PRS J-MOD100 Head John Mayer Signature Amp Head

Ex-Display model

Written by

Jed Van Wyngaardt

Please note: This item has been on display and has been re-priced as ex-demo stock.

Single Channel Beast

The amp is a Single Channel beast with a switchable gain stage and effects loop (which you can bypass) for when you want your mods/delays/reverbs after the gain stage.

The J-MOD100 doesn’t have Reverb built-in because Mayer uses external reverb tanks in the effects loop. At Mayer’s request, the Reverb tank wasn’t included in this design.

With 4x6L tubes we’re expecting that classic American clean sound with bucketloads of headroom and a bell-like top end. though, if we know John Mayer’s taste, it’s going to have a fat, full-bodied bass response too. And similar to his old Two Rock amps, the bass response will be tight and punchy with no loose, flabby frequencies running amok

Designed with Paul Reed Smith

John Mayer is a stickler for great, useable tone. Any guitar player will know and respect his guitar sounds and his approach to attaining these sounds. Together with Paul Reed Smith and Doug Sewell (Boutique Amp Designer at PRS) this amp was designed to handle Mayer’s live work with Dead & Company but still be versatile enough to work for the John Mayer Trio.

So, with a well thought out control platform, and the ability to tweak the amp to suit your exact guitar (Whether humbuckers or singlecoils) this amp is going to offer an open and expressive sound.

As per all PRS products, this amp is built with the highest possible components to yield the truest possible sounds. With a Cinemag output transformer and high-end capacitors in the preamp section for lush, vintage guitar tones.

Which Poweramp?

The amp has been built to be toured with, and so the Bias can easily be adjusted to accept loads off different power amp tubes to suit your sound. Prefer EL34s or KT77s? No problem.

Buy the matching cab by clicking HERE.

Here's what PRS say about the J-MOD100 Head

No compromise amp designed with John Mayer.

The J-MOD 100 amplifier was intimately designed by Paul Reed Smith, Doug Sewell, and John Mayer to not only handle Mayer’s live work with Dead & Company, but to also move seamlessly into recording and performing Mayer’s solo work. With a thoughtful control platform, impeccable build, 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.
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.
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).


  • 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
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