10 integrated amp. A nice combination.
Then at AXPONA last year (seems like a very long time ago) there were two rooms that made big impressions. One was a Goldmund system where notes just hung in the air. However, it ran well into six figures. :-(
The other room featured Nenuphar speakers by Cube Audio. The music was liquid and (to steal a line from Joni Mitchell) stuck to all my senses. So, earlier this year I finally put in an order for a pair of Nenuphar monitors. I decided on the baby Nens, the Mini Monitors. Jon at Refined Audio had one pair in stock.
Although they have the 8" drivers and are only 10" x 14" x 24" high they proved plenty loud enough for my 20' x 14' living room. Not that I listen at head-banger levels. The supplied stands put them a little high for me (I tend to sit low) so they ended up on maple butcher blocks topped with IsoAcoutics Apertas.
To be continued.... |
Agree that if the power amplifier was encountering a speaker impedance of less than 1 ohm (0,89 ohm) this is an enormous challenge for 'any' amplifier to manage. In fact most amplifiers would be incapatible of delivering the vast amount of current demanded by this low of a speaker impedance. There has to be an alternative explanation.it just doesn't seem as though this usually low speaker impedance if seen by the Vinnie Rossi amplifier would result in improved sound quality as reported by Stephen. Al (R.I.P.) we miss you.
Charles |
Stephen said the resistors were added to "each of the positive speaker terminals" which suggests a series connection to me.
Indeed, if it is paralleled with the speaker and connected across both the positive and negative terminals, then it's a very different situation. I'm not educated enough to know exactly the impact on this amplifier, but I do know that generally amps struggle with the current requirements needed for loads below 2 ohms. |
"Parts Connexion listing for the part which is actually a 1 ohm resister not a 100 ohm resistor as the listing states. Which interestingly enough brings the damping factor to 8."
I assume the two resistances (the speaker at 8ohm and the 1ohm added) are in parallel. Thus the total resistance would be related to the inverses.
1/8 + 1/1 = 1.125
1/1.125 = 0.889 ohms seen by the amplifier. The lower resistance makes for a lower damping factor (by a factor of 9 or so) which would be why Vinnie recommended adding the resistors.
Note: I am not a EE and I don't play one on TV. |
Yes I wondered the same in terms of the exponential (10x) change in the DF value with just a simple resistor addition. I'm surprised that its of such magnitude. But in practical terms the sound quality did improve.
Charles |
Obviously a positive outcome regardless of the reason, but this discussion just makes me more confused. In the numbers posted above, doubling load resistance doubles dampening factor while VR indicates that adding 1 ohm to the load cuts damping but a factor of 10??
Does anyone know what might differentiate between a resistor changing output impedance vs changing amplifier load? As I see it, this alters how much resistance is in the post-amplification circuit. Good that it worked, but color me confused.
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Hi debjit_g,
DF=Speaker impedance (In ohms) ÷amplifier output impedance.
So to lower the DF either the amp output impedance must increase (Denominator) or the nominal speaker impedance is decreased (Numerator). Unless there's something I'm missing. With amplifier specifications the lower the output impedance the higher the amp's DF. This usually reflects the amount of NFB employed in the circuit.
Charles |
@charles1dad I know some Avantgarde Duo XD owners uses SIT-3. The Avantgarde’s nominal impedance is 18Ohm which is way too high for the SIT-3. Hence many uses another 12Ohm register (off-coarse based on Pass recommendation) in parallel for the amp to see a lower load impedance just under 8Ohms. Its interesting that adding a register in series lowers the damping factor but this will also increase the nominal impedance. I am now curious if this technique could be applied with the SIT-3 and Nenuphars to further reduce the damping factor. I guess the only way to find out is to write to Pass :-)
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Speaking of DF, a couple of weeks ago I was cruising the intranets reading about damping factors and came across an article by a couple of guys who put together PA systems (which explains why they talk about speaker cable lengths of 50 and 100 feet).
At any rate, they noted that the DF decreases with longer speaker cables so I may try 8' versus 16' speaker runs. They provided some numbers:
50' 12AWG 8ohm DF= 49.1
50' 12 4 24.5
50' 12 2 12.3
100' 12 8 24.9
100' 12 4 12.2
100' 14 4 7.9
100' 16 4 4.9 |
Stephen,
Congratulations!
It’s interesting that this simple step reduces the DF by a factor of 10 and improves what was already a very high level of sound quality. This was an excellent suggestion from the knowledgeable Vinnie Rossi. It certainly does stimulate the curiosity of what happens if DF is reduced to 8. Fun stuff.
Cal,
Since an amplifier’s DF and output impedance have an inverse relationship I wonder if this output impedance is ’effectively’ increased with use of the resistors or is the nominal speaker impedance as seen by the amplifier decreased?
Charles |
Want to correct an error in the type of resistor mentioned above. I copied and pasted the Parts Connexion listing for the part which is actually a 1 ohm resister not a 100 ohm resistor as the listing states. Which interestingly enough brings the damping factor to 8.
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For future readers: In case the above link expires, please note that the link text is somewhat misleading. It is for a 1ohm 10w Jantzen Audio Superes resistor.
And @stephendunn, congrats on the outcome. And good information. I didn't know that a 1 ohm resistor in series with a driver had this effect. Apparently I need to learn more about damping factor calculation and meaning... |
I'm reporting on impact of adding a jantzen-audio-100-ohm-10-watt-audio-grade-superes-resistor--255-944 to each of the positive speaker terms on the Vinnie Rossi L2iSE. This lowered the damping factor driving the Nenuphars from 800 to 80 and was suggested by Mr. Rossi as an experiment. Immediate impression was the overall sound just got cleaner and more relaxed. After extended listening it was obvious those impressions came from a clearer/cleaner mid range and mid bass. The lower bass also sounded slightly better, not deeper, but as if the deepest notes weren't hitting a dead end. The other clear benefit was how much better the L2iSE sounded at low volumes. Everything remained in balance at a lower spls (before the mid bass on down sounded weak). Of course I was unaware the sound could have been improved in any of these ways--except in the loss of bass playing at lower volumes (and I'm talking pretty low here, with the L2iSE volume setting at 14 or 15 instead of the 24-27 where I normally listen). It looks a little weird to have these green resistors the size of lady finger firecrackers back there and to think of this huge sound coming through their little wires wrapped around the WBT speaker terminals and the banana plugs. But there you have it, my newly hot rodded L2iSE swinging even freer than before. What if I added another resister on each side and brought the damping factor down to 8 (which is what my SIT-1s batted at)? We'll see what Vinnie says about that. (BTW I am far from qualified to be recommending that you try adding these resistors to your own amp or integrated. My gear's designer was kind enough to entertain this experiment, guiding me to make sure that nothing was shorted when I connected the resistors. If you're considering such a mod, I would first run it by your amp's manufacturer/designer.) |
So curious about these expensive and exotic single driver speakers. I have a pair of omega alnico towers with matching 10” subs and love them, but have never heard magus or nenuphars. The omegas have a paper hemp cone with whizzed.
Anybody heard these next to the omegas? Wonder how much you get for the extra bucks. With dual subs, I’m out just a little over $4k for the omegas with teak veneer. |
For those looking for a preamp to go with First Watt etc. you might take a look at the Allegri Reference by Townshend Audio. Its a high quality passive design. |
Charles1dad, thank you for your thoughts.
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My Backert preamp is an original Rhythm, the 1.1 (they now sell a 1.3 version). There is a used 1.1 for sale now on Audiogon for $3500. The only thing I don't care for is that the Backerts invert polarity/phase so you have to reverse the red/black speaker connections. No big deal if you don't switch you gear around. That said, it's fairly easy to tell if things are inverted; it is kind of like pushing your music uphill....
Robert |
debjit_g
Tektron offers quite a range. Besides 2A3 and 300b they have a 211 tube integrated amplifier. This is pretty unique. Of course they have a plethora of non DHT pentode type el 34, KT 88,KT 150,6550 models. etc.
Charles |
thanks @stephendunn and @charles1dad. All excellent options and I will do some readings on them.
I remember writing to Tektron USA distributor before I bought the Nenuphars but did not hear back. I didn’t follow through at that time. Maybe its time to do a follow up. Has anybody heard in person how the Nenuphar sounds with the Tektron vs the First Watt or other amps ? I am hoping that the 2A3 can power the Cube’s to a comfortable listening level when the listening position is 8-9ft from the speaker.
I was also considering Triode labs, either a 2A3 or 300B integrated but they don't have a remote which is a deal breaker for me.
@rwpollock, yes I have heard great things about Backert. Which model are you using ? If I go with the tube pre route with the SIT-3, I am also considering Supretek DHT pre. I hope all these choices will be better than the BHK pre (which is no slouch) that I am currently using.
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If you want to stay with your FirstWatt amplifier, I have had excellent results with a tube preamp from Backert. All of their models have very long tube life and are very easy to tube roll (I recommend the Mullard 12au7).
Robert |
debjit_g,
Here's another possibility. The Canadian company Coincident has an integrated amplifier named the Dynamo. It is available in two versions, el 34 or 300b (A bit more expensive but I think excellent for the Nenuphar). Both of these are single end circuits rather than push pull. The latest versions have bigger and better output transformers and beefed up power supplies. Worth a thought.
Charles |
