Dual Modern Tube Amp Pedalboard

The Two Channel Dual Tube Amps Feed Pedalboard with Stereo BBE Sonic Enhancer Exciter


The Dual Tube Amp Pedalboard is a two channel distribution system for the Blackstar HT20R MRK II and Tone King Gremlin amps fed by twin LPD Signal Buffers to ensure clean balanced isolated feeds to the two amps from the BBE Exciter.

The system can select either amp or both with the JHS Active ABY switch box.

The LPD Compressor is used as a soft compressor mainly for proper "Gain Staging" to blend the "Modern Tube" sound with the "Boutique 80s Tube" sound from the Kelley F.A.C.S. amp.

The ABY feeds a BBE Sonic Enhancer Harmonic Exciter for psychoacoustics imaging control.

The Seismic twin 12" Celestion Creamback 75 shares a speaker with each of the two amps, as shown in the diagram. There are four mics used to record this configuration: one for each speaker.

The JHS Morning Glory & the BOSS Angry Driver uses the BOSS dual foot switch to switch between the JHS Angry Charley and the BOSS Blues Driver with one switch and additional Morning Glory Drive with the other.


The Tone King Gremlin tube amp is a low-wattage side American style amp, 7 watts, high gain Classic Class A vintage tube amp design.

An integrated Passive Resistor-based Power Soak loading attenuator allows volume level management. It does color the sound and is not used in the Cave design.

The factory KT88 supplied tube did not meet the Cave’s sound requirements as it was delivered from the factory. An EL-34 was substituted for the power section. The designed Class A amp is fully cathode biased for self-biasing.

The Blackstar is a two channel, Marshall type, tube amp that is used in the clean channel only. It complements the Tone King very well and blends perfectly with the Boutique Kelley F.A.C.S.