For Sale Quad Classic Integrated Integrated Amplifier (Valve)

Further Information

Purchased October 2024 as a floor stock Demo unit.

Lovely sounding KT66 Integrated Tube Amp.

Huge savings from new price.

25 watts of Class A goodness.

If partnered correctly this amp has great soundstage depth, width, instrument separation with plenty of meat on the bones.

I upgraded the KT66's with Genalex Gold Lions which have about 200 hours on them.

Will be suppied with original tubes as well.

The output section is configured as autobias so no mucking around biasing tubes.

From Stereophile review:

The new integrated is, essentially, a pair of Quad II amplifiers (ca 1953) powered with silicon rather than glass rectification and bundled with a perfectionist-quality control unit and a solid-state phono section. According to de Paravicini, the output section runs in pure class-A and is modeled after Walker's Acoustical circuit, in which a portion of the output transformer's primary winding is coupled to the cathodes of the KT66 output pentode tubes (as opposed to their screen grids, as in Ultralinear output circuits). Those transformers, of course, are designed by de Paravicini, and made in England to his very exacting specifications. The amp's output section is configured as autobias, and a bit of global feedback is used—although a less-than-typical amount is required, given that the Acoustical circuit itself provides local feedback, with apparently little loss of gain and power.

The small-signal tubes in the Quad II Classic—four 12AX7 dual-triodes and two 6922 dual-triodes—function as the phase splitter/driver stage for the voltage-hungry output section; the Quad's line stage is passive. The phono section is described as "a simple and elegant.

The casework and controls of the Quad II Classic are clearly influenced by the classic Quad 22 control preamplifier (ca 1959): The faceplate is shaped is the same manner, with a similarly big, beautiful volume control. The new Quad's source selector is a four-stop slider in a crescent-shaped slot with an old-style needle indicator above. From the outside, it gives that end of the Quad's faceplate a somewhat enigmatic smile. 

Listening
The first things that struck me about the Quad's sound were its up-front presentation—this wasn't at all a laid-back performance—and its readily apparent sense of drive with up-tempo music. The musical timing of all recordings was well preserved, although the Quad II Classic sounded especially fleet of foot with quick, snappy acoustic music such as David Grisman's "E.M.D.," from the first, eponymous album by the David Grisman Quintet (LP, Kaleidoscope F-5).

With line and phono sources alike, the Quad's midrange was lush and warm, with decent contrast between timbrally light and dark sounds in the mix, albeit less natural texture than I expected. In my system, driving the Audio Note cone-and-dome speakers, the Quad's most notable shortcoming was a lack of extension at the frequency extremes—especially the bottom end. Through the Quad II Classic, the dB's' "Happenstance," from their Repercussion (LP, Albion ALLP 400032J), sounded overly midrangey: the inverse of the rightly maligned hi-fi "scoop." There was fine punch and presence in the electric guitars, and the drumming sounded acceptably forceful, but the electric bass lacked that last bit of extension and power, and the Quad's slight lack of top-end sparkle conspired to make the voices sound a bit dull and lacking in presence.

Chamber music and very well-recorded symphonic fare were better served by the Quad's timbral balance. Of the former, the II Classic did a splendid job with the richly recorded sonorities of the Affetti Musicali's recording of Biber's Mysteriensonaten (CD, Winter & Winter 910 029-2). It missed a lot of the natural texture in that recording, but the Quad did allow the music to unfold with near-hypnotic intensity. As to the latter, recordist René Laflamme's masterful recording of Hindemith's Escale Romantique, performed by Daniel Myssyk and the Ensemble Instrumental (ripped from the Fidelio sampler Escales, no catalog number, www.fidelioaudio.com), was clear and spacious through the Quad amp, yet engagingly rich and warm.

Note the Quad ii Classics do not come with a remote control. I used the Line Out from my T+A Dac 200 into the Quad which enabled me to use the T+A Dac 200's remote control for volume. There was minimal sound difference this way, perhaps due to the Quads full power draw always being on due to the Class A design.

Receipt provided for Quad & tubes.

Thanks for looking.