presenting an amplifier for all seasons...

KE ENGINEERING/ deHavilland Model 50A Mono Amplifier


"...The sound was perfectly beautiful. An Esoteric CD player into the deHavilland Mercury III linestage was providing the signal to a pair of the deHavilland 50A  Signature mono amplifiers which was powering a pair of Wilson Benesch's Curves, all the cables were Kubala-Sosna.

This was a room that I found myself returning to more than once, when I was tired of all the noise. Most importantly, it was a system that allowed you to really enjoy music."

                                      --Jack Roberts , DAGOGO , 2009 RMAF Report.



    	" Well, I've had the amps up and running for two and a half weeks, and my wife and I have listened to music
almost every day during that stretch. All I can say is that the sound gets better and better. But whether the Shunyata
is breaking in and improving the performance of the MSB equipment, or the amps are rounding into shape (probably a combination of both),
the results are fantastic and at times magical. 
	" Together with the Joseph Audio Perspective speakers, I have never had as musical AND realistic
a sound system.  What I marvel at is the ability of the system to reproduce ALL the musical details,
but to do it with ALL the tonal color and sense of rhythm of live music. 
 	I know the amps are a big part of that because while I got bits and pieces of that with the Rogue Cronus
Magnum, I never got the whole package.
				Courtesy of David B, KE50A owner (Baton Rouge, LA), Oct 15, 2013.



       Design Highlights: 

 * Unique Interstage Transformer Drive. Full Triode mode and 45 watts. 

 * Twin Tube Rectifiers. Sweetness of tube rectification,  and very soft start. 

 * Choke Input Power Supply . Old School voltage regulation without fragile transistors.

 * Paper and Oil Signal Capacitors.

 * Tube Regulated Bias Voltage Supply.  Easy and stable bias setting with onboard meter.

 * Point-to-Point Wiring . Old School hardwired audio circuitry.

 *Heavy Duty Chassis .Fabricated from CNC machined parts-- from solid billet aluminum.

 *Conservative Operation of Power Tubes. KT88/6550 tubes operate well below 

                                                                maximum ratings. Easy on the tubes.

 * Cardas Speaker Binding Posts





Design Summary

*40 Watts RMS Output, 4, 8 ohms .

*Dual tube rectifier, high current power supply, very soft starting

*Choke Input power supply

*Interstage transformer final signal drive

*Triode wired KT88 output stage

*Tube regulated bias power supply

*Onboard bias meter

 *Dimensions 17-1/4"L x 9-3/8" W x 9-1/2" H, Weight 42 lbs.

Tube Complement:

2x KT88 (6550, 6L6GC, 1614, Kt90 are direct substitutes in the 50A )


2x 6CG7

2x 6CL6 

2x 6CK3 (9-HP pin basing)

50A Model and Pricing 

 US Direct Price per pair, (effective Oct.22, 2018)  $8,800.

50A Show Reports  & Reviews

"though I've heard the Wilson Benesch Curve floorstanders ($9950/pr) many times before, I found

 that they sounded spectacularly good as driven by Kara Chaffee's amazing deHavilland [KE-50A]

 tube electronics. Nothing I heard at RMAF, save perhaps for the far more expensive Vandersteen/ARC system, could touch this rig for sheer midrange purity, detail, and three-dimensionality."                                        

                                                               Chris Martens, Feb 2010 The Absolute Sound


"deHavilland/ Kubala-Sosna/ Esoteric/SoundsReal Audio room. I have my reasons for voting this room "the best" and here they are. It played music for me. Its presentation was very big and wide and spacious , yet intimate. It was as if the music was being played just for me..."

                                                               Thad Aerts , The Hi-Fi Reader Magazine #11


"If your speakers can get by with relatively moderate should strongly consider auditioning the 50A monoblocks. Their combination of top-to-bottom balance , clean and resolving highs, magnificent bass and slam, articulate speed and PRAT, and gorgeous brocade of sound , seems to me very hard to beat. In fact, I couldn't beat them. I gave into the music, sold the Air Tight ATM-2 , and bought the review pair of 50A. They took me back to the future and I've never been happier with my system's sound."  

                                  Garrett Hongo, UltraAudio Magazine / Soundstage Network Apr 2009