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GmbH SVP-1 Preamplifier Review

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GmbH SVP-1 Tube Preamplifier

Opening Statement

I started my review of the Vacuum State’s RTP-3D (January 2007), their all-out attempt at a “state of the art” preamp with these words: “This is going to be a very easy review because this is a very special preamp. So let me just say it right up front, this is the most accurate, dynamic, coherent, and transparent preamp I have ever heard in my system. Does that mean it’s the best preamp I have ever heard? Well, that all depends on what you mean by best.”

In my conclusion of the RTP-3D review, I then said, “In my experience, the Vacuum State preamp creates its own new category. It’s not just a tube preamp that isn’t overly warm and lush. Of course it’s not a transistor preamp that sounds like tubes. No it’s a tube preamp that combines almost all the qualities of the best transistor preamps.”

My reason for restating these two points is that the SVP-1 is cut from the vey same cloth. In fact I think some people will even prefer the SVP-1. Though it is certainly not quite as detailed or transparent as the RTP-3D. The SVP-1 most certainly is accurate, dynamic, coherent, and is another member of the Vacuum State category of tube preamps that can match the strengths of the best sand preamps, and still give you the glory of the very best tube preamps.

Design Concepts

According to the VESI website, the SVP-1 was designed to be a sonically “state of the art” unbalanced full preamp, in a minimalist chassis, offering huge value for money. Let me just say right now they have hit the bulls-eye in each of these design goals. To do this, they used a hybrid tube & JFET phono section, and an all-tube line section, plus zero negative feedback in both phono & line sections.

It was also designed to have an extremely low output impedance and high current drive, as well as an exceedingly wide bandwidth: 5Hz to 1MHz minimum. They also hoped to have “state of the art” noise levels and an extremely accurate matching of channel-to-channel RIAA equalization so the SVP-1 can have superior stereo imaging. It was also designed to have adjustable gain (three positions) to suit low, medium or high output MC/MM cartridges and to provide adjustable cartridge loading by use of extra RCA plugs containing the desired resistance.


The SVP 1’s appearance is typical VSEI. That would be functional elegance and simplicity. It has a blue power light, the logo, a brushed silver input selector and a volume knob on the brushed silver front panel. It actually has many more useful controls hidden on the back and inside. Looking at the rear panel, we see 18 sturdy I/O connectors that help the preamp achieve its outstanding flexibility. This flexibility makes it easy to obtain optimum setup for your amp and cartridge.

The tube compliment is six 6922 dual triode vacuum tubes plus one FET per channel in the phono stage. It is used as the lower half of a cascode that provides gain for low output moving-coils. Allen Wright, founder of VSEI, says by using the FET only as the lower half of a cascade, he is able to keep the transistor’s sonic signature from being heard in this design. He says the tubes used in the upper half of the cascode dominates sonically. I want to point out that the line-stage is completely tubed and it still has the special non-tube, non-transistor sound even when listening only through the line-stage.

There is a cutout on the bottom panel. This cutout contains four removable jumpers. These allow you to adjust the phono stage gain to be matched to virtually any cartridge. It is also possible to adjust the line stage gain simply by changing the value of one resistor per channel. You can change the loading on your phono cartridge simply by changing plugs in the extra phono inputs on the rear panel. Unlike many modern preamps the SVP-1 even has a tape-out .

Setup & Break In

I simply set the SVP-1 on the shelf above my Shindo Masseto so I could easily connect either preamp to my Wavac EC300B amp; I left the rest of my system just the way it was for the review. There is a little more to the setup of the SVP-1 than most preamps because of how flexible it is, but it is all pretty straight forward.

The matter of break-in cannot be overstated. I found the SVP-1 to sound thin and overly detailed when I first put it in the system. I was surprised because it wasn’t brand new. Warren informed me that the preamp needed to be plugged-in and turned on for at least 24 hours before it would sound right; it doesn’t have to be playing music. Even though this didn’t make any sense to me I left if on for about 36 hours before I played it again. I was shocked to say the least. This is a preamp that should be left on all the time, which is the manufacturer’s recommendation. This isn’t the same as break-in but it is very important.

I used the SVP-1 with the Ikonoklast Model 3s, the Teresonic Integrums, the Lowther America Alerion, and the B&W 805S loudspeakers. It was great with all of them, but it was special in the way it worked with the Lowther America Alerion.

First Impressions

The first thing I noticed about the Vacuum State SVP-1 was how much it sounded like its big brother. I wouldn’t have believed this possible considering the price of the SVP-1. There was that unbelievable lack of coloration and the bass had real punch and yet it was very, very tight. Then, like its big brother, there was that unique ability to sound like neither a valve nor a transistor preamplifier. I don’t know how Vacuum State accomplishes this, but with both the SVP-1 and the RTP-3D they clearly have this quality.

The Sound

If there is one thing I have learned in 35 years in this hobby, it is to be wary of components that wow you right off the bat. The reason is they almost are never musically satisfying in the long run. Nothing about the Vacuum State SVP-1 preamp jumps out at you and says “don’t I sound spectacular?” I think it is safe to say that you will find it very musically satisfying day after day for years to come. I surely have for the last few months.

Information and Detail

The SVP-1 is in the top echelons of detailed preamps that I have ever heard. I never noticed any loss of detail. Thank goodness, all that great detail and information doesn’t come with that razor sharp sound some detailed preamps give you. Neither does it shine spotlights on things that aren’t meant to stand out, in the way so many fast, detailed transistor preamps do. In fact, just the opposite is true. The music just flows naturally. I’m using the word detailed to talk about how much information it conveys. This ability to produce detail so naturally also allows it to be one of the best imaging preamps on the market; more on that later.

Scale, Dynamics, and Power

There is a lifelike naturalness to the sound of the SVP-1 that is very easy and fun to listen to. It never sounds like it’s trying to impress and it never seems to strain. Yet it is not overly warm or syrupy smooth. It is also an incredibly dynamic preamp, but it can play soft, whispering, and gentle music when it’s called for. Not only is it dynamic, but it has superb micro-dynamics as well.

I did not find the VSEI RTP3d to have the scale or the bloom of the Shindo preamps. The SVP-1 has the scale, but still not quite as much bloom. Allen would say this is because of the lack of coloration. He may be right, but I like the scale and bloom of the Shindos.

The Midrange and Top End

It should be said that the SVP-1 is a fluid, sweet preamp with a natural, musical sense of presence. This preamp allows you to relax and enjoy the music. It is very neutral and natural in its sound. It invites you to listen deep into a musical performance. Let me say it one more time: This preamp has a midrange that is very accurate, dynamic, coherent, transparent, and musically involving.

Voices and instruments are clear, right in the room with you. They are very tightly focused, articulate, but never etched-sounding. The coherency of the preamp keeps voices or instruments in their place even as they go up and down in frequency. Between the preamp’s coherency and tonality, instruments sound like themselves.


I now need to talk a little about the fine bass of the SVP-1. In the review of the VSEI RTP-3D I said, “the bass is the tightest I have ever heard from a tube preamp, I think from any preamp.” Well I’m just going by memory, but I feel the same way about the bass of the SVP-1. The bass is one of the areas that the Vacuum State preamps that makes me say they seem to have created a whole new category of sound, for they sound tighter and quicker then tubes. Yet, the bass has more air and life than transistors.

Soundstage and Imaging

In several of my reviews I have said, “I don’t want strings floating around in some black velvet space like some modern painting that show strings and notes but no instrument or musician. I want to hear the body of the guitar, I want to hear the floor under the bass, I want to hear the sound of the strings inside a piano.” The SVP-1 doesn’t commit any of these transgressions. The SVP-1 produces the most natural soundstage I have heard. It images precisely and is very tightly focused. The soundstage is very wide, very deep, and everything has its own space in the soundstage.

Yes, it places instruments and voices all over a three-dimensional space, but not like they’re hanging in space, but like they are occupying space. Combined with the Wavac EC300B, and the Lowther of America Alerion loudspeaker, I get the most incredible lifelike soundstage and imaging I have ever heard. It is spacious and rock solid at the same time. I don’t know what else to say about the soundstaging and imaging. It will surely depend on your amp and speakers, but be assured it possesses the potential for world-class soundstaging.

Pace, Rhythm, and Timing

I know that many audiophiles and reviewers say that a piece of equipment can’t have pace, rhythm, or timing, but you know by now that I feel those are qualities of the performance that good equipment allows the listener to hear and feel. Admitting that truth, it seems obvious to me that some equipment allows PRaT to flow into my room much easier than others. This was the only area where I felt the Vacuum State RTP-3D was less than the very best. I have no idea why, but the single box SVP-1 seems slightly better in this regard. It may not still be on par with my reference Shindo Masseto, but its close, very close, and that’s at nearly half the price of the Masseto.


How does the Vacuum State SVP for $6300 sound as good or better than many preamps that cost much more and sometime much, much more? Simple, Allen Wright has applied all of his best to this design, and chosen very carefully where to save money. I am pleased to say the result is a preamp that is capable of letting us hear music.

Comment From Vacuum State GBMH:

Jack’s review is very, very good. In the time Jack had the SVP-1 in his system, we have designed and put into production its successor – the SVP-2. It is EXACTLY the same design, parts, circuit and appearance, with a few changes mostly to make its construction easier and more consistent. But a few new features have been added to help the owner:

* Compared to the SVP-1, the new SVP-2 has one extra line input, bringing the input count up to 6 – one MC/MM phono, one specific digital line, and now four general line inputs, as well as keeping the tape output and two main outputs. The back panel is quite full!

* The phono gain selection has been reduced from three to two, as two have proven to cover all the cartridges likely to be used by an audiophile, but we have added two levels of line stage gain selection to further help integrate the SVP-2 into systems that may use very different sensitivity speakers and/or amplifiers.

Today, it’s not unusual for one client to have an 82dB/watt mini-monitors, and another to own an 102dB horn, a massive 20dB/watt difference. An adjustable gain line stage can really help here to keep the volume control knob in a sensible position – and not crushed down in the 7 to 8AM position on the dial.

* These gain selection sockets have been moved from the underside to the rear panel, making them easier to access.

* Jack comments on the SVP-1 not quite being able to match his Shindo preamp’s “bloom” and “PRaT”. Shindo owners seem to be a very specialized
group, loving what the Shindo’s do. Personally I find this “bloom” and “PRaT” comes at the expense of a good dose of second harmonic distortion, and I for one prefer the ultra-low distortion and clearly defined “space” of the Vacuum State designs, finding it closer to what I hear at a live acoustic concert.

I believe Jack has written a great review and captured the essential points of a design that we feel very proud about – and I thank him for the review, and you for publishing it.

Allen Wright (Founder & CEO)
Vacuum State GmbH

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