Final weekend, I visited an outdated good friend who lives close to Walden Pond of Henry Thoreau fame. I hadn’t visited him since earlier than the pandemic. He had simply completed including a wing to his home that included a devoted hi-fi listening room the scale and form of a small church. Beneath a cathedral ceiling, the candy spot featured seating for no fewer than 30 company. Apart from serving as his predominant listening roomhe has one other one which’s smallerit serves as a big residential parlor with a child grand piano to be used in chamber music performances, which function prominently in his and his spouse’s social calendar.
It was a high-SPL thrill to expertise his towering, field-coiled RCA theater horns (above) powered by RCA 845 amplifiers. We listened to highlights from his assortment of grasp tapes performed again on his 30ips Studer deck and to black discs performed on certainly one of his Fairchild 750 document gamers. The snacks have been effective, and the individuals have been all smiles, full of excellent tales and kind-heartedness.
I doubt many audiophiles have skilled a private house sound system that moved this a lot air or pressurized a room this large. I stored pondering, “Man oh man, these huge bass horns make common woofers sound like emphysemic mice.”
My good friend’s high-ceilinged house was completely sized and formed for his big audio system. That is as a result of it was designed rigorously by an acoustician and constructed for no different function than to point out off his classic horns at their greatest. That room was neither too useless nor too reverberant. The voices of individuals in dialog have been unusually intelligible, even at a long way, even in a sea of sound with 110dB peaks.
On the best way again to NYC, my BFF runnin’ buddy, who was driving, laughed, saying, “Herb, do you assume objectivist audiophiles host listening events like this?” I snickered. “In the event that they do, they do not invite me.” Then, silently, my Herb-brain questioned what measurementphiles may discover in regards to the sound in the event that they have been there at the moment listening with us to horn audio system and tube amps made within the Thirties.
It was nearly midnight. As we drove house within the rain, I relaxed with my emotions of renewed kinship with a gaggle of buddies I hadn’t seen in years. I felt grateful for being included on this outlier cohort of DIYers, turntable geeks, R2R tape-heads, and big-horn aficionados.
For the document: As that Walden Pond system performed music, company (together with me and a gaggle of non-audiophile neighbors) applauded after each observe.
Thöress EHT MKII Built-in Amplifier
Midway by way of studying Robert Schryer’s 2023 Montreal Audio Fest reportthe one dated March 30 with the picture of these 1970 Rectilinear Highboy audio systemI slammed on my brain-brakes. Remembering Artwork Dudley’s April 2015 assessment of Reinhard Thöress’s implausible, vertically oriented 300B amplifier, I Googled “Thöress” and started studying in regards to the extra conventional-looking amp Rob was describing: the $10,995 EHT MKII hybrid tube-MOSFET built-in. Inside minutes, I had emailed firm founder and chief engineer Reinhard Thöress and importer Erik Fortier (of Phonographe America, footnote 1) asking if I may borrow a assessment pattern. I used to be cranked by how cool and strange this amp regarded within the photographs and by Robert’s description of its 20W-into-6-ohms, no-feedback topology.
The EHT built-in amplifier is made in Aachen, Germany. It comes with a palm-sized (2.5″ × 5″) plastic distant that claims THöRESS in large pink letters throughout the highest, and Quantity in smaller black letters on the backside. It has solely two buttons: one labeled Quieter (quieter) and the opposite labeled quantity up (louder). That is it. No mute or input-selector buttons. It is the classiest-looking, funnest-to-use distant management I’ve ever seen. It would not want a Mute (Mute) button as a result of the EHT’s motor-driven Alps potentiometer drops the quantity to silence in two seconds.
At evening, the Thöress EHT’s asymmetrically organized entrance panel showcased three backset, backlit, retro-looking plastic knobs and an influence buttonall haloed by tender, shadowy, lava-orange gentle. Protruding from the chassis prime are two of probably the most extremely revered voltage-amplifier tubes: octal-based 6J5 medium-mu triodes, every of which is basically half of a 6SN7 twin triode. These tubes’ uninteresting emitters glow the identical coloration orange because the front-panel management lights. The impact of this gentle is distinctly comforting.
Throughout daytime, that orange gentle glows solely faintly, but it surely properly accents the industrial-gray German-tech coolness of the EHT’s fantastically completed aluminum casework, with its anodized printing and shiny, powder-coated chassis lid. To my outdated German gear-head eyes, the EHT’s shapes, surfaces, and colours appear well-orchestrated to precise the corporate’s PR tagline:
THöRESS…A Tribute to Skilled Audio Elements from the Golden Age of the Digital Tube!
I feel the EHT is the coolest-looking built-in I’ve found, however after I requested my accomplice “bb” what she considered Thöress’s type, she declared it “Too masculine!” It is a good factor I by no means informed her about my Lanz Bulldog tractor fetish.
I typically joke that almost all audio gear appears like a mix of what it seems to be like and the place it was made. These two components are normally inseparable, so I confess to starting these auditions anticipating the made-in-Germany Thöress EHT to sound prefer it seems to be.
Design
In response to the Phonographe web site, the EHT MKII amplifier “is predicated on a singular minimalist single-ended zero-feedback vacuum tube MOSFET hybrid topology which we name EHT Topology (E/intakt-H/ybrid-T/riode, single-ended hybrid triode).” That appears like marketing-speak to me, however I imagine {that a} single, voltage-amplifier triode driving an easy-to-drive, unity-gain, current-sinking MOSFET output buffer, operated in single-ended mode with “excessive idle present and low output impedance,” is a sublime resolution to the issue of how you can drive a variety of audio system with a low-powered, no-feedback amplifier.
Reinhard Thöress has written a paper, accessible on his web site, that addresses the query of why single-ended topologies are superior to balanced circuits. The again panel of the EHT has 4 single-ended RCA inputs plus two pairs of high-quality speaker-wire binding posts. Concern of scratching the green-gray coat dissuaded me from eradicating the highest cowl, however in line with the web site, inside there is a C-core energy transformer, a legion of high-quality German-made capacitors, and point-to-point wiring. Enter impedance is specified at 100k ohms, output impedance at a mere 0.3 ohmsusefully low for a tubed amplifier. Voltage achieve, with the quantity management set to max, is 26dB. The EHT MKII measures 17″ (434mm) × 17.7″ (450mm) × 7.2″ (184mm) and weighs 39.6lb (18kg).
Listening
I’ve used one or one other BBC LS3/5a audio system because the late Seventies, so my ears are sensitized to how in another way totally different amplifiers allow these little sealed-box two-ways to challenge musical vitality into my roomso sensitized that I’ve come to imagine that this vitality projection (I additionally consider it as dynamic presence) is, together with rhythm-keeping, a key determinant of my system’s engagement issue. It appears to be the primary factor that makes recordings come alive in my room. With the EHT driving the Falcon LS3/5a’s, at first all I seen was smoothness, a deep spatial rendering, and a extremely refined instrumental tone. That was earlier than I performed string quartets by my most beloved fashionable composer: György Ligeti (György Ligeti Version, Vol.1Arditti String Quartet 16/44.1 FLAC, Sony Classical/Tidal). I listened repeatedly to Ligeti’s String Quartet No.1, Metamorphoses Nocturnes. Someday throughout my third pay attention, I spotted how a lot recorded vitality the Thöress amp was projecting throughout Quartet No.1’s prolonged silences. This wasn’t noise, or distortion (these issues are static and inert); this was stay, morphing, three-dimensional vitalityvitality that is on the recordingfloating tangibly between, round, and above my Falcon Gold Badges. What made this noteworthy was that I could not keep in mind experiencing vitality like this earlier than. I may hear and really feel this near-silence vitality coming by way of even throughout a scorching day with my home windows open and a fan turning at low velocity.
That silence-energy I seen is probably going a reverb-compression impact used on the recording, one thing the producers did to maintain listeners from pondering their stereo switched off or reaching for the quantity management. No matter it was, it was rather more noticeable with the Thöress built-in than it was with my selfmade “hybrid separates,” the tubed, Lab 12 Pre 1 preamp driving the Parasound Halo A 21+ amplifier.
Additionally attention-grabbing: The Hana Umami Blue shifting coil cartridge’s clean, refined supply was nearly an excessive amount of of a very good factor mixed with the EHT’s clean, refined sonics. Enjoying the 2009-remastered model of Astor Piazzolla’s 1986 recording Tango: Zero Hour (Nonesuch/American Clavé Recordings LP 075597915297), an album I can not cease learning and having fun with, I used to be a bit let down by its politeness and lack of Argentinian chunk. This recording must seize the listener by sounding edgy, tense, and intensewith bits of postmodern irony seeping by way of. As an alternative, it simply sounded extraordinarily good.
Footnote 1: Thöress. Internet: thoeress.com. US distributor: Distribution Phonograph Erik Fortier. Tel: (514) 622-8966. E-mail: phonograph.america@gmail.com. Internet: phonograph.ca
