JDS Labs C421 (C421 v1.01) Headphone Amplifier

Brushed Aluminum Headphone Amplifier with Bass Boost, Low Battery Detection, Dual Gain


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This item has been discontinued

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c421-black thumbnail

JDS Labs, Inc C421 Black Edition Headphone Amplifier

OUR PRICE: $184.00

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Product Features:

  • Desktop Headphone Amplifier
  • Signal is transferred through 0.1% thin film resistors for transparency and minimal distortion
  • Power circuit provides continuous voltage boosting so the music stays strong until battery depleted
  • Low battery indication announced during last 45 minutes of battery use
  • Stylish brushed aluminum housing
  • New active-true ground topology enables fail-safe charging while giving benefits of an active ground circuit
  • Implemented on a 4-layer PCB that has dual internal ground planes to provide maximum signal integrity
  • USB powered smart charging

Technical Specifications:

  • Dual Gain: 2.3x or 7.0x (+7.2dB or +16.9dB)
  • Bass Boost: +8dB peak
  • Battery: 1200mAh, 3.7V Li-Ion battery
  • 3.5mm input and output jacks, gold plated
  • Run-Time: 11 hours (approx.)
  • Charge Time: 5 hours
  • Frequency Response: 20-20,000 Hz
  • SNR: > 110 dB
  • THD: < 0.0041%
  • Crosstalk: < -57dB
  • Output Impedance: 0.1 ohms
  • Volume Potentiometer Taper: 3B
  • Primary stage opamp: OPA2227
  • Dimensions: 2.46"W x 0.55"D x 3.83"H
  • Authorized Internet Dealer
  • 1-year Manufacturer's Warranty

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 - 20000 Hz
Input Connection
This is the manner in which the headphone amplifiers receive an input audio signal.
3.5mm Mini-Jack
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.
Output Impedance
This is the output impedance of the headphone amplifier.
0.1 ohms
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

Rating Distribution

5 Star
4 Star
3 Star
2 Star
1 Star

Average Attribution Rating


Greenbelt, Maryland

Big sound in a small package!

October 7, 2012

After using this amp, and experiencing nothing short of "musical bliss", I would surely recommend it. Right out of the box, this little amp had my headphones rocking like never before. It feels really solid, looks really good, and sounds really great! The people who made this amp really put a lot of thought into it. It shows. You can charge it multiple ways, use it as a desk top or portable, and it let's you know through colorful LED lights its status. It can drive all headphones with ease. I have several and I'm a witness! I really have nothing negative to say about it! Do yourself a favor and get one!

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Product Summary


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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 C421 (C421 v1.01) Headphone Amplifier

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JDS Labs C421 (C421 v1.01) Headphone Amplifier

Brushed Aluminum Headphone Amplifier with Bass Boost, Low Battery Detection, Dual Gain


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