The MAS Effects SHO Boost with upgrades is a one-of-a-kind take on the SHO boost, a boost pedal design, built with a Crackle Ok knob plus an additional Master Volume control. What sets this particular build apart is a working VU meter with a custom-tailored driver board for it, so the needle moves with your playing. It was listed on the MAS Effects store at a regular price of £128.00, later shown at a sale price of £174.00, and it is sold out1.
The VU meter
The meter is the centerpiece of this build. MAS Effects fitted a working VU meter with a custom-tailored driver board for it, and the meter has a warm backlight when the effect is engaged1.
Two rear-panel controls shape the meter's behavior:
| Control | Location | What it does |
|---|---|---|
| 3-way switch | Back | Takes the signal from the input, from the output, or turns the meter off1 |
| Sensitivity/gain knob | Back | Adjusts how responsive the needle is, which the maker calls great for switching between humbuckers and single coils1 |
MAS Effects notes the VU meter is not suitable for accurate measurements, though the maker calls it useful and informative as well as just plain cool1.
Footswitch and bypass behavior
The pedal uses a soft-touch foot switch with relay-controlled True Bypass1. The switch behaves differently depending on the pedal's state:
- A press toggles the effect on or off as usual.
- Holding the footswitch while bypassed temporarily enables the effect.
- Holding the footswitch while engaged temporarily bypasses it.
- Holding the footswitch down while powering the pedal up toggles auto-on, so you choose whether it engages or bypasses when plugged in1.
Enclosure and availability
The pedal is housed in a vintage CB tester enclosure. MAS Effects describes it as fairly sturdy aluminum, but says you need to treat it with respect as it will not withstand heavy footwork1.
As a one-of-a-kind build, this version is sold out1. Players interested in the maker's other work can look at the MAS Effects St. Patrick's Boost, or browse other boost pedals more broadly.
Questions
Is the MAS Effects SHO Boost true bypass?
Yes. MAS Effects describes the pedal as having relay-controlled True Bypass, so when it is bypassed a relay routes your guitar signal straight past the boost circuit. The soft-touch footswitch handles engaging and bypassing, and holding the switch down gives momentary access to the opposite state.
Is the VU meter on the SHO Boost accurate?
No. MAS Effects notes that the VU meter is not suitable for accurate measurements. The maker still calls it useful and informative, and it is driven by a custom-tailored driver board with a sensitivity/gain knob on the back that adjusts how responsive the needle is.
What does the Crackle knob do on the SHO Boost?
The pedal is a SHO boost with a Crackle Ok knob plus an additional Master Volume control. The Crackle Ok knob is the boost's gain-style control, and the added Master Volume gives a second level of output control over the boosted signal.
What is the enclosure made of?
The pedal is housed in a vintage CB tester enclosure. MAS Effects describes it as fairly sturdy aluminum, but says you need to treat it with respect because it will not withstand heavy footwork.
Is this SHO Boost still available?
No. The pedal was listed as sold out on the MAS Effects store as of October 2026, and it is a one-of-a-kind build, so no further units of this exact version were made.
Sources (1)
- SHO Boost with upgrades, MAS Effects
