HC1 High Current Headphone Amp


  • Partial Kit
  • Documentation
  • Intermediate

The HC1 is an expandable, high-powered headphone amp designed specifically for critical studio monitoring.

The HC1's circuit employs parallel amp stages for greater power and lower distortion. This parallel-opamp concept has been known in theory for decades and was put to practical use in Douglas Self's "5532 OpAmplifier" power amplifier. As a result, the HC1 sounds clean and clear even at high gain and when driving low-impedance headphones.

Because everyone's monitoring needs are different, the HC1 is designed to be customized. The power and audio input connectors are screw terminals, so you can attach whichever jacks you need without soldering. You can also daisy chain multiple HC1s to make a multi-channel headphone amp.

The HC1 is a great project for intermediate builders who enjoy the challenge of choosing their own chassis and inputs.


  • High-current, dual-amp design
  • Screw terminals for power and audio input
  • Stereo, unbalanced audio input
  • Accepts 9v battery or DC wall-wart power input
  • Mounting holes for case mounting
  • Runs about 50 hours on a single 9V battery
  • Does not include power or audio input jacks

Partial Kit Includes

  • Printed Circuit Board (PCB)
  • 2x NE5532 opamps
  • All resistors and capacitors required
  • TRS 1/4" headphone jack
  • Volume potentiometer and knob
  • Screw terminals for power and audio input

Source Your Own

  • Power supply or batteries
  • Chassis
  • Input jacks



  • Input Impedance: 20kΩ
  • Current Draw: 10-20mA
  • Gain: 0-10dB (customizable)
  • Power Supply: 9 to 44VDC

Customer Reviews

Based on 19 reviews
Eric Boyd
Spectacular value

Built this thing in about an hour on my back porch with Walmart's finest, cheapest soldering iron. Using a Ryobi battery for power. Highly recommended, this thing is really capable and has no noise whatsoever that I can hear at max volume on sensitive headphones. These cases were cheap, their contents were delicious, and I find the stupid sight gag to be delightful.

Paul Musco

A truly fantastic headphone amp.

John David Kassai
What a cool/useful little thing!

Fit it in 1590b enclosure. Use it to mix on my laptop and occasionally as a hard wired IEM for drummers and other studio work. Wow. Sounds amazing. Started using it for video games and anything else I could find. Easy kit to build. Super flexible. 10/10

Mihhail Rihter
Simple and effective

Great unit for beginner building skills.
Easy to follow build instructions. Fits into a 1590B guitar pedal housing.

Scott DaleyI
Excellent Headphone amp.

I was looking for a headphone amplifier module I could use in a 2.1 A/V preamp project i was working on (PGA2310, 4 RCA inputs, 4 HDMI inputs, 1 phono input and subwoofer output). I modified the unit to operate on +/-12Vdc supply to give it more headroom. I carefully designed the preamp output buffers to have 0 offset and removed the input coupling caps to the HC1.The sound is crisp and with direct coupled inputs has solid bass with excellent transient response. I am impressed!

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