Tech. As already covered in my intro, ribbons differ wildly from planarmagnetics. "Unless it's long, narrow, between two lateral magnets, clamped only on top and bottom and regardless of impedance or percentage of plastic foil covered by a conductive layer, it won't be a true ribbon. The one exception are Apogee-style quasi ribbons which use a plastic substrate foil to carry conductive traces connected in series to increase impedance."
Aside from large surface shadowing by magnets and their obvious airflow and related timing issues, planarmagnetics face modal behaviour from tight surface clamping resembling a drum skin. And because their voice-coil traces must be glued/bonded to the plastic foil, they add "dead weight". Only a ribbon turns each atom of its moving mass into an actively driven unobstructed conductor. Why aren't ribbons more widely produced? "A really good true ribbon cannot be mass produced and requires ancillary components."
Specs. Magna weighs 530g with composite glass-fibre/aluminium 10cm-diameter shells finished in hard-waxed American walnut veneer and anodizing. The grille is 3-phase etched stainless steel, the bridge titanium aluminium nitride hard-coated brushed stainless steel. The soft-cushion headband's skin side is suede. The click-stop height adjuster has five steps. The ear pads are memory foam faced in lamb suede, textile on the inside, perf leather on the outside. The circular ear-pad opening is 64mm. The input connectors are 3.5mm female TRRS. The twin ribbons are corrugated aluminium with a 'silent metal' viscous damper skin. The combined surface area is 16.8cm². Excursion potential is ±4mm. Max SPL are 115dB. Impedance is 0.038Ω which rises to 0.27Ω with the dedicated 1.8m S2 headphone cable terminated in a female XLR4. The amp-to-interface cable is 1.5m. The three ribbons of Immanis increase the surface area to 25.2cm², shell diameter to 11cm and impedance to 0.057Ω which the 1.8m Star-8 MkII headphone cable raises to 0.29Ω. Max SPL add 3dB. The circular ear-pad opening increases to 74mm, weight to 610g. The grill adds gold plating. Other than size, weight and colour, the two differ also in the detailing of their bridge, headband stitching and included cable. The Magna ribbons have almost 29% more surface than the CA-1 driver to equal the SR1. The Immanis ribbons nearly double the CA-1's surface and outsize the SR1 x 1.45. Between each other, Immanis brings 50% more surface area to bear than Magna and incorporates a larger front chamber.
The interface styled as a headphone stand contains a toroidal step-up transformer which converts a voltage-drive amplifier output to a current-drive signal for the ribbons. Suitable amplifiers to be used with the interface will have low output impedance, less than 10mV of DC offset and now be loaded by 32Ω (8Ω/16Ω on request). "The reason for a single-Ω interface is simple. We no longer chase max power but compatibility with all decent headfi amps. For reference, where the SR-1 needed six watts for a given high broadband SPL and the CA-1a 3.8W, Magna now gets equally loud on just 2.4 watts and Immanis is down to 1.5 watts. Immanis only needs 25% of the SR-1's power. If we're talking ~6wpc amps like the upcoming Auris Headonia 10th Anniversary 300B, it has discrete transformer outputs into 25, 50, 100, 150, 300 and 600Ω so delivers full power into our interface. No problem there!" Another suitable DHT valve amp also from Serbia should be Trafomatic's 9wpc/50Ω Primavera with SV811-10 driven by 6S45P.
Back on Alex's graphic above, I'd never considered the very practical consequence of a ribbon's 100% conductivity in its fullness before. The voice coil of a dynamic mid/woofer classically attaches right behind the small circle made by its dust cap. It's the only area our amp drives actively. The rest of the diaphragm just tries to follow along without flex or delay whilst being slowed down by a mechanically resistive two-part suspension. A ribbon has no suspension or separate voice coil whence the input signal is distributed/applied to the diaphragm. Our amplifier sees and drives every fraction of the foil simultaneously and directly. No wonder that a ribbon's go'n'stop is so instantaneous compared to slower heavier only partially driven driver types. Our amp has full control over the transducer's entirety. It explains how a ribbon can track the signal so precisely. Meanwhile the ±4mm Xmax of the corrugated Raal 1995 foils is shocking for headphone drivers. Shouldn't it predict quite caffeinated dynamics?
Expecting anything less seems ill-advised in fact. 115/118dB SPL capability for Magna/Immanis rather signs on that dotted line. These figures in particular sit in stark contrast to popular perception of ribbons being very dainty fragile little things fit only for tweeter duty when crossed out high at 3kHz and steep on a 4th-order filter to seriously restrict their operating bandwidth. Proximity loading and hard-earned design/manufacturing chops would seem to make all the difference in our Serbian ribbon headphones aimed at both consumers and studio pros, the latter not exactly known as snowflakes of the whisper realm. On Alex-curated amps, "for Magna & Immanis, the current direct-drive SAEQ HSA-1c actually isn't my favourite. The VM-1a was great but is no more. SAEQ owner Dragan Domanovic is visiting today with a new high-end amp. I'll report back on that. The new Auris amp unveiled at CanJam NYC has the right power for our interface unlike the Woo/Felix 2A3/300B versions whose 100-120Ω transformer taps into our 32Ω interface distort at low volumes. Give me a few days to come up with more. Personally I'd aim for a nice valve amp with our interface over direct-drive solid state. Your Vinnie Rossi 300B preamp direct-coupled into the Mosfet 'follower' is phenomenal topology of course. Agreed also on the Trafomatic Primavera."
A square or rectangle inside a circle leaves obvious gaps. Here we see the large 'leakage zones' Alex mentioned earlier on each side of the central ribbon cluster. One gets closed, the other remains open.
February 6th: "I still don’t have parts for the stand/attachment but made you a photo of assorted bits like cup rings, ribbons, grills and driver bodies with magnets. My photo arranging skills aren't great but you can see our work in progress."