The PastFx Preamp Crunch Plus is a stand-alone analog preamp pedal: the isolated preamp circuit from the PastFx Chorus Ensemble, put in its own enclosure and expanded with an extra volume control. The circuit it isolates is a recreation of the preamp from the Boss CE-1 chorus ensemble, the pedal that started the whole compact chorus category. PastFx describes the resulting sound as "characterised by its warm, chimey crunch, saturation, and natural compression as the Level Control is engaged"1.
The original Preamp Crunch came about, according to PastFx's manual, "after many requests to have the bypass channel of The BOSS® CE-1 in a stand-alone unit"2. The Plus version keeps that circuit and adds a Master Control, so you can push the preamp into crunch without a jump in output level. It sits alongside the PastFx Preamp Crunch in the maker's range, and belongs to the broader family of preamp pedals.
The controls
The Plus keeps the control set of the original and adds one knob. PastFx describes what each does13:
| Control | What it does |
|---|---|
| Level Control | Determines the amount of crunch in the preamp signal, and shapes the overall tone, gain level and volume output1 |
| Master Control | Adjusts overall volume to compensate for higher gain settings on the Level Control, or to achieve unity gain at any point in the Level sweep1 |
| Pot Mod switch (internal) | Switches between two different potentiometer values for the Level Control, which can allow the signal to clip and crunch earlier1 |
| Bypass switch | Selects True Bypass or Buffered operation1 |
The Level Control is the heart of the pedal. It is not a simple volume knob: turning it up increases the gain through the preamp circuit, and the signal begins to clip and crunch. Because that same control also affects output level, the Master Control exists so you can set the amount of crunch first, then bring the volume back to match the rest of your pedalboard. The Pot Mod switch is inside the enclosure, so it is a set-and-forget modification rather than something you toggle between songs13.
The pedal also carries a Normal / effect footswitch, as listed in the original Preamp Crunch manual2.
The Plus version of the Preamp Crunch Classic
The Preamp Crunch line has two versions. The Classic is "the isolated preamp from our Chorus Ensemble in its own enclosure"1. The Plus is an expansion of it, and the difference is the Master Control. PastFx states that "with the Master Control set fully clockwise, the Preamp Crunch Plus operates with the same stock circuit as the Preamp Crunch Classic"1, so a player who wants the Classic's behavior can simply run the Master wide open.
The pedal also includes an inbuilt buffer circuit "which can be added or removed as desired"1. According to the original manual, the buffer was added "to restore high frequencies lost on the high input sensitivity setting" that some users experienced with the Boss CE-11. On the original Preamp Crunch, the buffer switch is only available when the effect is activated2.
"The PastFx Chorus Ensemble Preamp Crunch is the most faithful recreation of the The BOSS® CE-1's preamp."
Power and bypass
The Plus runs on a 9V center negative power supply drawing 55mA, or on a 9V battery1. The original Preamp Crunch manual gives the same figure in more detail: the pedal "can draw up to approximately 55ma, so 100ma minimum PSU should be more than adequate," and it calls for a regulated, isolated linear or transformer-based supply with a 9VDC 2.1mm jack, negative tip2. That current draw is modest by modern standards, but the manual's preference for an isolated supply is worth noting if you run a daisy chain.
Internally, the pedal generates the correct bipolar voltages, +/- 14V and 13V1. The original manual explains that the pedal operates off the same bipolar voltages as the Boss CE-12, which is how a 9V supply can feed a circuit designed around higher internal rails.
For switching, the Plus offers a choice: True Bypass, or Buffered operation selected via an on/off switch1. The original Preamp Crunch manual lists True Bypass2, so the selectable buffer is the newer pedal's refinement. If you want to read more about where a buffer fits in a signal chain, see buffer pedals.
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Questions
What is the difference between the PastFx Preamp Crunch Plus and the Classic?
The Plus is an expansion of the Preamp Crunch Classic, which is the isolated preamp from the PastFx Chorus Ensemble in its own enclosure. The Plus adds a Master Control for overall volume. With the Master Control set fully clockwise, the Plus operates with the same stock circuit as the Classic.
Is the PastFx Preamp Crunch Plus true bypass?
It offers True Bypass or Buffered operation, selectable via an on/off switch. The original Preamp Crunch manual lists True Bypass, and notes that its built-in buffer switch is only available when the effect is activated.
Does the PastFx Preamp Crunch Plus run on a battery?
Yes. It requires a 9V center negative power supply drawing 55mA, or a 9V battery. The original Preamp Crunch manual states it only requires a standard 9VDC pedal power supply or 9V battery.
How much current does the PastFx Preamp Crunch Plus draw?
It draws 55mA. The original Preamp Crunch manual says the pedal can draw up to approximately 55mA, so a 100mA minimum power supply should be more than adequate.
What does the Pot Mod switch do on the PastFx Preamp Crunch Plus?
It is an internal switch that selects between two different potentiometer values for the Level Control. Changing the potentiometer value can allow the signal to clip and crunch earlier.
Is the PastFx Preamp Crunch Plus analog?
Yes. Its circuit type is listed as analog, and it is a stand-alone recreation of the analog preamp from the Boss CE-1 chorus ensemble.
Sources (3)
- Preamp Crunch Plus, pastfx.com, 2026
- PastFx Chorus Ensemble Mini Manual final, PastFx, 2020-12
- Preamp Crunch Plus by PastFx, RockBoard PedalPedia, 2026
