Aural Ecstasy – The VTA ST-120 Power Amplifier
In today’s cyber marketplace, it is almost a given that “seller feedback” is expected to be instant and automatic hyperbole – but it is rare that such extravagant praise is actually warranted. In the case of the VTA ST-120 power amp, designed after the venerable Dynaco ST-70 warhorse, but with completely upgraded and improved circuitry by Tubes4HiFi’s Bob Latino, and lovingly built for me by William Gratrix (forum name “Audiobill”), the expected superlatives actually pale in comparison to the experience I am having with this fantastic and affordable piece of audio equipment.
In short, the ST-120 is a miracle. The sound quality, versatility, and value of this unit is comparable to amps costing four times as much. And affordable options, such as a protective 17 second time delay relay (to soften the power-up surge), a high-quality stepped attenuator which allows one to tailor input levels to a preamp optimum or even forego a preamp altogether, and available alternate output impedance taps (choose two of 4, 8, and 16 ohms) make this amp, delivered to my door within two weeks of my order, ready to plug-and-play with a well-selected set of eight fine tubes, a steal at $1732.
At 60 WPC, the ST-120 can power even moderately inefficient speakers to satisfyingly punishing levels in a reasonably modest listening space. I have a set of notoriously power-hungry B&W Matrix 803s which are perfectly served by the VTA. {N.B. Older B&Ws will be found to sound much more controlled and smooth driven by the 4 ohm taps!}
The standard-issue triode/ultralinear switching capability allows one to effectively alter the size and shape of the stereo image in a way which must be experienced to grasp. Triode mode will sound more intimate and laid-back to most ears, like a small club environment, while ultralinear mode might be likened to moving to arena-sized or concert hall ambience. Source and mood will dictate what sounds best at any given moment. It’s a great feature.
But how does it sound? Well, the only way I can tell you is to state that the ST-120 is the closest thing to the ideal of “a wire with gain” that I’ve ever heard. Given good-quality sources, well-matched speakers, and a well-designed listening room, you can expect your gear to disappear, leaving nothing between you and your music. It doesn’t get any better than this, folks. Bass is naturally extended and as solid as your speakers can deliver, while highs are uncommonly detailed and smooth without any sense of harshness or fatigue. In short, miraculous.
Several other things to note: this unit runs cooler than any comparable amp I’ve ever used. Top temperatures at a “full gallop” will climb no higher than 200F at most (measured by laser therm on the output tube plates.) Power transformer was measured at the same time at only 130F. This means that you are getting top-flight sound delivered efficiently by components which are being only conservatively driven. This amp is built to last, and further, it is designed to ensure that all tubes and components are going to remain well within proper tolerances for much longer than one might expect.
It is worth noting that you can expect the sound of this unit to improve in subtle ways over the first hundred or so hours. I waited four days since I first powered it up to write this report. I’m not even close to getting the “full monty”!
Add to this the incredibly responsive customer service that you can count on from both Bob L. and Bill G., who will patiently answer your questions – even dumb ones – and the fact that, should you have even a modicum of ability with a soldering iron, the amp is available in kit form for as little as $909, and the experience of buying a superb power amplifier which truly deserves rave ratings is yours.