Classic late 50's Harman Kardon styling make this incredibly rare set an absolute showstopper. The AX20 Integrated amplifier, paired with the HK20 tube amp. When we first acquired the AX20 Nocturne in 2020, our goal was to complete the set. Finally, after nearly 18 months, we we able to find the very rare HK20 monoblock. Specifically designed for each other, this unique set was offered at the dawn of stereo, with the stereo-ready integrated AX20 to be paired later with the HK20. For serious vintage collectors only, this set will pair very nicely with efficient vintage speakers.
Production
1958-59
Condition
8/10
Serial No.
2690377 / 2913669
Orig. MSRP
$108.90 AX20 / $59.95 HK20
Restoration
- Full 30-point service check
- Replaced (2) EL84 & (1) EZ81 - JJ
- Cleaned controls, switches, and chassis
Factory Specs
AX-20 Nocturne
Type Integrated mono tube amplifier
Power Input 105-125 Volts (AC)
Power Output 20 watts into 8Ω (mono)
Signal Jacks RCA
Speaker Terminals Screw Type
Frequency response 15Hz to 30kHz
Total harmonic distortion 1%
Damping factor 5
Input sensitivity 0.5V
Signal to noise ratio 90dB
Speaker load impedance 8Ω or 16Ω
Tube Complement 7: 12AU7, 12AT7, 12AX7 (2), EL84 (2), 6CA4
Dimensions 12"w x 4"h x 11"d
Weight 18lb
HK20 Mono Amplifier
Type Mono tube amplifier
Power output 20 watts into 16Ω (mono)
Frequency response 15Hz to 30kHz
Total harmonic distortion 1%
Damping factor 5
Input sensitivity 0.5V
Signal to noise ratio 90dB
Speaker load impedance 8Ω to 16Ω
Tube complement 1 x 6CG7, 2 x EL84, 1 x EZ81
Dimensions 10"W x 5"H x 4"D inches
Weight 14 lbs.
Documentation
Harman Kardon AX20 Advert
Harman Kardon HK20 Instruction Manual
The History of Harman Kardon
Harman Kardon runs on two mottos – the first, to reproduce sound exactly as the artist intended it to be heard. Their audio speakers are created to produce beautiful and clear music just as you would hear in recording studios. The second, is to make music look as beautiful as it sounds, through their cutting-edge...
[ Read More ]
Liner Notes
60 seconds. That's all it takes to create a complete stereo electronic center with the new Harmon-Kardon Nocturne, Model AX20. To convert your present system – component or console – to stereo, simply plug the AX20 into your present amplifier. This one connection does it all.
With the AX20 there's no shuttling back-and-forth between two different instruments (you can even touch your present amplifier out of sight); no adapter box to complicate matters. This one unit – the AX20 – controls the power to both amplifiers. It also controls treble, bass, volume, contour, balancing, and equalization for both.
The AX20, in brushed copper and black, is strikingly handsome in appearance and outstanding in its performance characteristics. The amplifier delivers 20 watts of hum-free, distortion-free power (40 watt peaks). An exclusive new high-gain phase inverter, utilizing both positive and negative feedback, drives the output tubes with minimum phase shift and excellent stability. As a result, the power amplifier has instantaneous recovery time resulting in uniquely clean and faithful transient response. The AX20 actually produces more clean, useful power than conventional 30 watt amplifiers.
The preamplifier is a dual stereo device incorporating ganged bass and treble tone controls, loudness control, contour control, rumble filter, balance control, mode switch, speaker selection, and function switches. Selectable equalization is provided for records and tapes. The second preamplifier delivers half volt output at low impedance.
Stock No.
7739965374685
