ADDAC 812V LED Voltage Meter (Archived)
Two rows of glowing LEDs that turn voltage into something you can see. Simple and trimmable, built for the black-panel era of Eurorack.
Overview
Nobody buys an ADDAC 812V because it's revolutionary. You buy it because you want to see what your modular is doing, not just hear it. This is a dual voltage meter for Eurorack, built by ADDAC System during their run of clean, functional, slightly retro-styled utility modules. It's not a sound generator and not a processor. It's a diagnostic tool that doubles as a mood ring for your rack. With 11 pairs of LEDs per channel, it shows voltage from -5V to +5V in real time. And yes, it looks ace - that phrase came from a forum post, and it's hard to argue. The black panel, the symmetrical layout, the soft glow of red and green LEDs climbing up and down. It's the kind of module that makes people stop and ask what that one does.
The 812V is part of ADDAC's legacy lineup, a series of meter modules that includes the 812A (audio level), the 812VU (VU meter), and the 200A (another audio meter). It's not flashy, but it's purpose-built: dual inputs, each with its own LED bar graph and buffered thru output. The thru output means you're not breaking your signal chain to monitor it. You patch in, you see the voltage dance, and the signal passes through clean. It sits in the background until you need it, then gets very handy when you're debugging a wonky LFO or checking CV levels from a sequencer.
Some people just love meters. One forum user admitted they're a sucker for anything with VU-style visuals, and the 812V taps into that. But it's not magic. Its accuracy hinges on your power supply - if your rails are drifting, so is your metering. And while it's trimmable (a nice touch), it's not a lab instrument. One dealer called it a quick-and-dirty voltage checker: "A quick and easy way to check your voltage levels."
Specifications
| Manufacturer | ADDAC System |
| Model | 812V |
| Product Type | Eurorack module, dual voltage meter |
| Panel Color | Black |
| Voltage Measurement Range | -5 V to +5 V |
| Number of LED Indicators | 11 pairs of LED |
| Function | Buffered thru outputs for each input |
| Eurorack Format | 3U |
| Width | 4 HP |
| Depth | 40 mm |
| Power Consumption | +12V 100 mA, -12V 100 mA |
| MSRP | $134 |
Key Features
Dual LED Voltage Display
The core of the 812V is its dual LED meter - two independent bar graphs, each made up of 11 LED pairs that light up progressively from -5V to +5V. It's a bipolar display, with likely red for negative and green for positive (though the fact sheet doesn't specify colors). The feedback is immediate, so it's easy to spot a CV source drifting, an envelope peaking too high, or a random voltage staying within bounds. It's not audio-level metering - that's what the 812A is for - but for control voltages, gate timing, or LFO outputs, it works well. And because it's dual, you can monitor two signals side by side, say your sequencer output and the modulated result after a lag processor.
Buffered Thru Outputs
Each input gets a buffered thru output. You don't have to choose between monitoring a signal and passing it along. Patch your CV into the 812V, let the LEDs do their thing, and the buffered output sends a clean copy down the chain. No signal degradation, no loading issues. That makes the module an active part of your patch, doing double duty in its 4 HP. Not every meter module includes this.
Trimmable Meters
The LED voltage meters are trimmable. Over time, or with temperature shifts, LED thresholds can drift, and the trim lets you recalibrate so that when the meter says 0V, it's actually 0V. It's not something you'll tweak daily, but it's there when you need it.
PSU-Dependent Accuracy
Here's the catch: the module's accuracy is PSU dependent. If your modular power supply isn't stable, your readings won't be either. ADDAC didn't build in internal voltage references and relied on clean rails instead. That keeps the design simple and the price down, but it also means the 812V is only as trustworthy as your case's power. In a well-regulated system, it's fine. In a crowded rack with noisy supplies, you might want to cross-check with a multimeter. It's a trade-off, not a flaw. You get visual flair and utility, but not lab-grade precision.
Collectibility & Value
The ADDAC 812V is no longer available. Schneidersladen, one of Europe's largest modular retailers, lists it as "not available anymore." That doesn't mean it's rare, but you'll need to hunt on the used market. There's no data on current resale prices, common failures, or repair costs. Given its passive role and lack of moving parts, it's likely to hold up well, and no one is reporting failed LEDs or trimmer issues, at least not in the available sources. Because it's not a sound-generating module, it may never command a premium. Collectors might seek it out for completeness in an ADDAC-heavy system, or for its clean black-panel look. One user called it "sexy." Others questioned its range: "I'm not sure I'm feeling the 812V that only shows -5v to +5v?" That's a fair point. If you're working with signals beyond ±5V, you'll hit the ceiling fast, though ±5V covers most CV duties.
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