The Virtu preamplifier is a rare feat, indeed. The physical size of it is imposing from a conventional preamp standpoint. The masterpiece K10 preamplifier by Robert Koda weighs over 50 pounds for just one single chassis. The Virtu is over 90 pounds, similar in weight to the Tidal Impact Stereo amp. The sheer weight of it comes primarily from the hand-wound transformers made by Peter Brem. There are a total of six transformers inside the Virtu. It consists of two input transformers, two inter-stage transformers and 2 output transformers for both channels. The 1st stage has amplifies 10db, and the 2nd stage 14db. The power supply is a regulated between -12v and +22v. The size of it is small relative to the main chassis.
The circuit design is unconventional. The position of the volume control is located at the very end of the circuit. That literally means all incoming signals are always amplified in full amplitude as there is no disruption in the signal path until the end. With this design, the path from input to the potentiometer is always totally opened. The big volume control on the right is an attenuator determining how much signal is allowed to be amplified. The concept is equivalent to a passive amplifier but the Virtu is an active line-stage that requires a power cord.
The gigantic gain switch is used to reduce/increase should incoming gains from DAC or phono stages is too high or too low. If the gain is too large causing an overload, a small light in the color of green for left and red for right channel starts blinking.
Under the transparency of the Tidal Sunray T1 system, I have to do many preparations before formal evaluation can be properly conducted. The Virtu is moved to place atop the Ohio XL+2 platform by SRA. Even the small power supply has its own SRA board. A master reference ground wire by Tripoint was used in between the almighty Troy and the Virtu main chassis. The Argento Flow is chosen as the power cable for the Virtu. A pair of FMR RCA is used in between the Vekian dac and the input of the Virtu. The Virtu is then connected via FMR XLR to the Calysto mono amplifier by Analog Domain GmbH.
The Virtu preamp took about 30 minutes to stabilize. I speculate it will take weeks to fully mature. One thing that strikes me right at the beginning is the dynamic capability of the preamp. In fact, I had to toggle the gain switch at the back of the Vekian DAC to “low”. If not, the presentation will become too forward. This is interesting because I always listen with high gain with Tidal Prescenio. Nevertheless, the fact that the Virtu has a totally open path from input to output explains the immediate feeling of power and dynamic.
There are tremendous of things going on in the musical scene when I played Dave Brubeck’s Live Recording at Carnegie Hall. All these actions are presented in a holistic perspective. Localization of different musical objects is less precise than the Tidal flagship but all the ongoing motions inside the recording renders an atmosphere of “you are there”. The whole musical picture is uncut with a tonal balance slightly bias towards the warm side. I can detect very small details moving in motion even at the farther end of the z-axis. At the same time, the musicians at the center of the stage started playing their respective instrument with their bodies moving. At certain interval, I feel as though one guy was kicking the double bass. The revelation of extreme minute motion everywhere is quite a new experience. With the Tidal Prescenio, all the minute details are equally there but they are presented in a calmer manner. I am still adjusting to the new perspective. Put it this way, with Tidal Prescenio you can even see the edge of the soundstage or even the ventilation exits somewhere in the ceilings. With the Virtu, I could feel the "summation of all minute motions" within the recording venue that defines the virtual space. Think of it as a bottom up approach to build up the soundstage.
I don’t want to rush any statements until time allows the machine to mature further. At this level, everything is relative. Subjective preferences dictate the result in the end. Probably, I need to change cables to get a different impression first. The speaker positions also matters because the energy interaction between the speakers and the room has changed. No meaningful comparisons can be done without speaker positions adjustments.
To be continued……