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Vacuum State Electronics - FVP5A tube preamp kit

what the manufacturer himself listens to...
[VSE preamp mainframe]
[Italian version]

Product: FVP5A tube preamplifier (readily built, kit, or circuit)
Manufacturer: Vacuum State Electronics - Allen Wright
Approximate price: US$7500 (built), US$3530 (complete kit), US$800-1000 (phono/line modules)
Reviewer: Werner Ogiers
Reviewed: November, 2001

Having read my Tube Preamplifier CookBook review you know I have been counting the days until I got one of Allen Wright's creations where I wanted it - between my own turntable and power amp. More specifically the single-ended FVP5.

True, I could not get a production version of that preamp: instead it had to be Allen Wright's personal development platform, evolved over two decades from one of the very first preamps ever made by VSE.
The circuit itself was the latest FVP incarnation, 5A, meaning a hybrid FET/valve two-stage MC/MM phonostage with passive RIAA, and a full-valve cascoded line amp (older versions used valves and MOSFETs in the output stage). The power supply comprises one SuperReg serving both channels - Allen's AD797 opamp-based shunt regulator, itself a beasty of fairly high complexity. The differences with the 'real' FVP?
Well, for starters, what you can order through Vacuum State, be it readily built or supplied as a kit of components and modules, has a beafier power supply transformer. Then there is an impressive and large custom-built case, more a mainframe for accepting the myryad of circuit boards/modules available from VSE. (Incidentally, this VSE mainframe supports regular Wright-designed circuits as well as alternative versions and even circuits like the Loesch preamp.) And then there is of course the issue of component choice: the demo FVP had Sovtek 6922s and Audyn KP-SN foil-and-polypropylene caps. Not extremely fashionable, perhaps, but remember, this is what Allen listens to.
If you want more, there is more, VSE selling now their own secret KP capacitor which recently got out at the top of a German capacitor shootout.

[FVP5A schematic]

Fully aware that I had a lab prototype on my hands, I ignored all cosmetics (or lack thereof) and operational foibles (occasional loud bangs in my fridge-infested garage/workplace, but, please note, troublefree operation in the main system in the living room). No, this machine was in purely for its sonic performance.

A quick sanity check on the workbench, operating at MC gain with a Thorens TD-160 and AT OC-9 cartridge (or did you think that only the Japanese could dream up impossible combinations?), proved that the FVP excelled in speed. There was plenty of gain, and not really too much noise.

Soldering out two resistors reduced the gain to what I needed in the main system, and after the move over the following was noted: if you want a cuddly tube warmth then forget it. I know solid state stuff that sounds more like tubes (or rather: tube vices) than this one does. No. The FVP5A sounded effortless, unforced, and impressively unimpressive. What do I mean with that? Well, there was a lifelike naturalness which made other equipment sound like it was so obviously trying to impress. Which, of course, doesn't...

[Preamp mainframe]

So dynamics were there, in full glory, explosive when called for, soft and whispering when required. This brings me to one of two aspects in which the VSE FVP5A bettered anything I've heard before: portrayal of drums and percussion. Insofar my Quad ESLs could replay these sounds, this was really it.

Of course, this has to do with the exemplary speed delivered by this preamplifier. Tonally this was reflected in a seemingly boundless treble (remember that this is one of a few phonopreamps that corrects for the real RIAA curve used by actual cutting lathes). The speed also showed up as an overall balance that is slightly lightweight. Take Geoff's Audion for an example that sounds decidedly more rounded and massy. However, I can imagine that the production version with its larger power section goes some way in redressing this. And even then it might be a matter of taste: I used the LFD power amp which on its own isn't exactly lush.

On the other side of the scales, we find a bass that is well-extended and tight and detailed. Playing at rather high levels, in a large room, and with my old Magnepan speakers, this made a real impact. But it wasn't just bass, no, rhythm was there too, and in abundance!

I said above that the FVP5, to me, is of reference calibre in two respects. Well, the second is imaging. This unit consistently put down a picture of width well beyond the loudspeakers, and of a depth and architecture that I deemed impossible in my room: I haven't heard this before, I think it will be a long time before I shall hear anything like this again!

Concluding

So as you have gathered by now, the VSE FVP5 made for some very musical listening experience. Fine dynamics and utterly astonishing imaging render music replayed though it into something so much more lifelike, real and above all interesting, than often is the case with audio systems.

Rests me to say that I only used LP replay to come to these conclusions. I don't think I have a digital source at hand to do this wonderful preamp any justice. And frankly, I also think that those building/buying a VSE component are, before anything else, interested in the replay of vinyl, not?

system used

  • turntables: Michell GyroDec MkV/VC with Orbe platter, Michell GyroDec MkII/QC, Thorens TD-160
  • tonearm: SME IV, Thorens TP-16
  • cartridges: Benz Micro MC Scheu 1.6mV, Audio Technica OC-9
  • CD-players: none!
  • power amp: LFD PA0
  • loudspeakers: Quad ESL-57, Magnepan SMGb
  • interconnects: solid copper in Teflon tubes

Geoff's verdict

This was one of those reviews where time and circumstances conspired to allow a dual-test. I made the first contacts with Vacuum State, and Allen was eager to oblige. Combine this with a planned trip to Brittany and it was obvious that Geoff too would have a listen to the FVP. Eventually I got tied up rebuilding part of the house we just bought, and so the FVP first was sent off to France. These are Geoff's findings. Note that Geoff used the FVP5A in high-gain mode (I did so in low gain mode), comparing to his own low-gain Audion preamp plus the Dynavector current-mode step-up device. So in case of the VSE pre, Geoff's resident Dynavector DRT-1 cartridge saw a high 47k impedance, while driving the Dyna/Audion combo it saw the zero Ohms of the current input. Quite a difference. - Werner

After having read Allen's two books, the first on pre-amps, the second on cables, I was intrigued to see what happened when all this was put into practice. And so a month down the line I was presented with a large cardboard box by the deliveryman. Opening it all up revealed a much loved, modified and abused (?) pre-amp, indeed the one that Allen uses himself to try out new ideas. In effect it was up to full FVP5 spec but the disconnected balance controls and jury rigged phono switch showed how it was a "mule". Cosmetically it looked like a 20 year-old integrated, not a state-of-the-art valve pre-amp, and I even had to remove the top cover as the extra valves would generate too much heat for the 'old' slots. BUT I was expecting all this, Allen assured me that under the bonnet it was cutting edge and directly comparable with the production FVP5A.

[An older version of the FVP]

What did surprise me though was the weight. Generally hi-end amps are sold by the pound and here I had something that felt like a budget CD player. The thin alloy casework provided part of the answer but the main reason was the small mains transformer: not a lot bigger than the "wall wart" freebees. My own Audion Silver Knight pre has an off-board power supply that must weigh two times as much as the complete FVP5. Looking further the whole thing was wired with very fine solid core copper wire as per the Wright pre-amp book.

So I was faced with a pre-amp that I'd guess was worth 200 to look at. p> Sound.

Plugged in and warmed up overnight the sound that greeted me was certainly NOT of the 200 variety!

So what makes this ugly duckling into a swan? First comes that most difficult trick, producing a realistic soundscape. I have a copy of the Sheffield Labs 'Harry James - King James', a disc that is so far ahead of almost any other recording it wants to make you string up every marketing exec, producer and recording engineer by the thumbs until they promise to match it. It's recorded, direct to disc in a chapel, and boy can you 'see' the walls with the Wright pre. It's not clinical, stripping bare every instrument, rather there's a big orchestra bound between (and beyond) the speakers, and reaching both way back and slightly in front of them. The music is not totally to my taste but the intoxicating rasp of brass, the tight drumkit and sheer energy mean it's a disc that's almost impossible to take off... This is high-end stuff no matter what the box looks like.

My own Audion held up its end well here, producing a slightly more energetic and meaty rendition, albeit lacking some of the FVP5's depth and precision. Here I point the finger to the Dynavector step-up I used with the Audions MM stage. This is an amazing device endowing any top MC with a power and weight you'd not believe. Here the FVP5's MC phono stage missed out, and substituting the Trichord Dino and squirting this direct into the Audion did rather redress the balance.
I might add that the Dynavector step-up was designed specifically for the DRT-1 and as such is a stunning match (at a price). That the FVP5 should fall behind a little in direct comparison is then less of a surprise. Werner did also point out that the FVP5 wasn't loading the Dynavector to it's optimum 30ohms so...

And these basic characteristics continued through the raft of records I played over the next month. Where there was detail, soundstaging or rhythm to be found on a disc the Wright pre picked it out. It was extremely neutral (compared to direct feed to the power amps) and indeed natural. "Take Five" is a great test for this as though a great recording, it hasn't been messed about with.
The result being the most beautiful sax and piano tones, the kiss of hammer on string, the 'wet' of the reed - lovely... Compared with the power amps driven direct the FVP5 gave the sound a solidity and presence leaving the 'naked' power amps sounding edgy - the different elements of the orchestra coalesced into solid images rather than the relatively unfocussed blur of the direct feed. Only when forced to go completely "over-the-top" as with Nirvana's 'Breed' did the Audion leave it sounding a little weak.

I suppose you want to know what it sounded like on CD? - Well when I got round to it, it continued to shine - natural, fluid, detailed. But again the Audion was a tadge meatier, perhaps more manipulative but in the end more fun with the kind of rock music I often listen to. Playing Jazz split the two, though the Audion could sound a little 'thick' at times in comparison with such an elevated performance.

My Conclusions?

Resolutely high-end, the FVP5 offers a neutrality and 'beauty' that you can just guess costs a lot. It's a very difficult beast to fault, in the entire month it never missed a beat and the general performance left little to be desired. It's very much a 'low colouration device', a category that I'd put the Cartridge Man's 'Music Maker', the 47Labs Gaincard power amp and the Euroacoustics EA-140 speakers in. In direct comparison it was an easy match for my own valve pre, though I guess that if forced to choose I'd go for the Audion for the sort of music I prefer. If I played more jazz or Classical the tonal purity and openness of the FVP5A might well pull me the other way.

Geoff Husband

© Copyright 2001 Werner Ogiers and Geoff Husband for TNT Audio Magazine (http://www.tnt-audio.com)

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