micro-Thumpinator v2

The micro-Thumpinator is a bandwidth optimizer designed for bass guitar. It removes the low frequency signals that are outside the range of notes produced by the instrument.

Infrasonic frequencies cannot be reproduced by standard bass cabinets but they often make amplifiers clip, especially when they are set to boost the lower frequencies. The Thumpinator filters the signal content optimising the energy delivered by the amplifier. Low-frequency clip is substantially reduced and the sound is tighter especially at high volume levels.

The micro-Thumpinator accepts instrument and line level signals. It can be used between preamplifier and amplifier, between bass and amplifier or anywhere in the effect chain (line or instrument level). It can also be connected directly to an audio interface.

Watch this video to see the effect of the micro-Thumpinator on an amplifier's performace.


  • Cut-off frequency: ~25Hz
  • Slope: 36 dB/oct
  • High input impedance (~2MΩ)
  • Low output impedance (<150Ω)
  • Power supply: direct current (DC), 7-11V, 2.1mm centre negative, regulated. It can be daisy chained.
  • Current usage: ~50mA @ 9V
  • Small footprint (enclosure: 84mm x 44mm x 23mm, 3.3"x1.73"x0.9")
  • Hand-built using the finest components

  • At [sfx] we keep our devices design constantly under review. For this reason, the specifications are indicative and they may vary without notice.


    Where should micro-Thumpinator be in the signal chain?
    Unfortunately, there is no short answer to this question. We recommend to try first with the micro-Thumpinator at the very beginning of the signal path. The micro-Thumpinator is also an excellent buffer and if you use a passive instrument with true-bypass pedals, the micro-Thumpinator will help in preserving the tone. We also recommend you try other positions in the signal chain.

    I have an octaver pedal. Should I put micro-Thumpinator after the octaver?
    If you use an octaver (especially, a digital octaver), putting the micro-Thumpinator will help you remove the frequencies that your amplification system cannot convert into sound.

    Can I power the micro-Thumpinator at 18V? I heard that powering pedals at 12V or 18V increases the headroom.
    Although it is true that some pedals when powered at 18V perform better, with the micro-Thumpinator it is not necessary to go above 9V. The main reason is that the micro-Thumpinator has a circuit that increases the internal operating voltage, giving you all the headroom you need with a standard 9V power supply. Moreover, the internal power supply circuit of the micro-Thumpinator creates a dual-rail power supply that delivers a more stabile voltage to the audio part of the circuit.

    Can I have a micro-Thumpinator with a variable frequency control? One of my friends bought a HPF with a knob that sets the cut-off frequency...
    We designed the micro-Thumpinator with a single goal in mind: audio performace. Although it is possible to design and build high-pass filters (HPF) with variable frequency, they don't even come close to the performace of the micro-Thumpinator. From the power supply circuit to the enclosure, the micro-Thumpinator is designed to deliver the best possible sonic results. In simple terms, the micro-Thumpinator is the sniper of the infrasonic frequencies: if your signal has a component below the cut-off point, the micro-Thumpinator will remove it leaving everything else untouched.

    Can I connect the micro-Thumpinator directly to the low impedance input of my sound card?
    Yes, you can. The micro-Thumpinator output circuit can drive low impedance inputs without signal degradation.

    Can I use the micro-Thumpinator in the effects loop of my amplifier? Can I connect the micro-Thumpinator to the input of a power amplifier?
    Yes and yes.

    When I use my micro-Thumpinator with my amp, everything sounds tighter. Can I use it instead of a compressor during recordings?
    The micro-Thumpinator is not a compressor and it cannot replace a compressor. However, it can help hugely during recordings removing the need of an external compressor. Every time a bass player starts a note, the attack of the sound contains a significant amount of infrasonic noise. This is often managed with a compressor placed before the audio interface and as the micro-Thumpinator removes the infrasonic noise, it also mitigates the initial peak. With a lower initial peak, the input level of the audio card can be incresed leading to a better signal-to-noise ratio. Of course, the signal can be compressed at a later stage with plug-ins.

    Can I have a micro-Thumpinator in a specific colour?
    We order enclosures based on the market availability and sometimes only some colours are available. We cannot offer a colour selection because we don't know which colour will be availabe at the time of shipping but generally speaking, black is the colour we have in stock more frequently.

    Customer comments

    First things first. Now that I have one, I cannot live without it. What this unit did for my tone is very simple to explain, it controlled it. I am a finger player and enjoy the type of attack that folks such as Entwistle enjoy. Hard when needed, which is the important part of this. Before, when I would attack the strings hard, I would get all kinds of unpleasant artefacts from my cab. Mostly, the dreaded thump. Will this unit take that away entirely? No, which is a good thing. What it leaves is what you would expect... a solid finger tone without all the extra low end thump. I really had to a/b the Thumpinator a few times before I understood how it changed my signal. At first, I was left wondering what the hell it was even doing. Then I started actually playing a song and voilà, there it was. I could "go places" I was shying away from before. I could really attack my string, properly compressed after the Thumpinator mind you, and not fear a bad response. I sat in my band room for 2 days going over each of my riffs and changing them to what I had originally intended. No more will I have to be cautious.

    I was always told as a young man that the tone was in my fingers. Now, that tone can be heard as intended.

    I highly recommend the micro Thumpinator for any finger players. It simply controls your signal. I cut through better overall and I can beat it if I want without remorse.

    In regards to effects, for those that use them, having a solid signal has only helped. I run the Micro Thumpinator first in my effects chain, allowing effects to do what they need to do with the signal, rather than try to control it after. In the end, running it first was the best route. A controlled signal... hell. Who would have thunk it?

    Thanks [sfx]; I am going to be buried with this thing.

    - Paul C, USA

    Max, The Thumpinator is a winner. The difference is amazing.

    - Stu Cook (Creedence Clearwater Revival 1967-1972, Clearwater Revival Revisited)