The VAC Sigma 170i iQ uses two pairs of Gold Lion KT88 tubes for its output stages and eight small-signal tubes. The tubes are identified with a number, this between the pins of the small-signal tubes. The tube locations are clearly indicated in the manual and the top panel has each tube socket marked with the appropriate tube number. I carefully followed the numbering when installing the tubes before connecting the amplifier first to my Audio Precision SYS2722 (see the January 2008 "As We See It"), then to the magazine's higher-performance APx555 analyzer in…
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Time for some towers. In recent months, a succession of standmount speakers has passed through my listening room: GoldenEar BRXes, Bowers & Wilkins 705 Signatures, Marten Oscar Duos, original KEF LS50s, and the new LS50 Metas. All these loudspeakers sounded excellent, though different from one another. I felt that a floorstanding loudspeaker would make for an interesting change.
Italian company Sonus Faber is primarily known for its high-performance, relatively high-priced designs, like the $130,000/pair Aida that Michael Fremer reviewed in October 2018 or the $15,900/pair Guarneri…
The Lumina IIIs reproduced the 1/3-octave warble tones on Editor's Choice with good power down to the 80Hz band. While the 63Hz and 50Hz tones were quieter, the 40Hz and 32Hz tones had reasonable weight, the latter aided by the lowest-frequency mode in my room. The 25Hz and 20Hz warble tones were inaudible at my usual listening level. The half-step–spaced tonebursts on Editor's Choice spoke cleanly down to 100Hz but were lighter in weight in the bottom two octaves. When I listened to the speakers' back and side panels with a stethoscope while these tones played, I could hear some fairly…
Sidebar 1: Specifications
Description: Three-way, reflex-loaded, floorstanding loudspeaker. Drive-units: 1.14" (29mm) "DAD" (Damped Apex Dome) tweeter, 5" (150mm) pulp-cone midrange unit, two 5" (150mm) pulp-cone woofers. Crossover frequencies: 350Hz, 3.5kHz. Frequency range: 40Hz–24kHz. Nominal impedance: 4 ohms. Sensitivity: 89dB/2.83/m. Power handling: 50–250W.
Dimensions: 38.9" (989mm) H × 9" (228mm) W × 10.9" (278mm) D. Weight: 35.1lb (15.9kg) each.
Finish: Matte walnut or wengè baffle with maple inlays. Piano black is also available. Leather-wrapped top, sides, and back.…
Sidebar 2: Associated Equipment
Analog Source: Linn Sondek LP12 turntable with Lingo power supply, Linn Ekos tonearm, Linn Arkiv B cartridge, Channel D Seta L phono preamplifier.
Digital Sources: Grimm MU1 and Roon Nucleus+ file servers; Ayre Acoustics C-5xeMP universal player; PS Audio PerfectWave DirectStream D/A processor and MBL N31 CD player/DAC, Ayre Acoustics QA-9 A/D converter.
Preamplifiers: MBL N11, Pass Labs XP-32.
Power amplifiers: Parasound Halo JC 1+ monoblocks.
Loudspeakers: KEF LS50.
Cables: Digital: AudioQuest Vodka (Ethernet), AudioQuest Coffee (USB…
Sidebar 3: Measurements
I used DRA Labs' MLSSA system and a calibrated DPA 4006 microphone to measure the Sonus Faber Lumina III's frequency response in the farfield and an Earthworks QTC-40 mike to measure the nearfield and in-room responses. I measured the speaker's impedance with MLSSA, checking the results with Dayton Audio's DATS v2 system.
Sonus Faber specifies the Lumina III's sensitivity as a high 89dB/2.83V/m. My estimate was even higher, at 91dB(B)/2.83V/m. The Lumina III's impedance is specified as 4 ohms. The impedance magnitude (fig.1, solid trace) remains between 4…
I'm waiting for a bypass.
My heart did not attack me. My arteries aren't clogged. I'm awaiting an electrical bypass to save my audio system's life.
As I reported last month, my audio system started choking on the house juice immediately upon power up after an emergency power generator was installed in my house. The system isn't running on generator power, but the generator's installation required installing some other hardware in the AC signal path: a switch that automatically transfers the house's power system to the generator when the power goes out. It's that new hardware that…
The transfer switch messed up everything. So what happened? As Powell pointed out, when the generator was installed, some of the original wiring was removed and replaced. The "hot" leads" are switched by the transfer box, same as with most electrical panels, so the ground and neutral are always in contact with the new circuits and devices in the box. The previous, better arrangement for dissipating RF has been replaced by parts more susceptible to RF noise. Add to that the longer path required to accommodate the switch, including several junctions, and it's likely to have a higher AC…
Before returning home from the EISA convention in Antwerp two years ago, I spent a quiet, relaxing afternoon in The Loft, a luxurious shared space reserved for first- and business-class travelers, presented by Lexus and Brussels Airlines.
In addition to surprisingly good food and free-flowing alcoholic beverages, some airport lounges contain some really useful traveler amenities, like private showers and beds. The Brussels/Lexus space went above and beyond. I thought I'd had too much to drink (which I had) when I peered into the room and saw a Mark Levinson audio system featuring the No.…
I checked the vertical tracking force; it was on the money, at 2.3 grams. I checked the stylus rake angle, using a digital microscope. If whoever set SRA on the No.5105 did it the way most people do—by setting the arm parallel to the record surface, assuming that this will result in the proper stylus rake angle—well, it worked. Due to Ortofon's manufacturing excellence, the SRA was 93°; one degree beyond 92 compensates for stylus drag.
If you buy the No.5105 sans cartridge, you'll find the included cartridge setup instructions useful and nicely constructed, if basic. A single-point…