Project Horizon is a sister amplifier to Project Sunrise even sharing the same PCB. Understanding the want and need for a version specifically built for high impedance headphones, Project Horizon was born. Horizon costs a bit more than Sunrise as it takes quite a few more parts and a much higher voltage power supply. Horizon is quite a beast and just like Sunrise III, she is very musical and offers loads of adjustability combined with the ability to roll a ton of tubes. Horizon is a real staple to our lineup and also has been reviewed and loved globally!

Each factory built amplifier is meticulously hand built and tested prior to shipping. Solder work is outstanding and clean with no flux or fingerprints left on the board. Pride in workmanship is evident from every angle of this amp. What you see in photos is the quality of build you will get!

Features of Horizon 3.1:

• Designed for higher impedance headphones. Best suited for headphones 300-600ohm but OK with headphones 120-600ohm
• Line output for pre-amp use (volume controlled)
• Manual bias design with easy-set LED bias system, no multimeter needed
• Manual voltage setting with quick access through top cover
• Variable input gain with easy to swap module
• Capable of utilizing a wide range of 6v and 12v tubes. More options available with adapters (500mA heater current default, 1A available with option supercharger module)
• Selectable output impedance per quick access jumpers located on the sides of the amplifier
• Lightning quick protection circuit with tube warm up delay
• Onboard RGB LED under the tube to dial in a color that suits you
• Top quality components sourced in the US from reputable distributors. No gray market or counterfeit components that plague other manufacturers (designed for the long haul)
• Beautiful piano gloss black .096 thick double sided PCB in 2oz copper with top and bottom ground planes & gold wash. Will not bend or flex while inserting a tube
• Class A output stage, no overall Feedback
• Medical grade power supply included
• 5 YEAR WARRANTY on G1217 built amplifiers
• Shipped, built and kitted from the US
• US / Netherlands design team

For Advanced Tuners:

• Input capacitor section is drilled for multiple capacitor footprints. 2, 2.5, 3.5, 5 or 7.5mm spacing available
• Output capacitor section is drilled for 7.5mm
• Power supply capacitor section is drilled for 7.5mm
• Input capacitors can be bypassed for optimal sound (can result in a scratchy sound only when adjusting volume)

• Variable output resistance, selectable from 1.5, 35 and 120ohm

Actual Project Horizon Measurements

• Single ended, class-A output stage
• Power consumption: 13W continuous, 19W peak.
• Power supply: 48VDC (0.55A cont, 0,8A peak)
• Input Resistance: 11k / 31kOhm gain module dependent
• Input Sensitivity (6N23): 270mV (dependent on tube)
• Gain: 20dB (dependent on tube) Changed from the original higher 26dB specification
• Max Output voltage (no load): 14.1Vrms at 300ohm
• Output Resistance: Selectable 1.5, 35 or 120ohm
• Frequency Response: 10Hz – 160 KHz (-0.5dB) with 32ohm load
• Frequency Response: 4Hz – 400 KHz (-3dB) with 32ohm load
• Signal to Noise ratio: 91dBA (dependent on tube)
• Crosstalk: -88dB (dependent on tube)
• THD: > 0.013% (dependent on tube)
• Suitable for: 120-600ohm Headphones

Dimensions:

• 6.5L X 5W X 2.75H in inches

Weight:

• Acrylic Chassis 1lb (without power supply)
• Aluminum Chassis 1.34lb (without power supply)