The Demon FX Microtube D7K "Bass" Preamp is a Demon Fx preamp pedal, currently around $78.80. Close alternatives include the Electro-Harmonix Nano Operation Overlord and the Ashdown James LoMenzo Mega Drive. It pairs well with the Electro-Harmonix Big Muff Pi and the Fulltone OCD.
Demon FX Microtube D7K "Bass" Preamp
Demon Fx · pedal
The Demon FX Microtube D7K is a budget bass preamp and overdrive pedal from the Chinese effects manufacturer Demon FX, designed in the Darkglass Microtubes B7K circuit tradition with a 4-band active EQ plus hi and lo pass filters. Delivers aggressive transistor bass overdrive with extensive bass-specific EQ for modern aggressive bass tones. The D7K provides Darkglass-B7K-adjacent performance at budget pricing.
What stands out
“Delivers aggressive transistor bass overdrive with extensive bass-specific EQ for modern aggressive bass tones”
— from the listing
“The Microtube D7K delivers B7K-adjacent bass preamp and overdrive performance with a 4-band active EQ and high/low pass filters at a budget price, suited for metal and modern bass players who want Darkglass-style aggressive bass tone shapin…”
— from the community notes
“The Demon FX Microtube D7K is a budget bass preamp and overdrive pedal from the Chinese effects manufacturer Demon FX, designed in the Darkglass Microtubes B7K circuit tradition with a 4-band active EQ plus hi and lo pass filters”
— from the listing
“Strengths: 4-band active EQ plus high and low pass filters provide extensive frequency shaping for aggressive modern bass tones”
— from the reviews
“In the signal chain bass preamps sit before the amp or DI”
— from the community notes
- bass
- filter
- aggressive
- eq
- low pass
- overdrive
- modern
Good for
- Live
- Silent Recording
- Studio
Price updated Oct 24, 2026
Genres the Demon FX Microtube D7K "Bass" Preamp is commonly used in
- Metal
- Djent
- Alternative
cited
Inferred from shared tonal signals, not a stated genre tag. - Funk
cited
Inferred from shared tonal signals, not a stated genre tag. - Soul
cited
Inferred from shared tonal signals, not a stated genre tag. - Acoustic
cited
Inferred from shared tonal signals, not a stated genre tag.
Pedals that stack with the Demon FX Microtube D7K "Bass" Preamp
Electro-Harmonix Big Muff Pi
Electro-Harmonix
9% matchElectro-Harmonix Big Muff Pi leans toward fuzzy, and that's a real, usable character to pair with
Comes earlier in the signal chain
Fulltone OCD
Fulltone
9% matchWhat Fulltone OCD brings here leans toward full — that's worth building a pairing around
Comes earlier in the signal chain
Electro-Harmonix Small Stone
Electro-Harmonix
8% matchRun Electro-Harmonix Small Stone after Demon FX Microtube D7K "Bass" Preamp in the signal chain, clear of Demon FX Microtube D7K "Bass" Preamp's own gain stage
Comes earlier in the signal chain
Ashdown Macchiato Compressor Guy Pratt Signature
Ashdown
7% matchAshdown Macchiato Compressor Guy Pratt Signature's own compressed character is the real reason this is worth trying
Comes earlier in the signal chain
Caroline Guitar Company Meteore
Caroline Guitar Company
5% matchKeep Demon FX Microtube D7K "Bass" Preamp's aggressive voice out front: Caroline Guitar Company Meteore goes after Demon FX Microtube D7K "Bass" Preamp in the signal chain so its pristine voice doesn't muddy it — goes in the amp's FX loop (or last, into a clean amp)
Comes later in the signal chain
Dunlop - MXR Carbon Copy Deluxe Analog Delay
Dunlop
5% matchPut Dunlop - MXR Carbon Copy Deluxe Analog Delay after Demon FX Microtube D7K "Bass" Preamp in the signal chain, clear of Demon FX Microtube D7K "Bass" Preamp's own gain stage — goes in the amp's FX loop (or last, into a clean amp)
Comes later in the signal chain
Cheaper alternatives
Boutique & premium upgrades
MXR Thump Bass Preamp
MXR
64% similarityShared character: filter, bass
Mesa/Boogie Subway Bass DI Preamp II
Mesa Boogie
50% similarityShared character: filter, bass
Walrus Audio Mantle Analog Bass Pre-Amp/DI
Walrus Audio
49% similarityShared character: filter, bass
Ampeg Classic Analog Bass Preamp pedal
Ampeg
48% similarityShared character: bass
Electro-Harmonix Battalion Bass Preamp/DI
Electro-Harmonix
47% similarityShared character: bass, overdrive
One Control Sonic Silver PEG Bass Pre-amp
One Control
46% similarityShared character: bass
Similar character
Electro-Harmonix Nano Operation Overlord
Electro-Harmonix
53% similarityShared character: bass, overdrive
Ashdown James LoMenzo Mega Drive
Ashdown
53% similarityShared character: filter, bass, aggressive playing
EarthQuaker Devices Scrolls V1
EarthQuaker Devices
49% similarityShared character: bass, aggressive playing, overdrive
Ampeg F17-1
Ampeg
41% similarityShared character: bass
See all alternatives to the Demon FX Microtube D7K "Bass" Preamp (cheaper + boutique) →
Questions people ask
What are good alternatives to the Demon FX Microtube D7K "Bass" Preamp?+
The closest matches in character are the Electro-Harmonix Nano Operation Overlord, the Ashdown James LoMenzo Mega Drive, the EarthQuaker Devices Scrolls V1. Budget picks: Demon FX Microtubes A7K Bass Preamp, Demon FX Bear PAW Analog Bass Preamp. Boutique upgrades: MXR Thump Bass Preamp, Mesa/Boogie Subway Bass DI Preamp II, Walrus Audio Mantle Analog Bass Pre-Amp/DI.
What pairs well with the Demon FX Microtube D7K "Bass" Preamp?+
Strong matches from rig and tone-complementarity evidence: Electro-Harmonix Big Muff Pi, Fulltone OCD, Electro-Harmonix Small Stone — Electro-Harmonix Big Muff Pi leans toward fuzzy, and that's a real, usable character to pair with.
How much does the Demon FX Microtube D7K "Bass" Preamp cost?+
Around $78.80 (live listing price, updated Oct 24, 2026).