Marshall JCM900 Series Filter Capacitor Replacement Set

Marshall JCM900 Series: 2100, 2101, 2100SL-X, 2101SL-X, 2500, 2501, 2502, 2500SL-X, 2501SL-X, 2502SL-X, 4100, 4101, 4102, 4500, 4501, and 4502

Default capacitors selection is based on Evatco's Recommendation  - You can choose other brands via the drop down menus above 

Restore original high-headroom clarity, punchy low-end response, and long-term reliability to your vintage tube amplifier with this specialized Marshall JCM900 Series Filter Replacement Set from EVATCO. Engineered specifically for High Gain Master Volume, SL-X, and Dual Reverb JCM900 chassis, this recapping kit replaces aged, leaky factory electrolytic capacitors with premium high-voltage dual-section and bias capacitors designed to eliminate power supply hum and safeguard your transformers.

Whether you are performing routine maintenance or a full circuit restoration, sourcing high-grade, correctly rated filter capacitors is essential for maintaining dynamic responsiveness, tight bottom-end punch, and bulletproof performance in vintage Marshall circuits.

Circuit & Model Compatibility

This all-in-one capacitor replacement set is tailored specifically to fit classic Marshall JCM900 series models featuring the following model designations:

• Marshall JCM900 Series: 2100, 2101, 2100SL-X, 2101SL-X, 2500, 2501, 2502, 2500SL-X, 2501SL-X, 2502SL-X, 4100, 4101, 4102, 4500, 4501, and 4502

How to Ensure You Are Ordering the Correct Set

Marshall amplifier circuits varied across production runs and revisions. Before purchasing, follow this quick checklist to confirm compatibility:

1. Inspect the Can Capacitors: Open the chassis or inspect the layout to confirm your amp uses two (2) clamp-mounted dual-section (50uF+50uF) high-voltage filter cans rather than PCB-mounted axial or single radial caps.
2. Verify Model Number: Confirm your amplifier model is listed above (including MKIII High Gain, SL-X, and Dual Reverb variants).
3. Check Bias Circuit Values: Verify your bias supply circuit uses axial 10uF bias capacitors rated at 150V.
4. Need Help Confirming? Take clear photos of your amplifier's chassis interior (specifically the existing filter cans and bias circuit) and contact the EVATCO technical support team before purchasing—we are happy to verify your layout.

Parts Included in This Set & Their Circuit Roles

Default components included in this kit are listed below along with their specific function within the Marshall JCM900 power supply and bias sections. We source trusted brands such as F&T / Mersen and Sprague to ensure exact physical fit and high reliability inside classic chassis layouts:

• 2 x F&T 50uF + 50uF - 500V Dual Electrolytic Can Capacitors: Main reservoir, screen grid, and preamp power supply filter cans.
• 2 x Sprague 10uF - 150V Axial Capacitors: Bias supply filter capacitors for stable, noise-free grid bias voltage to output valves.

Benefits of Recapping Your Vintage Marshall Amp

• Eliminate Mains Hum & Noise: Original decades-old filter capacitors lose capacitance tolerance and leak DC voltage, introducing frustrating 50Hz/100Hz background hum into your signal path.

• Restore Tight Low-End & Clean Headroom: Fresh filter sets stabilize high-voltage power rails, preserving tight bottom-end punch, fast transient response, and pristine headroom.

• Protect Output & Power Transformers: Shorted or dried-out power supply capacitors put heavy stress on rectifiers and transformers—leading to catastrophic component failures.

Premium Components for Classic Tube Amps

Every EVATCO filter replacement set features trusted high-voltage electrolytic capacitors chosen for exact value tolerances and physical fit inside vintage Marshall chassis. Order your Marshall JCM900 Series filter capacitor replacement kit online today. EVATCO offers fast delivery across Australia and worldwide shipping for all your valve amplifier parts and tube amp restoration needs.

Disclaimer: MARSHALL® and specific amplifier model designations including JCM900, SL-X, 2100, 2101, 2500, 2501, 2502, 4100, 4101, 4102, 4500, 4501, and 4502 are registered trademarks of Marshall Amplification PLC. EVATCO is an independent retailer of aftermarket upgrade components and restoration parts. EVATCO is not affiliated with, sponsored by, or officially connected to Marshall Amplification PLC. All trademark references are used strictly to describe product compatibility.