Has anyone tried 2A3 amplifiers?

@eric5kim Eric, @riaa_award_collectors_on_facebook is correct.

I’m on my second set of 2A3 amps driving the Nenuphar V1s.

Questions?

@david_ten which 2A3 are you using? 
does it have enough headroom for large orchestral works/rock/electronic music? 
If listening at 88db need at least 10db of headroom for peaks  

Eric 

I can highly recommend using a TEKTRON 211 tube amp (integrated) with the Cube Audio Nenuphars! Before the TEKTRON I used a NAT Single HPS. The TEKTRON is much better!! This is an addictive combination!!

Good to see the Bakoon 13R and Enleum 23R now getting the recognition they deserve.

@V10 thanks for your comparison, very useful. What other amps have you had experience of my I ask?

I saw that Cube Audio has used Tektron amps at shows in the past. My problem with Tektron isnt the sound but the top plate on their amps starts pitting over time. Some call it Patina....I call it Rust Spots which is really ugly IMO.  They need to fix that before I will purchase one.

There is definitely a distinction between acquiring a "natural" patina and rust. 🙂

Charles

@eric5kim Eric, both of my 2A3 amps were designed and built by Scott Sheaffer (Found Music). I picked up the first pair of monoblocks used. They were built for member Mike Lavigne. I commissioned the second set. They are a 4 chassis build. You can see the amps and their power supplies in my virtual system page.

I listen to electronic music fairly often as well as large orchestral music; and rock to a lesser degree. I find that my system delivers with all three genres. If anything, it is my room (which is mostly untreated) that exerts a role once the volume levels are 95 dB and up.

As a reminder, I have the V1 Nenuphars.

Much more important than raw power output numbers, in my estimation, is the quality of the amplifier build AND how well the incoming power (into the audio room, conditioning if used, and power cables) has been addressed. Component and cable isolation also factors in.

Members who are more versed in tube amplification, like @charles1dad and​​​​@larryi , may be worth reaching out to... or they can comment.

High dB peaks, especially with classical music, and the level of power needed before distortion and clipping, is covered in many threads. Many advised me against the 2A3 amps I chose. My experience has proved otherwise, with respect to the Nenuphars.

which 2A3 are you using? does it have enough headroom for large orchestral works/rock/electronic music? If listening at 88db need at least 10db of headroom for peaks

@david_ten  Thank you David. Those 2A3's are a beauty

Eric, I also owned the Melody I2A3 integrated amplifier which was paired with Vaughn Audio Loudspeakers. That is the extent of my exposure to 2A3 amplifiers.

A reminder. While dusting off the Nenuphars this morning, I noticed one of the four outer screws on the driver 'front assembly' was very loose. They are T-25 screws.

Interesting comparison compilation from Cube Audio.

Leonard Cohen 'In My Secret Life' Nenuphar / Nenuphar Mini / Jazzon

Another compilation / comparison, this time with four different music tracks (from Cube Audio):

Nenuphar / Nenuphar Mini / Jazzon comparison

I realize you know this...listening via an outboard DAC/Headphone Amp and Headphones highlights remarkable differences in the presentations.

Stumbled on this mini-review of the Nenuphar and I don’t believe it has been posted here yet. I find it to be the best description of their sound character I have seen:

https://eastendhifi.com/cube-audio-nenuphar-speakers-a-desert-island-speaker/

@dlcockrum 

Thanks for providing that link.  As a non Nenuphar owner I confess that I have much admiration and respect for this speaker. It seems to nail all of the criteria and parameters that I find most important, even mandatory. I remain exceedingly happy with my Coincident Total Eclipse II speakers (13 years 😊).

The Nenuphars are 1st on my list if I ever decide to change speakers. I do believe that they represent an extraordinary achievement. I completely understand your happiness and satisfaction with them. I believe they’d be a superb match with my Coincident 300b SET mono blocks with their low damping factor and zero NFB design/circuit.

Charles 

@dlcockrum   Thanks for sharing the link!!!  

Video from the Cube Audio Room /// 2022 Praha Audio Video Show, courtesy of Cube Audio.

Jazzon Cube Audio Room Praha 2022

Cube Audio Jazzon Speaker review by Dawid Grzyb // HiFi Knights

Jazzon Review by Dawid Grzyb of HiFi Knights

Installed the V2 drivers on Friday. I had +1.4dB of Roon DSP at 100Hz set on the V1s. I eliminated the Roon DSP before hearing the V2 drivers for the first time. The V2s definitely require a break-in period. I am hearing some of the differences as demonstrated in the Cube Audio in the V1 vs V2 youtube video. I do prefer the V2 over the V1 drivers and will go into more detail after 100 hours of burn-in. Refer to my recent review of the Farad Super 3 power supply on stereotimes.com for my complete system configuration. The V2s require more gain from my Ayon Audio S-5 preamp to power the First Watt SIT-1. My preamp volume runs from -60 to 0. I typically play music between -47 and -35 (-30 is half volume) with the V1 drivers and now I play music in the range of -39 to -32 with the V2 drivers. The V2s start to open up after about 20 hours of playing.  I think it's a big plus that I have been able to eliminate the Roon DSP 100Hz bass boost with the V2s and I anticipate being able to move the Nenuphars further away from the front wall which are currently 11" as measured from the rear of the speaker cabinet.

@mikeg   Mike, congratulations on moving to the V2 Nenuphars and thanks for sharing your early findings.

Since I have the V1s and am using a 3 watt amp, the additional gain needed for the V2s is both noted and significant for my situation. 

Looking forward to your detailed impressions after the 100 hour mark.

Completely unaffiliated, but I saw a Bakoon 13R up on USAM... thought I'd draw attention here since a number of people were talking about using a Bakoon with their Nenuphars.

I’m at the 75 hour mark on the break in. The V2s definitely take longer to break on and that was confirmed by Jon Ver Halen. The V2s are opening up more and the need for more gain has dropped some. I never run out of gain on the V2s while using the FW SIT-1 which I was concerned about prior to the upgrade.

I think eliminating the Roon DSP 1.4dB of bass at 100 Hz and down (shelf) which I needed on the V1s is huge advantage for the V2s. V1 and V2 are both good but having more body and meat on the bone on the V2s eliminates the need for adding one or two subwoofers (in my case 2) because I can’t locate a single subwoofer centrally. So in a sense for my system, the $1500 V2 upgrade cost is well worth it considering 2 REL subwoofers, interconnects, and power cables would cost $7600. I also think the V1s with their added presence are a little of too much of a good thing. I mainly listen to jazz and I can say that I never have ear fatigue with the V2s. The V2s seem to match better to my all silver based cables which is a big plus also.

I tried my best to maintain the speaker position and toe in when I swapped in the V2s. On some recordings with the V1s, there was a less center fill and sometimes instruments were localized to the individual speaker. I never experienced with the V2s. The vocals are also more pinpoint on the V2s.  One might say the V2s soundstage better. The magic of the V1s is clearly carried over to the V2s but he V2s extract every last bit of musical energy and impact on the recording.  This is just my opinion. I also think reviewing a full range speaker such as the Nenuphar with a subwoofer doesn’t give the whole story on the performance of the speaker.

Moving from the V1 to the V2 eliminates (Or diminishes) the need for subwoofers? Quite an observation and outcome. I still believe that a lot of the V1-V2 differences are driven by specific system make-up and subsequent synergy results. It just seems that existing source, amplification, cabling etc can tilt driver preference in either direction. Then of course there is the large Spector of individual listener bias and taste. I still contend that both are superb options. 
Charles

@mikeg Mike, good to know that the V2 driver is requiring less gain as break-in progresses.

I’m confused about your findings on the ’center fill’ / ’localization' to the individual speaker’. I don’t experience this in my system. Is there an explanation for why this may be happening with the V1s in your system? Thanks.

Congratulations on ’loving’ your V2s and the upsides they have resulted in.

Posting this for those who may be interested in utilizing Cube Audio drivers in a DIY setting. 

@realworldaudio  sometimes posts within the general forum. I find what he shares thoughtful and helpful.  He recently installed the Fc8 driver in his Voigt Pipe cabinets. He has a YouTube channel and this video covers his Fc8 driver impressions, immediately after the install.

Cube Audio Fc8 driver in Voigt Pipe speaker cabinets

@david_ten The V2s disappear better on all recordings than the V1s.  The extended bass and high frequencies result in better soundstaging and center fill.  It might be that I needed to move the V1s closer together than the V2s.

I haven't validated yet but I also think my Ayon Audio Odin SET tube based amp will better mate or bed in with the V2s.  

@mikeg   Thanks, Mike.  Also, great to hear that your Ayon SET may be the preferred pairing.

@david_ten What I mean related to the Ayon SETs is that the V2s would pair better than the V1s.  If you remember, Cube Audio didn't like the pairing of the V1s with 300B based amps which I think is closer to the SET tube used by Ayon Audio. The V2s pair extremely well with the FW SIT-1.  As it has been stated by others, the V2s will pair with more amps and that is another reason Cube Audio went in that direction.

If you remember, Cube Audio didn’t like the pairing of the V1s with 300B based amps

I was under the impression that Cube Audio specifically had lower power, high output impedance amplifiers in mind to pair with the Nenuphar characteristics. 300b/2A3/PX 25 etc were the intended targets. Thus the very damped driver via very powerful magnets/motor. Exactly why an amplifier with high damping factor is not seen as advantageous. A good quality 300b SET would seem an excellent Nenuphar partner.

Charles

@mikeg  Mike, my memory might be failing on this but I don't remember Cube "not liking V1s paired with 300B amps."  What I do remember is a preference by Cube Audio for 45 and 2A3 amps. If you have more information on this from Cube, please share.

Based on my experience with the V1, the ~8 watts of output, typical of 300Bs, is (per my estimation) the bullseye for 'ideal' SET power to drive the V1s. 

I'd expect a high quality design / execution of a 300B amp to be linear and neutral and be an effective pairing for the V1s. Chosen 'voicing' of the specific design, per the owner's preference, is an obvious factor.

If you remember, Cube Audio didn't like the pairing of the V1s with 300B based amps

@charles1dad ditto. I was under the same impression. Inquiring minds want to know what backs up that statement.

@juanmanuelfangioii

In all candor I don’t believe there is a backing up statement. Certainly due to personal taste preference one might prefer a 45 /2A3, nothing unusual there. By the same token other listeners may prefer the 300b. Normal variance depending on numerous audio system factors.

Charles

Here's some food for thought:  I think this a question for Cube Audio with respect to the V1 and they will see it as a mute point.  Why did Cube Audio have a list of compatible amplifiers when they offered the V1s?  You don't see a recommended list for the V2s. Why did the Mono & Stereo Review state: "For tube amplifiers, Cube Audio recommends such designs based on 2A3, Px4, 45 tubes" and not 2A3, Px4, 45, and 300B tubes.  Have you ever seen Cube or Refined Audio specifically demo with 300B based amps? I remember addressing this exact question at some point in my search.  

Seems like considerable conjecture in all honesty. I can’t think of any logical reason why a 300b amplifier would not be a fine choice. Certainly no technical reason. I’d love a comment directly from Cube Audio on this topic. I would be very surprised if they said there is some reason to avoid the 300b. Again, to me it appears to be a terrific pairing.

Charles

@mikeg Mike, in addition to simple preference, perhaps the industry association for shows, etc. may have been a factor. Tektron Audio and Cube Audio in Europe. Refined Audio being a Pass Labs dealer factors for the US shows.

If Grzegorz has reasons for not recommending a 300B or for putting it lower on Cube’s recommended list...I’d love to know the reasons.

Here is a screenshot of the recommended amplifiers (I believe this was the list when the V1 was in existence) from Cube Audio.

A number of 300B amps are in the "Amplifiers that work well with Cube Audio speakers" list.

[Note: I was not able to re-format the font size, etc. below] In other words, I'm not shouting!!! 😊

Amplifiers that are working very well with all Cube Audio speakers

Up to 4’000 Euro

• First Watt SIT-3

• Feliks 300b Arioso

• Fezz Audio Lybra 300B

• Fezz Audio Mira Ceti 300B

• Music book 250 Power

• Naim Audio XS2

• Naim Audio Uniti Atom

• Sun Audio 2A3

• Quad Artera Pre + Power

• Tsakiridis AEOLOS PLUS EL34

• Tsakiridis Hermes EL84

• Tsakiridis ORPHEUS 211

4’000 - 10’000 Euro

• Aesthetix Mimas

• Bakoon amp13r

• FANTINI 2 GM-70

• First Watt SIT-1

• Manley Stingray II

• Quad II Classic

• Sun Audio 300B

• Tektron TK211SI REF

• Tektron TK2A3/300BPSE-I-REF

• Tektron TK300BS-I-ECY

• Verdier 300B

• Viva Solistino integrated

Over 10’000 Euro

• Absolare Intergrated SE

• Aesthetix Calypso Eclipse + Quad II80 Monos

• Aesthetix Janus Eclipse Pre + Line Magnetic 503 Monos

• Aries Cerat GENUS integrated

• Aries Cerat Incito-S + Concero 25Aries Cerat GENUS integrated

• EAR 509

• Grandinote Genesi + Demone

• Grandinote Shinai integrated

• Shindo Cortese 300B

• Wyred4Sound Pre + Quad II 80 Monos

• Tektron TK211MPSE REF Mono Pair

@david_ten 

Thanks for taking the time to find this amplifier list. It is self explanatory. 
Charles 

@realworldaudio Janos, you are welcome!

A double welcome: one for joining the Cube Audio family via your new Fc8 drivers and another for your posting here.

Thank you for sharing your detailed, initial impressions. If the Fc8 follows the F10 Neo drivers, expect a long (mostly enjoyable) break-in period and a positive (significant) improvement delta.

For those that are unfamiliar with Janos, he is based out of Hawaii and has a YouTube Channel dedicated to audio. His YouTube Name is Real World Audio. Here’s a link to his ’videos’ page:

Real World Audio

@david_ten The following paragraph precedes that amplifier list and this what was stated one time as referenced in the Mono & Stereo review of the Nenuphar:

Magus are dedicated for rooms of 12 - 25 square meters. They are a perfect match for a tube amp with at least 3 Watts per channel. Our personal preference is somewhere around 2A3, Px4, 45 tube-based amps.  Nonetheless, most solid-state amps (especially those working in A-class) are also an amazing match for the Bliss C.  When it comes to placement, they can be placed both forward and placed right against the back wall. They like about 5-10 degrees of toe-in.

“Our preference” is the distinction I picked up on and 300b amps were not included.
 

@realworldaudio That was an excellent summary and I find your speaker cable mod (single run for the positive and five runs of speak cable for the negative) very interesting.

@david_ten Thank you David for the warm welcome!

It is a pleasure to join the company of like-minded audiophiles. A little background on me: I have experimented with Voigt pipes in various forms and interpretations, drivers, rooms, and how they fare with associated electronics for over 20 years. I had the pleasure to spend my audio journey with like-minded friends, in a very strong local DIY community, and an amazing mentor (Stu Ono) who was regarded as a fountain of knowledge by a good number of the US leaders of high end audio industry.

I can say the Cube Audio has truly raised the bar! I have the version 2 of the Fc8, and currently breaking them in my Voigt pipe cabinet (which has been my most successful Voigt pipe). 

Cheers, Janos

Welcome to the thread Janos, 🤙🏽 I’ll bring the malasadas lol I kid!

Hi,

anyone know what the bias settings should be for a Tektron TK2a3/50si amp

2a3 tubes

300b tubes

50 tubes

any help would be appreciated.

Ron

@stereodynamics   Ron: I would ask Tektron Italy directly.

From their website:

General inquiry info(at)tektron-italia.com

Support request support(at)tektron-italia.com

@cal3713   There is an Enleum 23R listed now as well. 

@stereodynamics   Are you all set on the bias settings?

I'm curious about which tubes you prefer with your Tektron amp and your overall thoughts of the unit? 

It has been a pleasure and an education participating in this thread. Learned a bunch that helped me appreciate not only my Nenuphars but this hobby.

I’ve moved on from the Nenuphars to the Boressen Z2 Cryo edition speakers. A leap forward in everything I love about the Nens (and more), but at a cost of $10K plus. I’ll be posting a review of the Z2’s as a separate thread in the next month or so.

A pampered pair of white Nenuphar V1s will be going up on ’Gon shortly.

@stephendunn  Stephen, speaking for myself, it has been an absolute pleasure having your insights, perspective and wisdom on the thread. 

I look forward to learning more about the Boressen Z2 speakers from your future thread.

You will be missed on this thread. Given your knowledge and experience with the Nenuphars, I hope you continue posting here.

@david_ten  Thanks, David!

+1 David. Best of luck to Stephen.

Charles

@stephendunn those Boressen speakers seem like some sort of voodoo magic. Seems like anyone who hears them is amazed. They are probably at the top of my list of speakers I'd love to live with for awhile at some point. Enjoy!