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Integrated amplifier

Price: 17 900 zł

Manufacturer: QUAD/International Audio Group, Ltd.

Unit 4, St Margaret’s Way, Stukely Meadows Ind. Est.
Huntingdon, Cambs PE29 6EB
01480 447700
United Kingdom


Text: Wojciech Pacuła
Photos: Wojciech Pacuła
Translations: Marek Dyba

QUAD was founded in 1936 by Peter Walker, who died on Dec 10th 2003. QUAD is surely one of the audio companies that have been active for the longest period of time. QUAD is an abbreviation that translates to: “Quality Unit Amplifier Domestic" or "QUality Amplifier Domestic" – depending on whom you ask. A complete and beautifully illustrated history of this company was issued in 2002. It was titled Quad: The Closest Approach. Its author – an American, Ken Kessler, worked for many years for British audio magazine - „Hi-Fi News” (although he had a short episode with „Hi-Fi Choice” too, when it seemed that he couldn't get along with the new management of Hi-Fi News – I informed you about the whole story in one of my leaders; Ken Kessler, Quad: The Closest Approach, International Audio Group Ltd., Cambridge, England, UK 2003). You might find a short Peter Walker's bio written by John Atkinson HERE. His first product – preamplifier QA12 – entered the market in 1949, and two years later he offered first power amplifier. Best known Quad's products are electrostatic loudspeakers - ESL-57 from 1957 and even bigger sales hit – ESL-63 from 1982. In 1993 QUAD Electroacoustics was sold to an investing group associated with Farad Azim, ex-owner of another famous British brand - Mission. And finally company was bought (together with factory) by International Audio Group, Ltd., that was also an owner of companies like: Mission, Castle, Wharfedale and Audiolab. New owner moved QUAD to China together with production lines, machinery and know-how.

As I said first power amplifier called Quad entered the market in 1951 and offered output power of 12 W. QUAD II was introduced in 1953 and offered 15 W. Never ever during its long history has Quad offered any integrated tube amplifier, at least until now. QUAD II Classic Integrated was designed by Tim de Paravicini, an owner of EAR-Yoshino. It was not his first involvement in „vintage” project as couple of years earlier he had designed new version of QUAD II monoblocks. Integrated has power output higher by 10 W comparing to the original II power amp, because Tim increased anode voltage for power tubes (although after that it is still smaller than standard one – see below). At the same time to extend tubes life he decreased voltage to the screen grid. Front panel reminds me the one of QC-twentyfour preamplifier, but instead of push-buttons there is a rotary selector. QUAD has been known for using specific tube modes in their amps for a long time – it's been in fact one of the most important Walker's patents. In QUAD II KT66 tubes were not used in triode mode (the one preferred by his friend D.T.N. Williamson), nor in the ultra-linear mode as preferred by David Hafler and Herbert Keros. Peter Walker connected the grid to the same voltage as the anode which allowed tubes to work in a tetrode mode. At the same time he divided primary transformer's winding to supply separately anode and cathode. This allowed to: feed power tube with voltage of negative feedback (which decreased distortions) and allowed to feed KT66 with lower than standard anode voltage, hence forcing higher efficiency of the whole set up, and extending tubes lives. Paravicini followed same pattern when designing Integrated.


Recordings used for testing:

  • Anja Garbarek, Briefly Shaking, EMI, 8608022, Copy Control Disc; review HERE.
  • Depeche Mode, Sounds Of The Universe, Mute, STUMM300, 2 x 180 g LP; review HERE.
  • Diorama, Cubed Deluxe Edition, Acsession Records, A 114, 2 x CD; review HERE.
  • e.s.t., Leucocyte, ACT Music+Vision, ACT 9018-1, 2 x 180 g LP; review HERE.
  • Frank Sinatra, Nice’N’Easy, Capitol/Mobile Fidelity, UDCD 790, gold-CD; review HERE.
  • Jean Michel Jarre, Oxygene, Dreyfus Disques/Mobile Fidelity, UDCD 613, gold-CD.
  • June Christy, Something Cool, Capitol Records/EMI Music Japan, TOCJ-90033, HQCD.
  • King Crimson, In The Court Of The Crimson King, Universal Music K.K. (Japan), UICE-9051, HDCD.
  • Kings of Leon, Only By The Night, RCA/BMJ Japan, BVCP-40058, CD.
  • Laurie Anderson, Homeland, Nonesuch, 524055-2, CD+DVD; review HERE.
  • Led Zeppelin, Led Zeppelin, Atlantic/Warner Music, WPCR-11611, CD.
  • Madeleine Peyroux, Careless Love, Rounder/Mobile Fidelity, Special Limited Edition, 180 g LP; review HERE.
  • Mark Knopfler, The Trawlerman’s Song EP, Mercury Records, 9870986, CD.
  • Peter Gabriel, So, Virgin, SAPGCD5, SACD/CD.
  • Pink Floyd, Wish You Were Here, EMI, 529071, CD.
  • Savage, Tonight, Extravaganza Publishing Srl/Klub80, CD001, 25th Anniversary Limited Edition, CD; review HERE.
  • Yes, Fragile, Atlantic/Mobile Fidelity, UDCD 766, gold-CD.

All Japanese issues are available at CD Japan.

If you read Jason Kennedy’s review for „Hi-Fi +” (Issue 73; you can read it HERE) you will find out that he liked most Quad's smoothness and muscularity. And I agree with that. But we can find out something quite different when reading a review from British „What Hi-Fi? Sound and Vision” (review HERE), as they praised nice detail, resolution and no coloration. I'm not trying to undermine anybody's reliability but their findings are quite different. I had a chance to listen to this amp paired with all loudspeakers tested for this issue of „High Fidelity” (plus my own reference speakers) and with high-efficiency Zingali Twenty 2.08. The sound was bit different with each pair of loudspeakers which proves that not all of them matched well via 8 Ω binding posts (and that's the only choice here). The biggest difference I heard with Everything But The Box speakers, when the sound was very distinct, precise without strong bass. Variable phase alignment with passive EQ on the high frequencies allowed me to use „-3 dB” setting. Then everything was back to normal. Obviously different impedance course forced amplifier to work in a different way. That proved that one couldn't define „the only right sound” or „the only right combination”. My guess – it's what happened to „What Hi-Fi? Sound and Vision”.

Considering what I heard with different loudspeakers and cables I would describe Quad's sound as warm. Simply warm, beyond any doubts. It offered warm, lush sound which was much as good old Quad's school. But not 100% „old school” - I think Leben CS-660P sounded more like old Quads. As already mentioned so defined timbre is strictly connected with presentation's panache. These two elements „fix” all auditions. This presentation's panache is a very important factor as this is what differentiates this amplifier from almost every solid state one. All such amps sound lean an dry when compared directly to Quad even if, to the moment, you were sure that particular device offered smooth presentation with good tonal balance. To get a prove I compared it with ISEM Xtasis, which for sure was a smooth, well balanced amp. All that is a result of some Paravicini's trick, but it worked really well.

I started with some old rock recordings, namely with Fragile by Yes – this particular version was remastered by Mobile Fidelity, which means job was done with ... equipment prepared and modified by Paravicini. You could say that this was some kind of my wishful thinking, that I needed to see some mystical connection between all the elements that leaded to the sound I heard. You might laugh but I have experienced many times some kind of coherency between products manufactured by the same company. Small adjustments brought by individual elements accumulated and delivered some much greater final effect than it could have been expected. It is explainable. That's what I intended to get when played Fragile. After couple of tracks I realized that synergy, if any, didn't have same meaning as the sonic character of the amplifier. Or maybe it did? I wasn't really sure. What was really important was fantastic, big, rich, warm classical guitar at the opening of this album. The rest of the band that entered bit later sounded more quietly so it wasn't the same, but there was no impression of sound getting lean which happened quite often when I'd played same piece with solid-state amps from similar price level. Maybe with one exception - Emitter I by ASR (Emitter II was reviewed HERE). Yes, this might be the best lead showing unique qualities of both ASR and QUAD.

As soon as I defined the „personality” of tested amplifier I decided to push it to the limits to find out what it couldn't do. It was important to set a base line, to be sure that I wouldn't miss something out during next auditions. Recordings with electronic music like Cubed by Diorama, Tonight by Savage, or Jarre's Oxygen sounded very nice, with good tonal balance but without proper drive. Although amp presented large phantom images, huge soundstage but the pace&rhythm were not one of its virtues.

There were moments when I got surprised with the big drum sound, or kick-drum like in Only By The Night by Kings of Leon. But this wasn't the effect of something I called „progressive” dynamics. Dynamics I mean by that is the one that expresses particular event in the music but also rushes the whole piece forward, speeds us piece's „pulse”. Hereby described dynamics was limited to shorter period of time and to smaller structures. When the recording was dense with many instruments playing at the same time Quad was unable to deliver it all in an orderly way. Same thing happened to bass presentation.. Using this amp with loudspeakers with medium sensitivity of 87 dB and reasonable impedance run (although rather around 4 Ω not 8 Ω) will not deliver to you as good control or selectivity as many other competitors, both tube and solid-state. All you have to do is to play Sleep from Briefly Shaking, with powerful low bass and you should know I am right. Also Laurie Anderson's Transitory Life from Homeland sounded rather soft and round in a bass range.

Having said that we may come back to the elements Classic Integrated does very well, that make it a strong competitor at its price tag. I don't believe that some devices are prepared to play well some particular kind of music. If it happens it must be some kind of designer's mistake, or device's character. It doesn't happen among devices at higher price levels. But theory doesn't always go along with practice. I am not an idealist, I like to think about myself as a pragmatic man (although my way always calls me an optimist…), so except for preparing a description of a device in absolute terms I always also try to find some place for it on the market, to understand what was the idea behind the product, for whom it was designed.

That is why knowing this amp's pros and cons I tried to find its niche on the market – it was already obvious that it was not an universal product. To put it in some simple words – all not so high-quality recordings, those with limited number of instruments in them, vocal recordings in general – all these, after being „processed” by Quad would sound absolutely stunning (unless you were addicted to high resolution as this wasn't a best quality of Quad). I was able to listen with a great pleasure, for the first time in a long, long time, to Peter Gabriel's So - European version from 2003. As I mentioned in Terra II Pro EBTB review, this was quit bright and dry version. Classic revealed its not very flat frequency response right away. But at the same time this amp played strong, full bass, and added some weight to midrange that I was really missing before. And vocals? Beautiful! June Christy in Something Cool, Mark Knopfler in The Trawlerman’s Song EP, Frank Sinatra in Nice’N’Easy – let me stop here – their voices were shown with huge volume, were placed in the center of the stage, in front of the listener, but without sharp edges around them. Adding volume to the midrange, so helpful with Gabriel's album, didn't really ruin anything here, even though it should have had. Presence of this effect was shown as bringing closer to the listener elements placed behind vocalist (June Christy, Frank Sinatra), in magnifying them. Also guitars (Mark Knopfler, Yes, Kings of Leon) sounded fantastically deeply. The proportions comparing with the rest of the instruments weren't perfect but who cared? I would personally wish that guitars always sounded this way. With only one exception (Emitter I) I have never heard strings so nicely joined with the rest of instruments in Sinatra's song. I knew it wasn't most accurate presentation as strings were recorded somehow „separately”. But if I was to use this amp not for reviews but for pleasure I simply wouldn't care about it. It might happen, in a warm sounding system, that Quad will always sound in similar, predictable way. Simply nice. It means there will be no great differentiating nor resolution. That's what you might get with Quad. But if you are OK with that and you can also live without fast, precise bass, than QUAD Classic Integrated with its fabulous look, history and tradition, man with the name and face behind it, and with so „friendly” sound might become your ultimate choice.

And the integrated phonostage? Well, it's not bad, not bad at all, but if you have a turntable costing as much as this amp than you should probably think about some higher-quality phonostage, with better resolution. But if you have some Pro-Ject up to 5000 PLN, or Rega etc, than you can easily rely on the phono integrated into tested Quad.


This new amplifier from Quad is simply beautiful! Classic, compact - beautiful! Classic Integrated Amplifier is a stereo integrated amplifier with solid-state power supply. Its power output rated at 2 x 25 W at 8 Ω might not sound impressive but from my experience for a middle-size room with some reasonable loudspeakers it should be more than enough to achieve satisfactory volume levels without any audible clipping.

It is a very classic push-pull design in class A with „kinkless tetroded” KT66 as power tubes. Just to remind you – it is also a favorite tube of Mr Hyodo of Leben Hi-Fi Company, that he used for example in CS-660P. Tubes used in tested amp were branded with Quad's logo but on the metal base I found also Tung-Sol brand name (a company from Russia). Double triodes 12AX7 came from the same manufacturer. They serve as phase inverters and they also drive power tubes. Between them there is a gain stage with 6922EH from Electro-Harmonix. Placement of tubes on the top panel is quite specific but also well-thought-out. Looking from the front side of the device we notice first quite big casing in the center that houses power transformer. At both its sides there are power tubes in rows. All low-output tubes are placed in the back, near the output. Behind there are also casings housing output transformers. All these elements are hidden under special black cage cover. That is one of the very few cages that make covered device look better! You can take it off after unscrewing some bolts with (also delivered) Phillips screwdriver. Which reminds me a similar solution in TRI TRV-300B amplifier.

All the edges are curved like in all Quad's devices made fifty years ago. Color – golden metallic – looks fantastic and is also characteristic for Quad's products. Also volume control knob and input selector are Quad's classics. On the front panel you will also find a tape loop button and on/off (mechanical) switch. On the back panel there are five line inputs plus one marked „phonostage” (there is a small switch that allows user to chose between MM and MC input). Next to it there is a grounding post. At the left side there are two pairs of speaker binding posts – these are for 8 Ω loading. All the posts are OK, but the general high quality build and finish would rather ask for something more. Speakers posts are placed too close to each other so I would strongly recommend using banana plugs. The device is supported by four rubber feet. As I said Integrated is very classic. But in my opinion some details are … too classic – there is no remote control, no balance adjustment, no mono switch (useful if you want ti listen to some mono LP recordings).

The electrical design is not over-complicated (tube devices are usually quite simple) And it is their simplicity that makes them play mostly better than solid-state competitors. Separate stages are placed on separate PCBs. In the input stage there is a PCB with RCA jacks soldered directly to it. Signal I switched in hermetic relays that are driven by a high quality selector placed in the front panel. Signal goes from here with a long, shielded cable to classic „Blue Velvet” Alps pot and than to the back of the device to the preamp stage. That in fact means that placing input tubes at the back of the device doesn't really bring any real benefits. It could bring some if the pot was fixed to PCB next to the input. It seems to be possible to do – pot's axis should be much longer (like in many devices) and this would do it. Attenuation of power grid hum is carried out by four huge capacitors with 220 μF each (and another one in preamplifier section) and eight smaller in preamp. Voltage for both channels is delivered separately. There are very nice passive elements like e.g. Wima capacitors. There is a solid-state phonostage bolted to the back panel and enclosed in a shield. There are a lot of cables and connections inside. Obviously there is a possibility to configure this amp for 4 Ω speakers as the transformer has appropriate tapping. It must be configured though by manufacturer or distributor.

There is no remote control!

Technical data (according to the manufacturer):
Tubes: 4 x KT66; 4 x ECC88; 2 x ECC83
Inputs: 3 x Line, 1 x MM/MC (selectable), 1 x Tape Monitor
Phono input sensitivity: MM – 2 mV RMS, MC – 200 µV RMS
Stereo power output: 2 x 25 W/8 Ω
THD: 0,06%/15 W/9700 Hz
S/N: < -95 dBr (ref 25 W/8 Ω)
Frequency responce: 20 Hz-20 kHz at +0 dB/-0,5 dB
Crosstalk: <75 dB
Gain: 34 dB
Dimensions (HxWxD): 200 x 310 x 380 mm
Weight: 19 kg

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