World Premiere Review!
The letters VAC is not an abbreviation for vacuum, although the VAC Renaissance Mk V does have five miniature twin triode vacuum tubes on board. The company banner is actually an acronym for, Valve Amplification Company. This Mk V preamplifier is something entirely new in the VAC lineup for 2017. There is a basic MkV line stage preamplifier without the phono stage that sells for $9990. That configuration uses just two miniature Dual Triode tubes. The Renaissance Preamplifier Mk V, under evaluation here, contains an optional MM/MC (moving magnet and moving coil) phono amplification stage that adds three additional 12AX7 tubes. With the optional phono stage on board, the cost increases to $12,990. Interestingly, the VAC company are not very specific about the exact type of tubes required. The specification tells us that you can substitute the following, 6DJ8 / ECC88 / E88CC / 6922 / 7308 as these are once again all similar miniature dual/twin triode vacuum tubes.
The Body Of Evidence
Directly in the center of the front panel is another rectangular opening containing four items, they are an LED that is illuminated red when in standby and green when the tubes are warmed up to operational status. Next is a switch to turn power On or to Mute the output. Next to that is another two position switch labeled Mode, Stereo or Mono. Switch to mono operation and both channels are summed for a mono source. Lastly, within that cutout area is the Remote Control sensor. Farther to the right on the front panel you will see two black knobs. First is the Volume control, next to this is a three position source Selector switch labeled very simply as 1, 2, and 3.
Around back there are some unconventional things going on. The three line source input connections are designated as L 1 and L 2. The third switch position L 3 is intended to engage either of the two separate MM/MC phono cartridge inputs. Of course L 3 selects only the single active phono input and these cartridge connections are all unbalanced RCA jacks. Very unusual is the built-in phono amplifier, which is in two parts and housed in two separate areas at the rear chassis. On one side there is a section for Moving Coil (MC) cartridges and next to that is another separate section for Moving Magnet (MM) cartridges.
The first MM section provides the gain and RIAA equalization required for basic phono playback. This is the heart and lungs of the phono stage, as it were. The MM jacks have independent loading at 47 kOhms and 100 picofarad, as is appropriate. The MM/MC switch disconnects the MM jacks and connects the gain/EQ stages to the dedicated MC input. The key features of the MC input are two precision, wide-band step up transformers actually the same type found in the VAC Statement Phono Stage and a dedicated variable resistive loading switch. So, MM and MC share the tube gain and EQ sections, but have separate input, loading, and MC gain provisions.
There are six preset resistive loads built into the MC portion. So on the left rear panel there is a knob to select the resistive loading for the MC cartridge input. They are, 50, 80, 125, 200, 300, and 470 Ohms. And on the right rear side of the amplifier is another knob used to select either the MM or the MC amplifier input. The thing is of the four preamplifier input source connections two are RCA unbalanced phono inputs that go to the MM or to the MC amplifier. This permits only one type of cartridge to be used at a time and only with unbalance cables.
The remaining two line level inputs L1 and L 2 (on my sample) have dual provisions for either unbalanced our balanced connecting cables. So what you will find is a bit unusual. Right alongside of each type of input there are RCA jacks for the left and right channels and also two left and right channel XLR jacks. The same two interconnection choices exists for input L 2. Therefore both types of cabling may be used to drive the L1 or L 2 inputs. However on the bottom panel of each input L 1 and L 2 there is a small two position Grounding Switch. You must set that switch to match the line cable you are using and so you cannot use both at the same time. This feature was saved for last for clarity.
In appearance, the preamplifiers output cables can be unbalanced RCA or balanced XLR, which is similar to the L1 and L2 input connections. They may look the same, yet these are the Mk V preamplifiers output connections to the power amplifier. You will find them on back panel next to L2. Lastly, there is a third set of unbalanced RCA jacks and another set of balanced XLR connectors that allow you to drive a power amplifier with either balanced our unbalanced cables. Here is my one complaint. Even though two of the input spaces are taken by the optional phono amplifier, I still wish that there was one more line input available as audiophile reviewers have many pieces of gear.
Plugged In And Powered On
The amplifier is a study in what a very modern tube amplifier sounds like, true to the source. Luckily, there is a slim glimmer of audiophile hope and that has to be about a certain liquid harmonic structure. So you sit and listen and at first nothing sticks out and everything just sounds correct. You need to get your mind into a quiet place and once you get there specific tonal textures emerge. VAC's Renaissance Mk V preamplifier with MM/MC phono stage has an organic quality that can touch your emotions. If only honest human feelings were present in all music. But then it must be captured at the source from a stage or in the studio. No matter if it be from magnetic tape, vinyl LP, digital compact disc, or digitally streamed to you.
Unfortunately, this heartfelt and truly organic quality is getting harder to find. As I write this, the recording of Judy Garland's concert at Carnegie Hall is very much present in my thoughts. Yes that's a vinyl recording, and that "you are there" intimate quality is hard to find on a compact disc. But there is a possible compact disc contender that qualifies based on shear sweeping raw emotion. That is the CD album, Nils Lofgren Acoustic Live. For people who have attended a recent high-end audio show, surely you must have heard "Keith Don't Go", since that CD track from the album was played in more than one room.
This is very close mic'ed recording capturing the explosive transient impact of steel guitar strings. The VAC Mk V pre with phono stage gets the transient impact and the strings metallic bite, plus the reverberant diminuendo of the guitar body perfectly. At this point we are not done, as we still need to explore dimensional imaging and what appears in the space between speakers. This is a must on the "must have list", and for that we have to explore that quality on vinyl.
Flipping through my stash of flea market finds one after another, the quality all proved to be just mediocre. At the risk of repeating myself, please allow me talk about Another Page by Christopher Cross. This studio album Is a favorite because of the clarity and depth complexity of the center image. The first cut side two, Its "All Right" the backup vocals repeat the phrase, "Its all right I think we are gonna make it". The spacing between those voices in the center are well defined. The tonal inflection and timber in each voice comes through with perfect clarity. The fast paced tempo is pure energy driven by a bass guitar and key board. This makes for an excitement laced complex instrumental arrangement. So far no surprises, this is what I'm accustomed to hearing when playing this recording with my Adagio Phono amplifier.
VAC On Vinyl
During this audition I find the stereo image now has a deeper center stage. The backup singers are spaced more clearly as separate individual entities inhabiting their own reverberate space. This combined with a very unexpected continuance. This is a word Harry Pearson once used to describe a gradual natural decay of a musical tone. More simply put every musical component seems to fade into silence in a very natural way.
What's going on? Every minute detail revealed by the VAC Mk V I believe can be accounted for by one supremely important characteristic. It does portray a stereo stage overlaid by a deeper quieter blacker back ground. Because of that, everything is painted in greater relief.
The VAC Renaissance Preamplifier Mk V with MM/MC phono stage
Phono Stage (optional)