A fair question, and one of the few that attracts wisdom and selflessness as readily as their opposites. My own answers aren't set in concrete, but readers should know that the following survey falls into the latter…
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Like most people, I'm not interested in long, windy essays about audio reviewing, having barely enough time and interest for audio itself. But I do perk up when the debate turns to the audio reviewer's purpose in life: Should I write about everything that crosses my path, or should I limit my attention to those products that interest me, and that stand a chance of being good?
Horn Shoppe Horn: $775/pair
Like other SET-oriented companies, the Horn Shoppe began life when an audio do-it-yourselfer decided it was time for his passion to become his profession. In this instance, the solder jockey is Ed Schilling, the passion is designing rearwave horns for full-range drivers, and the product is the Horn. Ed and his dad now spend every workday making affordable horns and other loudspeakers for their mail-order clients, some of whom have even started a chat room dedicated to tweaking them (the speakers, that is—not Ed and his dad).
The Horn uses a Fostex full-…
Sidebar 1: Specifications
Horn Shoppe Horn: Single-driver horn-loaded floorstanding loudspeaker. Drive-unit: 3.5" paper cone. Impedance, sensitivity, frequency response: not specified (see text).
Dimensions: 30" H by 6.5" W by 11.5" D. Weight: 28 lbs.
Serial numbers of units reviewed: None.
Price: $775/pair. Approximate number of dealers: factory-direct only.
Manufacturer: The Horn Shoppe, 460 Laura Brodie Road, Leesville, SC 29070. Tel: (803) 657-7990. Web: www.thehornshoppe.com.
Sidebar 2: Associated Equipment
Analog sources: Linn LP12 turntable, Naim Armageddon power supply, Naim Aro tonearm; Rega Planar 3 turntable, Rega RB-300 tonearm; ZYX Airy S, Lyra Helikon Mono, Supex 900 Super, Dynavector DV10x5 cartridges; Tamura L2-D step-up transformer.
Digital source: Sony SCD-777ES SACD player.
Preamplifiers: Fi Preamp, Naim NAC32-5, Cary SLP98P.
Power amplifiers: Audio Note Kit One (300B), Fi 2A3 Stereo, Naim NAP110.Loudspeakers: Quad ESL-989, Lowther PM2A & PM6A in modified Medallion horns.
Cables: Interconnect: Nordost Valhalla & Valkyrja, Naim…
Sidebar 3: Measurements
Despite its minuscule drive-unit, the Horn Shoppe's Horn is very sensitive, at an estimated 94dB(B)/2.83V/m. Its impedance also stays above 8 ohms over the entire audioband (fig.1), meaning it is both sensitive and efficient. But the raggedness of the traces in this graph is a little alarming, as are the peaks at various frequencies, implying the presence of resonances.
Fig.1 Horn Shoppe Horn, electrical impedance (solid) and phase (dashed). (2 ohms/vertical div.)
Examining the cabinet's vibrational behavior with a simple accelerometer…
It was late May 2002 and I was about to leave the Free Republic of Bay Ridge, Brooklyn, for the high-class hallways of the New York Hilton and Home Entertainment 2002, so I could file daily reports for www.stereophile.com. As he was giving me last-minute instructions, webmaster Jon Iverson said, "I don't know whether or not you followed Hervé Delétraz's articles on building his amplifier, but he's going to have a sample at the Show. You should drop in and check it out. It sounds kind of interesting."
I had seen Delétraz's amp stories, but I'd only skimmed them, so I dropped by…
Never operate the Hi/Lo switches when the amplifier is turned on. And never, ever switch on the NHB-108 when it's not connected to a loudspeaker.
That's about it for "need to know" information.
Oh wait—there's the whole "eyes" thing. Remember when I said that I thought the glowing power indicators and power switch inadvertently resembled a face? Apparently, Delétraz thought so too. He's named the power switch the Power Nose and the LEDs the Eyes.
With the power switch off, the NHB-108 remains in standby mode. The Nose toggles it into and out of standby, and the Eyes glow…
Sidebar 1: Specifications
Description: Solid-state power amplifier. Inputs: unbalanced voltage-mode (RCA), unbalanced "Zeel" (BNC), balanced (XLR). Output power: 100W RMS into 8 ohms (20dBW), 160W RMS into 4 ohms (19dBW). Voltage gain: 26dB into 8 ohms. Input impedance: >100k ohms, 5Hz–200kHz (RCA); 50 ohms ("Zeel"). Output impedance: <0.33 ohm, 20Hz–20kHz. Frequency response: 10Hz–100kHz, +0/–0.5dB. THD: <1%, 7Hz–77kHz. Signal/Noise Ratio: >105dB(A) ref. rated power.
Dimensions: 17.25" (440mm) W by 6.75" (170mm) H by 13.25" (335mm) D. Weight: 65 lbs (30kg).
Serial…
Sidebar 2: Associated Equipment
Digital Sources: Krell DVD Standard DVD-V player, Musical Fidelity Nu-Vista 3D CD player, Polk XRt12 Reference XM satellite radio tuner with Musical Fidelity X-DACV3 D/A processor.
Preamplifiers: Blue Circle BC3 Galatea Mk.II, Conrad-Johnson ACT2, Krell KAV-280P, Mark Levinson No.320S.
Power amplifiers: Conrad-Johnson Premier 350, McCormack Audio DNA-500.
Loudspeakers: Aerial Model 20T, Canton Ergo 702DC, Krell Resolution 2, Sonus Faber Cremona.
Cables: Interconnect: Audience Au24 SE, Shunyata Research Aries. Speaker: Audience Au24, Shunyata…
Sidebar 2: Measurements
As mentioned by Wes Phillips, its generous output stage bias causes the NHB-108 to run hot. After the preconditioning period of running at one-third power into 8 ohms, its chassis and heatsink were very hot. (A thermal cutout shuts the amplifier down if the chassis temperature exceeds 70ºC.)
The amplifier is very fussy about how it is used. Turning it on without a load attached blows the 6.3A fast-blo fuses, as does unplugging an input jack. Several times during the testing I inadvertently blew fuses, and got quite proficient in replacing them, even though…