December 2000

Herron Audio VTSP-1A Pre-Amplifier And VTPH-1 MM Phonostage
Review by Karl Lozier
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VTSP-1A pre-amplifier

  Herron, Keith Herron, Herron Audio; keep those words stored in your personal memory system. I think you’ll be hearing those names more and more in the future. If it were my decision, in keeping with some tradition, only the word “Herron” would grace the front panels plus the appropriate model number in much smaller print. Continuing with appearance, the units are identical in size, color (dull black) and only the pre-amplifier has and needs the machined knobs. Width of front panel is typical of most preamps; width of the basic case is nearly an inch narrower right and left. Overall height including the feet is less than 4 inches and depth is not quite 11 inches, including rear protrusions and front panel knobs. Overall effect is relatively small and unobtrusive; weight of each is approximately 14 pounds. Each unit has a vertical row of 3 green LED’s and if stacked one on the other, the rows form a straight vertical alignment. Basically the LED indicators show in order: power on, voltage gradually increasing to filaments, and output on (with automute disengaged).

VTSH-1 MM Phonostage

The phono preamp unit is available in two versions. The “basic” version is the VTPH-1 MM for use with almost any moving magnet type of phono cartridge or a few high output moving coil models.  It has an all-tube signal path using selected, hand matched, burned in and then bench tested l2AX7WA/B tubes, two per channel plus a single shared 12AT7WC – I’ll discuss tubes in greater detail later on. But remember this; do not change those tubes for any reason without Herron’s specific approval. Gain is rated at 44dB and is very adequate for any cartridge with 1-milliVolt output or greater. There is a possibility of being satisfactory for use with some cartridges rated at around 0.7 to 0.8 milliVolts, but with a touch of added noise; double check to be certain. The moving coil model VTPH-1MC is the same unit except for the addition of a FET front-end amplifier with an additional 22dB gain for a total of 66dB with extremely low noise. All four tubes in the VTSP-1A pre-amplifier are hand matched, burned in (48 hours) and bench tested 6922 tubes. A number of competitive units also use the 12AX7 type of tubes in their phono sections while relegating the 6922 tubes to the line section or basic pre-amplifier.

I need to go into some detail about appearance and features, as it is a “fer piece” between dealers; many of you have to travel a great distance to see these relatively new units. Herron’s web site offers a great deal of information and a picture, so you may not need much of the info in the next few paragraphs. Feel free to skip them if you just want to languish in the soft caress of my wonderfully descriptive words and phrases describing their aural delights. Think about this situation for a few minutes. What would you do if you had just finished designing a superb stereo pre-amplifier and now want to manufacture and sell them. Maybe even sell enough of them to allow you to eat regularly. What to do?  It hits you in a flash! Take your precious creation to a couple of dealers and let them drool over it  - just decide which dealers you allow to have that honor. First try to find the dwindling few serious or high-end dealers left, those who are not just pushing home theater, like, where are the other three channels? You get a bit of  luck and finally find a dealer who will actually sit down and listen to your creation. He’s reasonably impressed and thanks you for the audition. How many units should I ship, you eagerly inquire? The answer is none – you scream what! Why not? The dealer handles two well known brand name competitors plus a lower price line that looks great and sells for even less money and has all sorts of gizmos and gimmicks, useful and otherwise. What to do said the chicken to the egg. Who goes first? Try to appreciate the myriad of problems facing a new product line. True even if the design engineer has a solid educational background in the field and has proven himself with many years of experience in the professional or commercial field, which Keith Herron has certainly done.

You don’t need to tell him that you’re not extremely impressed with the outer appearance of the units.  He’ll simply agree with you and perhaps ask how much more you’re willing to pay for esthetic beauty. Great metal design work and machining is expensive and often very slow to obtain. Look inside the units and you’ll be more impressed with both parts and workmanship. Then, it may hit you; there are no “famous name” parts used or stuck around in places that may impress budding audiophiles. Keith Herron is an audio design engineer and takes pride in being able to offer products with some of the lowest distortion and noise figures in the industry.  He also is a music lover, like live symphonic music at Powell Hall in St. Louis. The parts that sound best to him are the parts that go into his products, period. One of the best examples and the toughest to deal with has been the volume control. It is a stepped device, an electronic attenuator and he uses one for each channel. There are 128 precision resistors and 128 electronic switches on each chip!  The part is the best sounding volume control that anyone at Herron Audio has ever heard. Unfortunately the control, even with all those steps did not have enough range top to bottom. The manufacturer was not willing to change the amount of range. Herron designed a unique servo system to extend the range of control by a downshifting of the attenuators at around the 8:30 setting of the volume control at the same time that the electronic switches are shifted.

The shifting point can be heard if you listen carefully because the electronic switches must operate slightly faster than the servo – a mathematical restriction of the circuit (known as hystersis) to maintain stability. The end result is a 142-step volume control with claimed perfect tracking. Herron will supply additional info if desired. Earlier this year Herron figured out a way (with eighteen part changes) to measurably and audibly improve the volume control servo/system. The end result is even lower distortion and noise than that shown in Stereophile Magazine’s impressive test results for the earlier version. Even greater clarity, better dynamics, bass, and soundscaping/staging have resulted. The audible and measured changes were significant enough to warrant an upgrade designation of VTSP-1 to 1A. The reviewed preamp is the VTSP-1A and this review is one of the firsts to be made of the upgraded version. Contact the factory for information about upgrading the earlier model. No other changes have been made to either unit and none are planned at this time. They came to market as fully thought out and developed units.

Functions or features can make or break a decision to buy or not.  Here again personal taste or requirements come into play. In my life as an audio writer I need or at least want to be able to exactly repeat a gain/volume setting, quickly at any time. I can’t do that with the ultra smooth action of Herron’s pride and joy control; I can’t feel most of the steps to count them and there are no marks for the knob’s pointer to aim at to even approximately repeat. Some other units have an LED display indicating exact and repeatable gain/volume settings-certainly gets my vote. However, in a number of competing units, there are so few (less than 40 in some) steps to the gain control, that I can’t find an exactly preferred setting at anytime! Herron does have a balance control, some competitors do not; I have to have one even if its an internal set and forget type. Many competitors think that might subtly degrade sound quality; Herron says that does not audibly occur in his design.

Herron has a stereo/mono switch on the VTSP-1A pre-amplifier. I don’t care personally, but some of the remaining few music-loving audiophiles older than I, are still spinning their 78’s and old mono RCA’s and demand that feature. Muting is automatic at startup and shutdown with regulated soft-start DC filament supply and controlled warm-up of tube filaments and high voltage. Those features I love to see and do appreciate, if not demand. They are positive indicators for longer tube and parts life. Throw in a mute switch and two pairs of main outputs plus a tape loop and it’s clear that Herron offers a reasonable degree of features and flexibility. Here I should make it clear that Keith Herron will do almost anything to avoid typical electrical switching contacts. He traces that back many years to when as a consultant he found the solution to an extremely vexing (and expensive) problem that a number of experts for a major corporation could not solve over a period of weeks. 

A very large (thumb size) gold contact simply would not give consistent performance, no matter what was done to it and that was with a relatively high voltage. With the small areas of contact and low voltages generally used in consumer audio, Herron will not use typical switching contacts if at all possible. Input source selection incorporates gold contact sealed relays right at the input connection. This type is not prone to dirt, corrosion or the type of wear of conventional selector switches. The pre-amplifier and both phono units have four levels of high voltage regulation and in excess of 70,000 uF of energy storage with the phono unit having a bit more than the preamp. 

The phono units are bare bones except for an A.C. polarity switch on the back panel near the A.C. power switch same as with the VTSP-1A preamp. Try the A.C. polarity switch both ways.  If you hear a difference in sound quality leave the switch in that position on the pre-amplifier. If you also have the phono preamp simply set its switch in the same position. Personally, I would have probably preferred a signal polarity switch, but that would be in the signal path, a definite no-no design feature. A remote control is not offered. A built-in type of location for all these Herron units would preclude access to the power on/off switches on the rear panel.  Easy solutions include plugging into accessible surge protector devices or devices such as the increasingly popular PS Audio’s Power Plant units. If you use the PS Audio units (I do), do not increase the power setting above 60Hz: Herron designed his units to reject higher frequencies, as they’re typically distortion products! I’ve had no hint of trouble in the almost four months of use with the Herrons plus Power Plant combination except one phono tube developed an intermittent noise and was immediately replaced by Herron.

Since then there’s been no noise, I mean really no noise; this is the quietest preamp yet to reside in my listening room, both phono and preamp units. Everything worked flawlessly in both units, as one would like to expect in this price range.  Both units ran just barely warm at all times. I consider separate units (preamp or phono) from $2,500 to $5,000 each or a pre-amplifier plus built-in phono section from $5,000 to $10,000 to be in the “near luxury” group. Anything more expensive is the “pure luxury or cost-is-no-factor” group of best performance and esthetics possible regardless of cost. Competition in Herron’s near luxury group is stiff with quite a few choices.

Well, finally it’s tally ho – on to the chase (sound that is) as we used to say at the old homestead (in my dreams maybe).  I’ve used the units for three solid months, extremely pleasurable for the most part but I was temporarily waylaid for awhile. I had started off listening to only the VTSP-1A preamp (line-stage) using a moderately priced DVD player with my CD’s and a few DVD audio discs at 24-bit/96kHz. Results had been kind of ambiguous; greater clarity, dynamics lower noise level, etc., but very unsatisfying.  I finally plugged in the VTPH-1 phono unit. This version is for relatively high output cartridges, like typical Grado and Shure moving magnet models and only a few moving coil types. I have been using the Grado, The Reference model, for quite awhile now.  Why, you ask, don’t I use a moving coil phono cartridge? Since Grado has the U.S. patent rights as the inventor of moving coil cartridges, I ask you, why do you think Grado does not manufacture moving coil phono pickups?  (See my review in The Audiophile Voice Vol. 6, Issue 4, Oct 2000).

 Check out Rick Rosen’s interview of the legendary master of mastering engineers, Bob Ludwig in the October 2000 issue of Stereophile magazine. Ludwig states the following, “the Grado cartridge is fantastic, it’s the best LP playback I’ve ever heard in my house so far, or in the studio.”  “CD’s come a long way, but there’s no question that a well-cut vinyl disc yields a sound that our ears find extremely musical.” Many in our industry admit to using the Grado pickup for musical enjoyment (I’ve been doing so for about three years now) even though lip service may be given to “it has to be a moving coil model and very expensive to really sound good.”

I called Keith Herron and basically said, “what’s going on here, the LP sound is terrific, the CD’s in general sound poor by comparison?  As soon as I said it, I realized the lack of logic behind my first thoughts. All sound signals were going through the Herron VTSP-1A pre-amplifier. Herron asked which DVD/CD player I was using, and I think he almost laughed while saying something to the effect, “you realize that it was a turntable manufacturer that is given credit for starting the rumors of how great that moderately priced unit was”. Yes, I know that I replied, and also that a number of manufacturers use the unit as the basis for their own brand DVD players. He replied, “yes, but it has to be extensively modified – get a better player”. I remembered that probably the best CD sound I’d heard in my listening room was about a year and a half ago with a 35 pound Denon model DVD-5000 THX certified, HDCD and DTS compatible player.

I did not purchase it then, because I also mistakenly assumed that by now I’d be using a 5 or 6 channel DVD-Audio model player in my listening room. I’d hate to guess how much longer I’ll be waiting; its probably only going to occur in my home theater room. So, I called David Birch-Jones of Denon and he found one for me in California and had it shipped right out to me. The model had been discontinued many months ago because so many others like with me were not spending big bucks on a DVD player “that was to soon be obsolete” and unable to output the extra channels of the someday forthcoming DVD-Audio discs.  Are you one of those still waiting?

Now the comparisons between CD and LP became less immediately obvious. Herron had also told me that no currently available commercial source of digital playback can compare with the sound of his master tapes and first generation copies of master tapes that he uses for listening comparison testing. He also said that his opinion is that no digital source equals a good LP played on a good turntable/arm combination using a fine phono pickup cartridge.

Continuing the chase, like there goes the furry little critter; the Denon clearly was feeding a much-improved signal to the Herron preamp. It was obvious that the transparency of the Herron preamp was revealing any and all the failings of the previous DVD/CD player as well as imperfections of any of the CD’s used. I want to make it perfectly clear that there was never any hint that the Herron preamp added to or exaggerated any distortion or flaws of the source’s signal. This characteristic indicates extremely low levels of distortion. I believe that I had grown so accustomed to added distortion products in the treble range that I at times thought the Herron’s sound reproduction to be sublimely soft.  If not that, then it was simply musical. Various instruments and instrumental details were being revealed for the first time in my listening room. I’m not talking about light taps on a triangle or soft high frequencies notes of the flute but happenings in the mid-bass to lower mid-range area. There was no obviously increased emphasis in the high treble ranges whatsoever, but there was a beautifully pervasive sense of clarity and dimensionality.  As expected, the bass response of the Denon DVD 5000 was impressively solid and powerful into the sub thirty Hz range with exceptional bass detail. Examples:

First up, I listened to one of my two favorite light classic/pop conductors, (the other is Arthur Fiedler) Frederick Fennell.  The album is another showpiece from Reference Recordings Beachcomber RR-62CD; I also have the LP. It features the HDCD process and presents a close perspective lacking only a bit of depth on soundscaping. Full, rich and solid with great detail results in a fun listening session.  Even with the particularly good bass quality of the Denon DVD 5000 player, the two strong drum hits on the second cut, Russian Sailors’ Dance by Gliere had some resemblance to a recorded canon shot – very impressive, but a bit different than I’m used to hearing in a concert hall.  Next, with one of their newest releases, RR-93CD featuring compositions by Aaron Copland, sound reproduction seemed even better. 

The superb bass response, a naturally full blooming quality with great power, should really turn on bass freaks. In fact, a couple of the drum strokes were almost overblown. All this was particularly apparent in the last movement of his third symphony. The beginning of this movement actually incorporates the section known as Fanfare for the Common Man. This part is well known and easily recognized on its own. Two easy listening jazz recordings help show off the Herron's musical quality. Listen to the fingering and detail of Ray Brown’s double bass on Days of Wine and Roses on Oscar Peterson’s We Get Requests album on Verve V6-8606 with runs up and down the scale; bass reproduction was beautifully and clearly presented. Also pay attention to the naturally full presence evident on the JVCXR series [0022-2] of Pablo’s recording of Duke’s Big 4; Duke Ellington of course.

I would sincerely advise all readers, after finishing this long overview and review, to click on our Archive icon and then the Viewpoints icon and scroll to Dick Olsher’s articles: Recommended Components Under the Microscope and Nibbling on the Audio Food Chain. I believe you’ll be glad you did.

Tube swapping is a popular pastime for audiophiles who enjoy tweaking.  If you change tubes even just tube brands in these units, Keith Herron assures you that you like distortion of some kind.  How’s that you ask?  Different tubes have different electrical properties. Different electrical properties wind up changing things like noise, distortions and frequency response. Herron was able to achieve exactly the same audible and measurable qualities from different tubes. All he had to do was change the values of some of the associated resistors, capacitors and etceteras. Therefore he simply chose one of the more consistent and readily attainable tubes and carefully matched his circuits to their inherent electrical properties. Change the tubes and you change audible and measured performances. If you prefer the change you prefer distortion, it’s that simple. The change could result in a brighter sound or a richer sound, but that change is not what the designer wanted, period. They are optimized for the factory supplied tubes; don’t change them. Herron's unique circuits operate the tube sections at low plate voltage and current for barely warm operation with long tube life. 

The RIAA (phono unit) filter is passive and was designed with both computer input (more than a hundred combinations) and listening into the final design. Finalization occurred 4/22 in 1996 and the PC board still carries the part 422 in memory of that event. Keith says that all those parts are still hand selected and only approximately five percent are selected and used! Neither unit has any global feedback. Further “his units, unlike some tube circuits, provide full frequency response from the lowest low to the highest highs”.  My listening evaluations support that premise fully.

Firing up the VTPH-1 Herron phono preamp gave subjectively similar results as with the basic VTSP-1A pre-amplifier, only more so and then some! To say I was impressed is a bit of an understatement.  I really starting pulling out and listening to a number of pop and jazz records that I simply do not listen to when reviewing components. The dynamics were wondrously convincing.  Previously obscured instrumental details immerged from most of my LP’s and some recordings I thought to be just so-so were revealing hidden beauty. Unfortunately some of the so-so recordings were revealed as being a bit worse that I had previously thought, as a result of the greater clarity/transparency provided by the Herrons; faults were not exaggerated in any manner, nor more irritating, just more disappointing. I had difficulty in segmenting my thinking about just certain areas of reproduction. The total experience was routinely getting in the way of trying to dissect for purposes of review explanations. Examples:

Listening conclusions with my vinyl recordings added to my musical enjoyment. There was generally a feeling of fullness and natural roundness (three-dimensionality?) to the soundscaping created.  Frequency extension was at least as good and seemingly a bit better and smoother in the high end; all this in comparison to CDs. The joker in all this appears to be the fact that it has been common for many if not most, companies to deliberately roll off the bottom end response of full range (usually classical) recordings.  Some of the best companies, in more recent years, such as Reference Recordings and others were giving us everything on their LP’s. The RR-62 album, Beachcomber, mentioned previously does not take second place in any way compared to the CD.  In a vice-versa switch, I was very pleasantly surprised to hear how excellently a more recent CD remastering of old recordings can turn out. Specific example being a Mercury compilation album produced in 1993 [434-308-2]. The suite from Rimsky-Korsakov’s “Le Coq d’Or” was recorded in July 1956. In a few respects, it may surpass the original LP. Extended listening sessions over the past months revealed that some old Mercury LP’s and many of their few Living Presence series of CD’s have a particularly natural and full deep bass response. 

Exactingly, that translates to the bass sounding and feeling much the same as in the concert halls I attend most often. A final mention is for an old favorite, Saint-Saens Third (Organ) Symphony [EMI Greensleeve Label ESD 7038], at one time also available on the U.S. Kapp label with equally excellent sound. I treat the first movement (not the audiophile approved finale) as one of the most sublimely beautiful compositions I’ve ever heard. I’ve never heard it sound it so beautifully natural, and the deep low-level pedal note near the end accents it all with feeling.

Audible perfection may not yet be here, but the Herron phono/preamp combination is fully satisfying to me audibly. If I could talk Keith Herron into a couple of functional changes I’d be satisfied in every respect.

If I had to sum up the Herron combination in three words, I’d chose: musical, musical, musical or perhaps musically unbeatable or music lover’s pre-amplification or vinyl superiority emphasized.  If translation is needed let me try by saying that any music lover would appreciate the audible performance of the Herrons. Further, I believe that the superiority of Herron’s units is probably significantly better than any commercially available pre-amplifier that is three or more years old. I hope my opinion of the Herrons is perfectly clear. What about audiophiles? Are they different than music lovers and if so in what ways? What’s your personal well thought out answer to that? We have all heard it said that a typical audiophile has not listened to all the movements of a symphony or concerto “during the past two months” nor to an entire jazz session and so on. Audiophiles can never seem to resist dissecting performance parameters such as ”listen to those highs, wow – what dynamics, its really got slam, its got more of this or that or so on”. 

Typical audiophiles, yeah I know, none of you are typical, may not be quite as impressed with the Herrons as I was and am.  They certainly won’t be as impressed with just short term listening comparisons. Some of the superiority of the Herrons takes a bit of time to become apparent and I don’t mean they require a long warm-up period! Other pre-amplifiers (and one is sitting a few feet from the Herron) have more bass – but extended listening will usually reveal less detail in the bass to lower mid range area.  Many preamps will have apparently better, or at least more, highs than the Herrons – the result is usually what is called hyper-detail and typically results in listener fatigue. At times, the Herron may seem to be a bit soft or rounded, but it is all there and it is most certainly natural and musical, period. At this point in this summary I can say that less than 24 hours ago, as a member of the board of directors of the local playhouse, I attended the opening night of Meet Me In St. Louis. What a coincidence. Herron Audio’s hometown is in the title.  Our live musical accompaniment group had no more in the way of “highs or treble” then the Herron. As music lovers realize, much or most live music seems to have no readily apparent “highs”, the middle frequencies just seem to go on and on with no obvious change or demarcation.

In my mind, at times, I retain a slight question as to whether the Herron VTSP-1A pre-amplifier is fully the equal of the VTPH-1 phono preamp unit. I feel that I do not have any equipment, digital or not, that is a reliable reference input source for any really meaningful listening evaluation. Therefore, I’m basically evaluating both units at the same time. I would love to have either Keith Herron’s or Dick Olsher’s master tapes and play back machine to use – just for a couple of days guys!  Both Herron units use essentially the same circuitry. How can I consider the phono unit to be possibly unbeatable at this time while I’m listening through the Herron preamp unless I assume it’s fully the equal of the phono unit?  I’d like to know if there’s anything superior in the near luxury ($5,000.00 per unit maximum) price range. We respectfully request any manufacturer to submit any contenders for review at any time.

I’m very fortunate that my wife, Pat, is also a music lover. She’s also been impressed with the Herrons’ (both units) sound quality. When I told her it was time to pack the units for return, she surprised me. She said that she could tell that I hated to part with the Herrons. I agreed that was true. Lucky me, guess what I’m getting for Christmas? You’re right, now I don’t have to pack the units!

Addendum:

Before the Herron units arrived, I had conclusively determined that replacing the stock AC power cord of the PS Audio Power Plant with the impressive Dominus model by Audio Purist improved clarity, detail and high frequency attack and decay. My impressions, not yet proven to me, are that perhaps there was not as much improvement with the Herron units. A possible explanation, if true, is that the Herrons have better input filtering and rejection than some other units. Just before finishing the listening tests for this review, I had access to two more of these ultimate type of AC power cords form Audio Purist. I replaced my amplifier power cords (BEL Mark III units) with them and heard another slight but definite sound improvement. Particularly noticeable this time was the feeling of more power, solidity and control up through the upper bass range. If later listening tests do not fully support these preliminary impressions, I will report that to you.

* In my listening room, because of room problems and less than ideal loudspeaker placement, translate a rating of 98* to mean as good as any similar type of product listened to under the same conditions has ever performed as accurately as I can remember.

Keith Herron Accepting "Best of Show Award"

Editors Note: At the 2000 CES/T.H.E. Show the Herron Audio room won the Enjoy the Music.com Best of Show Award! Their room was, by far, the best sound being reproduced. Please click here to see more.

VTSP-1A Rear

VTPH-1 Rear

Herron Audio
12685 Dorsett Road, #138
St. Louis, Missouri 63043
Voice: (314) 434-5416
Fax: (314) 434-6629

Website: www.herronaudio.com 
Email: keith@herronaudio.com