The DSM & Humboldt Simplifier DLX is what the maker calls a "zero watt dual channel & reverb stereo amplifier": a pedal-format amp with no power stage at all. In place of a speaker output it gives you two fully independent preamps, a cabinet simulation section and a full stereo reverb, so it can feed a PA, an audio interface or headphones directly. It is made by DSM & Humboldt and listed by Premier Guitar at $459 USD as of its June 2023 review12.
What a zero-watt amp means for a player
Because there is no output stage and no speaker, the Simplifier DLX behaves like the front end of an amp plus a cab sim in one box. You run your pedalboard into it, then take a line out to a PA or interface, or plug headphones straight in. The maker includes a high grade headphone amp with an aux input for silent practice1. For home players, that means amp tone at any hour; for gigging players, it means the preamp and cab sim go direct to the desk.
Two preamps, three voices each
The DLX carries two fully independent preamps1. Each offers a trio of amp voices: AC Brit, American and MS Brit12. The two channels are not identical copies of each other. Premier Guitar's reviewer noted that "DSM added phase-splitter saturation to give channel A the feel of a cranked amp," while "Channel B is mellower with a smoother top end"2. That makes it practical to run one channel as a clean base and the other as a hotter voice, or to set up two different amps for stereo.
The cabinet simulation section can be set between combo, stack and twin configurations2.
Stereo operation and outputs
Stereo is built into the jack layout: the input, thru and send jacks are all stereo, and each 1/4-inch jack along the side handles TRS cables2. The input mode is switchable between a mono two-channel amp setup and stereo, with each preamp getting a dedicated output via XLR or 1/4-inch2. In practice that means you can send each channel to its own output for a wide two-amp rig, or run it as a mono two-channel preamp.
Reverb
The DLX includes a full stereo reverb, with a mix control for each channel independently1. Premier Guitar's review describes using the right and left mix controls for the reverb2. Three reverb modes are on offer1:
- Short: room style
- Mid: plate style
- Long: ether style
What reviewers said
Premier Guitar's reviewer came away positive on the tones: "The reverb is beautiful, clean tones are punchy and warm, and there's enough gain for nearly any gig this side of nü-metal"2. On price, the same review observed that "At $459, it's not exactly priced for an impulse buy"2. Guitar.com's review, from December 2022, listed the DLX at £349 GBP in the UK3.
Where it sits in the Simplifier family
The DLX is part of a line that began with the Simplifier Classic and continued with the Simplifier MK-II. The DLX's two independent preamps and per-channel reverb mix place it as the dual-channel, stereo-oriented member of that family, alongside the single-channel models12.
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Questions
How much does the DSM & Humboldt Simplifier DLX cost in the US?
Premier Guitar's review listed the Simplifier DLX at $459 USD, noting that it is not exactly priced for an impulse buy. In the UK, Guitar.com's review gave a price of £349 GBP. Prices are as stated by each publication at the time of its review.
What is a zero-watt amp?
DSM/Humboldt describes the Simplifier DLX as a zero watt dual channel and reverb stereo amplifier. It is an amplifier design with no power output stage, so it produces no speaker-level output. Instead it delivers a preamp and speaker-simulated signal directly to headphones, an audio interface or a PA, giving amp tone without a speaker cabinet.
Are the Simplifier DLX preamps analog or digital?
Premier Guitar's reviewer described the Simplifier DLX as a pair of individual analog preamps. The reverb and the mic-position emulation are digital, so the unit combines an analog preamp section with digital effects.
Can the Simplifier DLX run in stereo?
Yes. The input, thru and send jacks are all stereo, and each 1/4-inch jack along the side handles TRS cables. The input mode can be set to a mono two-channel amp setup or to stereo, with each preamp getting a dedicated output via XLR or 1/4-inch.
What amp voices does the Simplifier DLX offer?
Each of the two preamps offers three amp voices: AC Brit, American and MS Brit. The maker lists these as the three preamp types. Channel A adds phase-splitter saturation for the feel of a cranked amp, while channel B is mellower with a smoother top end.
Does the Simplifier DLX have reverb?
Yes. The Simplifier DLX includes a full stereo reverb with a mix control for each channel independently, and Premier Guitar's review notes right and left mix controls for the reverb. Three reverb modes are available: Short room style, Mid plate style and Long ether style.
Sources (3)
- SIMPLIFIER DLX, DSM/HUMBOLDT, 2026
- DSM & Humboldt Simplifier DLX Review, Premier Guitar, 2021-09-16
- Two Notes ReVolt Guitar Review, Guitar.com, 2022-12-27
