Adcom GFP 555 II Preamp and GFA 545 II Power Amp Reviewed

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Adcom GFP 555 II Preamp and GFA 545 II Power Amp Reviewed

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Marvelling at the lack of speed which afflicts this industry, I'm pleased to note that -- at last -- Adcom has made it to the UK. No, I'm not wearing my Stars'n'Stripes necktie, but I do admit to above-average curiosity. After all, this brand is a market leader in the States, kicking serious tush in the sector best described as 'entry level high end'. Knowing about it mainly from the a heavy ad campaign and a run of rave reviews, I find that Adcom ought to have special appeal for the British audiophile: it's imported yet not expensive.

Sadly, though, for Adcom, it suffers not so much from the inevitable if slight price hikes as it wings its way across the Atlantic but from something unique to all imports into the UK. Even with sympathetic pricing, the Adcom -- while not entirely losing its bargain appeal -- has to compete with the toughest of our home-grown defenders in an area where the British excel: mid-priced separates from the likes of Exposure, Mission, Musical Fidelity, Audiolab, Arcam and every other audiophilic manufacturer which aims its wares at the hobbyist. And the British have had this market almost completely to themselves because the only other sources for cost-effective separates (Japan and the USA) have failed on either of two counts: lousy pricing or lousy sound. Aside from the presence of Hafler and PS Audio, the Yanks are barely represented in the UK at the sub-£1000 pre/power combination price point.

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Adcom's GFP 555 II pre-amp and GFA 545 II power amp cost £499 each, for a combined price just £2 below the four-figure mark. And that tariff will pay for all manner of worthwhile British-made alternatives. But, immediately, you notice something about the Adcom combo which cannot be matched by British brands: it looks like high-end hardware. Most of the British, for whatever reason, continue to make gear which looks like -- let's just say that it's iconoclastic, which is noble if somewhat stupid. It limits the appeal mainly to British consumers who stubbornly encourage non-standard panel widths, unique colours and everything else which makes hi-fi mix'n'match an aesthetic nightmare. Adcom gives entry level buyers the look of pukka top-end gear, however boring the idea of a jet-black, 430mm fascia may seem.

The GFP 555 II pre-amp commits its first sin by including such anti-purist facilties as tone controls, a headphone socket, subsonic filter and tone contour, but it hastily makes amends by providing both a tone defeat and a second set of main outputs which bypass the tone and filter controls as well as the protection of the coupling capacitors. The sonic gains are obvious, so I did all of my listening with the amp connected to the bypass sockets. The pre-amplifier sounds dark, soft and thin when you feed a signal through all of the non-essential circutry.

The front panel is, indeed, loaded. At the extreme left is an on/off rocker and a power-on LED, the headphone socket (the 'phones run off a separate internal amplifier), balance, bass and treble rotary controls, tone defeat, contour (loudness), low filter, mono and external processor buttons, two rotary source selectors for play and record and volume control. At the back, the Adcom features gold sockets for phono (47k ohm/100pf), three line sources, two tape decks in both directions, the external processor and normal and bypassed outputs. Also on the back are an earthing post and a mains fuse.

The GFP 555 II uses a low-impedance power supply with enlarged traces on the double-layer PCB for minimal loss and improved stability. The power transformer is mu-metal shielded, so the sound is hum- and buzz-free. All capacitors are metallized electrolytics while the resistors are 1% Roederstein metal film types; so much for low prices precluding the use of designer components. The signal path amplifier uses premium grade ICs chosen for low noise, low distortion and low DC offset. All stages operate in Class-A and the entire signal path is direct-coupled when the pre-amp is operated in the bypass mode. The phono amp has been optimized for m-m and high-output m-cs; I tested it using Deccas, high-output Audio-Technicas and a Koetsu and found it adequate if not thrilling. This pre-amp is definitely a product of the line-level-sources era.

Operationally, the Adcom made me think 'Japanese', and that's meant as a compliment. No drama, everything worked as it should -- I'd forgotten what it was like to just flick a switch without shielding my eyes from debris or my ears from bangs and pops. Am I getting older or something?

Ditto for the power amplifier. After a few recent disasters, scale models of the bombing of Dresden, I've approached amplifier switch-on with dread. The Adcom? Not so much as a 'click', other than the mechanical sound of the rocker switch engaging. Again, this is hi-fi-as-appliance: A black box, ennui relief in the form of a grooved section on the upper half of the fascia, an on/off switch and LED indicator, a brace of multi-way binding posts and gold-plated inputs. Oh, and a mains fuse. The only other distinguishing characteristics are three warning lights, two for 'instantaneous distortion alert' to warn you of excessive THD, IM, slew-induced distortion or clipping, and a light to indicate the awakening of the thermal protection circuit. Even beating the crap out of this amp with some tough loads, I couldn't get the lights to flicker once. Which surprised me, because this amplifier -- though rated at 100W/channel into 8 ohms -- doesn't come across like a real piledriver. Even the literature mentions its suitability for non-headbanging conditions

Adcom's middle-of-the-range amp uses a Triple Darlington output stage, a large potted toroidal transformer and large, high-grade power supply filter capacitors to provide stability with awkward loads. While it didn't exactly make the Sonus Faber Extremas sing, neither did it pop its corks. There are no electrolytic caps in the low-frequency signal path or feedback loop path, with the only caps used in the circuit being precision non-polarized types. A servo circuit minimizes DC-offset at the outputs. Large heat sinks and adequate ventilation kept this cool at all times, even when the unit was attached to Apogee Stages. The output section contains 12 discrete transistors, and I'm assuming Class AB operation.

Time and again you're reminded that this is a middle-weight, mid-priced, mid-everything set-up. Despite lip service to the audiophile sector, the Adcom devices are too user-friendly, too tweak-free to frighten off non-hobbyists. If you look at the globe with the Japanese at one extreme and the British at the other, this American offering rests firmly in the middle. And not just in terms of ergonomics or perceived value but sonically as well.



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HTR Product Rating for Adcom GFP 555 II Preamp and GFA 545 II Power Amp

Criteria Rating

Performance

3.5

Value

5

Overall

4.5

Disagree with our product rating? Email us and tell us why you think this product should receive a higher rating.


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