Those of us old enough to remember CRT Televisions and over-the-air broadcast remember the magic of interference which would manifest as squiggly lines of white noise, usually horizontal, any time someone operated an electrical device in the house or neighbourhood. This interference was caused by noise over the A/C that would be picked up by the TV Tuner as RF. Well, the noise is still there even though Television technology has improved enough that it is not as noticeable, and it makes up a large part of the noise floor of your audio gear, which is why line conditioners are so popular among audiophiles. Unfortunately, inline (serial) line conditioners can be current limiting which is a real problem for say power amplifiers, thus to help deal with this problem we now have the Vera-Fi Audio LLC Main Stream – Master Class Dynamic Parallel AC Line Conditioner.

Vera-Fi Audio LLC Main Stream – Master Class Dynamic Parallel AC Line Conditioner

In appearance, the Vera-Fi Audio LLC Main Stream – Master Class Dynamic Parallel AC Line Conditioner is similar to the popular Vera-Fi Audio LLC SnubWay. It is Reuleaux triangle shaped, about the diameter of a high-end power cord connector, and about 4¼” deep (not including the tines). The casing appears to be aluminum with a sandblasted finish and a black aluminum end-cap, while the plug itself is clear plastic with copper tines (second only to pure silver in conductivity).  While the SnubWay concentrates on Switch-Mode Power Supply noise on the line, the Main Stream employs a combination of reactive elements to create tuned parallel filters designed to focus on frequencies within the audible frequency spectrum reducing the levels of noise specifically known to interfere with audio equipment to provide inky black backgrounds without impeding current flow. Vera-Fi Audio LLC’s topology excludes the use of any type of resonant transformer as a wave shaping device and rather only removes unwanted frequencies.

The bullet points from Vera-Fi Audio LLC are as follows:

• Capable of reducing system background noise to vanishingly low levels

• Reasonably priced

• Milled extruded aluminum case

• Designed for a long life of continuous service

• A faint blue glow shows it is working

• Laboratory tests prove the effectiveness of Main Stream via Fast Fourier Transform graphs

In lieu of printed specifications, Vera-Fi Audio LLC provides a printout of their actual test data. (Note: the Main Stream was originally named Puron 2 during initial testing)

Living with the Vera-Fi Audio LLC Main Stream – Master Class Dynamic Parallel AC Line Conditioner

The first thing I noticed was that the effects are not necessarily immediate. As soon as I received the Vera-Fi Audio LLC Main Stream – Master Class Dynamic Parallel AC Line Conditioner I plugged it into the closest outlet to my work area and left it to run for a few days at which point I noted that the ever-present hum of my computer speaker system had all but vanished.

Next it was time to break out my reference system: an LSA VT-70 Tube Integrated Amp, Audio-gd R2R-1 DAC, Black Dragon Cables, Core Power Technologies A/V Equi=Core 1000, Vera-Fi Audio VBH-1 (Vibration Black Hole) isolation feet, XSA-Labs Vanguard Loudspeakers, two Veri-Fi Audio LLC Vanguard Caldera 10 Active Subwoofers, and Dan Clark Audio E3 Planar Magnetic Headphones. If I have one complaint about my magical VT-70 it is its incredible sensitivity to external noise, in fact, I have to use a dedicated Music Server rather than my Computer as signal source as noise is transmitted from the computer to the amplifier via the USB connection to the DAC.

Booting up Qobuz and selecting Laurie Anderson’s new album “Amelia” (24-bit/96kHz) and was floored by the inky black background, which was especially noticeable listening to an artist who not only makes full use of high resolution by layering multiple acoustical instruments and vocals, but leans heavily into the dramatic pause.

On an impulse, I disconnected the USB from my Music Server and plugged it into my Computer to only be blown away by the complete lack of a noise that I could never find a cure for previously despite employing a host of different line conditioners. Cuing up “Wild God” by Nick Cave & The Bad Seeds and was even able to hear a slight tape noise that would sporadically appear in the recording that one would expect to be covered by the baseline tube noise, but there was simply no noise whatsoever coming from the equipment. If I stopped the music and turned the volume all the way up, I could barely hear the Computer noise, but as half volume is ear bleed levels, that put the noise floor significantly below the rated 88dB of the amplifier.

Conclusions on the Vera-Fi Audio LLC Main Stream – Master Class Dynamic Parallel AC Line Conditioner

The Vera-Fi Audio LLC Main Stream – Master Class Dynamic Parallel AC Line Conditioner was a real eye-opener. It’s not that I didn’t expect it to work, mains voltage is one of the primary sources of noise, especially in tube amps which can be very sensitive to external influences, it’s that it worked for things I didn’t think there was a cure for. It really is a must-have device, particularly if you are using high-power amplifiers that don’t lend themselves to conventional line conditioning, and I’d wager that if it was working in parallel with the Vera-Fi Audio LLC SnubWay the effect would be even more dramatic. On top of that, as audio tweaks go, it is rather unobtrusive and inexpensive.

It should also be noted that though designed for audio, the advantages of the Main Stream and SnubWay can bleed over into other devices such as TVs and Computer Monitors clearing up artifacts that you don’t even realize are there.

All in all, the Main Stream is an incredible value and an extremely simple way to improve your audio system without introducing any negative effects (such as changing the tonal balance, or reducing the dynamic range), two thumbs up, Vera-Fi has done it again.

$295.00

Manufacturer’s Website: https://verafiaudiollc.com/products/mainstream