Dual Stage Amps
Built to Take a Beating
Information About Modifications and Services
The modifications are amp specific. If you do not see your amp here, send an email to see if your inquiry can be fulfilled.
- Marshall** 1959, 1987, JTM 45, 36 watt (diy and boutique made) and the 18 and 20 watt.(* Cannot be done for the 18 and 20 watt)
- Services
- Restorations
- PTP (point to point) board replacement
- w/Sozo caps (Best Mustard replacement caps money can buy)
- Filter cap replacement
- Transformer replacement
- Mercury Magnetics Transformers available
- Heyboer Transformers available
- Mods
- PAB (Preamp Boost) A preamp boost which creates more distortion, no extra tube needed.
- PPIMV (An amazing sounding type of master volume!)
- Mustard Cap upgrade
- Allen Bradley NOS Carbon Comp resistors
- JCM 800 and 2203 style master volume
- Half power switch (Pentode/Triode switch as seen on the 2550 Jubilee amp)
- tube shutoff switches (allows you to literally shut off a tube and there is no need to change the impediance on you amp, its just not as loud.
- effects loop
- solid state (mosfet driven at high voltage) - fantastic sound, used mainly when a tube cannot be drilled due to space.
- Tube effects loop-very transparent with dedicated send and return controls and footswitchable bypass.
- 1959 (plexi) to 2203 switch
- EL34 to 6550 conversion and vice versa*
- Resonance or "Deep" mod (more Bass)
- Power Transformer replacement w/ High Low voltage mod for Brown Sound/VH feel*
- passive boosts(* but usually they are already there)
- Superlead to Superbass conversion and vice versa (Either the 1959 or 1987 handwired amps or reissues.
- Randy Rhoads mod. (keeps the 2 channel, 4 hole input but has 1 channel that is cascading and the other of a plexi)*(it can be done, but circuit must be changed.)
- High cut Control as seen on the AC15 and AC30.
- EL34 to 5881 conversion or running them together.(my personal favorite; best of both worlds in my opinion.
)* - Variable feedback control or disabling it completely. Allows for more power amp distortion, if thats what you like.
- Egnater tube mix control (only with amps with 4 power tubes. Amp will be modified to work with other tubes. 1 set in the middle pair and a different set in the outer pair.)
- Dual/quad bias circuits for unmatched tubes
- individual tube fusing/leds to indicate whether tube has died. Tube is shut off safely and led is lit when it shorts or fails.
- Ef86/5879 input circuit mod
- mellow/agressive switch (a design of mine that transforms a amp from plexi to metal panel in one switch)
- powerscaling instalation**
- Hiwatt**
- Reissue
- PTP replacement board
- filter cap replacement
- Mods
- PAB switch (Preamp Boost switch)
- Mustard Cap upgrade
- Allen Bradley NOS Carbon Comp resistors
- New bias circuit for using 6l6's in a Hiwatt
- Mod to the Jimmy Page Hiwatt as heard on the song,"Heartbreaker"
- gain mod that makes use of available gain on tap in the stock circuit.
- Half power switch (Pentode/Triode)
- Tube shutoff switches (to shut off tubes as stated before)
- Egnater tube mix control (only with amps with 4 power tubes. Amp will be modified to work with other tubes. 1 set in the middle pair and a different set in the outer pair.)
- Dual/quad bias circuits for unmatched tubes
- individual tube fusing/leds to indicate whether tube has died. Tube is shut off safely and led is lit when it shorts or fails.
- Reissue
- Vox**
- AC15 and AC30
- PTP boards
- Mustard Cap upgrade
- Allen Bradley NOS Carbon Comp resistors
- filtercap replacement
- general maintenance
- ef86 input circuit mod (if not already there)
- addition of top boost channel. (if not already there)
- AC15 and AC30
- Fender**
- Silverface
- Redo the circuit to sound like the better sounding blackface model
- Paper in oil cap upgrade
- Allen Bradley NOS Carbon Comp resistors
- Filter cap replacement
- general work
- Silverface
- Ephiphone Valve Junior Head or Combo**
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- Mercury Magnetic transformers available
- Mustard Cap upgrade
- Allen Bradley NOS Carbon Comp resistors
- Heyboer transformers available
- 6v6, 6l6, el34 mod
- gain boost mod
- treble, middle, bass eq mod (known as FMV tonestack)
- Treble Bass interactive eq mod (Known as a low loss james/baxandal eq)
- Egnater tube mix control (when using parallel tubes, usally in pairs of el34/6l6 and el84/6v6)
- Effects loop, with both types as stated previously
- DC heaters for hum problems
- PTP handwired board replacement
- filter cap replacement
- tremolo addition (speed, intensity controls)
- negative feedback switch/control
- ef86 input circuit
- reverb mod
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- Fender Champ **
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- Gain boost
- Upgraded speaker.
- Paper in oil cap upgrade
- Allen Bradley NOS Carbon Comp resistors
- Addition of Treble, Middle. and Bass circuit.
- Addition of tremolo circuit
- Effects Loop (solid state or tube)
- DC heaters for hum reduction
- filter cap replacement
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**All trademarks belong to their respective owners. Dual Stage Amps is not in any way affilated with Marshall, Epiphone, Hiwatt, Fender, Kevin O'Connor/Powerscaling, or Vox.