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

Hi rwpollock

could you elaborate please on your particular set up for evaluating these amps, the make of preamp and/or dac used with the First Watt amps and dac if any with the Bakoon and LTA? Do you use the VR with its dac board?

"I am curious how the L2iSE would stack up against some of the better lower watt SETs out there but none have found their way through my door. "

I'm thinking that would be a good project for this winter....
Currently I am trying different tubes in the preamp section.
Robert

"Could you elaborate please on your particular set up for evaluating these amps, the make of preamp and/or dac used with the First Watt amps and dac if any with the Bakoon and LTA? Do you use the VR with its dac board?"

The source is an Aurender N10 paired with a Holo Audio Spring DAC (Level 3) or a COS D1. With the power amps I used a Backert tube preamp, the original Rhythm. The 12au7 tubes were upgraded with NOS Mullards.

I found that I preferred some tubes in the signal path. The SIT-2 and SIT-3 were very close when used directly with the COS (no preamp). To these ears the SIT-2 improved more when the Backert was added to the chain. I could easily live with either of the FirstWatt amps or the Bakoon, but the LTA lacked some musical magic. I never did get entirely comfortable with the volume control on the Bakoon.

Robert

Robert  Please share your findings with tube trials in the VR L2iSE.  I have only tried Electro Harmonix and Elrog 300bs and the Linlai 2A3.
The latter was a clear winner, I mentioned it's attributes in an earlier post and Srajan has a very positive review.  Like to hear what you're rolling.  The Nenuphars obviously love tubes and are a great lens of their different qualities.

My first comparison was between the Electro Harmonix 300b that came with the amp and an EH 2a3 set. I preferred the 2a3 as the 300b tubes were 'slower' even though they had a richer sound. That trade-off was solver with a set of Takatsuki 300b -- the best of both worlds and my current favorite. I do have some KR Audio T-100 DHT on order. I will keep you posted.

In the meantime, I have tried some NOS tubes: 71A and 112a (Most the old tubes seem to run at 5V). The 71A were a bit lean, but the 112a Cunninghams are now in second place after the (pricey) Takas.

Fun days and an embarrassment of riches....

Robert
 

Re the different solid state amps:
I wanted to note that the main difference for me was that the FirstWatt amps had a bit more of the mid-range-icity that is a major attraction of tube SETs.

Robert

I realize that the 300b tube is being discussed in the context of utilization for preamplifier section duty. I've only used them as output tubes in power amplifiers.  I do believe that to get the best from this splendid (My opinion) tube you have to use the premium level options which admittedly are expensive (But worth it).

Elrog, EML,KR, Takatsuki,  these are going to yield exceptionally good sound quality. Worth the cost if you have the level of audio systems/components under discussion here. The Nenuphars will easily reveal the improvement these higher tier 300b tubes provide. I wouldn't cut corners. 
Charles 

Thanks Robert for the reply.

Currently I’m using the Bakoon 13R with a Bakoon dac, which is out of production. We should see a new dac from them at some point.

Since we’ve been discussing amps...here are two short clips of the Nenuphar being driven by Absolare’s Hybrid Integrated SE. Posting since I don’t recall mention of an Absolare pairing in this thread. Please correct me if that isn’t the case.

Courtesy of Dükkan Hifi, a dealer in Turkey. Note the use of Townshend Audio Supertweeters. There is a comment regarding their negative impact on sound quality, though Dukkan mentions in-person listening for a better / correct evaluation. I personally don’t see [hear] the need for the addition of supertweeters. Curious, nonetheless...Anyone using them with Cube Audio speakers?

https://www.youtube.com/watch?v=z0bLmC5rkig

https://www.youtube.com/watch?v=Ti2iJ7tXuqQ

For those of you who have the Nenuphar Mini speakers, here is a longer (mix) clip from Dükkan Hifi .

Driven by the Aesthetix Mimas Integrated Amplifier.

https://www.youtube.com/watch?v=IpM_9NfTL6U

Note: For all videos, the dealer recommends listening via headphones.

Robert  Thanks for update on tubes.  I believe the Takatsuki are VR's preferred DHT's for the L2iSE.

Charles  I wish I knew the 300b better as a driver.  Wondering in fact if there's anyone on the thread who is driving the Nens with the 300bs, can't recall.  Would love to hear their impressions.

David  From specs and reviews I think the Absolare Hybrid Integrated would be a terrific match and the audio I hear confirms.  BTW I did try using my Townshend super tweeters with my Nenuphars and honestly could not hear that they contributed to sound quality.  Could it be amp dependent?

@stevendunn, 
I can't recall a single mention of a 300b SET amplifier and Nenuphar pairing. I believe that it would be as successful as the 2A3 SET  amplifier. Both excellent choices with different sonic signatures and presentations. 
Charles 

Same here. In full agreement with Charles’ post.

I can’t recall a single mention of a 300b SET amplifier and Nenuphar pairing. I believe that it would be as successful as the 2A3 SET amplifier.

Stephen, I explored various 300B options but, as you know, doubled down on the 2A3.

Going by gut feel from having the Nenuphars for two and a half years, I believe the ~8 watts from a high quality 300B amp is the "goldilocks zone" for power (in terms of driving the Nenuphars with a SET amp).

There are far more quality 300B amps (relative to the other SETs) including stereo versions; and greater availability / choice in the used marketplace. It’s interesting and surprising that we don’t have mention of 300B - Nenuphar pairings.

"It’s interesting and surprising that we don’t have mention of 300B - Nenuphar pairings."

For whatever reasons, this thread got started with a focus on solid state amplifiers and has discussed/explored tube amps only minimally. I suspect it is because Jon Ver Halen at Refined Audio (the first Cube Audio distributor in the US) uses First Watt amplifiers.

Robert

@rwpollock, 
That's a good observation.  Ironic in the sense that the design concept from the very beginning of the Nenuphar was to mate with low power SET amplifiers. It's been established on this thread and elsewhere that solid state amplifiers can be paired very successfully with the Nenuphars. 

I do know that David has outstanding results with his superb 2A3 SET mono blocks. I believe my Coincident Frankenstein 300b SET mono blocks would be a successful match with these speakers. 
Charles 

@stevendunn,
In a way I’m not surprised by your listening impressions using a super tweeter. I just do not believe that the Nenuphar needs this assistance in the ’vast' majority of listening situations. Cube Audio developed a remarkable wide/full range driver. Many owners find they do just fine without utilization of a subwoofer. Definitely need/preference based.
Charles

Charles  However Srajan did have a positive experience using the two Advantages Audio super tweeters with the Nenuphars: https://6moons.com/audioreview_articles/avantages2/
These are omni directional super tweeters for what that's worth.

Hi Steven , I have zero doubt that some listeners will find super tweeters and subwoofer augmentation beneficial with the Nenuphars.  I was just expressing the point that many will find them just fine "au naturel" 😊.
Charles 

I did ask Jon why he didn't use tube amps. He smiled and said he was good friends with Nelson Pass....

Jon also used Pass/FirstWatt amps and preamps back in his Lowther America days.

Robert

I just hooked up a pair of Sophia Electric 91-01 mono blocks to my Nenuphar minis. I really haven’t had time to listen much at all so too early to assess but in the brief time listening I am liking what I’m hearing. The reason I went for these amps is the owner was including an almost new pair of Takatsuki 300b’s. I started listening with a pair of included Shuguang black treasure series 300b’s. They were fine but a little lean sounding. I just put in the takatsuki’s and wow, huge difference. Tone is richer and soundstage wider and deeper. Everything just got bigger and more alive sounding. When I get more time with this combo I’ll report back. I’m also moving and will have a much better listening space but that won’t be until mid September. 
I’m also wondering if anyone is using a sub with their Nenuphars? I’m using a pair of REL T5i’s. I’ve been really impressed by these little subs. I don’t have them turned up much but they really blend well. 

@rwpollock  Robert, good point and on the money. Srajan Ebaen's initial review also shined a bright light on the SIT amps, and then Bakoon.

As Charles mentions, it is perhaps incongruous that few on this thread have followed the designer / builder's lead with 45 and 2A3 pairings. 

I received very strong pushback on going the 2A3 route, from many, since they were highly skeptical of the ability of 3.5 watts to properly drive a 92dB / 6 Ohm rated speaker. 

Charles was steadfast on the pairing and I'm so glad I followed his advice. Once again: Thank You Charles.

@abd1, 
My then new (2009) Frankenstein MK II came standard with  EH 300b tubes and they were solid performers.  I soon upgraded to the Shuguang black Treasure 300b which was an immediate and obvious improvement.  I later moved on to the Takatsuki and like you said, "WOW"!! Better in every conceivable way. 

David I know as high as your expectations were, the Found Music 2A3 SET and Nenuphar pairing has exceeded them. 3.5 watts of supreme quality and implementation. 

 Certainly specific situations dictate choices but too often more power (Watt quantity) is the default recommendation when in fact  watt quality is the answer.  David you were generously rewarded by sticking with your well reasoned convictions. 
Charles 

A strong recommendation for using headphones / earphones / IEMs for the video playback.

The comparisons between audio output via my laptop speakers vs. the 3.5mm laptop analog out vs. the Audioquest Dragonfly Red DAC/Pre/Headamp to Sony WH-1000XM4 headphones and Noble Audio 4C IEMs are (obviously) vastly different.

I'll try playback via USB Audio Pro / eXtream Software Development (The Netherlands) next.

Sony leash is stock. Custom Linum / Estron (Denmark) leash for the Noble 4C.

I'm not in my audio home base, for the time being, and cannot access my primary headphone systems.

I'm running my Nenuphar with the Apherion dual AMT Supertweeter.  I found the addition of the supertweeter to enhance the listening experience,  especially with sound staging and the subtle but imo important treble decays.  I went back and reread some of the reviews and this was mentioned.  I had mine crossover at 12khz and -2dB.

I also run the Nenuphar with a pair of Rel S510 subs.  I like them but could easily live without. I had crossover set at 20hz and volume up at 4 clicks.

The Nenuphar provides a strong foundation for owner to customize the sonic spices to their liking, a sprinkle of bass here and treble there provides different experience and I enjoy the journey and customization depends on my mood.  At times I do turn off all effects to enjoy the Nenuphar sans crossover, and love that I have that option.

khragon Thanks for posting about your use of the Apherion supertweeter. I’m curious about how you have them installed. If they sit on top of the speaker, the rake would make them point far over the listener’s head at the front. My understanding is supertweeters are highly directional. Or do you have them propped so they fire straight ahead? Maybe the Apherion drivers provide more dispersion. Insights into installation would be appreciated.

Here are some photos of the setup:https://goo.gl/photos/rinLZWzHoBvCizNLA
I have the supertweeter on the same plane as the speaker, both slightly toed in into the listening position.

khragon Impressive set up!  Thanks for sending photos.  Rare to see the Nens with the grills.  Don't think mine even came with.  More importantly I see how you've installed the Apherions (and subs) and I'm thinking I will try the supertweeters given they have an in-home audition period.  I have had speakers in the past that benefited from forward only firing super tweeters, but think the dual design is the way to go, adding depth and probably air to soundstage.  I am in a relatively small room and although width of ss does not seemed cramped, depth does. With the SIT-2s in place, along with the help at either end of the spectrum, I bet your Nens sing. 

khragon Meant to ask what pre you have in front of the SIT-2?

Would an 300B amplifier with the following specs be suitable for the Nenuphars?

10W per channel
Damping Factor 10 at 8Ω load at 1kHz
-6dB of negative feedback

Khragon, did you ever compare Apherion with the Townshend? Thanks.

I am using a full PS Audio stack:

P15 Power Regen
DSD DAC Sr
BHK Pre

I used to have BHK250 amp buy sold that in favor of the SIT2.

Sorry I didn't compare the Aperion to any other brand.  I did compare their TOTL model the dual AMT to the lower aluminum ribbon model.  I think I could live with the aluminum ribbon model, they were very close.  With exception of the sensitivity so for maximum compatibility later on I went with the AMT, that and I thought it's a bit more airy.. but that could be the price bias taking.

@yorkshireman, 
At 10 watts I'm assuming that this is a SET amplifier utilizing a modest 6db of negative feedback (Many SETs are zero negative feedback). The damping factor is pretty modest as to suit the Nenuphars (Per design objective). I can not anticipate any problems with this amplifier. 
Charles 

@charles1dad 

Thanks for the quick and informed response, very much appreciated.

Yes it is a SET amp and as you pointed out slightly unusual with the -6dB, very small, and natural negative feedback, just for better bass.

@charles1dad 

Do you think an even lower watt amp would/might be even better? and do you have any suggestions?

@yorkshireman,
I can not say with any authority that a lower power amplifier would unequivocally be better, certainly as good. @david_ten is enjoying truly splendid results with his superb 2A3 SET . I feel more strongly that the absolute quality of the amplifier is priority number 1.

 The best quality SET you feel that you can afford. SET circuits are straightforward and no mystery. Key criteria are high quality parts, output transformers and very stout power supply. The Nenuphar will readily exploit these amplifier attributes.
Charles 

As far as specific recommendations go there are no shortage of worthy candidates. Have you determined a budget comfort range?
300b SET are more plentiful and are also generally more expensive than 2A3 SET amplifiers. Again, depends on what level/tier of quality you seek. The better the amplifier,  the better the Nenuphar will sound. 

Charles

Thanks again... 

@charles1dad

The amp is an Allnic T1500

http://allnicaudio.com/product/t-1500-mk2/

I think without going up to Kondo, Shindo, Tron, separates a secondhand integrated is about where my budget ends which is at around £3500 GBP - $5000 USD

Do you think this would be high enough quality?

@yorkshireman, 
Just saw your post (Watching the NBA champion game😊). 
I believe that the Allnic is an excellent choice. 

1Established and highly respected manufacturer. 
2 High standard built quality chassis construction. 
3 Very high quality output transformers.
4 Robust power supply.
5 Very thoughtful  soft start mechanism. 

This should sound quite wonderful paired with the Nenuphars. 
When you're able/willing to, buy the best 300b tubes you can afford. 
The one drawback to the 300b is the premium level choices are not low cost. In this case you get what you pay for.  

With an SET of this caliber and the high level Nenuphars there's little rationale for compromising on 300b tube quality.  You'll be rewarded.
Charles 

@charles1dad

Another bonus is that it only uses 2 300b tubes. 

Thanks again Charles for all your help and advice.

You are welcome.  I believe that you'll be exceptionally pleased  long term with the Allnic-Nenuphar pairing.
Charles 

@yorkshireman In addition to Charles' excellent advice, some things to consider:

- I believe Srajan used Allnic amplification components with the Nenuphars. Might be worth revisiting those sections of his reviews specific to the Nenuphars AND specific to Allnic, to get a better feel for the pairings and synergy. Those reviews are from 2+ years ago.

- If you are still considering a new integrated I'd keep an eye out for those that allow for negative feedback control.

- I've been revisiting Peter Breuninger's Nenuphar Mini review for evaluating laptop based headphone listening purposes and the sound quality of that setup stands out. I believe the component used was the 'Tektron Stratosphere TK2A3 300BPSE i Ref' which allows for use of multiple output tube types. This would allow you to go with 300Bs as well as lower power tubes. I believe Tektron is fairly priced and may be within your budget.

All the best in your search and let us know how it all comes together with your Allnic T1500 or another amplification route.

6 Moon’s Srajan Ebaen did review the 30K flagship Allnic L 10000 DHT line stage that utilizes the 300b and lacks an output transformer thus an OTL component. The Allnic 1500 integrated amplifier uses the 300b in a traditional power amplifier output stage fashion with output transformers . Although different types of audio components, I agree with David. The review provides useful information/insight concerning Allnic’s design, technical and engineering competency. They are a high quality manufacturer of audio products. 
Charles

Srajan once told me he was very fond of the Allnic cables. Seems like a company with a good product line up. 

@yorkshireman As you'll no doubt see, prices can be all over the place for various SET designs. Charles rightly points out that the circuits are simple, so if you can, look for "under the hood" pictures that show you parts and power supply quality of the build.  If you're not confident evaluating, then post links here and I'm sure many will opine.

If you can at all swing it, I would recommend mono-blocks (or a single chassis dual-mono design).  I built my own amplifiers (from pre-made Nelson Pass boards), and the change in sound quality when going from a standard stereo build to a mono-block design with independent power supplies was quite substantial.  There is good reason why all cost-no-object designs have independent power supplies, as the two channels create distortion when they are simultaneously pulling on the same transformer. 

Thanks david_ten, toetapaudio, charles1dad and cal3713.

I know the more expensive Allnic separates use point to point wiring but the integrated amps use a PCB.

There's an image of the inside of a T2000. 

https://www.stereonet.com/forums/uploads/monthly_2018_10/L9740204.thumb.JPG.cba63850ad0d73ed4e7a1eee...

KS Park told me that the T1500 also uses a PCB, so probably very similar.

I've been using an Allnic T2000 which uses 4x KT120 tubes at 50-100W (Pentode/Triode) which was OK but I think was maybe too powerful and has maybe been damping things a little.

I've been trying (just as an experiment) my old SS Olive Naim Nait 2 20w which doesn't actually do a bad job.

I know purity of signal path is very important with tube amps.

I suspect that the internal environment of the T1500 is less crowed with fewer parts as SET is simpler. Higher power push pull amplifier will have a higher parts count.
Charles