The Crazy Tube Circuits Locomotive is an overdrive pedal built around a real tube. Rather than clipping diodes, the components most overdrives use to shape their distortion, Greece's Crazy Tube Circuits put a 12AY7 tube at the heart of the drive circuit, in a purple enclosure with true bypass switching1. It sits among the maker's other drives such as the Venus, Heatseeker and Rapture, and in the wider field of overdrive pedals.
The controls: Gain, Tone, Clean and Mean
The Locomotive keeps its control set to four knobs, each with a distinct job1:
| Control | What it does |
|---|---|
| Gain | Sets the amount of overdrive |
| Tone | Shapes the treble response |
| Clean | Blends in the unaffected signal |
| Mean | Sets the drive level |
The Clean and Mean knobs work as a pair: Clean controls the unaffected signal while Mean sets the drive level, so you can balance how much overdriven edge sits on top of your basic tone1.
What reviewers said
Premier Guitar's reviewer came away positive. On the core sound:
"Warm, pure-sounding overdriven tones."
The reviewer found the pedal "expressed a convincingly natural and warm breakup out of the gate," and noted that with a bump of the tone dial to 3 o'clock it showed a sensitive tone dial, strong dynamic response and clarity in the low end and overall response. The review also mentions the pedal was tested with bass1.
Swapping the tube
Because the drive circuit centers on a 12AY7, the pedal's character can be changed by changing the tube. Premier Guitar notes1:
"The 12AY7 can be replaced with any standard dual triode (like a 5751) to explore more tube flavors1."
That makes the Locomotive unusual among overdrives, where the voicing is fixed by diodes or transistors and cannot be adjusted in this way1.
Videos
BassTheWorld.com
Patrick Hunter
Distortion LTD
Questions
Does the Crazy Tube Circuits Locomotive use clipping diodes?
No. Rather than clipping diodes, Crazy Tube Circuits put a 12AY7 tube at the heart of the Locomotive's drive circuit, according to Premier Guitar's review. That is what sets it apart from most overdrive pedals, which use diodes to shape their distortion.
Can you swap the tube in the Locomotive?
Yes. Premier Guitar notes that the 12AY7 can be replaced with any standard dual triode, such as a 5751, to explore more tube flavors. Players who want a different response from the drive circuit can do so with an off-the-shelf tube.
Is the Locomotive true bypass?
Yes. Premier Guitar describes the Locomotive as a true-bypass pedal, so when it is switched off your guitar's signal passes through without the pedal's circuitry loading it.
What does the Clean knob do on the Locomotive?
According to Premier Guitar, the Clean knob controls the unaffected signal, while the Mean knob sets the drive level. Together they let you blend how much clean signal sits alongside the overdriven part of your tone.
Sources (1)
- Quick Hit: Crazy Tube Circuits Locomotive Review, Premier Guitar, 2018-08-02
