The MAS Effects Volume + Expression Slider is a small passive slider, rather than a rocking foot pedal, that a player can use as either a volume pedal or an expression pedal. MAS Effects describes it as being like the popular little black Amp Box, a compact passive volume attenuator: put it in a series effects loop to get fully cranked tube amp sounds at polite volumes, or place it in the pedal chain to knock off a few dB123. In its expression role, it plugs into any pedal with an expression jack to give remote control of that pedal's parameter312.
The key point about the combo version is that it does one job at a time. MAS Effects states plainly that it "can be used as either an expression or a volume pedal (not simultaneously)"421. It is a desktop or mic-stand-friendly alternative to a floor pedal, aimed at players who want a slider they can nudge with a finger rather than a rocker they work with their foot5.
How it works as a volume control
For volume use, you plug mono TS cables into the side input and output jacks and use the slider to bring your signal down to a better level5. MAS Effects suggests two placements:
- In a series effects loop, to get fully cranked tube amp sounds at polite volumes3
- In the pedal chain, to reduce volume by a few dB, like the little black Amp Box3
One thing worth knowing before you buy: the potentiometer has a linear taper, and MAS Effects notes that this "makes it feel a little more sensitive on the lower half of the slider"5. If you are used to an audio-taper volume pedal, the response under your fingers will be different.
How it works as an expression pedal
For expression use, a 1/4 inch TRS stereo cable goes in the top jack and connects to the expression input of another pedal, giving remote control of that pedal's parameter53. The cable is not included3.
Compatibility depends on the potentiometer value you choose4:
| Potentiometer | Works with |
|---|---|
| 100k (B100k) | Most EQD (EarthQuaker Devices), Strymon, EHX, Matthews Effects, and more42 |
| 10k (B10k) | Boss, and perhaps others42 |
There is a real compatibility limit here. MAS Effects states the expression connection "will not work well with Eventide, Line 6, or others that use mono TS cables"5. Pedals with that wiring scheme need a different expression solution.
Versions, finishes and price
The slider comes in a family of versions and finishes, including Abduction and Split Skull artwork options5. The lineup splits into two functional versions2:
| Version | Function | Price |
|---|---|---|
| Expression pedal | Plugs into any pedal with an expression jack for remote control | $39 USD2 |
| Volume control / Expression combo | Either role, not simultaneously | $59 USD2 |
UK listings show the combo at £55.00 and the Expression version at £36.0036. MAS Effects notes these are often made to order and can be customized for additional fees3. Previous special editions have existed, including a desktop expression pedal prototype special edition3.
The Expression + Volume Slider comes in two potentiometer options: a 100k linear potentiometer (B100k variants), which works well with EQD, Strymon, EHX, Matthews Effects, and more, and a 10k linear potentiometer (B10k variants), which works for Boss and perhaps others2.
How it compares with a conventional volume/expression pedal
Questions
Can the MAS Effects slider be a volume pedal and an expression pedal at the same time?
No. MAS Effects states the combo version can be used as either an expression or a volume pedal, but not simultaneously. You choose one role at a time: run it into a pedal's expression jack with a TRS cable, or place it in your signal chain with TS cables to control volume.
Which cable goes in the top jack of the MAS Effects slider?
A 1/4 inch TRS stereo cable goes in the top jack for expression use, and it is not included with the pedal. The side jacks take mono TS cables for volume use. Note that the expression connection will not work well with pedals that use mono TS expression wiring, such as Eventide and Line 6.
How much does the MAS Effects Volume + Expression Slider cost?
The Volume + Expression combo version is listed at $59 USD. The Expression-only version is $39. MAS Effects notes the sliders are often made to order and can be customized for additional fees. UK listings show the combo at £55.00 and the Expression version at £36.00.
Does the MAS Effects Expression + Volume Slider need power?
No. It is a fully passive device with no power requirement, so there is no battery, adapter or power supply to worry about. That also means it draws nothing from a pedalboard power supply and can sit anywhere in your chain or on a desktop without a power connection.
Can it work as an expression and a volume pedal at the same time?
No. The maker is explicit that the combo version can be used as either an expression or a volume pedal, not simultaneously. Switching between the two roles means changing how it is cabled: TRS cable to an expression jack for expression control, or TS cables in the side jacks for volume.
Sources (6)
- Expression and Volume Slider Pedal, MAS Effects (shop.mas-effects.com)
- Expression and Volume Slider listing, MAS Effects
- Expression and Volume Slider Pedal, MAS Effects
- Expression and Volume Slider Pedal, MAS Effects
- Slider Expression and Volume Pedal by MAS Effects, MAS Effects
- MAS Effects, MAS Effects (shop.mas-effects.com)
