Darkglass Microtubes B7K Ultra Bass Preamp Pedal

Preamp Pedal for Electric Bass Guitar, with Overdrive, 4-band EQ, and DI Output
Darkglass Microtubes B7K Ultra Bass Preamp Pedal image 1
Darkglass Microtubes B7K Ultra Bass Preamp Pedal image 1
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Darkglass Microtubes B7K Ultra Bass Preamp Pedal
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Prime Your Bass Tone for Any Application

Whether you're plugging into a bass amplifier or going direct, the Darkglass Microtubes B7K Ultra bass preamp pedal is a great way to optimize your bass tone. It combines a powerful preamp, independently switchable overdrive, and a 4-band EQ to deliver ample sonic options. Toggle switches for the mid EQ bands allow for precision tone shaping, while the Attack and Grunt switches determine how your highs and lows are effected by the overdrive circuit. The blend control balances your dry tone and the overdrive, meaning you can dial in growling overdrive without sacrificing your fundamental tone. To bolster your bass tone for performance or recording, Sweetwater can highly recommend the Darkglass Microtubes B7K Ultra bass preamp pedal.

Darkglass Microtubes B7K Ultra Bass Preamp Pedal Features at a Glance:
  • Preamp pedal for electric bass guitar
  • Independently switchable overdrive, with a Blend control to balance dry tone and overdrive
  • 4-band EQ with switchable mid frequencies allows you to explore a wide tonal range
  • +/-12dB boost/cut range for each EQ band
  • Attack and Grunt switches set the amount of treble and bass to be overdriven
  • Direct output for live sound systems or recording devices, 1/4" out for bass amplifiers
Find your signature bass tone with the Darkglass Microtubes B7K Ultra bass preamp pedal.

Additional Media

13 Best Effects Pedals for Bass Guitar

Tech Specs

Type DI box, Overdrive, 4-band EQ
Form Factor Pedal
Inputs 1 x 1/4"
Outputs 1 x 1/4", 1 x XLR (direct out)
Power Source 9V DC power supply (sold separately)
Width 4.7"
Depth 4.2"
Manufacturer Part Number DAR MTB7K ULTRA

Customer Reviews

Based on 4 reviews
Write your review

Best bass preamp pedal money can buy

I've been playing bass for over 15 years and playing live for over 10 years and I have used tons of preamp pedals (sansamp and mxr m80+ just to name a couple) and this blows them out of the water. This pedal has enough tone shaping options to do any sounds you can think of and enough gain to nail any distortion tone you can think of. I gig a lot and front of house guys love the direct output its clean and sounds amazing every time. Bottom line to don't waste your money on other bulls*** get one of these you won't be disappointed. Yes it is a lot of money but you never need another preamp pedal.
Music background: Bassist in several metal/hard rock bands subs session player for over 10yrs


Pedal sounds great. Can be used as seperate eq and overdrive in front of an amp or as a DI box using the xlr. if you plain modern rock/metal this is the pedal to get.
Music background: I play bass for Wendigo records recording artist Nephilym

If God were to speak.......

If God were to speak the sound this box makes is what his voice would sound like! This thing has a sound that I can't really put into words. It has so many sounds in fact that you can get lost in the settings. The really nice thing is that you really can't make anything sound bad with this unit. Be forewarned that the EQ in this box is really powerful. So much so in fact that you will hear your bass in new ways. This thing has a way of extracting tones and sounds from your instrument that you never knew were there. Even in the most subtle settings, when you think it's not working or doing anything, it's adding a character and color to your sound that you don't really realize it there until you take it out of the chain. If you think your bass sounds good now, run it through this. Then take this box out of the chain after you played through it for a while. Even your most expensive high end bass will sound dull and lifeless compared to when you had this box in the loop. Yes, this thing is that good. If you like the sound of the B3K you will really love this thing. Every bass player needs this. You have got to get one asap! To sum it up, this unit is: 1. High quality 2. Built very well 3. Has tons of options and sounds 4. Is expensive but worth every penny 5. Does things that I haven't heard any other product do In short you need this! I'm glad I got mine! Believe all the hype about Darkglass products because it's true! They aren't good. They are GREAT!
Music background: Assistant Engineer Wall of Shadows Studio and Session Bass Player.


I had been reading the reviews, following Darkglass threads on talkbass and just wondered could what people are saying about this box be true or is it hype? Well I have to tell you after trying many other pre-amp pedals available (Tech21, Aguilar, MXR, ART....) This one with the ability to select low and high mids and the bass and treble settings in the best I have tried so far. My basses sound better than ever. This is a great addition to your board and that is just the pre-amp section, there isn't enough room to cover the switchable distortion/overdrive but WOW on that as well. It took me over a year to pull the trigger but when Sweetwater started to carry this product I knew it was time to try it and man am I glad I did!
Music background: Bass Player

Sweetwater Advice

Andrew Teeple

Whether I want overdriven tone or pure bass distortion, I know I can count on my Darkglass Microtubes B7K Ultra bass preamp. There's a ton of tone tweaking available on this box, which lets me sculpt every aspect of my sound. There's a reason this pedal never leaves my rig!
See also: Bass Effects, Darkglass, Darkglass Bass Guitar Pedals & Effects