The Ceriatone Overtone Special HRM  Bluesmaster 100 is another handsome Ceriatone perspective on classic American high-gain tone. The Overtone Special HRM Bluesmaster is a more traditional version of a certain “D” circuit iteration.  These amps are commonly referred to as “Bluesmaster”.  Compared to the HRM, the Bluesmaster is like a Blackface amplifier on steroids, PCP, Spanish Fly, and about everything else you tried in the ‘70s, ‘80s, AND ‘90s. The clean channel tonestack in the Bluesmaster is very different compared to other OTS amplifiers.

The midrange is slightly scooped (although not nearly as much so as a Blackface), which is heavenly for clean and slightly clipped tones.  Another large departure is in the Preamp Boost, which is MUCH higher gain and MUCH fatter sounding than all other OTS models.  Because of this, the overdrive channel is particularly liquid-like in high gain settings, and absolutely perfect for bluesy lines.  This also allows the player to have a great crunch tone in the clean channel (with PAB engaged), and then go into serious high-gain in the overdrive channel. 

Like others in the HRM series, the Bluesmaster has an internal adjustable tonestack (treble, middle, bass) for the overdrive channel.  This allows the player to fine tune gain tone to their liking.  Each channel also has it’s own independent Master Volume control. Like other OTS amps, we have labored carefully to select the finest components to suit the design.  As with all Ceriatone amplifiers, it uses our specially designed, custom transformers for superior reliability, frequency response, and feel. 

Current lead times are listed on the main page at

Note: PPIMV mounted on Front Panel will be either mounted in place of pilot lamp (Marshall styles) or a hole will be drilled (OTS styles).
          PPIMV mounted on Rear Panel will always be in place of a Speaker Output Jack.


Power Output   100 Watt        

Feature Overview
Hi and Lo Inputs
Push-pull Bright switch on Gain control
Mid-boost, Deep, and Rock/Jazz toggle switches
Treble, Middle, Bass equalization (shared between channels)
Overdrive channel with Drive and Level controls
Internal Treble, Middle, Bass tonestack trimmers (overdrive channel)
Separate Volume controls for each channel
Footswitch Included (Channel and Preamp Boost)
Rear panel OD Trim (fine tunes response of overdrive channel)
Passive effects loop
Full/Half Power switch
4 / 8 / 16 Ohm Selectable
Dual Speaker Outputs
External Bias Adjust

Power : 4 x 6L6GC
Preamp : 3 x 12AX7/ECC83
Rectifier : Solid State

OTS HRM Bluesmaster 100 Watt Configuration Options:

  • Chassis I - $1,393.50
    (Fully working chassis. Includes footswitch. Tubes and cabinet not included.)
  • Chassis II - $1,555.50
    (Fully working chassis w/ tubes. Includes footswitch. Cabinet not included)
  • Amp Head I - $1,649.50
    (Fully working chassis installed in a head cabinet. Includes footswitch. Tubes not included.)
  • Amp Head II - $1,811.50
    (Fully working chassis installed in a head cabinet. Includes footswitch.)
  • 112 Combo Amp - $1,937
    (Fully working chassis w/ tubes installed in a 1x12 combo cabinet. Includes footswitch. Speaker not included.)
  • Amp Head w/ C-lator Built In - $2,132
    (Fully working chassis installed in a head cabinet with a C-lator Tube Driven Effect Loop Buffer built into the cabinet.) Includes footswitch.)

Main photo is for illustrative purposes only and advertised base pricing is for Chassis I without tubes. Photos may include options that are not included if you order the standard version of the amp or don't order all options available. We also may not offer all options available and/or shown in main illustrative photos. Photos are of products assembled by Ceriatone. We no longer sell kits. Black Tolex is standard on all amps unless otherwise stated in product description.

Ceriatone amps are custom made, 100% hand-built, point-to-point hand-wired amplifiers using the highest quality components and custom wound transformers. Each amp is thoroughly tested and burned in before it is shipped to you. Even with long lead times Ceriatone takes no shortcuts or makes any changes to their build standards in the production of their hand-built amps. This is Ceriatone quality.

Pricing shown on includes the shipping cost to the USA only. We only ship to the USA, Canada and Mexico. Shipping to Canada, Mexico, Puerto Rico and the US Virgin Islands will have additional shipping. We'll invoice the difference in shipping and it is due at the time the order is placed.

Paypal is our payment processor and you do not need a Paypal account to check out. They do offer 4 types of payments. Any Debit/Credit card with one click pay, PayPal 4-Pay, use your Paypal account, or use PayPal Financing (6/12/24 months) at checkout.

Write a review

Note: HTML is not translated!
    Bad           Good

OTS HRM Bluesmaster 100 Watt

  • $1,393.50

Available Options

Tags: overtone special, hrm, bluesmaster, 100 watt, ots, ceriatone