Marshall Mods
Plexi through JVM — JCM800 and earlier are favorites. Email for current availability.
I offer many different mods for Marshall amps, from simple gain boosts to extra gain stages and effects loops. Tube swaps (EL34, 6550, 6L6, KT66, KT88), re-voicing, restoring, master volumes, effects loops, preamp outs, half-power mods, and basic maintenance.
I work on Plexi, JMP, JCM800, JCM900, JCM2000, DSL, TSL, Vintage Modern, JVM, SLX, Silver Jubilee, Major, and 30th Anniversary models. Email me with what you're looking for and we can discuss all options.
Prices below are from the classic FJA catalog and may be outdated — confirm before booking.
Plexi, JMP, JCM800 mods
Standard mods are the bottom-line price to get inside that model and make circuit changes. While I have a mod in mind based on customer feedback, mods are adjusted to fit your needs.
Ultimate Plexi mod
Tweaks the amp circuit to be truer to vintage Plexi tones.
Ultimate 80's mod
Added gain and voicing for 80's rock tones. Cleans up well with guitar volume. Modern rock gain levels too. No added gain stage.
FJ mod (F'n Jose) — Jose/CCV type
My version of the Jose/CCV/Atomica type tones mod.
FB mod (F'n Brutal) — Aldrich type
My version of the Aldrich mod. Formerly the Nick Mod.
FML mod (F'n Missing Link) — Elan/Metalhead type
My version of the popular Elan/Metalhead mod. Includes loop and noise gate.
80's Mod +
Similar to Ultimate 80's, with an added gain stage. Cleans up with guitar volume. No extra tube.
SS Mod
Added tube gain stage. Metal, 80's rock, and modern rock voicing. Cleans up with guitar volume.
SSX Mod
Added tube gain stage for brutal metal — deep, thick, thundering tones. Extreme gain version of the SS Mod.
JFD Mod (Jerry's F'n Destruction)
My take on the SIR #39 mods as used by Slash and George Lynch. Added tube gain stage.
JFD+ Mod
SIR #39 style with added gain stage, effects loop, and channel switching for a clean channel.
Output transformer upgrade
Newer Marshall reissues often benefit from a warmer, more organic vintage tone. Older Marshalls don't benefit as much.
DSL / TSL mods
Standard DSL/TSL mods tighten the amp, increase gain slightly, improve the clean channel, and add meatier mids. I fix the speaker output design flaw that causes OT failure. My mods don't disable the deep switch or neuter gain like some competitors.
Output transformer upgrade — Can warm up harsh, edgy reissue high end. Added choke — DSL/TSL amps don't have one from the factory; improves punch, sustain, and noise.
Vintage Modern mods
Standard mod gives meatier tone with crunchy mids. Several gain and voicing options available.
Two channel mod
Matches Body (low) and Detail (high) channel volumes for usable dual-channel Plexi/JCM800 tones. PPIMV still works. Requires drilling the front panel.
X-treme metal mod
Two channel mod plus extra gain stage on the high range channel.
Solo boost
Foot switchable solo boost — a loop boost doesn't work on the VM. Requires front and rear drilling.
Added gain stage / Added choke
Extra tube stage for more gain; choke improves bottom end and sustain (VM has no factory choke).
Silver Jubilee mods
Standard mod — Early circuit updated to latest revision. Choke available for 2554 combo. I generally keep Jubilee mods conservative to preserve value.
Added gain mod — Reversible. Oz mod — Added tube gain stage; prefer beat-up, non-collectible amps only.
Class 5 & Haze mods
Class 5 — 80's tone mod for more gain, mids, and tighter bottom; optional master volume.
Haze — 80's tone mod or Modern Rock/Metal mod (closed-back cab suggested for tightest tone).
Marshall mod prices
All mods include a general check-over, clean pots and jacks, re-tension tube sockets, test caps and tubes, and bias check.
Plexi, JMP, JCM800 — models 1987, 1959, 2204, 2203
| FJA custom built Plexi clone amp | $4595 and up |
| FJA Ultimate Plexi tone mod (fine tune your reissue) | $895 |
| FJA Ultimate 80's mod | $995 |
| FJA 80's mod + | $1025 |
| FJA FJ mod — Jose/CCV type | $1095 |
| FJA FB mod — Aldrich type | $1195 |
| FJA FML mod — Elan/Metalhead (added tube gain stage, loop & gate) | $1895 |
| FJA SS mod (added tube gain stage) | $1295 |
| FJA SSX mod (added tube gain stage) | $1295 |
| FJA JFD mod — #39 type (added tube gain stage) | $1295 |
| FJA JFD mod + — gain stage, clean channel, and loop | $1695 |
| Options — Plexi / JCM800 | |
|---|---|
| Depth mod | $100 |
| Mid sweep mod | $100 |
| Custom output transformer | $495 (100W) / $425 (50W) installed — Mercury +$125–150 |
| Tube effects loop w/ return level | $525 and up |
| Tube type change (6L6, EL34, 6550, KT88) | $195 (plus tubes) |
| Foot switchable solo boost | $475 |
| Add 2nd channel | $695 and up |
| Post phase inverter master volume | $275 |
JCM800 — models 2205 & 2210
| FJA JCM800 2205/2210 mod | $895 |
| Depth mod | $100 |
| Mid sweep mod | $100 |
JCM2000 DSL / TSL
| FJA DSL/TSL mod (including DSL100H) | $995 |
| Foot switchable solo boost | $425 |
| TSL / DSL custom output transformer | $495 (100W) / $425 (50W) — Mercury +$125–150 |
| TSL / DSL custom choke | $200 installed |
Vintage Modern
| FJA Vintage Modern mod | $995 |
| 2 channel mod (low/high range, includes voicing) | $1095 |
| Xtreme Metal mod — 2 channel + added gain stage | $1095 |
| Add choke | $200 installed |
| Mid sweep mod | $100 |
| Mid boost (different than stock) | $100 |
| Foot switchable solo boost | $595 |
JVM
| FJA JVM mod | $995 |
| FJA 80's type mod — Jose type | $995 |
| Add choke | $200 installed |
Silver Jubilee
| Convert early revision circuit to last revision | $995 |
| Added gain mod | $995 |
| Oz mod — added tube gain stage | $1195 |
| Add choke to 2554 | $200 |
Class 5
| 80's type tone mod | $895 |
| Master volume (option for above mod) | $250 |
Haze
| 80's type tone mod | $895 |
| Modern Rock/Metal mod | $895 |
Other mods and custom work available.