Louder Than Liftoff

Pentode Tube Saturation Colour


  • Fully Assembled

Pentode is the first module to bring true tube saturation to the Colour format. True to the spirit of the Colour format, Pentode employs minimal, carefully selected components to achieve a coveted, vintage tone. A single NOS tube running at its true plate voltage is overdriven to produce the musical saturation that can only be described as "tube color."

Design Notes

There something so visceral and satisfying about listening to audio reproduced by a tube circuit. Pentode increases the perceived loudness of your source by saturating the transients (audio sorcery!) and adding musical 2nd and 3rd order harmonic distortion. As the ratio of RMS to peak energy grows by turning up Colour's Saturation knob, sonic density is magnified, volume is increased, and the sound becomes gigantic. That's why we like to call Pentode a Gigantifier!

-Brad McGowan, Designer, Louder Than Liftoff

MKII Improvements

Pentode MkII intensifies vibrant color in the source by adding musical second- and third-order harmonic distortion. Expanding on the design of the original Pentode Colour, the user may now select between one of two tube bias settings to fine-tune the harmonic spectra. The RICH setting presents a lively blend of both even and odd order harmonics, which enhances presence and pulls the sound forward in a mix. This setting configures the tube to deliver the original Pentode tone many have grown to love, especially on guitars and vocals. A new FAT bias setting configures the tube for mostly second-order order harmonics for a thicker, rounder tone. It evokes a more vintage vibe that some may associate with classic tube equipment using triodes.

You can further sculpt the sound and sonic texture with the new two-band Baxandall EQ, which follows the tube stage. The elegant simplicity of this circuit has attracted hi-fi and pro audio designers since its invention in 1952. Revolutionary for its time, it still remains a classic due to its effortless tone bending powers. In our implementation, the Bass and Treble curves, and their unique interaction were inspired by an obscure 1960's tube mixer. We tweaked by ear for optimum musical synergy with the rest of the circuit.


  • NOS Raytheon 6418 subminiature tube
  • Two bias settings (via jumper): Rich and Fat
  • Regulated DC filament supply
  • 2-band Baxandall EQ inspired by vintage 1960's tube mixer
    1. Bass and Treble bands individually bypassable via jumper
    2. EQ gain adjustable via trim pots: +/-8 dB
    3. Recommended applications: subtle tube frequency contouring, bus sweetening, mix-ready vocal and guitar presence, big bass
  • Class A biased buffers using audiophile grade op amps
  • Wima MKP film caps
  • Compatible with DIYRE Colour

Pentode is offered fully assembled and tested by Louder Than Liftoff. It and LTL's other Colours will not be available as DIY kits.

Note on Tube Microphonics

There is a real vacuum tube in this thing. One thing that real tubes have that emulations don't is microphonics. Due to the vibration sensitive nature of the 6418 tube, some units may experience a low-level ringing for a couple seconds when the unit is bumped or the bypass/engage switch is pushed. 

Customer Reviews

Based on 8 reviews
Versatile, glue-like

Compared to some of the other modules this might be one of the more "invisible" ones as the core sound goes- and yet, I've found it can do a super great job of getting guitars, snares, even vocals to sit. Pushed, it definitely compresses, and pushed super hard the tube starts to show though leans brighter. It's a little more obvious in the fat setting, but most of my testing has been in rich, which is my preference overall for the sources listed above. I imagine it's probably amazing with bass on the fat setting. The Bax EQ is also super useful and wonderfully musical sounding- m/s processing it can really widen or open things up a bit. Over the master bus it performs an amazing glue and I will be committing all my mixes through it henceforth. I don't have a lot of outboard gear, and I heavily recommend anyone who's in a similar position grab this for some of the 3D-ness soft stuff can't seem to replicate.. though in a bunch of chromas or mister focus' I could see studios of any size benefitting. Gain staging with this one is very important (as is for all of them but y'know.)

Not sure about the tone on this one

Was excited to see a tube colour module, however after spending a good amount time with a pair of these, I decided to sell them. I find that the tone is on the harsher side than many triode circuits that I've heard, most of which have that nice round midrange sound. It will reduce dynamics without dramatically coloring the signal, but when pushed I find the sound harsh rather than warm. I honestly can't say if this is due to pentode vs. triode, available power, or the physical size of the tube compared to say, a 12AX7.

Rob schnapf
Pentode is my favorite colour

I think I own 6 different colour modules now and this one is my favorite.
Slowly dial in the sweet spot for each track.
As you start to saturate it it darkens nicely.
Love it in the mic pre and really dig it in the new colour modules with the transformer.
For me It really seems to be the most flexible of the modules as it has such a wide range of sonic usefulness.
It's not just a distortion box. It is a very capable module and I'm glad I got two of them.....

Top notch

I got two and they sit in my busses since the first day. Drums, bass, keys, horns...
Adds fatness and presence at moderate drive levels and a nice growl without harshness when fully driven.
Everything sounds better through this


This module works on almost anything in a positive way. Even when it is pushed it still won't sound ugly. It has this really cool way of smoothing over the high end while still adding a nice sparkle to things. Try it on mandolin. Do it.

Related Products

Liquid error (layout/theme line 342): Could not find asset snippets/hulkapps-restock.liquid