PRS J-MOD 100 John Mayer Amplifier Paul Reed Smith

Write a Review

The J-MOD 100 PRS John Mayer amplifier

No compromise amp designed with John Mayer.

The J-MOD 100 amplifier was personally created by Paul Reed Smith, Doug Sewell, and John Mayer to not just deal with Mayer's live work with Dead and Company, however to likewise move flawlessly into recording and playing out Mayer's performance work. With an insightful control platform, perfect form, and high-quality components, the J-MOD 100 is a fully-realized, high-end piece of audio gear for players who want the purest and most expressive musical experience.


World-class Craftsmanship Creates Expansive Tone

Designed with John Mayer to be his go-to guitar amplifier for performance and recording, the PRS J-MOD 100 John Mayer Signature tube amp delivers an amazing tonal range. This 100-watt single-channel amp features a switchable gain stage for higher-gain tones. With four 12AX7 preamp tubes, four 6L6 power tubes, and a premium Cinemag Texas 100 transformer, you can cover everything from glassy cleans to rock leads with articulation and detail. Factor in a total of three speaker outputs and a series effects loop, and the PRS J-MOD 100 John Mayer Signature amp is ready for any application.

Thoughtful control platform and feature selection.

The J-MOD 100 amplifier is a single channel amp featuring a switchable gain stage and effects loop. The amp’s tone stack features a beautiful, spread out tone that is at once huge and clear. When the gain stage is kicked in, the amp gets rich in harmonics and delivers a bit more bite. The versatility provided by this setup allows the J-MOD 100 to deliver a huge variety of sounds whether using singlecoils or humbuckers.

Additional tone-sculpting features include a bright switch, which adds more high-end to your tone, and a presence control that boosts the high-end in the power amp section of the amplifier, giving you a livelier, more complex tone. There is no reverb built into the J-MOD 100, but an effects loop was requested by Mayer for his reverb tanks. The amp’s effects loop (and gain boost) is controlled by the footswitch, so players can use any reverb or effects unit desired with this amp.

Wide tonal range

PRS designed the J-MOD 100's tone stack for wide, spread-out tone that is huge and clear. In addition to Treble, Mid, and Bass controls, a Bright switch is available to add top-end sparkle (or compensate for dark humbucking pickups). A Presence control adds in-your-face immediacy to your sound. Ultimately, John Mayer wanted this amp to be a blank sonic canvas, ready to highlight all the nuances and subtleties of his playing style. Spend some time with the J-MOD 100, and you'll find a world of expressive possibilities — and no matter how you end up shaping your tone, it's sure to retain incredible articulation and punch.

Elegant and robust construction.

The J-MOD 100 amp features five separate boards, all with over-sized traces for tonal integrity. Each board is dedicated to a particular part of the circuit: preamp section, power section, front panel controls, bias jacks, and the effects loop. Not only is this an elegant way to build with fewer long wires extending across a larger board, it is also a more robust way to build as there is not a single, large board that needs to flex during transport. The amp is hand-wired at PRS in Maryland, USA with a truly artistic level of craftsmanship. The J-MOD 100 also features a “laydown-style” power transformer for build integrity.

High-quality components.

The J-MOD 100 pairs hand-crafted construction with top-of-the-line components, including a Cinemag output transformer and high-end capacitors in the preamp section. The result is authentic vintage tone with rich harmonics that sit at the player’s fingertips for a thoroughly expressive and transparent musical experience.


Built with serviceability in mind.

Mains fuse, B+ fuse, and bias adjustment jacks are accessible on the back panel of the amp, so changes and adjustments can be made without needing to open up the amplifier. In addition, the amp will accept many different power tubes types, including EL34, 6CA7, KT77 (with re-bias).

“I think amplifiers are such interesting, complex animals. The J-MOD 100 is the result of a lot of searching...what is my sound? What are the elements of all these amps I own that should be chosen to go together in one amp and have this really distinct voice? What we ended up with is a really open and expressive amplifier that I feel is a real evolution and a step forward in guitar amps." – John Mayer

PRS J-MOD 100 John Mayer Signature Tube Amplifier Head Features:

  • Designed with John Mayer to be his go-to amp for performance and recording
  • 100-watt, single-channel design with switchable gain stage for lead tones
  • Series effects loop for incorporating reverb and other effects
  • Cinemag Texas 100 output transformer for harmonically rich output
  • Easy to maintain thanks to rear-panel access points for fuses and biasing
  • 2-button footswitch included (Effects Loop/Gain Boost)


Watts 100 (nominal)
Channels Single-Channel with Switchable Gain Stage and Effects Loop
Power Tubes 4 x 6L6
Preamp Tubes 4 x 12AX7/ECC83S
Output Transformer Cinemag Texas 100
Output Jack Configuration Two parallel Jacks with 4 and 8 Ohm selector switch, one 16 Ohm jack. (3 total jacks)
Fixed/Adjustable or Cathode Bias Fixed (adjustable)
Dimensions (Unboxed) 26” Wide, 10” Tall, 10” Deep
Weight 39.8 lbs
Colors Stealth with Salt and Pepper Grill Cloth and Gold Piping