Marshall Modifications Catalog

QUESTIONS? NEED MORE INFO?

Not sure which modification is right for your Marshall? Contact me before ordering. Tell me your amplifier model and what sound you’re looking for.

SELECT THE MOD THAT INSPIRES YOUR CREATIVITY

Click a modification below to jump directly to its details. Please confirm compatibility before ordering.

External & Removable Marshall Mod (Beta)

MARSHALL MODIFICATIONS

1. Original MetalHead Gain Modification
2. Active Tube Effects Loop
3. Bass Boost
4. Channel Switching
5. Line Input
6. Line Output
7. Pee-Cup Noise Reduction
8. Master Volume 1
9. Master Volume 2
10. JCM800 Conversion
11. 100W to 50W Conversion
12. EL34 to 6550 Tube Conversion
13. Built-In SoundBakery Attenuator

SERVICES & ORDERING

1. Return Shipping
2. Pre-Mod Repair & Setup
3. How to Order & Ship Your Amplifier

HOW TO GET YOUR MARSHALL MODIFIED

All MetalHead Electronics Marshall modifications are personally performed and tested by me, Elan Memran.

1. Contact me before ordering.
Tell me your amplifier’s make, model, year if known, and which modification you want. I will confirm compatibility and let you know if any other work is needed.
Contact MetalHead Electronics.

2. Place your order after compatibility is confirmed.
Select your approved modification below and complete checkout. If you are shipping your amp, add return shipping to your order if needed.

3. Arrange shipping or drop-off.
After your order is placed, I will send shipping instructions or arrange a drop-off appointment. You have two options:

• Ship your amplifier to MetalHead Electronics after receiving instructions.
• Bring your amplifier in person by prior appointment.

Do not ship or bring your amplifier before receiving instructions.

4. Modification and testing.
Once I receive your amplifier, I will perform the agreed work, test it, and arrange return shipping or pickup.

Modification Turnaround Time: Approximately 2–4 Weeks

Most modifications are completed within 2–4 weeks after we receive your amplifier, depending on the work required and our current workload. Shipping time is not included.

90-Day Limited Service Warranty

MetalHead Electronics provides a 90-day limited warranty covering our modification work. The warranty applies to the specific work we performed, not unrelated problems elsewhere in the amplifier.
Read the full warranty details.

AMPLIFIER COMPATIBILITY

MetalHead Electronics modifications may be available for compatible Marshall amplifiers, including:

• MK2
• 1986 / 1987
• Origin
• 1959 / 1962
• DSL5 / DSL20
• SC20 / SV20
• 2203 / 2204
• JTM / Plexi / JMP
• DSL100h
• JCM800

Marshall clones are also welcome.

Other brands, including Fender, Peavey, Friedman, and similar tube amplifiers, may also be compatible.

Don’t see your amplifier listed?
More models may be available. Please contact Elan Memran to confirm your amplifier and the modification you want before ordering or shipping it. Not every modification is suitable for every model.

EXTERNAL & REMOVABLE MARSHALL MOD

Want the original MetalHead Electronics high-gain sound without permanently modifying your Marshall? Our external plug-in system uses model-specific adapters and a separate control box. No drilling or permanent soldering on compatible amplifiers.

The External Marshall Mod is currently in beta testing. Registration is open, with no payment required.

Learn About the External Marshall Mod & Register for Beta Testing

WHAT GUITAR PLAYERS ARE SAYING

In a February 2024 Rig-Talk discussion, an owner of an original 1983 Marshall JCM800 2204 modified by Elan Memran wrote:

“One of the meanest sounding amps I’ve owned.”

Soundstorm, independent owner post on Rig-Talk (February 1, 2024).

Read the original forum discussion |
More player comments

RETURN SHIPPING

If you ship your amplifier to MetalHead Electronics, you are responsible for the shipping cost to us.

If you are shipping your amplifier, add return shipping below when placing your approved modification order. Do not add it again if return shipping is already included in your order.

If you bring your amplifier in person and pick it up when completed, no shipping charge is required.

Add Return Shipping to Your Order:

Pre Mod Repair And Setup (optional)

Before modifying your amplifier, I recommend checking its overall condition to make sure everything is working properly.

This service includes inspecting the amplifier, checking for existing problems, and performing necessary adjustments to help get your amp in the best possible condition before modification.

This service is optional and is not required to order a modification.

Any repairs requiring additional parts or extensive work will be discussed with you first.

The Original MetalHead Gain Modification

One of my original MetalHead Electronics modifications. An additional tube and two gain controls are added to your amplifier, giving you more gain, longer sustain, and better control over your high-gain sound.

IMPORTANT: If you have a four-input Marshall, your amplifier must first be converted to a JCM800-style circuit using Modification #10.

You will need to add Modification #10 to your order before the Original MetalHead Gain Modification can be installed.

More Information

Active Tube Effects Loop

An additional tube is installed to create an active tube effects loop. The circuit is designed to drive your effects while maintaining the amplifier’s signal level and sound quality.

Bass Boost

Adds more low-end punch and fullness to your Marshall, giving your amplifier a bigger, fatter sound.

Channel Switching

Switch between your Marshall’s original sound and the MetalHead Electronics high-gain overdrive using a remote footswitch.

IMPORTANT: The Original MetalHead Gain Modification must be installed first.

Line In

Connect an external preamp directly to your Marshall’s power amplifier section, allowing you to use your Marshall as a tube power amplifier.

Line Out

Connect your Marshall’s preamp output to an external power amplifier while keeping the sound and character of your Marshall preamp.

MetalHead Pee-Cup Noise Reduction

The MetalHead Pee-Cup Noise Reduction circuit helps reduce unwanted noise and feedback associated with extreme high gain.

Designed for players who want high gain and sustain with better noise control.

IMPORTANT: The Original MetalHead Gain Modification must be installed first.

Master Volume 1

Adds a master volume control to four-input and other non-master-volume Marshall amplifiers, giving you control over the amplifier’s overall volume.

Master Volume 2

An alternative master volume modification designed to give you better control over your Marshall’s output level while maintaining its natural tube amplifier character.

Convert 4 Input Amp to 2 Inputs JCM800 Style

Converts a compatible four-input Marshall to a higher-gain, two-input JCM800-style preamp circuit.

IMPORTANT: This modification is required for compatible four-input Marshall amplifiers before installing the Original MetalHead Gain Modification.

100-Watt to 50-Watt Conversion

Adds a selectable power-reduction option to compatible 100-watt Marshall amplifiers, allowing you to switch between 100-watt and 50-watt operation.

The 50-watt setting reduces available output power. Actual volume reduction depends on the amplifier, speaker cabinet, and playing conditions.

EL34 to 6550 Power Tube Conversion

Convert your compatible EL34-equipped Marshall to 6550 power tubes for a fuller-bodied, punchier sound with rich harmonics.

The conversion includes replacement 6550 power tubes, the required bias setup, labor, burn-in testing, and a final amplifier check. Circuit compatibility and any additional work needed will be confirmed before ordering.

50-Watt Head: $200 (two 6550 tubes)

100-Watt Head: $325 (four 6550 tubes)

Both prices include the tubes, labor, re-biasing, and burn-in.

Not all EL34 amplifiers can be safely converted without additional changes. Contact me with your amplifier model before ordering. Tonal results vary by amplifier, cabinet, and playing setup.

Please note: Dino Cazares’ Marshall used 6550 power tubes, not EL34s.

Contact MetalHead Electronics About This Conversion

Built-In SoundBakery Reactive Load Box & Attenuator/DI

Crank Your Amp. Control the Volume. Keep the Tone.

Get Elan SoundBakery reactive load technology installed directly inside your tube amplifier.

This modification allows you to drive your amplifier into its natural tube saturation while controlling the actual speaker volume. Enjoy your amp at lower listening levels without needing a separate external attenuator.

The built-in reactive load is designed to preserve the amplifier’s natural tone, dynamics, touch sensitivity, and feel.

FEATURES

• Built-in Reactive Load Technology – Designed to simulate the changing impedance of a real speaker cabinet.
• Adjustable Attenuation – Reduce the speaker volume while driving your tube amplifier.
• True Bypass Switch – Bypass the attenuator and return to normal amplifier operation.
• Silent Stage Ready – Operate without a speaker cabinet when the reactive load is properly engaged in silent-load mode.
• Balanced XLR Output – Connect directly to a recording interface, mixer, or PA system.
• Direct Recording – Record the amplifier’s output and use your preferred cabinet simulation or impulse responses.
• Internal Installation – No separate external load box to carry.

TRUE BYPASS & SPEAKER SAFETY

IMPORTANT: A properly matched speaker cabinet or other suitable load MUST be connected when the reactive attenuator is bypassed.

Speaker-free operation is permitted only when the built-in reactive load is correctly engaged and configured for silent operation.

Never operate a tube amplifier without the required speaker or load connected.

INSTALLATION REQUIREMENTS

This modification is available only when there is sufficient room inside the amplifier chassis for safe installation.

If there is not enough space inside your amplifier, you will need to purchase the external Elan SoundBakery unit instead.

Every amplifier must be evaluated for compatibility and available chassis space before the modification can be approved.

Please contact Elan Memran before ordering.

All installations are personally performed and tested by Elan Memran at MetalHead Electronics.

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MetalHead Electronics and the Elan product lines share the same designer, Elan Memran.