ALM Busy Circuits HPO

The ALM Busy Circuits HPO is a clean and compact 2HP stereo headphone amplifier, perfect for small Eurorack systems where space is limited. Designed for night-time patching, live cueing, or portable systems, the HPO delivers clear, uncoloured sound straight to your headphones.

It features stereo left and right inputs, with normalization from left to right for mono signal compatibility. Simply patch one cable to the left input, and the signal will feed both channels. The level is adjustable via the front-panel potentiometer, and the stereo output works with standard 3.5mm headphone jacks.

Whether you're setting up a compact travel case or just want to monitor patches in silence, the HPO is a no-brainer for any rack with a spare 2HP.

Key Features:
• 2HP stereo headphone amplifier
• Clean, uncoloured sound ideal for detailed monitoring
• Stereo inputs with mono normalization (L → R)
• Adjustable output level
• Compact and skiff-friendly
• Stereo 3.5mm headphone output
• Great for live cueing or quiet patching sessions
• Made in the UK