DI Input Loading Checker

What this tool is for

Calculate the resistive load, voltage retention, and entered load-ratio check for a guitar source and DI path. Recording tools convert documented device specifications and measured waveform evidence into loading, level, headroom, and timing comparisons. They never authorize speaker-level connections or powered-device repair.

Use it when you can describe the current state and need a defensible next check. It is not a shortcut around inspection: preserve the starting state, change one variable, and verify the result under the same conditions.

Before you begin

Obtain source impedance from a documented measurement at the relevant frequency or a reliable maker specification. Record the DI input and any destination connected through a parallel/thru path. Turn monitoring down before repatching.

• Use a stable, tuned instrument unless the page specifically investigates tuning.
• Name the physical reference, unit, and test condition beside every important number.
• Keep the original measurements so any reversible change can be returned to baseline.

Input guide

Measured source impedance (Ω)

provides a measured or counted input; confirm the allowed range and repeat the reading before relying on it.

DI input impedance (kΩ)

provides a measured or counted input; confirm the allowed range and repeat the reading before relying on it.

Optional parallel / thru input (kΩ)

provides a measured or counted input; confirm the allowed range and repeat the reading before relying on it.

Minimum load ratio to screen

provides a measured or counted input; confirm the allowed range and repeat the reading before relying on it.

Input labels describe evidence, not targets. A placeholder demonstrates format only; it is never a recommendation for a particular guitar.

How the result should be read

Treat the ratio and loss as a loading screen. If the result conflicts with listening or manufacturer guidance, verify whether the source value was actual AC impedance rather than pickup DC resistance.

Read priorities from top to bottom, but stop as soon as new evidence contradicts an earlier assumption. Save or print the result ticket with the entered conditions so another person can reproduce the decision.

Method and logic

The calculator combines entered DI and optional parallel resistances, compares their equivalent load with source impedance, and applies a simple resistive voltage divider. The minimum ratio is an explicit user criterion, not a site target.

The page keeps calculation and diagnostic claims deliberately bounded. Display rounding improves readability, while the underlying logic uses entered values; descriptive branches report relative tendencies and the evidence needed to confirm them.

Worked example

A 12 kΩ source into a 1 MΩ DI alone sees an 83.3:1 ratio. Adding another 1 MΩ input in parallel produces 500 kΩ and a 41.7:1 ratio; the optional destination changes the same recording path.

The example demonstrates reasoning, not a universal setup specification. Substitute real measurements and repeat the final test before accepting the next action.

Assumptions and limitations

Real pickups are inductive and frequency dependent. Cable capacitance, transformer behavior, active output stages, pads, input topology, and tone cannot be inferred from this resistive model.

Instrument design, service history, measurement error, and player technique can outweigh a calculator or checklist. Where manufacturer instructions exist for the exact hardware, use those instructions and record the revision consulted.

Safety and stop conditions

Turn monitoring and outputs down before changing connections. Never connect an amplifier speaker output to a DI, reamp box, pedal, microphone input, or audio interface unless the exact manufacturer documentation explicitly provides the compatible speaker-level load/input. Do not open an amplifier, power supply, or mains device. Stop for clipping, electrical sensation, heat, odor, damaged cables, unstable microphone stands, or a specification you cannot verify.

Related workflow

• Reamp Level Match Planner — Calculate a measured dB correction between an original DI reference and a reamp loopback.
• Potentiometer Value Selector — Compare common passive pot ranges by pickup type, brightness goal, and present symptoms.
• How to Measure a Guitar Recording & Reamp Chain — Capture comparable levels and transients without connecting a speaker output.

Open the related page that answers the next unresolved question; do not run every tool as if every system needs adjustment.