J. Rockett Audio Designs HRM V2

In this uber-thorough article, we’ve covered in-depth the increasingly popular niche of overdrive pedals emulating the legendary Dumble amps.

Nashville builder J. Rockett Audio, a company fascinated by everything overdrive, is featured in that list with three stompboxes: the Dude, the Lenny, and the more recent HRM, now upgraded to V2, another D-Style overdrive, this time inspired by a variation found on some Dumble Overdrive amps featuring an extra EQ circuit, impersonated here by the “Fat” knob – the other three knobs are your regular Level, Gain and Treble. That mod was dubbed “Hot Rubber Monkey” – hence the pedal’s name.

The circuit in question can produce a very low-mid centric, throaty sound that cuts through the mix without sounding harsh or overly punchy. V2 feature improvements in tone, not in features, delivering better tone at lower gain settings than its predecessor, in part because of a new set of NOS parts.

As usual for any J. Rockett creation, there’s more to hear than there is to say about it (their pedals are all about tone).

Here are the videos of it. See at the bottom of the page for info about V1.

J. Rockett HRM Hot Rubber Monkey V2, Builder’s Notes

The HRM V2 is designed to achieve the overdriven sounds of a D style amp with the HRM EQ mod” This EQ mod creates a very low-mid centric throaty sound where the guitar frequencies live” The touch sensitivity and quickness gives the effect of immediacy and cuts through the mix.

For this V2 version we were able to spend about a 2 years living with an actual Dumble Amplifier with the HRM EQ mod. This allowed us to really drill down on the subtle nuances to make an even better version than the previous HRM. This pedal, even at lower gain settings, will bloom and feedback making it feel like the real thing. We found some very nice NOS parts that enhance the authenticity of the V2
version and most importantly it makes it fun to play.


  • Level: Controls the overall output and is very interactive with the gain control
  • Midrange: Controls the important “guitar” midrange and control the thick low mids.
  • Gain: Controls the amount of gain and is very interactive with the volume control
  • Top End: Controls the top end and helps tweak the amount of bite in contrast to the low mids.

J. Rockett HRM Hot Rubber Monkey V1



J. Rockett HRM Hot Rubber Monkey, Builder’s Notes

The Hot Rubber Monkey is a re-creation of the overdriven sounds of the legendary D style ODS amp but with the HRM EQ mod.

9 volt Negative tip adapter and a 5.5mm x 2.1mm jack.

Analog – 18mA Current Draw