Valve Amplification Company (VAC) Essence 80 iQ Monobloc Amplifiers by Don Shaulis


VAC Magic in a Small Package

At the many audio shows I attended, few rooms stuck in my memory, but one brand did—Valve Amplification Company (VAC) equipment powered many of the best-sounding rooms. By powering, I am being inclusive of the entire analog line between the source and speakers including the phono stage and line stage. Except for my all-time favorite room by a lot, The Force from PERFECT8 Technologies, I hardly remember any VAC-powered speakers. I remember how frequently and consistently VAC captured my attention. I remember entering rooms with speakers I had not previously liked and gained a new appreciation following a change in amplification to VAC. I vowed to have VAC magic in my system someday.

I started my journey with VAC with the excellent Sigma 170i integrated I purchased during my “integrated phase.” My thoughts were to keep cost and space requirements down and performance up. The Sigma 170i certainly fulfilled that desire nicely, and I highly recommend it. But I am sure my wonderful readers are familiar with the story. There is no rest for the wicked or an audiophile, especially if the audiophile is wicked.

Inherent audiophile restlessness and a new home provided me space to expand to two systems and a partial return to separate components. After adding a VAC Master line stage to my main audio system, I wanted to match it with a VAC tube amplifier. To my disappointment, the smallest VAC amplifier, Signature 200 iQ, weighed 100 pounds. That was a nonstarter. A torn rotator cuff tends to limit equipment options. The Master line stage is large and heavy but comes in two chassis. I could handle either without assistance or risking a friend’s back helping me, and it did not require seasonal swapping. VAC does make two-chassis amplifiers, but the weight of each chassis exceeds my limit. I wished for a VAC amplifier in a weight I could manage.

My wish was answered with the introduction of the Essence line of small-chassis components consisting of a line stage, phono stage, and monobloc amplifiers. At 40 pounds each, I could handle the Essence 80 iQ monoblocs (Essence 80s) without risk of injury. With a 9″ width, two can share a single shelf space. In my system; they share a single 21″ wide platform of 1.875″ walnut butcher block topped with a Symposium Acoustics Svelte platform and Rollerblock Jr. HDSE footers. Now, I could finally have a larger taste of what I heard at shows playing in my home and a perfect companion to the Master line stage.



Tweekgeek2017.gifEssence 80s are rated at 85 watts RMS continuous into 4, 8, or 16 ohms with separate taps provided for each. The tube complement is a matched pair of Gold Lion KT88s and two NOS Philips 6189W (12AU7 type) per chassis. The amplifiers incorporate VAC’s patented iQ Continuous Automatic Bias System and protection circuit. Early production units only have one input, so buyers must specify either the single-ended or the fully balanced version with direct-coupled input and output driver circuits. Kevin Hayes informed me that later production units will have dual inputs with a switch to select between single-ended or balanced. I chose the fully balanced version because my system is on two walls, and I use a 5.5-meter pair of Cardas Clear Beyond XLR cables to connect the Essence 80s to the VAC Master line stage. I also connect the line stage and monoblocs with a trigger cable. Now, I am spoiled. This is the first time I have been able to power amplifiers on and off with no extra steps.

VAC’s patented iQ continuous Automatic Stable Bias System is designed to keep each power tube’s true underlying idle current steady regardless of tube temperature, tube drift, input power variance, or load. This leads to a stable relationship between the output tubes and the speakers. While I do not understand the technology behind iQ, I can report on the results. My Sigma 170i also has the iQ circuit. Its performance was rock solid with every speaker I used, including my Sound Labs (reviewed here). Their inherent stability is why VAC amplifiers are partnered with many different speakers at audio shows with memorable results.

VAC claims the iQ System extends tube life and reduces distortion and noise. The VAC iQ System monitors and controls in real-time and alerts users when a tube is growing weak or has failed. In addition to improved sound, tube failure is reduced, and tube monitoring is enabled. Two LEDs on the front panel are used to indicate tube health. Each is designated for a specific power tube. If an LED glows green, it indicates the associated tube is weak. The amplifier will increase bias until the tube is replaced. If the LED glows red, the associated tube has a more serious problem. In the case of a serious tube failure, the iQ system detects the problem within a fraction of a second and shuts down the main power supply faster than the fuse can react. This protects both the amplifier and the associated speaker.

Each monobloc utilizes a 14-pound transformer and Cardas rhodium-plated binding posts. There is one more LED underneath the power toggle switch. It is small, green, and subdued. The chassis is machined from thick aluminum and is in the same style as its larger kin but lacks the familiar blue LED VAC logo. Like other VAC equipment, the monoblocs are available with either a black or silver fascia.  


The Essence 80s are everything you would expect from VAC. They give the best of solid state designs with the extra warmth and harmonic structure of the best tube designs. They are very detailed, nuanced, and musical. They are also truthful and revealing. While your best recordings will be enhanced, the Essence 80s will not magically cure harsh recordings.

I have heard too many systems that did not engage me because there was no definite center. Although that may primarily result from speaker placement and listening distance, amplification cannot be excluded. Paired with Sound Lab speakers, Essence 80s produces a spacious and holographic soundstage while maintaining a solid center image.

Some claim detail and musicality are mutually exclusive. I’m afraid I have to disagree. On the track “Angel” from Sarah McLachlan’s CD Surfacing [BMG B000002VT6], the Essence 80s reveal the long decay of the piano notes and the inflection in Sarah’s voice, which almost breaks at times. The raw emotion in that song is revealed by how quiet and grain-free the Essence 80s are. Sarah’s breathy exhalation of the last words in some lines demonstrates the music was most certainly in the details. The piano in this track is brilliantly used in moderation and complements Sarah’s voice. There is no cacophony of loud or aggressive playing obscuring the vocals. There is a very delicate interplay. The solid hammer strikes on the piano strings, punctuating and focussing attention while the long decay seduces.  

On the Bruce Springsteen & The E Street Band remastered live CD Hammersmith Odeon, London ’75 [Legacy Recordings B000E97X66], there is a 30-second lead-in and warm-up before Bruce does his signature 4-count and drops the hammer. What follows is one of the band’s more raucous renditions of “Tenth Avenue Freeze-Out.” Even on 86dB efficiency speakers with a wide impedance swing, the Essence 80s acted like they were coasting. The volume control on my VAC Master line stage is logarithmic. There are no markings, so it rotates clockwise from 7 to 5 o’clock, passing through high noon (or midnight if you prefer). I was rocking with this track at a setting of less than 10 o’clock. I do not remember playing any music higher than 11 o’clock. The rating of 85 watts is within the normal range for a pair of KT88 power tubes and much more than I could ever use.


My dedicated system has never sounded better. Essence 80 iQ monoblocs may be half-sized, but their performance is full-sized. They share the same technology, build quality, style, fit, and finish as larger VAC amplifiers. History has shown that VAC amplifiers work exceptionally well with a wide variety of speakers. Essence 80 iQ monoblocs nicely fill the niche where size matters as much as performance. These are the amplifiers I have been waiting for.

Price: $9990 each
Dimensions: 9”W x 15”D x 8.7”H
Weight: 40 pounds
Output: 85 watts into loads matching the selected output tap
Power Bandwidth: 13 Hz to 70 kHz
Tube Complement: 2 x KT88, 2 x 12AU7/6189
Voltage: factory configured for 100, 120, 220, or 230/240 volts
Trigger: 12V 
Included: manual, power cord, spare fuse
 Valve Amplification Company, Inc.  
 2172 10th Street, 
 Sarasota, FL 34237   
 Telephone: 941.952.9695     

Don’s Associated Equipment
Source Component Wall:
Shunyata Research Typhon T2 with umbilical cord
Shunyata Research DENALI 6000/S v2 power conditioner
Shunyata Research ALPHA grounding cables
Shunyata Research SIGMA XC power cord
Shunyata Research ALPHA v2 NR power cords (3)
Aurender N20 network transport
Bricasti Design M3 DAC/preamplifier
Valve Amplification Company (VAC) Master preamplifier
Audience Front Row AES/EBU cable
Cardas Clear AES/EBU cable
Cardas Clear High Speed USB cable
Cardas Clear Beyond XLR cables (1M & 5.5M)

Speaker Wall:
Audience aR6-TSSOX power conditioner
Au24 SE-i powerChord
Shunyata DELTA v2 NR power cords (2)
JPS Labs Aluminata power cords (2)
Cardas Clear Beyond speaker cables
VAC Essence 80 monoblock amplifiers
Homemade walnut butcher block amplifier stands
Yung Long Tiptoe spikes under stands and speakers
Sound Lab 545PX speakers

Miscellaneous in Multiple Places:
Shunyata Research Cable Cradle Wall Plates
Symposium Acoustics Svelte Plus isolation platforms
Symposium Acoustics Rollerblock Jr. HDSE isolation
IsoAcoustic OREA Isolators
PolyCrystal cable elevators
Homemade walnut cable elevators
Homemade acoustic panels 2’X4’ (5)


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