Conrad Johnson GAT Triode Preamplifier (Hi-Fi+)

Tubed preamplifiers
Conrad Johnson GAT
Conrad Johnson GAT Triode Preamplifier (Hi-Fi+)

The GAT drew the same reaction from every one of the grockles. The real people, muggles… non audiophile types:

“What the hell’s that?”

“It’s a preamplifier. It takes signals from the CD player and controls the big power amp.”

“It looks like something Captain Nemo might have used. How much is it?”

“Er, about £19,000.”

“[expletives deleted due to need to stay within the 1957 Obscene Publications Act, the 1697 Blasphemy Act, and the physical impossibility of getting a horse to do that to an archbishop]. Sounds bloody great, though!”

The dialogue, repeated more than once (although few were quite as creatively sweary), highlights much about the new conrad-johnson GAT preamplifier. It’s big. It’s visually distinctive. It’s expensive. And it sounds so good you don’t care. The GAT is the latest in a long line of limited-edition flagship preamplifiers from conrad-johnson, following in the traditions of ARTs and ACTs from the brand. There will be just 250 lucky GATters. The name is short for Great Anniversary Triode, but insiders (like Wes Philips) think it’s there as tribute to c-j’s well-loved customer service team-leader, Carwell Gatling.

Like the ACT before it, the GAT is a one-box valve line-only preamp, which only features single-ended inputs (five, two loops for processors or recording and two sets of single-ended outputs) and one that makes extensive use of microprocessor control. Channel switching relays, the 100-step volume control, balance and basic operation are all powered by a microprocessor, and the main ‘head’ section (where the main controls and displays live) looks very similar to the preamp that preceded it. Anyone you has used an ACT will also be used to the ticka-ticka-ticka sound as you work through those 0.7dB volume steps.

Unlike the ACT, with its offset, back-set control panel and the four clear plastic protectors for the quartet of tubes, the GAT looks very symmetrical. The centre control unit is flanked either side by a single 6922 triode, protected from the outside world by four quartered clear plastic protectors. The overall look does highlight the substantial feel of the preamp, and opinions converge on the GAT having a 1950s aesthetic… in a good way, more ’57 Chevy Bel Air than ’59 Edsel.

One triode per side might invite some questions from those who know their way around a preamp circuit. Digging deeper finds the GAT with a high-current MOSFET buffer stage and a solid-state discrete DC voltage regulator. From a strict valve-fascist standing that would make this a hybrid design, but few will call it that in reality. The advantage of solid-state voltage regulation is complete isolation from the mains circuit, while the MOSFET buffer means very low output impedance. That makes it more power amp friendly, or rather makes the use of long interconnect cables a distinct possibility. Like all c-j preamps, it inverts absolute phase, so turn your cables hot to cold and cold to hot at the loudspeaker end.

The typical c-j ‘no feedback, no electrolytics’ rule has been adhered to in the GAT. Every capacitor in the audio circuits (and their power supplies) is either a polypropylene or custom-designed Teflon type, while the circuit bristles with metal foil resistors and gold-plated silver contact relays that are sealed from the outside world. This is, of course, what you’d expect from a top-class preamplifier.

I’d say the clever part of the GAT is the blending of 21st Century control circuitry with mid-20th Century amplifier technology, but I guess the point of the GAT is it’s one big clever part. The microprocessor controlled start and stop processes are an example of the kind of forethought that went into the design. It goes into a minute-long auto-mute, to eliminate the sort of transients that occasionally hit during the first few seconds of tubes powering up and down. Most don’t bother, assuming that these early stage transients are not much of an issue if the power amp hasn’t started up. If you use these preamps with powerhouse solid-state amps that come to life in a second, those transients can get a touch alarming. In other words, if it wasn’t for the two tubes staring at you from either side of the front panel, you’d never guess this was a valve preamp.

That is, of course, until a minute after switching the amp on. Then it’s valves all the way, in all the right ways too. What strikes you first about the GAT is the midrange. It’s got something the classic old c-j amps had and sort of lost in trying to move with the times. That midrange is liquid silk; refined, open, natural, enchanting. The old romantic sound of c-j was made from this, but not like this. Instead, now we have new levels of openness and clarity, like you swapped your drive units for electrostatic panels… only with the dynamic drive of, er, dynamic drivers.

This is where we encounter the first bit of GAT-magic. It exposes more of what’s being played and yet doesn’t make that insight uncomfortable. If anything, it just makes you want to listen more to what’s going on in the music, but not at the expense of the music. This might be the only time in the whole history of all 250 GATs that anyone will ever say this, but it even does a good job of playing Tool albums. Yes, the GAT’s inherent ‘beauteous’ nature might blunt the heaviest of transients, but what you lose at the cutting edge of prog metal, you gain when you listen to anything acoustic.

Play anything with ambience and you are greeted with a soundstage that makes you feel like you were there in the room with the musicians. Move from a small jazz club to the Wigmore Hall and the soundstage resizes itself perfectly. Then you reach for those classic 1950s albums like Ella Fitzgerald’s American Songbook series, and you realise why hi-fi was all the rage back then; the GAT raises the bar and could make the pursuit of quality music replay cool again.

It’s not all Brylcreem and grey flannel suits. The way the GAT articulates sounds is sublime. Normally, articulation is read to mean the way the human voice sounds and whether you can better understand the singer. Here, it not only articulates voices perfectly, it seems to do the same to any instrument you put in front of it. I stuck on "Sweet Dreams" from the eponymous album by the late Roy Buchanan. Being a mediocre Fender Telecaster player, this is one of the ‘set pieces’ I try – and usually fail – to learn to play. Here though, the GAT managed to articulate Buchanan’s signature pinch harmonics well enough that I could almost copy the master, with the accent on the ‘almost’. Never mind, that instrument articulation represents GAT-magic part two.

GAT-magic part three is the discovery of seemingly endless dynamic range. My new classical discovery – The Flight of Icarus by John Pickard (Christian Lindberg/Norrköping SO, BIS CD 1578) – is a perfect example of this endless dynamics in action. The title track (which just about manages not to sound like incidental music from Planet of the Apes) consists of an orchestra playing pianissimo interspersed with a percussionist beating merry fortissimo hell out of his instruments at key moments.

On most preamps, you’d be at the volume control like a safecracker, turning it up and down to get the level precisely wrong at every moment. The GAT just takes this album in its stride. The quiet orchestral passages are not subsumed by any hint of a noise floor, while the headroom of your power amplifier or loudspeakers are the only limits to the musician bashing seven bells out of their tympani. Just remember not to set the volume level too high when listening to the quiet bits, or you’ll be wearing a pair of woofer cones as a fashion accessory.

Finally, there’s the breathtaking coherence of the GAT. You can listen to the most disjointed, angular piece of Acoustic Ladyland/Polar Bear style punk jazz (pazz? junk?) that to most people will sound like someone throwing a saxophone – and the saxophonist – through a wood-chipper, and the GAT will make sense out of the onslaught. You might not think this sounds like an exercise you would wish to repeat (many feel punk jazz albums sound like disco dentistry), but you should hear what it does to less extreme recordings. It’s as if everyone in music had suddenly gone to James Brown school, and started playing in that incredibly tight, close-knit way only ex-JBs (like Maceo Parker) can muster.

That’s not really the true ‘finally’ part. These were just the observations made by someone who’s seemingly most aware of dynamics, coherence, articulation and imaging. If I’d been wearing my ‘detail’ hat or my ‘rhythm’ trousers, I’d have been praising the GAT’s detail and its rhythmic properties. In that wholly positive respect, the GAT is protean in its shape-shifting; it sounds good to people especially in they way they want it to sound good, over and above all the other ways it sounds good.

The GAT represents the pinnacle of c-j preamp thinking, but it’s more than that. Over the last few years, the top preamp landscape has been largely redrawn, thanks to a crop of best-ever products. Ayre, Audio Research, Lyra and more have planted flags once more on this high ground. Now, conrad-johnson’s back in town!


SIDEBAR: Why Change?

If you follow top c-j preamplifiers closely, over the years, they’ve taken up less boxes and got steadily better. The Premier 7 of the late 1980s and Premier 7a of the early 1990s had separate boxes for each channel and a third power supply case. The ART (Anniversary Reference Triode) came along in 1998 to celebrate the company’s then impending 20th anniversary; this had a single preamp box and a separate power supply. Over the years, the ART went through a couple of significant revisions over the years, especially when the company’s original 250 models were expanded by a further 25 units in 2005’s ART3. Meanwhile the ACT preamplifier was launched in the early 2000s as the then-current, one-box limited edition flagship, followed in 2005 by the ACT2. Now, all of that’s gone… replaced by the GAT.

While it’s wonderful for a manufacturer, a retailer and a magazine to have a constant stream of new and exciting products to attract the attention of our respective clients, should a reference point has such a short time at the top before being eclipsed? If the GAT is reaching a new clientele, this isn’t a problem, but I can’t help thinking some of those prospective GAT owners will be considering an upgrade from an ACT2 bought just a few years ago. In fairness, I think most people would rather see the standard being raised by ever-better products whenever they appear than held back because of last year’s line-up, but too regular a series of upgrades can be a source of understandable frustration for those seeking the best of the best. And the problem is the GAT really is the best of the best.

In part, this is a problem of compulsion on the part of the listener (and, in fairness, the reviewer). You want the best and aren’t happy when the best that you own is superseded, making your product now the next-best. I have the same thing with camera lenses – my big Nikon 70-200 zoom has just been replaced with an improved model and, even though there’s nothing wrong with the five-year old lens I currently own, there’s a burning desire to trade up. My current 70-200 lens turned in stellar performance last year and it will do the same next year, even if there’s a more stellar body in the heavens. Sooner or later though, I know I’ll be spanking down the readies, because last year’s best is not best enough. I suspect exactly the same is true for the GAT. –Alan Sircom



Conrad-Johnson GAT Valve (Tube) Preamplifier

Inputs: five line level RCA phono, two processor/record RCA phono
Outputs: two preamp out RCA phono, two processor/record RCA phono
Valves used: 2x 6922 triodes
Gain: 25 dB
Maximum Output: 20V rms
Bandpass: 2Hz to more than 100kHz
Hum and Noise: 100 dB below 2.5V output
Distortion at 1.0 V output: less than .15% THD or IMD
Phase: inverts phase of all inputs at main out
Output Impedance: 100 ohms
Dimensions (WxHxD): 483x122x391mm
Net Weight: 15.9kg
Price: £19,000

Conrad-Johnson Design, Inc.

Distributed by:
Tel: +44(0)208 948 4153 

blog comments powered by Disqus

Featured Articles