The Broughton Audio Helion is a bass preamp pedal that puts the preamp section of the Traynor TS-50B bass amp on a pedalboard. Broughton Audio describes it as a combination of op-amps and transistors built to give a hard hitting solid state tone, and says that at higher gain settings the Helion creates a cutting grindy tone1. It sits among preamp pedals as a way to carry an amp's front end without the amp.
Where it comes from
The Traynor TS-50B was a solid-state bass amplifier first released in 19792. Broughton Audio names Shellac and The Jesus Lizard as examples of bands whose bass sound used the TS-50B amp, which gives an idea of the sound the pedal is chasing1. The Helion is not the only pedal project to draw on that amp: the independent project page Aion FX documents a TS-50B bass preamp build of its own2.
Controls and what they do
| Control | What it does |
|---|---|
| Bass, middle, treble | Equalizer for tone shaping1 |
| Boost switch | Gives even more gain at higher frequencies1 |
| Pad switch | Gives 12dB of attenuation at the output if line level is not needed1 |
The Pad switch matters when the Helion is feeding something that does not want a line-level signal: with 12dB of attenuation at the output, it can be tamed for an amp's instrument input or an interface1.
Power and headroom
The Helion runs on a 9V DC power supply, which is not included, with a standard Boss style connector and center negative polarity. Its current draw is approximately 15 mA1.
An internal power supply chip provides the full +/-15V supply as in the original amp, allowing plenty of headroom, according to Broughton Audio1. The 9V input is only the pedal's external supply; the circuit itself works at the higher internal voltages.
Size and availability
Broughton Audio lists the Helion's dimensions as 4.77" long by 2.6" wide, a compact footprint for a preamp1. As of 26 October 2026 the pedal was listed at US$190.00 on the maker's page1.
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Questions
What amp is the Broughton Audio Helion based on?
The Helion is the preamp section of the Traynor TS-50B bass amp, a solid-state amplifier first released in 1979. Broughton Audio rebuilt that circuit as a pedal, using a combination of op-amps and transistors, and an internal power supply chip provides the full plus and minus 15V supply as in the original amp.
What does the Pad switch do on the Helion?
The Pad switch gives 12dB of attenuation at the output when line level is not needed. It is there for situations where the Helion's full output would be too hot for what follows it, such as feeding an amp's instrument input rather than a line-level input.
Is the Broughton Audio Helion true bypass?
Yes. Broughton Audio states that the Helion has a true bypass switch, so the pedal's circuit is removed from the signal path when it is switched off.
How big is the Broughton Audio Helion?
Broughton Audio lists the Helion's dimensions as 4.77 inches long by 2.6 inches wide, so it takes up a modest amount of pedalboard space for a preamp.
Why does the Helion have an internal power supply chip?
An internal power supply chip provides the full plus and minus 15V supply as in the original Traynor TS-50B amp, which Broughton Audio says allows plenty of headroom. It is also why the pedal runs on a standard 9V DC supply while its circuit works at higher internal voltages.
Sources (2)
- Helion | Broughton Audio, Broughton Audio
- TS-50 Bass Preamp / Traynor TS-50B, Aion FX, 2022-06-02
