search
And the metalwork is superb. Ken Kessler's luxuriant book Quad: The Closest Approach (footnote 2) mentions the "tropicalisation" of the original chassis—a delightful concept—and the new amp seems equally ready to withstand any climate. My first reaction on unboxing the Quads was to wonder, Where did they get that paint? It's exactly right. The 2005 Quad II has the same thick, wetly metallic shade of gray—with just the faintest touch of olive drab mixed in—as its predecessors, and I think that Quad made the right decision in not trying to ape the way older samples have darkened over the…
Sidebar 1: Specifications
Description: Tube monoblock power amplifier. Tube complement: two EF86, two KT66, one GZ34. Output power: 15W (11.8dBW into 8 ohms). Frequency response: 10Hz–20kHz, ±0.2dB. Input sensitivity: 570mV for rated power. Rated load impedance: 8 ohms. Damping factor: 11.75 at 700Hz, equivalent to a source impedance of 0.68 ohms into 8 ohms. THD: 0.08% at 12W/700Hz. Residual hum and noise: better than –90dB (no reference level quoted).
Dimensions: 12.25" (315mm) W by 6.5" (165mm) H by 4.75" (120mm) D. Weight: 18.25 lbs (8.3kg).
Serial numbers of units reviewed:…
Sidebar 2: Associated Equipment
Analog Sources: Linn LP12 turntable with Linn Lingo power supply, Linn Ekos tonearm, Linn Akiva & Miyabi 47 cartridges; Rega Planar 3 turntable, Lyra Helikon Mono cartridge.
Digital Source: Naim CD5x CD player.
Preamplification: Linn Linto phono preamplifier; Fi, Lamm LL2 Deluxe preamplifiers.
Power Amplifiers: Lamm ML2.1 monoblocks, EAR 890.
Loudspeakers: Quad ESL-989.
Cables: Interconnect: Audio Note AN-Vx, Nordost Valhalla, Linn. Speaker: Audio Note AN-SPx, Nordost Valhalla.
Accessories: Mana Reference Table, Reference Wall Shelf…
Sidebar 3: Measurements
It was difficult to resist nostalgia as I set one of the Quad II Classic monoblocks up on my test bench; the original Quad II, made by what was then called the Acoustical Manufacturing Company, was the amplifier to lust over when I first became aware of hi-fi in the early 1960s. But I am a trained professional—I can't let such feelings interfere with the task at hand.
The Quad II's voltage gain into 8 ohms was typical of modern designs, at 26.55dB. Its input impedance was not typical, however, at more than 1 megohm across the audioband. The amplifier…
A truly great preamplifier lets everything through, both music and distortion, but with such generosity that neither...is cramped and narrow.—Larry Archibald(footnote 1)
Finding a truly great, full-function preamplifier is a quest at which I have had only limited success. For a long time, I used an Audio Research SP-10 that I purchased back in the summer of 1984, but gave up on that fabulous device because, while its phono stage was (is) one of the greatest, it was too colored for CD use, and tube-replacement costs became unrealistic. The SP-10 gave way to a passive Mod Squad Line Drive…
Thick pcb traces carry the output signals to one pair of RCA jacks via an output muting relay controlled by a front-panel switch; the signal is also taken to the complementary FET buffers. Each pair of FETs is tied together face-to-face to give the best temperature and transfer-function tracking. Parts quality is high, with WIMA film capacitors and what appear to be expensive Holco resistors used in the FET buffer circuitry. Metal-film resistors are used in the balance, tape, and power-supply circuits.
The last, in fact, occupy the lion's share of the active pcb real estate. The…
Comparisons
First up to the plate was the TLC-1's obvious competitor: its passive ancestor, the Mod Squad Line Drive Deluxe—for quite a while my reference for preamplifier non-signature. To my surprise, the Line Drive was more colored than the TLC-1 in its passive mode, its midrange sounding somewhat "squawky" in comparison. It also sounded more veiled, with less top-octave air. Dynamics and bass performance were about the same, however. When I used the TLC-1's buffered outputs, the difference was larger. There was a slight loss in space and image palpability, but the sound otherwise…
First up to the plate was the TLC-1's obvious competitor: its passive ancestor, the Mod Squad Line Drive Deluxe—for quite a while my reference for preamplifier non-signature. To my surprise, the Line Drive was more colored than the TLC-1 in its passive mode, its midrange sounding somewhat "squawky" in comparison. It also sounded more veiled, with less top-octave air. Dynamics and bass performance were about the same, however. When I used the TLC-1's buffered outputs, the difference was larger. There was a slight loss in space and image palpability, but the sound otherwise…
Sidebar 1: Specifications
Description: Solid-state, unity-gain stereo preamplifier with five line inputs and two tape loops. Measured frequency response: ±10Hz-200kHz, -0.25dB. Measured input sensitivity: 1.02V RMS for 1V output. Measured S/N ratio (unweighted ref. 1V output at 1kHz): 108/112dB (L/R). Input impedance: approximately 13k ohms. Output impedance: buffered, 250 ohms; passive, varies with volume-control setting; tape, 100 ohms. Maximum output: 12.5V RMS. Absolute polarity: non-inverting.
Dimensions: 19" (483mm) W by 11.75" (299mm) D by 2.625" (67mm) H. Shipping weight: 11…
Sidebar 2: System
The main comparison preamplifier was the Melos SHA-1 headphone amplifier used as a line-stage (footnote 1), while the Mod Squad Line Drive Deluxe and the Classé Six reviewed by Larry Greenhill in February (footnote 2) also saw some action. Power amplifiers included the YBA 2 HC, Mark Levinson No.20.6es, and Audio Research Classic 120s. Loudspeakers used during the review period included the B&W Silver Signatures, Velodyne DF-661s, and Green Mountain Diamantes.
Front-end components were a Linn Sondek LP12 (Cirkus/Trampolin/Lingo)/Ekos/Arkiv setup sitting on…
Sidebar 3: Measurements
The TLC-1's measured gain was actually a little less than unity, at -0.15dB. Its input impedance was a moderate 12.25k ohms with the volume control set to its maximum position, while the source impedance from the buffered outputs was a whisker under 70 ohms. The buffered tape outputs featured a 101 ohm impedance, while from the passive main outputs, the source impedance varied from 26 ohms with the volume control set at its maximum position, to around 1700 ohms with it set to 12:00 (when the gain is approximately -16dB). DC offsets were unmeasurable, and the TLC-1…