Distributed by Fidelis AV, Nashua NH

4P1L D.H.T.  S.E. headphone amplifier

The Emotion is Sonnare Audio’s first commercial product. It is the culmination more than 20 years of research by Founder Daniel Cheever, MSEE, The designs’ topology has its roots in the Research work Daniel spent throughout a 7 year effort on this 2001 Masters Thesis “A NEW METHODOLOGY FOR AUDIO FREQUENCY POWER AMPLIFIER TESTING BASED ON PSYCHOACOUSTIC DATA THAT BETTER CORRELATES WITH SOUND QUALITY”.


Indeed the roots of this type of circuit topology sprang from even earlier investigations into the unique and astounding sound qualities of single ended triode amplifiers. These amplifiers measure questionable “FTC THD” but sound sublimely musical.

The EMOTION will drive all Planar Magnetic or Dynamic Headphones. The output is transformer coupled with a custom gapped transformer wound in U.S.A. The 8ohm output tap is used. For higher impedance headphones the reflected impedance back to the tube is raised and thus the peak output voltage significantly exceeds the capabilities of solid state amplifiers of similar output power. The amplifier takes advantage of the lowest distortion power amplifying device known, of any age, any technology: the Soviet 4P1L. Each is configured single-ended as a Directly Heated Triode. These tubes are available in large quantities and are the darling of the Russian and German low powered amplifier craze.

The Emotion drives medium impedance headphones like the Audeze lcd line “ideally” with ruler flat frequency response and more than double the power of the Audeze “Deckard” headphone amplifier.

At the 2016 AXPONA Marketplace Showplace The EMOTION showed very well with the planar element HiFiMan HE1000. Please visit Herb Reichert’s write up. Accolades also were given driving the dynamic element Mcintosh MHP1000 headphones.

The distortion profile at all drive levels contains only 0.2 % 2nd harmonic distortion, with the 3rd harmonic at ~~ 0.05%, masked by the 2nd. Most importantly the balance between these harmonics does not change in ratio dynamically.  Sonnare believes the alarming sound clarity is unique because of the use these ultra-low distortion devices connected in a unique, patent-pending topology, NOT in spite of circuit simplicity or the use of vacuum tubes.


Front Panel


·         Volume knob.

·         Power switch

·         Power On indicator

·         A PAIR ¼ stereo headphone jacks

·         Mini XLR. Balanced Stereo

·         “staging” adjust , each channel, with ammeter


Rear Panel

·         IEC power input jack. 120VAC 50-60Hz

·         (2) RCA input jacks

·         9pin DIN jack for expansion to other Sonnare products. Coming soon!

Tube Complement

·         2x 4P1L

Directly heated pentode. Connected as 100% triode. From Soviet Fighter Jet. Hermetically sealed pins. Loctal Base. Will exceed 2000Hrs.


·         2x 7N7 or 2x 6SN7

This tube is widely available N.O.S. and is the final version of the low mu 6SN7GT. It is the identical structure as this venerated low-mu dual triode in a stronger glass envelope with significantly better vacuum sealed pins.


Sonnare Audio       Daniel Cheever, Founder. Salem, MA 01970.