Pursuing the Ultimate Music Experiences

Audio Federation High-Fidelity Audio Blog

Mike and Neli went on a little audio adventure

Mike and Neli went on a little audio adventure to visit Audio Note in the U.K., the Munich High-end 2019 show, and the Acapella Audio arts factory where we listened to the Sphaeron Excalibur speakers (pictured) for most of the day.

Details galore forthcoming after sleep and uploading and sifting through several thousand photos, 100s of videos and many recordings of various systems in 24×96 hi-res audio.





Acapella Sphäron Excalibur – The holy grail of high-end audio loudspeakers

Acapella Audio Arts has upped the bar significantly with their new statement-level loudspeaker, the Spharon Excalibur:

Frequency range: 15 Hz to 40K Hz.

4 x 18 inch woofers per channel

Sensitivity: 103-107 dB / 1 W / 1 m

Impedance: 8 ohms.

Over 2500 pounds. Each.

1 x ION plasma tweeter per channel

From $620,000 a pair. Active version available for additional cost.

The specifications really do tell the story here. Very big. Very efficient. And, given the Acapella brand sound, it will sound like music, and not a high-school science-day project or mad scientist’s laboratory experiment gone bad.

Don’t believe it? Stop by the store in Duisburg Germany and hear for yourself.

That is exactly what the German Lite Lifestyle technology magazine did.

They go into quite some detail – it is a long article, but in German.

We translated the first paragraph to English below [you haven’t experienced life until you and your spouse attempt to translate the same bit of text together, let me tell you…].

Without further ado…

Acapella Sphäron Excalibur – The answer to all questions

What is the maximum amount of effort that we can put towards achieving the high-end ideal of pure, natural and undistorted playback of sound? How far can we go in pursuit of precision, vividness and coherence? An answer to these questions can be heard in Duisburg, where Acapella Audio Arts, renowned manufacturer of horn loudspeakers, has their rarely built Sphäron Excalibur on display. We seized the opportunity to listen to this magnum opus, and are happy to share our insights.


Audiophile power: The massive Sphäron Excalibur is 2.40 metres tall and occupies nearly 1.7 square metres. This loudspeaker system is finished in black acrylic cabinets with red horns.


Does anyone really need this level of performance? At the pinnacle of high-end audio, that is the wrong question. Here, one aims for a higher goal. One aspires to experience unprecedented quality. One strives for the maximum achievable performance, constrained only by the limits of known science and available technology. One ignores costs, number of materials and market analysis in order to gain new know-how at the leading edge of sonic reproduction. This is the driving force for Acapella co-founder Alfred Rudolph. After building the sensational Sphäron, the ultimate horn speaker system of that time, he asked: “Can it be done better? Will I be able to improve it further? Or, more poetically: “Can I, as in the Arthurian saga, pull this sword from the stone?” And so the Sphäron Excalibur was born.

More here.



Acapella Audio Arts – The Audio One music server

Acapella has recently come out with a music server. You’ve seen it at shows, but it is now in production and we’ve been using it here on both the big and small systems for a month or two now.

On the big system we run it into the Audio Note “Fifth Element” DAC at 24×96 and it sounds very good. Not as good as the very expensive Audio Note CDT-Five transport, but sometimes the laziness bug strikes and one just wants to set it and forget it.

On the smaller system we use the Audio One’s on-board DAC [which we also use on the big system sometimes when we want to experiment – it is VERY competitive (or better) with everything we’ve heard at the price].

The unit perfectly complements the rest of the gear in this system, which are honestly some of my personal favorites of all time and which I could happily live with forever (AN SORO integrated, AN/E Spe HE speakers, TT2), which are all in the $6K to $10K range.

We’re not giving up on CDs just yet [but if YOU are, let us give you our address and instead of just throwing them away… :-)], but their days are numbered and some are getting harder to find and more expensive – and some are now 50 cents.

Audio One music server, Price: $6875.00 USD




Audio Note U.K. level-5 volume controls

Volume controls? Yep. Volume controls.

Audio Note’s more expensive pre-amplifiers have high-performance and awesome-looking volume controls. Hand soldered resisters are used for discrete levels of attenuation – arranged in a couple of different geometries that are pleasing to the eye [well, MY eyes anyway!] as well as the ear.

The red, square-looking one in the photos has more “steps” and allows for finer control of the volume between soft and loud. AN believes in high-gain preamps and so do we, but we wanted a little more control over the playback and recently had Nick at True Sound install the red volume control in our M9 Phono preamp.

We are liking the change. 🙂

It is taking  us both awhile to get used to setting the volume 5  clicks in and still being able to hear ourselves talk [which can be a good thing and a bad thing ;-)].

OK. Enough with the spouse-humor [sorry Neli :-)]. We also upgraded the M9’s umbilical cord between its power supply and control unit a few months ago, a major improvement.

Audio Note U.K. doesn’t stay still and keeps improving things. Which is good. Because after some amount of time, I am always ready for something that brings me closer to the epiphanies of hope and beauty that music can deliver to world-weary tired souls – like mine. And maybe like yours too.

HRS M3X2 platform cutaway

An awesome diagram of all the pieces and parts of an Harmonic Resolution Systems M3X2 Isolation Base. These platforms are used many places in a HRS-based setup: as amplifier stands, as shelves in equipment racks, as turntable bases.

Audio Note M9 RIAA Signature Phono Stage

Going through old directories finding tons of photos that never made it to the blog. Here is just a couple of them.

The M9 RIAA is a two box phono stage from Audio Note U.K. which is by far the best phone stage we have heard with respect to revealing [aka letting through. aka not stepping all over] the parts of the music that make music sound like music. What more could one ask for? [a serious question. Can’t think of anything!]

This now lives in Fred Crowder‘s system [M9 RIAA reviewed at DAGOGO].


Giving some lovin’ to our Audio Note SOOTTO power cords….

Audio Note has a long history of making power cords. We haven’t always been fans but the statement SOOTTO power cables ($11k-ish for 1.5 meters) and the affordable ISIS power cables ($450-ish for 1.5 meters) have made our ears very, very happy.

[don’t know about you, but if I can at least make my ears happy, it helps me to solider on to the next sucky tomorrow]

The SOOTTO is comparable to other cables in this price range (e.g. Nordost Odin 1) but is less aggressive and more emotional. Extreme detail but not etched detail like some other cables, which lets through the subtle variations in harmonics and dynamics that are needed to understand and appreciate what is the fantastical adventure happening in each note of each song we want to listen to.

The Audio Note ISIS power cord is an all-around performer in the vein of the SOOTTO [and is just slightly smaller in diameter] and we use them freely when we do not have enough SOOTTO on hand to power a system out. Sounds better than power cords at 5-times the price and we have [and sell!] a LOT of these.


Splicit Reel Audio Products

[We still haven’t entered the world of reel-to-reel tape yet, but these people seem nice and have a wealth of accessories for when we do]

Splicit Reel Audio Products “Splicit Reel Audio Products is the nation’s innovative supplier of analog audio tape and accessories carrying a full-line of reel to reel products including Capture Audio Tape and PYRAL/RMGI, splicing block and kits, leader tape, splicing tape, reverse foil tape, NAB aluminum reels, 7″ plastic reels, demagnetizers and setup boxes and more.”