Carl's Custom Amps British Vintage 12W to 1/10W Marshall Plexi Tones with London Power Scaling

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Carl's Custom Amps
Las Cruces, NM, United States
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About This Listing

Carl's Custom Amps British Vintage 12

12W to 1/10W of Classic Marshall Plexi Tones with London Power Scaling and Tube Swapping 

For the foreseeable future build times will be between 8 to 14 weeks. We are experiencing very high demand. Each amp is built one at a time with great care so no rushing is possible. Thank you to everyone who has purchased for your business and patience!


For some time players have been requesting I build low wattage Plexi style amp. Now I’ve done it! The British Vintage 12 takes inspiration from the 60’s and 70’s non master volume Marshall Plexi amp's overdrive but does it at low volumes in light weight compact head. It got those vintage Plexi tones and takes pedals really well. Crunch and punch in small head! The Fat switch lets you get fat early 60's tones while the crisper stock position is reminiscent of the later 60’s and early 70s Plexi amps with crisp attack. A switchable boost adds crunch and sustain to the sound.  The sound of all those great hard rock bands will be there at your fingertips! 

At the heart of the amp is London Power Scaling which controls the output power of the amp transparently allowing the player to get power tube overdrive at low volumes. Many other builder have “wattage” or “Power” controls but London Power Scaling is different—-it’s simply the best way to get power tube overdrive and low volumes.

The amp comes with a El-34 but any of follow tubes can be used with no bias changes: KT66, KT77, KT88, 6L6GC, 5881, 6L6WGB, 6V6, 6CA7, and 6550.

For players looking for cleaner 60’s Marshall tone ask about my JTM mod that lowers the gain and ships with KT66.

I also offer a few styles 1x12 and 2x12 ext cabs for the amp fitted with Weber Legacy speakers for that pre-rola Celestion sound. Be sure to ask!


12 Watts all tube Power that can be turn down to 1/10W and all points in between.

Uses 1 X EL34 and 2 X 12AX7s

Power switch

Solid state rectifier

Single Input

Volume, Treble, Bass, and Middle, Limit, and Power controls

Fat and boost switches allows many tonal possibilities

8 and 4 Ohm Speaker Out

Cathode bias so there is no need to bias tubes

Galactic Grounding, dc elevated heater system, and smart layout ensures minimal floor noise with maximum touch sensitivity and note clarity.


Custom Wound USA made Output Transformer, Custom Wound power Transformer,  Cliff UK Jacks, Alpha pots, Malory 150 & Panasonic Tone Caps, Special Resistor selection for lowest noise and best tone, Ultra Long Life Filter Caps
Customer Comments:

“Hey Carl! Got the amp today and had a chance to noodle a bit. It has awesome overdriven tone, very organic. Was able to get some nice EVH tone just driving it with a tube screamer. It’s a loud 12w, my wife probably wishes I got the 7w version. Lol. Thanks again!”

Jeffery R.

“Carl, what an amazing amp; everything I hoped for. I am beyond wow'd. It's JTM Plexi for days. Sounds superb at in-home volume levels. The pull boost adds more gain, but not too much; Maybe early JMP? The Power Scaling is huge. Thank You.

Roland, Las Cruces, NM”

Reviews of this Shop


Product Specs

ConditionBrand New (New)
Brand New items are sold by an authorized dealer or original builder and include all original packaging.learn more
Made In
  • United States

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