Brand reborn

Like many, I thought Pink Triangle was long gone. This company, after all, wallows in the glory of being a part of the 'cottage industry', a brand unlikely ever to reach an annual turnover of nine figures, employees in the thousands and its own hall at the Internationalen Funkausstellung. Indeed, with hand on heart, I'm genuinely amazed that Pink Triangle is celebrating its 21st anniversary, even more than I'm staggered by Croft Acoustics' longevity. But most amazing of all is the Integral, which would have fooled me, too, if I hadn't opened the box myself. It certainly owes nothing to that great-sounding and innovative turntable on which the company was founded.

Pink Triangle's first integrated amp, the Integral is an extremely low feedback design utilising an unusual cascode topology output stage [see boxout]. Fully dual-mono, it's rated at 100W per channel into 8ohm, 200W per channel into 4ohm and 300W per channel into 2ohm, and proved more than capable of driving the Apogee Scintillas and Wilson Audio WATT/Puppy System 6.

All down the line

A line-level design – there are rumours of a matching phono stage for release in the future – the Integral provides an XLR balanced input marked CD, plus three line-level inputs via beautifully gilded phono sockets and facilities for two tape decks with record inputs for both. The Integral also encourages integration into a multichannel AV system or bi-amping, and a rear panel switch sets up the Integral to be driven directly from source components with variable outputs, such as Pink's upcoming Da Capo II CD player. All of the inputs are wired with pure silver wire, while the outputs are connected with silver-plated copper. Also on the back are WBT's wonderful EC-approved multi-way binding posts, with slots for spade connectors.

View of the Integral's 'humped' top panel, with recessed branding and central chrome section

But you won't want to look at this unit's tush. This amplifier is one of the best-looking components I've ever seen, and I wouldn't have registered one iota of surprise if I'd been told it came from Gryphon, Burmester, Bow or Primare. Finished in a fabulous charcoal grey anodising, its accents are chromed, including the huge, centrally positioned volume control mounted in a chrome sub-section. This is flanked by two rows of push buttons, each marked with an icon, for on/off, mute and the source selections. Each is accompanied by a blue light (why not pink?), and the volume control's illumination turns red when the Integral is set to standby.

Slim 'n' sonic

It's important to position this gem in the context of HFN's Great High End Integrated Amp Survey, which started with the Musical Fidelity A3, the Krell 300iL and the Gryphon Callisto, and of which there are at least five more to follow throughout 2002. Like these predecessors, the Integral is fully remote controllable (the handset even has provision for the forthcoming CD player), plus it's designed to match whatever separates you might consider at the same price point, especially by virtue of its exceptional power.

But Pink's model has a little ace up its sleeve: it's actually svelte. Measuring only 450x112x310mm (whd) not counting the sockets, it is delightfully, deliciously, deliberately compact. And despite the slight hump which runs across the lid, it will be stackable with the CD player – combined, the two will still be smaller than many integrated rivals.

The amp's front panel features source, mute and power buttons, plus a large, illuminated volume rotary

As far as this beauty is concerned, I have but one non-sonic complaint: the rows of viciously sharp heatsinks along the sides of the chassis. When will manufacturers learn to round off their corners? That aside, the Integral deserves some kind of award for its looks alone.

Rise to the occasion

Given its vast reserves of power and its choice of balanced and single-ended inputs, the Integral slotted nicely into the systems I was using, accepting the balanced outputs of Audio Research CD3 and Marantz CD12 CD players, via Transparent Ultra cabling. I fed a Musical Fidelity 3D into the single-ended inputs, and used the Integral to drive the aforementioned Wilson, Wharfedale and Apogee speakers, plus a burst of Quads and LS3/5As. I don't know what the retailers will point you towards but, so far, I couldn't find a single speaker which gave this amplifier a hard time. In that respect, it also matches the super-integrateds we've previously featured in this series.

Internal and external heatsinks are used for thermal management – although reviewer Ken Kessler found the latter to be 'viciously sharp'

Where the Integral parts from its predecessors, besides its diminutive dimensions, is in sonic presentation. Every one of the others, however capable they were of displaying the most refined, genteel manners this side of a Leak TL12, never let you forget that they were real powerhouses. I suppose that the best analogy would be likening them to Ferraris or Lamborghinis in the city, which never leave second gear. The Integral takes the opposite tack. At normal listening levels – in my case, 88dB at 2m – you'd swear you were using a sweet 50W or 60W classic, like a small Audio Research amp, or a 25-watter from the Golden Age. It's all about comportment, and Pink Triangle's amp suggests breeding totally not in keeping with the company's radical, guerrilla origins and turntables designed to make a statement.

Lid off shot shows the Integral's use of separate PSU transformers and multiple, low-ESR capacitor banks for each channel

Then, when it's time to either rock hard or go all orchestral, the Integral simply rises to the occasion, like a gentleman amateur sportsman of the 1930s metamorphosing into a Battle of Britain ace without so much as a twinge of his handlebar.

RCA inputs marked AV/CD, Pre-Amp and Tuner are joined by one set of balanced XLR ins, twin tape loop connections, a 'direct' line-in and WBT multi-way speaker terminals

Heady stuff

As I tend not to lean toward headbanging, it took me some days to discover the Integral's split personality (this was also partly due to the long burn-in period the manufacturer asked I undertake). All of a sudden, I have before me an amp with the dimensions associated with budget integrateds, yet it's providing all of the grunt necessary to deliver Kodo drummers, the Glory soundtrack, some Sousa and live Motörhead at teeth-rattling levels – with no clipping apparent.

Pink Triangle Integral Talking Technology

Owen Jones, the Integral amplifier's engineer, isn't especially forthcoming about his designs – Pink Triangle didn't even supply an owner's manual with our review sample. He did, however, prepare the following design notes, which is as close to a description of the Integral amplifier's workings as we are going to get...

'As with all Pink Triangle products, our key design objectives were neutrality and transparency. We were also keen to give the Integral the ability to drive just about anything bar an HGV. A decision was made at an early stage to put build quality of the new range firmly in the "battleship class". With the extensive use of tool plate alloys and custom extrusions we feel we've succeeded, the amplifier weighing in at a backbreaking 20kg.

'The cascode output stage of the Integral offers a number of benefits. The power handling and transfer function-determining parameters of the output stage are split, allowing the power transistors to be better optimised for their particular role. The transfer function is primarily determined by the emitter-follower section of the output stage. This operates at lower voltage and power, so a faster, higher-gain, more linear transistor can be employed, improving output stage non-linearity as well as reducing non-linear loading on the driver stage. The main power handling occurs in the common base section and this transistor can be chosen for its ruggedness, in the knowledge that its transfer characteristics have only a secondary effect upon the output stage.

'Conventional emitter-follower output stages normally employ emitter resistors to ensure thermal stability by providing local feedback to the individual transistors. This worsens crossover distortion by sharpening the turn-on knee of the transistors. In the cascode configuration, the emitter follower temperature cycling is lower than normal due to its reduced operating voltage and its thermal stability is therefore greater. This characteristic has been taken advantage of in the Integral to allow these resistors to be reduced in value, broadening the crossover region and linearising the output stage, thereby reducing the severity of any higher order distortion products.'

Review: Ken Kessler

Source: www.hifinews.com