The Caveman Audio BF2M is a dual buffer pedal: two independent unity gain buffers in one road-ready zinc-plated steel enclosure, each with its own input and output. The first stage is a high-impedance input buffer with a 1MΩ input impedance, and the second is a unity gain line driver that carries your signal along to your amp. Caveman Audio suggests it is perfect for serving as the first and last unit on any pedalboard, and it adds an isolated tuner output for feeding a tuner without loading your guitar signal1. For more on what this kind of circuit does, see the site's page on buffer pedals.
What it does to your signal
Caveman Audio, whose designer Steen Skrydstrup built custom systems for artists including David Gilmour, The Edge, MUSE, Steve Morse, Rammstein and Scorpions, describes the BF2M as a completely transparent buffering solution. The stated design goal was to retain the sound of your guitar plugged directly into the amp while providing an interface to add pedals, without altering tone or adding noise1. The same input buffer and output line driver circuits are the ones used in those custom systems, according to the maker1.
Buffer and line driver stages
The two stages are separate circuits, not one buffer with two jacks:
- Input buffer: a unity gain buffer with a 1MΩ input impedance, high enough that it does not load your guitar's pickups the way a long cable or a chain of pedals can1
- Output line driver: a second unity gain stage that leads your signal along to your amp, with an output load send rated for 1kΩ or more and a return impedance of 50kΩ1
- Isolated tuner output: a separate, isolated feed for a tuner1
Because the two buffers have separate inputs and outputs, the pedal can sit at the front of a board protecting the guitar signal and again at the end of the chain driving the cable to the amp1.
Power requirements
The BF2M needs 9V DC, center negative, and draws a minimum of 175mA. Caveman Audio is direct on the voltage question: "NO, the BF2M requires a 9VDC supply !!!" The maker adds that anything higher than 175mA is fine, and recommends Cioks power supplies for players who need multiple DC outlets1.
The 175mA minimum current draw is high for a buffer pedal. Many daisy chain outputs on small pedalboard supplies deliver far less, so the BF2M needs its own outlet on a supply rated for at least 175mA. 12V is not allowed1.
Buying direct
The BF2M is sold from the maker's own site. Caveman Audio offers a 30-day money back guarantee on all products, and all Caveman Audio and Skrydstrup products come with a 10 year warranty1. A PDF manual for the BF2M is available from the maker1.
Questions
Can the Caveman Audio BF2M run on 12V?
No. Caveman Audio states plainly that the BF2M requires a 9VDC supply and that 12VDC is not allowed. The pedal draws a minimum of 175mA, so any 9V DC center negative supply rated at 175mA or higher will work, and the maker recommends Cioks power supplies if you need multiple DC outlets.
What is the difference between buffer mode and line driver mode on the BF2M?
The BF2M uses two independent buffers with separate inputs and outputs. The first stage is a unity gain buffer with a 1MΩ input impedance that protects your guitar signal, and the second is a unity gain line driver that carries the signal along to your amp. Caveman Audio suggests using it as the first and last unit on a pedalboard.
Does the BF2M change your tone?
Caveman Audio says the design goal was to retain the sound of your guitar plugged directly into the amp, providing a completely transparent buffering solution without altering tone or adding noise. As with any maker's claim, it describes the intent of the circuit rather than an independent measurement.
What power supply does the BF2M need?
A 9V DC center negative supply capable of at least 175mA. Caveman Audio is explicit that 12V is not allowed, and because of the current draw it is worth checking that your pedalboard supply has a spare outlet rated high enough. The maker recommends Cioks supplies for players who need multiple DC outlets.
How long is the warranty on the BF2M?
Caveman Audio covers all Caveman Audio and Skrydstrup products with a 10 year warranty, and the company also offers a 30-day money back guarantee on all products.
Sources (1)
- BF2M dual buffer, Caveman Audio, 2025-06-02