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.
Engineer's notebook about the 50A
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 )
1x12AU7
2x 6CG7
2x 6CL6
2x 6CK3 (9-HP pin basing)
50A Model and Pricing
US Retail per pair, (effective July 10, 2009) $9995.
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 power...you 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