IV Bench: Diode I-V Curves for Pedal Builders

Explore interactive forward-voltage versus current curves for hundreds of diodes used in guitar pedals. IV Bench lets you compare parts side by side, understand how they conduct at practical currents, and pick the right device for your clipping or switching job.

What IV Bench Shows

An I-V curve plots forward voltage against forward current. It reveals the knee where conduction begins, the slope that hints at dynamic resistance, and how quickly voltage rises with current. You can see how germanium, silicon, Schottky, MOSFET body diodes, and LEDs behave in real pedal ranges. Instead of guessing “low Vf” or “soft clip,” you get numbers you can trust.

Why We Built It

We measure parts when we design pedals. Over the years that became a library of real curves across many diode families. Most players and builders never see this side of parts selection, yet it is the difference between harsh, dull, or just right. IV Bench turns our lab work into a tool you can use to compare, learn, and decide with confidence.

How to Use IV Bench

Search by part number or filter by family: germanium, silicon, Schottky, LED, MOSFET.
Hover the graph to read exact voltage and current values.
Click Freeze to keep a dotted snapshot while you load others.
Click Clear to remove frozen traces and start fresh.
Mean curve: always visible. It shows the averaged result of our measured samples for that device.
Optional Stack mode: sum forward voltages as if parts were in series (up to five devices) so you can plan clipping stacks.
Sort results by Vf at a reference current to spot low-Vf and high-Vf candidates quickly.
Use Find Similar to pull up close matches when you need a substitute.

Reading the Curves: A Quick Guide

Knee: where conduction starts to rise. Lower knee means earlier clipping or easier detection.
Slope: steeper rise means higher dynamic resistance and a firmer feel; gentler rise can sound softer.
Matching: two curves with similar shape and Vf produce more symmetrical clipping.
LED vs diode: LEDs sit higher in Vf and can give louder, more open clipping; diodes sit lower and compress earlier.
Leakage at low current: more common in germanium; affects bias and touch.

Stacking Diodes

When diodes are placed in series, their forward voltages add. Two silicon diodes each with a 0.7 V drop will begin conducting near 1.4 V together. Stacking is how builders fine-tune clipping threshold, headroom, and feel.

IV Bench’s Stack mode automatically adds curves together so you can see the combined conduction curve as if the devices were wired in series. It lets you visualize how mixed stacks behave, for example a germanium in series with a silicon, or an LED paired with a Schottky, and how those combinations shift the overall clipping knee.

This feature gives you a realistic picture of multi-diode clipping arrangements without needing breadboard tests. It helps you predict where the signal will start to distort and how the curve will compress.

Data and Method

All diode curves were measured directly using a Peak Atlas DCA75 Pro semiconductor analyzer under controlled, repeatable conditions. Each data point represents a real measurement, not a simulated value.

Measurement conditions

Temperature: 25 °C (room temperature)
51 measurement points per curve (0.00 V to 12.00 V)
Current accuracy: ± 0.25 mA
Voltage accuracy: ± 1% ± 0.006 V
Third lead: Open
Device: Peak Atlas DCA75 Pro

Each part is tested multiple times to check repeatability, then averaged into a mean curve. The result is a practical view of how each diode behaves across the entire forward-voltage range.

All measurements are DC sweeps, showing forward voltage (Vf) vs forward current (If). This data reveals conduction threshold, slope, and leakage behavior but not dynamic effects such as recovery time or capacitance.

Categories You Can Explore

Germanium signal diodes: smooth knee, low Vf, higher leakage.
Silicon small-signal diodes: classic 1N4148-style response, consistent and predictable.
Schottky diodes: very low Vf, fast switching, soft knee.
LEDs: higher Vf, different colors give different ranges, popular for louder clipping.
MOSFET body diodes: alternative textures and thresholds.

Practical Notes for Pedal Builders

For symmetrical clipping, pick two parts with close curves.
For asymmetrical clipping, mix a low-Vf with a higher-Vf device or change series count in Stack.
To raise headroom, use higher-Vf parts or stack devices in series.
To soften the feel, look for devices with a gradual knee and higher leakage at low current.

Common Questions

Are these typical values or exact promises?
They are measured examples. Device families have spread. Use the mean as a guide and verify in your own build.

Why does temperature matter?
Semiconductor Vf shifts with temperature. Warmer parts conduct at lower voltage, so a hot stage can clip earlier.

Why do some curves look noisy at very low current?
You are seeing the reality of leakage and measurement limits in the microamp region, which is valuable when bias points are sensitive.

Can I request a diode?
Yes. Send the make and exact part number. If you can mail a sample reel or a few pieces, we will prioritize it.

Can I use this to replace a hard-to-find part?
Use Sort by Vf at your target current, then Find Similar to shortlist substitutes with close curves.

IV Bench is free and will always be.

If you like what we’re doing, you can buy us a pizza to help us keep the lights on and ad-free.

What’s Next

We keep adding devices and refining the tooling. If a part you need is missing, ask for it. If you spot an outlier, tell us and we will retest. The goal is a dependable reference for builders, modders, and curious players.

The older version will not be maintained but is still available here.

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