March 21, 2020. The new VHX flagship model from Diezel amplification is available. This new head seems to be built on the famous VH4 head and embeds a DSP, a load box and an impulse response module.

4 channels, 4 KT77 power tubes (100 Watts) and 5 12ax7 preamp tubes… : that’s for the classical part. The VHX embraces digital technology by adding a DSP (signal processing, effects) with impulse responses capabilities. 64 IRs are preinstalled. I borrowed the pictures from Thomann (, as – as of today- I can’t find them on Diezel website(s) 😉

Diezel VHX front panel

The feature list is quite impressive :

  • 99 presets
  • IR output without a speaker connected (“CABLESS” operation)
  • built-in tuner
  • Presence, depth and mid-cut settings (mid-cut inherited from the DMoll and Herbert, a must-have for metal players)
  • Noise gate
  • Graphical eq
  • Serial, parallel and preamp loop (3 loops)
  • USB port (firmware update and IR loading ?)
  • MIDI connector for Diezel’s Columbus pedal
  • Bluetooth connectivity

The screen and buttons allows the configuration of the VHX :

VHX display and controls

The DSP seems to be able to run 6 effects :

PRE LOOP / PREAMP / FX 1/ FX 2 / FX 3 / FX 4 / FX 5 / FX 6 / CABSIM / POWERAMP

The embedded effects are :

  • DELAY 
  • LOOP A / B 

The cabinet IR controls is looking like this :

The back panel provides the cab connectivity as well as an USB port, an XLR IR output, the Colombus connector and midi connectors and an HP jack for connecting headphones.

VHX back panel

And finally, the VHX is powered by the … DOS : the Diezel OS

Available from Thomann, 3490 Euros.