David Berning Co Quadrature Z Mono-Block Power Amplifiers

These amps were purchased NEW in November 2017. 
The amp comes with 6 NOS Mazda 12AT7 driver tubes that were recently purchased from Brent Jesse.  
You pay for freight.  Payment accepted via Wire, Credit Card or PayPal.  Whether I will cover PP or CC fee depends on the offer.    
These will ship worldwide via FedEx.  If you are buying these outside of the country know that they will arrive with the tariffs due on them.    
Every now and then something extraordinary comes in on trade.  That is what these amps are.  Something truly extraordinary.  These are 220w per channel, mono-blocks using Berning's exclusive ZOTL circuit.  Want the incredibly engaging sound that other Berning designs give but you can't live with 40w of power...these are the solution.  
They are in wonderful condition as you will see from the photos.  There are few speakers in the world that this amp can't drive.  There is switchable feedback to optimize sound to your situation.  
They will ship quickly once payment is received.  

Other features and specifications include:

• Both single and balanced input, all balanced amplification.
• Special triode-like screen-drive output stage.
• Low negative feedback, no phase compensation used.
• Constant output impedance over entire audio spectrum.
• Built-in five-stage power-line filter and surge suppressor.
• Non-magnetic chassis prevents skin-effect induced distortion.
• Separate shielded enclosure for power supply reduces noise.
• Power consumption: idle-125 W; max-500 W. Power factor corrected.
• Line voltage required: 100-260 VAC, 50-440 Hz.
• Signal to noise: broadband (typical) 55 dB, all feedback settings. 20 kHz bandwidth (typical): 98 dB, NORM feedback; 92 dB, MED feedback; 86 dB, LOW feedback. All figures unweighted.
• Distortion (typical, at 8 ohm loads at 200 W): 0.3%, NORM feedback; 0.5%, MED feedback; 1%, LOW feedback. These double at 4 ohms.
• Typical output power at onset of clipping: 8 ohms 220 W; 4 ohms 270W.
• Frequency response at 5 W, 8 ohms; +0, -3 dB: 2 Hz to 90 kHz, NORM feedback; 2 Hz to 60 kHz, MED feedback; 2 Hz to 40 kHz, LOW feedback.
• Frequency response at 5 W, 4 ohms; +0, -3 dB: 2 Hz to 50 kHz, NORM feedback; 2 Hz to 40 kHz, MED feedback; 2 Hz to 30 kHz, LOW feedback.
• Full power bandwidth (-3 dB), 4 ohms: 20 Hz to 50 kHz, NORM feedback; 20 Hz to 36 kHz, LOW feedback. Low frequency bandwidth limit intentionally set by speaker protection (0dB down at 20 Hz).
• Typical output impedance (measured at 1 amp, 60 Hz): 0.8 ohms, NORM feedback; 2 ohms, MED feedback; 5 ohms, LOW feedback.
• Sensitivity, 200 W, 8 ohms: 1V, single-ended input. Feedback gain compensated.
• Input impedance: 35 k -50 k, depending on feedback setting, both single-ended and balanced inputs.
• Tube complement: (4) 33JV6 output; (2) 16GK6 driver; (3) 12AT7 input and gain.
• Size: 48 cm wide, 48 cm deep, 20 cm high, (19 X 19 X 8 inches), including connectors and feet.
• Net weight: 15 kg (32 lb); Boxed, 17 kg (38 lb).
• Finish: silver face and back anodized aluminum; top and sides: light gray paint with silver anodized accent bars. Also available in black anodized aluminum by special order.
• Comes equipped with Stillpoints TM isolation feet.