Aly James Lab VProm 3 [MAC]

• Product: VProm 3.0
• Developer: Aly James Lab
• Version: 3.0.2
• Format: VST, VST3, AU
• Requirements: macOS 10.15 or later
• Source: alyjameslab.com/alyjameslabvprom

VProm 3 is a drum machine plugin from Aly James Lab modeling the internal DAC, filter, and VCA circuitry of an early-1980s EPROM drum machine, rather than playing back recorded samples of one. It runs a real-time AM6070 µLaw DAC emulation with a tweakable per-voice decompression ratio, CEM filters in legacy or expert mode, and a 48 PPQN clock with adjustable 1-40ms drift for vintage feel. A built-in resampler converts any WAV into a µLaw-encoded EPROM binary, up to 64K per sample, across 14 voices. €56, VST3/AU, 64-bit only.

Key Takeaway

VProm 3 emulates the DAC and filter circuit path of a vintage EPROM drum machine directly, rather than playing back recorded samples of one, and includes a built-in resampler/burner for building custom EPROM sets from any WAV file. It carries no EQ or effects, and ships as 64-bit VST3/AU with no VST2 or AAX, so Pro Tools needs a wrapper.

Push the Ratio Past 1, Get Snap

VProm’s DAC emulation runs a real-time AM6070-style µLaw decoding path, matching the response curve of the chip used to decode and replay the original hardware’s EPROM sample data. On top of that base emulation, VProm 3.0 adds a per-voice, real-time control over the µLaw decompression ratio itself, letting the transfer function be tweaked away from its default response rather than fixed to a single decoding curve.

Set close to a 0.5:1 ratio, that control brings quieter details in a sample forward significantly; pushed above 1:1, it enhances snap and impact instead, functioning less like an authenticity knob at that point and more like a transient/distortion shaper built directly into the decode path rather than added afterward as a separate effect. At moderate settings, the same control approximates the chip-to-chip variation that existed between individual AM6070 units on the original hardware.

A producer chasing exact vintage authenticity keeps the ratio near default and uses the control only to account for the natural DAC variation real hardware units would have had between them. A producer using VProm more as a sound-design tool has a transient-shaping control living inside the sample playback stage itself, rather than needing a separate plugin after the fact.

One Knob in Legacy, Four in Expert

VProm 3.0’s CEM filter section runs in one of two modes: Legacy, which reproduces the original single-pulse-control behavior from earlier VProm versions, or Expert, which exposes trimmer, decay, pulse time, and envelope response as four separate, adjustable parameters. VProm 3.0 also adds an optional VCA envelope stage to the voice cards, which the developer notes is specifically important for accurately reproducing certain sounds — the bass drum voice in particular — that the filter alone doesn’t fully capture.

Because Legacy and Expert are both available per voice rather than as a single global setting, a kit built primarily around Legacy-mode simplicity can still put a single voice into Expert mode for deeper sound design on just that one drum, without converting the whole kit to the more complex control set.

A user who wants the original VProm 2.0 filter behavior with minimal parameters to manage gets that directly through Legacy mode. A user sound-designing a kit from scratch, particularly one relying on custom EPROM samples rather than the stock vintage sets, gets more precise control over decay and envelope shape through Expert mode instead.

48 Pulses Locked, Then Left to Drift

VProm 3.0’s internal clock runs at 48 PPQN rather than the roughly 960 PPQN resolution common in modern DAWs, locking trigger events to that lower-resolution pulse in real time while staying synced to the host. The effect reads as subtle rather than dramatic — most noticeable on swung or loose beats — since 48 PPQN is coarse enough to introduce small, consistent timing quantization that a full-resolution modern clock wouldn’t produce.

Real-Time Clock Drift is a separate, more noticeable effect layered on top, simulating the natural instability of a vintage drum machine’s internal clock rather than the fixed quantization the 48 PPQN pulse introduces. Its range is tweakable from 1ms to 40ms, covering everything from a subtle analog-style wobble at the low end to an exaggerated, loose, human-feeling drift at the high end.

A part that’s already tightly quantized in the DAW gets the most audible character change from these two features combined, since there’s more contrast between rigid input timing and the vintage-style imperfection layered on top. A part programmed with its own loose, human timing has less room for the 48 PPQN and drift effects to add anything on top of what’s already there.

27kHz In, 64K Bytes Out

VProm 3.0’s built-in resampler imports any WAV file and runs it through an emulated R-2R ADC with tweakable input-stage settings before capturing it at approximately 27kHz — the same rate the original hardware’s EPROM sample data was captured at. If the source WAV is already at or below 27kHz, the resampling stage is skipped automatically, and it can also be disabled manually if a user wants to bypass it regardless of source rate.

After capture, the sample can be previewed with µLaw 8-bit (12-bit quality) compression applied before committing, or saved directly as a µLaw-encoded .bin EPROM file ready to load into VProm. Maximum EPROM size is 64K, which works out to roughly 2.5 seconds of audio at 27kHz — a longer source WAV file gets automatically truncated to fit during the sampling process rather than rejected outright.

A short, percussive one-shot fits comfortably within the 2.5-second ceiling without any truncation concern. A longer sample — a full vocal chop or a sustained pad hit, for instance — loses whatever falls past that 2.5-second mark once resampled into an EPROM, since the format itself, not a plugin setting, sets that ceiling.

One File Recalls All Fourteen

The EPROM Management Panel in VProm 3.0 shows all 14 custom EPROM slots in one window, with waveform visualization per slot, direct loading on click, real-time auditioning, and a quick-reset option. A separate EPROM Library Browser sits alongside it specifically for previewing and organizing both custom and vintage EPROM files from an internal library, rather than requiring a system file browser for that step.

The new .VPromKit file format saves and reloads an entire custom EPROM set — file paths, voice assignment, CEM filter configuration, and hi-hat loop state — as one lightweight file, deliberately excluding mix settings, tuning, and other plugin-preset data. Loading a .VPromKit swaps out the drum kit itself instantly while leaving whatever mix or tuning was already dialed in in the current session untouched.

That scope-limiting was a deliberate choice — the format’s job is switching the sound source, not carrying the rest of a saved plugin state along with it, which is why a .VPromKit and a full plugin preset remain two separate save formats rather than one.

No EQ, No FX, Just the Voices

VProm 3.0 ships with no EQ and no effects processing built into the plugin at all — the developer states this directly as “no fake samples, no EQ, no FX — uncut.” Every voice’s output is the DAC-and-filter-modeled signal itself, unprocessed by anything beyond the mixer’s volume, pan, and the three routing modes — Single, Multi Post-Mixer, Multi Pre-Mixer — that determine where each voice’s signal goes.

That absence means shaping the drum sound further — compression, EQ, saturation beyond what the µLaw ratio control already provides, reverb — happens entirely outside VProm, on whatever track or bus each voice gets routed to. Multi Pre-Mixer mode specifically supports that workflow by sending each voice both to the main stereo mix and to its own dedicated output simultaneously, so a voice can be shaped externally while still contributing to a quick internal mix at the same time.

A producer who wants a self-contained drum machine with built-in tone-shaping will need to add that processing in the host regardless of which routing mode is used. A producer who already has a preferred outboard or plugin chain for drum processing loses nothing by VProm staying unprocessed, since Multi Pre-Mixer keeps that external chain and an internal reference mix both available without picking one or the other.

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