GTP 100 Watt Amplifier

Rated 5.00 out of 5 based on 1 customer rating
(1 customer review)


100 watt amplifier leveraging the glorious 1968 Plexi DNA, with dual preamp gain stages for infinite control over preamp gain structure

Approx lead time 4-5 weeks ARO

SKU: N/A Category:



In the world of auto racing, the GTP class is the highest level of performance in the LeMans Endurance series.  R&D teams from carmakers that normally make production vehicles get to push the limits with a blank canvas.  But if prototyping a new rig isn’t enough of a challenge, add the requirement that the design MUST withstand the highest levels of performance for an absurd length of time!  We thought this was an analogous landscape for where our design team needed to operate for its next creation.

We wanted to develop something that would complement the TS-50 on a 100 watt platform.  The 100 watt plexi was loved for its musical tone, but many felt the need to “push” the front end to get a bit more sustain and grit.  The GTP100 is for the guitarist who opts for the highest horsepower car on the lot but civilized when required, can change direction without losing composure, and run at the limits without failure.  Our solution to this is the GTP100.

The GTP100 has proven itself in all categories.  It:

  • plays virtually identically to a bone stock Super Lead at almost any volume with the Preamp Gains set roughly midway
  • will satisfy the pickiest of classic  VH tone chasers
  • provides enough overdrive to negate the need for a boost (TS-9, 6 band, etc.) which simplifies your rig
  • has stellar tone at manageable volumes


  • Based off ’68 Marshall 12xxx Plexi platform
  • Point-to-point handwired
  • (3) EHX & (1) JJ 12AX7 preamp stages
  • (4) EHX 6CA7 power tube stages
  • (2) preamp gain controls
  • classic Marshall tone stack w/presence
  • PPI Master volume
  • 1 input
  • 2 speaker outputs
  • impedence selector
  • FX loop
  • Tolex of your choice

Additional information

Weight N/A
Dimensions N/A

Classic black/gold, Black/black

1 review for GTP 100 Watt Amplifier

  1. Rated 5 out of 5

    Eric Fraser

    I’ve beeen using the Holbrook GTP 100 for live gigs and recording and the amp simply smokes. The simple design is its strength making it easy to go from great jangly rhythms with my Tele and getting plenty of sweet rich harmonic gain with my PAFs on the Les Paul. The mids are gritty, but not barky, and with detail that will turn heads. Kevin knows the most important components on the signal chain to deliver plexi goodness while giving must haves like an effects loop for pedals that need to be there.!LOVE THIS AMP!

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