JDS Labs, Inc C421 Black Edition Headphone Amplifier

Brushed Aluminum Black Edition Headphone Amplifier w/ 0.1% Thin Film Resistors

Good news and a little bad...

This item has been discontinued

But you may be interested in the newest model that's available.

c5-red thumbnail

JDS Labs C5 Professional Grade Portable Headphone Amplifier (Red)

OUR PRICE: $189.00

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General Features:

  • Black edition headphone amplifier
  • Dual Gain, 2.3x or 7.0x (+7.2dB or +16.9dB)
  • Bass Boost, +8dB peak
  • Alps Dual Analog Potentiometer
  • Low Battery Indication
  • 0.1% Thin Film Resistors
  • 1200mAh, 3.7V Li-Ion Battery
  • USB Powered Smart Charging
  • Synchronized +/-7V rails, NO power degradation!
  • 3.5mm Input and Output Jacks, Gold Plated
  • 4-Layer Printed Circuit Board
  • Aluminum Enclosure
  • Primary stage opamp: OPA2227
  • Authorized Internet Dealer
  • 1-year Manufacturer's Warranty

General Features:

  • Run-Time: 11+ hours
  • Charge Time: 2 hours to 80%, <5 hours to 100%
  • Frequency Response: +0.01, -0.41 dB (20Hz-20kHz)
  • SNR: Exceeded test equipment*, > 110 dB (20-20kHz)
  • THD: Exceeded test equipment*, < 0.0041%
  • Crosstalk: Exceeded test equipment*, < -57dB
  • Volume Potentiometer Taper: 3B
  • Enclosure Size: 97.5 x 14.0 x 62.5mm
  • Weight: 4 oz

Product History:

JDS Labs, Inc C5 Red thumbnail
(newest, current model)
JDS Labs, Inc c421 Black thumbnail
(previous model, replaced by JDS Labs C5 Professional Grade Portable Headphone Amplifier (Red))
JDS Labs, Inc C421 thumbnail
(previous model, replaced by JDS Labs, Inc C421 Black Edition Headphone Amplifier)

Headphone Amplifier Specifications

Amplifier Style
Some headphone amplifiers are designed to be portable and others are meant to be placed on a desk. This will tell you what style of amplifier this item is.
Digital-to-Analog Converter (DAC)
A Digital-to-Analog converter (also known as a DAC) converts a digital audio signal into an analog signal. This is especially helpful for listen to music from digital sources, such as iPods and smart phones.
Frequency Response
The range of frequencies the amplifier will reproduce (lowest frequency to the highest). Bigger is better, meaning the wider the range, the better. The optimal range is 20 - 20,000 Hz (which is the range of human hearing).
20 - 20,000 Hz
Output Connection
This is the manner in which the headphone amplifier will output the audio signal.
3.5mm Mini-Jack
Number of Outputs
Some headphone amplifiers have a built-in splitter so multiple pairs of headphones can be connected to it. The number specified here is the number of headphones that can be connected to the amplifier.
The width of the item from left to right (side-to-side) measured in inches.
The height of the item, measured from top to bottom, in inches.
The front-to-rear depth of the item, in inches. If the item is angled or slanted, this value is the bottom measurement.

Specials with this Item

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Warranty and Return Policy

Parts Warranty Duration
1 year
Labor Warranty Duration
1 year
Warranty Provider

Summary of Customer Ratings & Reviews

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Product Summary


Model Number

c421 Black



Internal SKU


Internal Product ID


Sonic Electronix Wiring Guide

Wiring Diagram Legend

Warning: The image depicted shows the resistance change when wiring multiple subwoofer terminals. Please refer to your subwoofer's owner's manual for the proper wiring of its terminals. Sonic Electronix, Inc. is not responsible for damage caused to your audio system or vehicle due to improper installation. Please call tech support at 1-877-289-7664 if you require additional assistance.

Product Name: JDS Labs, Inc C421 Black Edition Headphone Amplifier

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JDS Labs, Inc C421 Black Edition Headphone Amplifier

Brushed Aluminum Black Edition Headphone Amplifier w/ 0.1% Thin Film Resistors


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