Skip to main content
Radial Engineering

Radial Engineering Headload Guitar Amp Load Box 4 ohms

Add To Wish List
899.99 $899.99
6 month Special Financing
Limited time
Loyalty Points Icon
Loyalty Points Icon
Earn 7,200 reward points
($72.00 in credit)
Inventory Msg Check Mark Inventory Msg Exclamation In Checkout Promo Inventory Msg Download Icon
In Stock & Ready to Ship
Most orders placed before 3 p.m. ET ship same day (except weekends and holidays).

Style: 4 ohms

Radial Engineering Headload Guitar Amp Load Box 4 ohms4 ohms 4 ohms $899.99 Radial Engineering Headload Guitar Amp Load Box 4 ohms16 ohms 16 ohms $899.99
  • Free Shipping
  • Top Rated
  • Flexible Financing
  • Lowest Price
Product Warranties Icon Product Warranties Icon

Gold Coverage Protection

Protect your gear

Chevron Right Icon

Combination speaker attenuator and simulator that safely handles up to 130 watts RMS.

The Headload is a combination load box and attenuator that is capable of handling up to 130-watts RMS of continuous power and peaks of 180 watts. Inserted between the head and cabinet, it allows the guitar amp to be driven hard while reducing the output level to reduce the sound pressure on stage or provide the means for quiet recording in the studio. This enables the artist to optimize the tone from the guitar amplifier without having to perform at ear-blistering levels.

The 100% discrete fan-cooled design begins with a series of cement encrusted, epoxy coated copper resistor coils that are controlled via a 6-position rotary switch to set the desired power reduction from 100% down to 20%. A trim control provides fine adjustment when below 20%. The Headload output can be turned off for quiet on-stage use, recording or when practicing using the built-in headphone amplifier.

In order to ensure greater consistency from gig to gig, the Headload is equipped with a Radial JDX Reactor direct box. This captures both the signal from the head plus the reactive load from the speaker cabinet for a more natural tone. The JDX has gained tremendous popularity with users as diverse as Megadeth, Aerosmith, Rascal Flatts, Sting and Radiohead.

For engineers that prefer to combine a direct feed with a microphone, the Headload has also been equipped with a Radial Phazer “ phase adjustment tool. This lets you time-align the JDX direct feed with the microphone to deliver incredibly natural tones, or when pushed to extreme, create over the top effects. The JDX direct output may also be tailored to suit with a 6-position voicing switch to select from various cabinet emulation presets and fine tuned using a 2-band EQ to tame overly bright amps.

Available now in 8 ohms, the Headload is possibly the most useful load box ever made.


  • Radial JDX Reactor and Phazer for direct recording
  • Delivers great tone from your amp at low volume
  • Front vents allow cool air to circulate, driving by rear-mounted fan
  • Shelving EQ Control used to fine-tune the JDX output to suit your recording or live monitoring needs
  • Removable handle for rack mounting
  • Analog phase-shift control lets you adjust between 0-180 degrees and 181-360 degrees
  • Resonance enhacnes the EQ curve to compensate for the tone shift when the speaker level is reduced
  • Range Control knob lets you fine-tune the power level when set below 20% for greater control
  • Load Control knob is a six-positions rotary switch that sets the power reduction from 100% down to OFF
  • Rotary switch lets you chose between six cabinet emulation prest curves
  • 180/360 button toggles the phase shift from 0-180 to 181-360 degree
  • Headphone out
  • Phase adjustment tool
  • Analog phase-shift control lets you adjust between 0-180 to 181-360 degree
  • 1/4" out jack for connection to amp
  • 1/4" out jacks for connecting to speaker cab
  • 1/4" in jacks for connection from guitar
  • Reverse polarity to offset phase anamolies when combining Headload with PA system
  • JDX Pre-EQ/PA Output captures the sound from the JDX signla before the EQ - transformer isolated to eliminate hum and buzz caused by ground loops
  • JDX Post-EQ/Monitor Output captures the sound after the EQ for direct recording, feeding stage monitors or in-ear monitors
  • Lift to eliminate ground loops
  • Unbalanced Post JDX and EQ direct output used to feed additional gear after it has been processed by the Headload
  • Unbalanced direct feed from the amp used to send a pre-JDX signal to additional gear

Order today!


Headload Guitar Amp Load Box Specifications:

  • Audio Circuit Type: Reactive attenuation circuit with active equalization
  • Frequency Response: 90Hz at -3dB to 4KHz at -6dB, Low EQ: +/- 9dB @ 80Hz, High EQ: +/- 9dB @ 6Khz
  • Low & high resonance: 60Hz & 6.5KHz, shelving filter 6dB/octave slope, +12dB at 20% load setting, +9dB at 40% load setting, +6dB at 60% load setting, +3dB at 80% load setting, None at 100% load setting
  • Headphone output power: 400mW into 32Ohms
  • Headphones impedance: 32Ohms or higher recommended
  • Gain: -40dB typical
  • Intermodulation Distortion: <0.05%
  • Noise: -104dbu Unweighted
  • Input Impedance: 8Ohms
  • Output Impedance: 250Ohms
  • Total Harmonic Distortion: <0.05%
  • Gain Reduction: Variable from 100% to 0%
  • Equalization: Low & high frequency shelving
  • Load: Available in 4Ohms, 8Ohms, and 16Ohms
  • Power: Radial +/-15V 400mA power supply
  • Construction: 14 gauge steel chassis and outer shell
  • Finish: Durable powder coat
  • Size (LxWxD): 6.05" x 12" x 3.45" (154mm x 305mm x 87.6mm)
  • Weight: 8lb. (3.63kg)
  • Conditions: For use in dry locations only between 5C and 40C
  • Warranty: Radial 3-year, transferable

Questions & Answers

Do you have questions about this product?

Prop 65 Warning Icon
WARNING: This product can expose you to chemicals including Titanium dioxide (airborne, unbound particles of respirable size), which is known to the State of California to cause cancer, and Lead, which is known to cause birth defects or other reproductive harm. For more information go to
Shop with a Friend
Free Shipping
  • Free Standard Ground shipping (48 contiguous states, some overweight and Used/Vintage items excluded).
  • Orders placed before 3 p.m. ET usually ship the same business day.
Learn More
2-Year Free Warranty on Guitars

Every guitar or bass you purchase from Musician's Friend (electric or acoustic, New or Open Box) includes two years of protection from manufacturer defects.

Contact Us for Details
We're Here for You

Our Gear Advisers are available to guide you through your entire shopping experience. Call or Chat for expert advice and to hear the latest deals.

Contact Us
gear adviser
Want to customize your own bundle?
Our Gear Advisers are ready to help.
Our contact center is currently closed.
Request a Callback
Proactive Advisor Support Chat