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Gryphon Diablo 300

Herron VTSP-3A preamplifierYears ago, when I was first getting into high-end audio, I remember walking into a dealer’s showroom in Austin, Texas, interested in listening to some subwoofers for two-channel music. At the time I was using a simple two-way speaker that was restricted to about 40Hz, so I figured a good sub would help fill in what I’d been missing. The dealer had a stereo set of subs set up with a pair of speakers that were also restricted in the deep bass. When the subs were switched in and out, I heard a bit more bass depth, a bit more ambience, but nothing earth-shattering or obvious. Where’s the bass? I kept thinking. It’s like the things are barely on -- they’re hardly doing anything! No sale that day. 

As I’ve learned more about audio, I’ve realized what was wrong that day: I was. Novice listeners looking for egregious differences in A/B testing are effectively looking for colorations to catch their attention. I’ve since spoken to dealers who say that, during demos, novice audiophiles routinely turn subs up higher than is necessary or prudent, simply to make the subs “stand out” more -- just as I would have. Novices can search for colorations that align with their biases, but that doesn’t make those biases correct. Deliberately setting the subwoofer output too high may sell more subs, but any good dealer will readily admit that when a sub calls attention to itself, the music is not being reproduced accurately. 

I thought of all this during the listening and writing for this review of Herron Audio’s VTSP-3A preamplifier ($6850 USD). The Herron reminds me a lot of a properly configured subwoofer, rather than one whose gain has been turned up and its crossover set too high. The first contributes to an accurate presentation of the music, while the second imposes on the music exciting but inaccurate colorations. Some people may actually prefer the latter, but let’s not pretend that that’s what music actually sounds like. 


Keith Herron is a head-of-the-class engineering nerd who comes across as having a customer-first mentality that’s more than a mere slogan. Although Herron Audio has been in business since the mid-1990s, new models are few and far between, and owners of the earlier VTSP-2 or VTSP-3 can upgrade to the VTSP-3A for a nominal charge; as Herron said, “I don’t want my customers to feel screwed.” What a concept! That attitude became evident in unsolicited follow-up phone calls from Herron to see how things were going, along with system-matching guidance and suggestions. 

The VTSP-3A’s appearance exudes tasteful, functional quality -- nothing ostentatious. It’s the sort of product you’d expect to find at a John Deere dealer, not at Tiffany’s. Tipping the scales at only 15 pounds and available in black or silver, it’s solidly built; I could feel no resonances on the chassis. Inside I found no boutique parts or massive transformers, but neither did I find loose wires or a half-baked layout. A good circuit design will keep the amount of wire to a minimum, as wires are little antennas that can pick up radiated noise. 

The front panel is simple and highly functional. Two knobs, one each for balance and volume, flank an oval window that displays the volume level (more on this later). To the left of the Balance knob and to the right of the Volume knob are two series of five pushbuttons each: the left series are for source selection (Video, Tuner, CD, Aux, Phono, all single-ended, no XLR jacks), while the right series comprise a wish list of functionality: Mute, Mono, Invert (phase), Tape (loop), and Display (to dim the volume display). Except for Balance, all of these functions are also available on a remote control that’s about the size of a credit card. The VTSP-3A is designed to be left powered on at all times; it draws little current and radiates negligible heat. 

Herron VTSP-3A rear panel

The VTSP-3A has two additional features that, while used only during setup, are critical to maximizing performance. First is the Power Line Polarity switch, on the rear panel next to the power switch. Flipping this switch is akin to reversing the orientation of your power-cord plug. It’s not only that in some homes the polarity of the hot and neutral leads are reversed (although they are); it’s also about finding the lowest potential to ground. I’ve tested for this ever since I learned of it; it’s the way to ensure that you have the lowest level of background noise. 

The VTSP-3A also has something that every other active line stage I’ve come across lacks: variable gain. Generally speaking, a line stage is designed to do two things: select source and control volume. Passive line stages provide no gain, on the premise that most sources produce enough gain to make any added gain superfluous (and usually detrimental, as it adds noise or coloration). For the most part, this premise is correct. But matching the impedances of sources and amplifiers sometimes makes a passive line stage impractical, so an active preamp -- that is, one that amplifies the signal -- must be used. The question then is how much amplification, or gain, is the right amount? 

Let me quote Albert Einstein: “as little as possible, but no less.” Many line stages have fixed amounts of gain that may make 80% of the volume-control range unusable, with gradations too coarse to find the single right volume setting for the listener. The Herron VTSP-3A employs both high gain (12dB) and low gain (6dB), selectable via the front panel (the manual covers how). I found that 6dB was plenty, enabling very fine increments of volume control that made dialing in my listening sessions a pure joy. 

To control volume, many line stages have a common potentiometer, the Microsoft operating system of volume controls: ubiquitous but inherently inferior. Potentiometers use a “wiping” mechanism in which the degree of resistance of rotation of the knob is a function of the thickness of the resistive element inside the pot. It’s purely mechanical. This means it needs to be engineered and built to the level of micrometers in order to provide proper channel-to-channel tracking. If there’s even the slightest variation in the thickness of the pot’s resistive elements (and if there’s not any now, just keep using it and there will be), your soundstage depth and width will be compromised. More advanced line stages forgo potentiometers for better controls such as a stepped attenuator (which has one resistor per volume level), but frequently these are purely mechanical and cannot easily be remote controlled. More modern designs have a series of microprocessors that control a series of resistors, sometimes with excellent results. The VTSP-3A’s volume level is controlled by microprocessors, but with extensive work to keep the noise radiated by the microprocessors from polluting the signal. According to Keith Herron, the VTSP-3A’s volume control tracks accurately to within 0.1dB across channels, and the microprocessors enable the fine volume adjustments that I enjoyed each time I used it. 

In perhaps every review I’ve written, I’ve said, “You listen to your power supply.” By this I mean that the bigger the power supply, the better, and in general that’s true. Dynamics and deep bass are compromised anytime a component’s power supply is unable to meet the current requirements of a transient, and a poorly designed power supply will radiate noise to be picked up by the signal circuitry. On top of that, transformers have a tendency to vibrate; if these vibrations are not suppressed or eliminated, the result can be a reduction in the amount of low-level detail retrieved. The Herron VTSP-3A’s power transformer is about as big as what I’d expect to see in a $1000 Sony receiver. It may be fully enclosed (no vibrations), but it’s clearly not designed to deliver gobs of current. Keith Herron explained that, due to the VTSP-3A’s extensive voltage regulation and multiplication, its signal path requires milliamps’ worth of current from the transformer in order to satisfy demanding transients; theoretically, the power supply should be plenty big enough. 


While the Herron VTSP-3A went through some ups and downs over its monthlong break-in, my overall impression of it was simple: It didn’t do much, and I mean that in the best way possible. 

What caught me initially was the Herron’s ability to extract microdetails without spotlighting them. Israel Kamakawiwo‘ole’s solo performance of “White Sandy Beach” on Mele o Hawai‘i: Songs of Hawaii (Sony BMG, A701916), a wonderful compilation of mostly very well recorded Hawaiian music, stands out for its simplicity and beauty, but when I heard it through the Herron I was surprised to hear between phrases Iz’s labored breathing, which he was clearly trying to conceal and perform around -- a sad foreshadowing of his early death from morbid obesity. Listening to Yes’s “Yours Is No Disgrace,” from The Yes Album (CD, Rhino R2 73788), I could hear in the background a “Woooooo” from one of the band members during one of the transitions between propulsive tempo changes that this band does so well -- it was off mike, but the singer’s mike picked it up. When I can hear what the performers are doing among themselves, and unravel the small cues between musicians that are seldom heard offstage, then I know I’m hearing a very resolving system. The Herron VTSP-3A was a very resolving preamp. 

“Church,” from Lyle Lovett’s Joshua Judges Ruth (Curb/MCA MCAD-10475), is a great track for evaluating soundstaging. With the VTSP-3A, the soundstage was not holographic or enveloping, as with the typical tubed preamp. Instead, the performers were mid-hall, focused, and compact, reminding me of what I hear from solid-state preamps. 

One of my primary listening biases concerns dynamics. I think restriction of dynamic range is the biggest shortcoming of every audiophile’s system, and it’s not a problem that can be fixed; two loudspeakers are smaller than the smallest jazz trio, and a lot smaller than an orchestra. I immensely enjoy Led Zeppelin’s How the West Was Won (CD, Atlantic 83587-2), as it’s something the world needs more of: a live rock recording with great dynamics. The gear I like must be able to present the dynamics of a rock concert -- or at least do nothing to shortchange them. Like my overall impression of the Herron’s performance elsewhere, it did very little here in this department. It didn’t add punch or slam, and had an almost passive-preamp approach to dynamics. There was no hardness, no gain-related you’ve-gone-too-far moments when I cranked up “Bring It On Home.” The sound just kept getting louder as I turned the volume knob, with no part of the audioband emphasized at the expense of the rest. The sound never ran out of steam, never hardened, and so never disappointed in terms of dynamics. But while it was very evenhanded in this regard, it lacked the type of propulsive dynamics exhibited by the best line stages. The Herron wasn’t dynamically constrained; it just wasn’t as dynamically alive as the best I’ve heard. John Bonham’s drum rolls in “The Ocean” were fully articulated and had pop, but they didn’t explode into the room as well as they have through some other line stages I’ve tried. 

Listening to the title track of Frank Sinatra’s Nice and Easy (CD, Capitol 101724) gave me another nit to pick. The Voice was as fully resolved and nuanced through the VTSP-3A as I’ve ever heard in my home, but it sounded just a touch less like a baritone, a bit less chesty and bellowing. Sinatra never sounded wrong with the Herron, not by an inch or a mile, but he did sound just a bit less like the Voice of God as when he sounds his best: commanding, bellowing, powerful, and dramatic. The Herron had no push in the presence region, no analog-type voicing to make the lower midrange a bit more pleasant and Sinatra a bit more Sinatra-esque; if anything, the Herron sounded a wee bit leaned out in that area, and would probably make any system that’s already lean in that area sound too hollowed-out, forward, and thin. Fortunately, many analog systems (and almost every tubed component I’ve heard) are voiced with a slight emphasis here; the fact that the VTSP-3A wasn’t should be of little concern in system matching. 

As I mentioned in the introduction, short-term listening impressions are a mug’s game. The tonal characteristic that at first excites you about a component’s sound may grow fatiguing over time: treble extension becomes brightness, warmth starts to sound slow and thick, and what at first sounds like rich tonal color may become a suffocating coloration. Throughout my time with the Herron, no part of its sound invited a deeper look; in other words, there were no glaring sins of commission. Its flaws were more about what it didn’t do. I’ve heard myriad line stages that impose their own colorations on the music, colorations that, in the pursuit of synergy and neutrality, must be counterbalanced elsewhere in the system. Folks, the easiest way to promote synergy and neutrality is to add as little color as possible the closer you get to the source of the signal. While that’s an impossible goal, it should be pursued. If it’s true that “if you lose it at the source, you can’t get it back elsewhere,” similarly, if you color it at the source, you’re fighting that coloration the rest of the way. And if the signal is contaminated while it’s small, every gain stage downstream amplifies that coloration along with the signal, making it that much harder to get rid of. 

The Herron VTSP-3A added very little tonal character to the signal, and because of that, it won’t “sound” very impressive to most folks. It won’t stick out, won’t invite notice or attention. And that will be a shame -- in an A/B test, many listeners will fall for that mug’s game of first impressions, choosing the line stage with the more pronounced tonal color and character, which they’ll later have to try to counterbalance. The VTSP-3A is many things, but it definitely was not colored or full of character. It was the least colored line stage I’ve had in my house, and among the least colored I’ve ever heard. It will simply let you hear what your other components are doing. It’s that clear. 


It is my belief that the audio component that has the easiest job in a system (aside from the cables) is the preamplifier. All it needs to do is control source selection and volume to accomplish its stated purpose, which is a lot easier than the job a loudspeaker or a DAC has. That belief has been confirmed over the past year. In that time I’ve had some great line stages in my house that have narrowed the gap between mid-priced and über-priced far more than I’ve heard in amplifiers, sources, or loudspeakers. In my experience, it’s easier to find a reference-caliber preamp than any other piece of stereo equipment. Einstein Audio’s The Tube Mk.II ($18,400), the Edge Signature 1.2 ($12,200), and even the Audio Horizons TP2.1 ($2700) sounded quite satisfying in my rig, and provided some useful comparisons. 

The more expensive models had a bit more macrodynamic pop than the Herron VTSP-3A, as I heard with the live Led Zeppelin recording. Einstein’s The Tube is the best preamp I’ve heard for adding rhythmic drive and punch to a signal, but the Herron VTSP-3A had better upper-midrange nuance and clarity, and more textured bass. The Einstein has more punch and thrust, more forward soundstaging, and a more exciting sound, but the VTSP-3A had better bass definition. 

Versus the Audio Horizons TP2.1 the VTSP-3A exhibited no grain, and there was no volume level at which it compressed and hardened, as the Audio Horizons did when pushed too hard. With dynamics roughly equal, the Herron was the superior model, which it should be at more than twice the price. 

Closest in sound to the VTSP-3A was the Edge 1.2. The Edge was slightly superior, because it comes with a more muscular presentation and darker backgrounds. One of the drawbacks of tubes is a higher noise floor; the Herron could never match the tomb-like silence of the Edge in battery-driven mode. On the demerit side of the ledger, the Edge’s inputs are limited to three sources, it takes up a lot more space on the rack, its remote controls only the volume, it costs more than twice as much as the Herron, and, in my opinion, the Edge is ugly. If that matters. 

A buddy purchased Ypsilon’s PST-100 TA, which is getting attention as the best passive line stage the world has to offer. The Ypsilon weighs 50 pounds, and uses discrete taps off of custom-wound transformers to control volume. I’ve heard it in his system, and it really is remarkable. It doesn’t do anything wrong -- it’s as good a piece of audio electronics as is available. For giggles, I brought the Herron VTSP-3A over for comparisons in his system (Esoteric K-01 player, Edge Signature NL-12.1 amps, and custom-built speakers). It took a few hours before the Herron came back to life, at which point comparisons proved illuminating. 

Those hoping for a David slays Goliath moment should look elsewhere. The Herron VTSP-3A was no match for the Ypsilon PST-100 TA, which bettered it in every appreciable way and illuminated the Herron’s shortcomings. At $27,000 vs. the Herron’s $6850, that’s what should be expected. The Herron had a slightly higher noise floor, it didn’t provide the Ypsilon’s image solidity or impossibly extended harmonic decay, or match its propulsive dynamics. The Ypsilon had a tad more presence-region warmth, and that small but noticeable tonal improvement manifested as more lifelike sound; Sinatra’s “Voice of God” thing that I mentioned earlier. 

All that said, if you’d told my buddy and me that the Herron was the Mk.I and the Ypsilon the Mk.III of the same basic model, we’d have believed you. They were cut from the same cloth and sounded like close cousins. While the Ypsilon is the better line stage, the difference wasn’t night-and-day or revolutionary, but a step up in quality. Common to both models were an evenhanded neutrality, good detail retrieval, high levels of purity, and lack of character -- it’s just that the Ypsilon had the total package. Whether the improvements the Ypsilon offers are worth another $20,000 is your business; I’m just saying that the contest was much closer than I expected it to be. 


The Herron VTSP-3A line stage did nothing objectionable, and for that I have terrific respect for it. Its sins were more of omission than the more annoying ones of commission. It did its job of controlling source selection, mono/stereo, phase, and volume in the most unobtrusive ways, while providing an uncolored reproduction of the signal with the convenience of a full-function remote. It was a delight to use on a daily basis, and seems engineered to last. Sonically, it gave up little to the best out there (mostly in macrodynamic swings and presence-region voicing), and let me hear what the rest of my components sound like. It would be at home in a system of any cost, but whether you prefer the VTSP-3A or one of its competitors will depend on how much you want to hear your line stage. You won’t be hearing the Herron. 

For mature listeners, a must-audition product. 

. . . Ryan Coleman

Associated Equipment 

  • Speakers -- Rockport Technologies Merak 2 and Sheritan 2
  • Preamplifiers -- Audio Horizons TP2.1 (modified), Edge Signature 1.2, Einstein Audio The Tube Mk.II, Ypsilon PST-100 TA
  • Amplifiers -- McIntosh MC-501 monoblocks, Edge Signature NL-12.1
  • Sources -- Sony XA-5400ES CD player with Modwright Truth Mod; Esoteric K-01 CD/SACD player
  • Cables -- TG Audio interconnects, AudioQuest Redwood speaker cables, TG Audio power cables
  • Power conditioners -- Weizhi PRS-6, Oyaide R1 and WPZ wall plates

Herron Audio VTSP-3A Preamplifier
MSRP: $6850 USD.
Warranty: Three years parts and labor.

Herron Audio
12685 Dorsett Road, #138
Maryland Heights, MO 63043
Phone: (314) 434-5416

E-mail: keith@herronaudio.com
Website: www.herronaudio.com