The most important thing you can do with a thermionic valve is to hold it in your hand and study it with your eyes. More than you might think, what you see is what you get. High-energy electrons are boiled off the heater or cathode, pass through the wire control grid, and collide forcefully with that big black, gray, or silver thing—the anode, or "plate"—that occupies most of the space inside the bottle. What that anode structure looks like is probably what your midrange will sound like—ie, if the anode looks smooth and big and richly textured, those same…
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Sidebar 2: Specifications
Description: Tubed integrated amplifier. Tube complement: two 845, two 63P3, one 5AR4, two 12AX7. Line inputs: 3 (RCA). Input impedance: 100k ohms. Input sensitivity (integrated): 200mV. Output taps: 0, 4, 8, 16 ohms. Power output: 22Wpc into 8 ohms (13.4dBW). Frequency response: 10Hz–50kHz, –1.5dB. Harmonic distortion: 1% at 1kHz (A-weighted). Signal/noise ratio: 87dB (A-weighted). Power consumption: 320W.
Dimensions: 16.75" (430mm) W by 9.75" (250mm) H by 14.25" (365mm) D. Weight: 77 lbs (35kg).
Serial number of unit reviewed: 13040078.
Price: $…
Sidebar 3: Associated Equipment
Analog Sources: Technics SL-1200MK2, Thorens TD 124 turntables; Abis SA 1.2 tonearm; Ortofon 2M Black & CG 25 DI II, Shure SC35C, Soundsmith Carmen, Zu Audio DL-103 cartridges.
Digital Sources: Puresound A8000 CD player, Line Magnetic LM-502CA DAC.
Preamplification: April Sound GB-1, Blue Horizon Ideas Profono, Schiit Audio Mani phono stages; Simaudio Moon 350P preamplifier.
Power & Integrated Amplifiers: Hegel Music Systems H160, Simaudio Moon 330A.
Loudspeakers: DeVore Fidelity Orangutan O/93, Falcon Acoustics LS3/5a, KEF LS50,…
Sidebar 4: Measurements
I measured the Line Magnetic LM-518IA using my Audio Precision SYS2722 system (see www.ap.com, and the January 2008 "As We See It"). Before starting the testing, I followed the instructions in the manual and left the amplifier turned on for 15 minutes; then, without any signal, I adjusted the bias of each 845 output tube to the correct value. (Very little adjustment was necessary.) Next, I short-circuited the inputs and, with the volume control at its maximum, adjusted the hum-balancer potentiometers to give the lowest measured noise for each channel. I performed…
With 147 exhibitor rooms, 60 active CanJam exhibitor booths, 40 lobby exhibitor spaces, and 380 exhibitor companies from 23 countries, Denver's annual Rocky Mountain Audio Fest ranks as the second-largest consumer audio show in North America. The three-day show opens to the public on Friday, October 2 at noon in its familiar Denver Marriott Tech Center location.
RMAF certainly qualifies as the most friendly and community-oriented show in the US and, perhaps, the world. What other audio show has a Saturday "spouse outing" complete with van and driver; T-shirts for sale, whose proceeds…
Audiophiles who need something to do during RMAF should check out Soundings Fine Audio and Video. Situated just two blocks from the Marriott DTC at 8101 E. Belleview Ave X-1, Denver, CO 80236, the Denver retailer is having a party at 6pm Friday, October 2, and all showgoers are invited. They will be serving hors d'oeuvres, drinks, and adult beverages. Boulder Amplifiers has graciously given them the opportunity to have their new 2120 D/A converter in the store for the event.
Perhaps because I grew up in post-WWII England, with austerity and food rationing the norm, I learned at an early age the value of frugality. It was a financial stretch for me to buy, in the late 1960s, my first real audio system: Garrard SP25 turntable with Audio-Technica cartridge, Kenwood integrated amplifier, Wharfedale Super Linton speakers. Even when I could afford to upgrade the system, other than replacing the Garrard with a Thorens TD 150 and the Audio-Technica with a Shure, I went the DIY route. Back then, in the early '70s, I assumed that the advent of op-amp chips like the…
The DX's two USB output ports offer the choice of including the usual 5V DC supply or just the data connections. USB-connected DACs often derive their receiver's power from the bus, to isolate the analog circuitry from the digital, in which case the 5V port should be used. But if the USB receiver is powered by the supply of the DAC in which it is housed, the DX's data-only port should be used. The PS Audio DirectStream needed the bus power for the receiver, whereas Michael Lavorgna reports that the Auralic Vega does not (footnote 1). In light of my enthusiasm for AudioQuest's JitterBug, I…
Class-A amplifiers have a well-deserved reputation for being power guzzlers that run hot enough to burn fingers. They're inherently inefficient because their output devices conduct full current at all times, and much of that current is dissipated as heat—requiring, in the case of class-A solid-state amplifiers, massive heatsinks. This is why class-A amps tend to produce relatively low power, and tend to be heavy and expensive to buy and run. And these days, energy inefficiency is out of fashion.
These disadvantages are the results of class-A's advantages: When output devices are biased…
Also immediately obvious was less air on top than with the darTZeels, and a narrower soundstage that concentrated more of the orchestra between the speakers instead of spreading it out past their outer side panels. I'm not sure how this is possible with monoblocks; perhaps it had something to do with the Krells' somewhat less generous top-end extension.
The overall sound was definitely drier than the darTZeels, but this was still at the very beginning of my listening. I decided to stop analyzing and instead just listen for pleasure—the way I used to before this became a job—to find out…