ZVex Box of Rock Settings Guide
The ZVex Box of Rock is a two-in-one distortion and boost pedal that models a Marshall JTM45 amplifier circuit in a small enclosure. The left half is a "Super Hard On" (SHO) clean boost; the right half is the JTM45 preamp circuit clipping diodes producing the characteristic Marshall crunch. Together, they recreate the sound of a pushed JTM45 without requiring a loud tube amp. The Box of Rock is widely regarded as one of the most accurate "amplifier in a box" distortion pedals and is a benchmark for boutique British-voiced distortion.
The best ZVex Box of Rock settings start with: Volume at 5/10, Drive at 5/10, Tone at 6/10, Boost at 4/10. Adjust from there based on your amp, guitar, and room volume. For Blues: Volume 6/10, Drive 4/10, Tone 5/10, Boost 0/10.
⚡ Start Here — Recommended Settings
| Control | Starting Position | Range |
|---|---|---|
| Volume | 5/10 | Silent → Loud |
| Drive | 5/10 | Clean → Maximum |
| Tone | 6/10 | Warm → Bright |
| Boost | 4/10 | Off → Maximum |
These are universal starting points. Adjust based on your amp, guitar, and room. Scroll down for genre-specific settings and artist-documented positions.
What Each Control Does
Recommended Starting Settings
Safe starting positions for any style. Adjust from here based on your amp and room.
All values on a 0–10 scale. These are starting points — fine-tune by ear.
Settings by Genre
Drive at 4 with the Boost disengaged produces the natural JTM45 edge-of-breakup character that is perfect for blues. Tone at 5 (neutral) — adjust by ear to your specific guitar and amp. The Box of Rock at low drive settings responds particularly well to pick attack and guitar volume-knob adjustments, exactly like the real amp it models.
Drive at 6 with Tone slightly lifted produces the JTM45 crunch character that defined classic rock. The Box of Rock at this setting approximates the sound of Page, Clapton, and Green through a cranked vintage Marshall — without the volume required to achieve this from the real amp.
Engaging the Boost at 4 with Drive at 7 pushes the JTM45 section harder, producing a more saturated, compressed character that approaches 70s hard rock territory. The Boost acts like a transparent OD pushing the front of the simulated amp — exactly how the original technique worked.
Very low Drive with bright Tone produces a clean, slightly characterful tone suitable for country. The JTM45 circuit at very low gain adds a pleasant, valve-like warmth without obvious distortion. Tone at 7 gives Telecaster-style brightness.
Tips & Common Mistakes
- The Boost footswitch can be used independently as a standalone SHO boost — engaging it without the distortion side adds a clean, FET-based boost that is extremely transparent and musical.
- The Box of Rock is most authentic when run into a clean amp at moderate volume rather than into an already-distorted amp. The JTM45 circuit models a preamp and is designed to interact with a clean power amp.
- Tone at maximum can be bright to the point of harshness through some amps. If this is an issue, reduce the Tone control and compensate with the amp's treble control — the interaction between pedal and amp tone shaping is part of the voicing.
- Hand-wired versions (vexter) sound identical to the factory production versions. The ZVex canvas hand-painted versions are collectables but tonally equivalent.
FAQ
ZVex Box of Rock — Common Questions
Best starting settings for ZVex Box of Rock: Volume at 5/10, Drive at 5/10, Tone at 6/10, Boost at 4/10. Adjust from there based on your guitar, room, and playing style.
For Blues: Volume 6/10, Drive 4/10, Tone 5/10, Boost 0/10. Drive at 4 with the Boost disengaged produces the natural JTM45 edge-of-breakup character that is perfect for blues. Tone at 5 (neutral) — adjust by ear to your specific guitar and amp. The Box of Rock at low drive settings responds particularly well to pick attack and guitar volume-knob adjustments, exactly like the real amp it models.
For Classic Rock: Volume 5/10, Drive 6/10, Tone 6/10, Boost 0/10. Drive at 6 with Tone slightly lifted produces the JTM45 crunch character that defined classic rock. The Box of Rock at this setting approximates the sound of Page, Clapton, and Green through a cranked vintage Marshall — without the volume required to achieve this from the real amp.
Volume: Output level of the distortion side. (Silent to Loud). Drive: Input gain of the JTM45 preamp section. The character changes significantly through the full Drive range — from light crunch to full saturation. (Clean to Maximum). Tone: Treble emphasis. The Box of Rock Tone control is passive, like the original Marshall EQ, and produces a natural tonal change rather than an EQ curve. (Warm to Bright). Boost: The separate SHO boost level — when engaged, this hits the front of the JTM45 section harder, pushing it into more compression and saturation. A second stomp activates it independently. (Off to Maximum)
The Boost footswitch can be used independently as a standalone SHO boost — engaging it without the distortion side adds a clean, FET-based boost that is extremely transparent and musical. The Box of Rock is most authentic when run into a clean amp at moderate volume rather than into an already-distorted amp. The JTM45 circuit models a preamp and is designed to interact with a clean power amp. Tone at maximum can be bright to the point of harshness through some amps. If this is an issue, reduce the Tone control and compensate with the amp's treble control — the interaction between pedal and amp tone shaping is part of the voicing. Hand-wired versions (vexter) sound identical to the factory production versions. The ZVex canvas hand-painted versions are collectables but tonally equivalent.
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