The MESA/Boogie Subway Bass DI-Preamp Box is a bass preamp and DI box in pedal form, built around a solid-state preamp derived from the company's Subway D-800 bass amp. MESA/Boogie pitches it as "the Tone and Features of Our Subway D-800 in a Bass DI Pedal," offering what the maker calls "maximum Tone for minimum carry"1. For a bassist, that means one box can shape your sound, drive a power amp, and feed a PA or recording setup without an amp on stage.
MESA/Boogie lists the Subway Bass DI-Preamp Box as no longer available, with the product page left up for reference only1. Its successor is the Subway+ Bass DI-Preamp II.
A Subway-derived preamp and DI
The unit is a solid-state preamp pedal rather than an overdrive or distortion box: it shapes the clean character of your bass and routes it to wherever it needs to go. The circuit is drawn from the Subway D-800 amp head, so its voicing and EQ architecture follow that amp rather than a generic pedal design1. The single input has a switchable INPUT setting with PASSIVE and ACTIVE positions, which MESA/Boogie describes as handling both types of pickups optimally, so it works with anything from a vintage P-bass to a modern active 5-string1.
The controls
The control set covers gain staging, voicing, and a full EQ section:
| Control | What it does |
|---|---|
| INPUT switch | PASSIVE and ACTIVE settings to handle both pickup types optimally1 |
| Input Gain | Sets the preamp's input level1 |
| Variable Voicing | Sweeps from Flat to Vintage Scoop1 |
| BASS and TREBLE | Classic shelving-type tone controls1 |
| MID | Semi-parametric mid band for shaping or enhancing the midrange1 |
| DEEP switch | Switchable mode that enhances low end and rounds out the voicing options1 |
| Master Volume | Sets the overall output level1 |
The EQ is a fully active 4-band design with +/- 12dB of boost or cut. The BASS and TREBLE controls are shelving types, while the MID band is semi-parametric, meaning you can dial in not just how much midrange but where it sits, which is useful for cutting through a mix or taming a hollow-sounding instrument1. The Variable Voicing control sits outside the EQ: it moves the overall character from a flat response toward a vintage-style scooped mid voicing, and the DEEP switch adds enhanced low end as a further voicing option1.
Inputs, outputs and power
On the back panel the box covers the three routes a bass player typically needs. An instrument-thru output passes your unprocessed signal on to a stage amp. A balanced XLR mic-level DI output, with pre/post and ground lift switches, feeds a front-of-house console or recording interface. And line-level preamp outputs, unbalanced and balanced with a ground lift switch, are there to drive any power amp, so the box can serve as the front end of a full rig1.
Power is flexible for a pedal of this type: it runs on AC or a battery, and it auto-switches to the battery if the AC supply fails and a battery is installed1. The enclosure is aluminum, measuring 2.51 H x 6.875 W x 5.27 D inches and weighing 1.26 lbs1.
Lineage and the Subway+ II
The Subway Bass DI-Preamp Box has since been superseded. The Subway+ Bass DI-Preamp II is described by MESA/Boogie as a compact, full-featured follow-up that combines the features of the original two Subway preamp pedals into a single new model, in a 35% smaller format than the originals2.
The II's preamp is derived from the Subway D-350, D-800 and D-800+ bass amps, and it uses an extended-range J-FET input that adapts to active or passive basses2. Its control set builds on the original: a fully active 4-band Baxandall EQ with +/- 12dB of Bass, Low-Mid, High-Mid and Treble, a variable hi-pass filter from 30Hz to 150Hz that blocks sub-sonic frequencies, plus Deep and Bright switches for enhanced low end and top end2. It also adds a headphone output and an aux input for a media player, alongside the same balanced XLR DI output with pre/post EQ and ground lift, and line-level preamp outputs2.
For a player weighing the two, the original box remains a straightforward D-800-derived preamp and DI, while the II folds in more routing and filtering in a smaller chassis12.
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Questions
Can the MESA/Boogie Subway Bass DI-Preamp Box run on a battery?
Yes. It runs on AC or battery power, and it auto-switches to the battery if the AC supply fails, provided a battery is installed. That makes it a practical choice for gigs where mains power at the stage is unreliable or unavailable.
Does the Subway Bass DI-Preamp have an XLR output?
Yes. It has a balanced XLR mic-level DI output with pre/post and ground lift switches, so it can feed a front-of-house console or recording interface directly. It also carries line-level preamp outputs, both unbalanced and balanced, plus an instrument-thru output.
Is the Subway Bass DI-Preamp Box still made?
No. MESA/Boogie lists it as no longer available, with the product page left up for reference only. Its features live on in the Subway+ Bass DI-Preamp II, which combines the features of the original two Subway preamp pedals in a single, smaller model.
Does it work with both active and passive basses?
Yes. The single 1/4 inch input has a switchable INPUT setting with PASSIVE and ACTIVE positions, which MESA/Boogie describes as handling both types of pickups optimally. Set the switch to match your bass and adjust the Input Gain from there.
What does the Deep switch do on the Subway Bass DI-Preamp?
The switchable DEEP mode rounds out the voicing options by enhancing the low end. MESA/Boogie positions it as one of the voicing choices alongside the Variable Voicing control, which sweeps from Flat to a Vintage Scoop.
Does the Subway DI-Preamp have a ground lift?
Yes, in two places. The balanced XLR mic-level DI output has a ground lift switch alongside its pre/post switch, and the balanced line-level preamp output has its own ground lift switch.
Sources (2)
- Mesa/Boogie Subway Bass DI-Preamp Box, Gibson (www.gibson.com)
- MESA/Boogie Subway+ Bass DI-Preamp II, Black, Gibson (gibson.com)
