PrintableCharts
DI, REAMP AND PREAMP

1 / 2 · mockup · studio-desk

DI, REAMP AND PREAMP

three boxes on one ruler of levels — where each one leads from and to

Built as a memo rather than a table: the thing worth hanging it up for reads across the room, with the full reference in smaller type below it.

Three sizes in one archive — from a sheet on the fridge to a poster on the wall.

Premium$2.50

Payment and email are handled by Paddle. The download link arrives by email — no account, no password.

Formats
A4 · A3 · A2
What you get
Print-ready PDFs, one per size, with every letterform converted to outlines — nothing to install, nothing to shift.
Subject
music · everyone · reference · music room

The voltages on the ruler are computed from the definitions of dBu and dBV. Impedances and gains come from the published specifications of the named devices: Radial JDI, Radial X-Amp, Focusrite ISA One, Fender Twin Amp.

BETWEEN +4 AND −10 THERE ARE NOT FOURTEEN DECIBELS BUT 11.8

It looks as though the difference is a subtraction: four minus minus ten is fourteen. But «+4 dBu» and «−10 dBV» are counted from different references: dBu from 0.7746 V, dBV from one volt.

In volts that is 1.228 V against 0.316 V, which is exactly 11.8 decibels. That is how much a consumer output has to be lifted, not fourteen — otherwise two decibels of headroom go missing and nobody looks for them.

The 0.7746 V reference is not arbitrary either: it is the voltage that dissipates one milliwatt into 600 ohms. Those 600 ohms came to audio from telephone lines; the requirement to match impedance is long gone, the reference stayed.

On the sheet

  • The voltages on the ruler are computed from the definitions of dBu and dBV. Impedances and gains come from the published specifications of the named devices: Radial JDI, Radial X-Amp, Focusrite ISA One, Fender Twin Amp.
  • Colour carries meaning, but meaning never rests on colour alone — the sheet reads in black and white.
  • Nothing about how it was made: the sheet carries only what the reader needs.

Printing

  • Three sizes in the archive: A4 — 210×297 mm, A3 — 297×420 mm, A2 — 420×594 mm.
  • All text is converted to outlines. No fonts to install, and nothing shifts on another machine.
  • White background and sparing fills — it prints on a home printer without draining the cartridge.
  • Margins of at least 10 mm: a home printer cannot print to the edge.
  • No stroke thinner than 0.3 mm, so nothing disappears in print.

Why the numbers can be trusted. Every countable number here is computed from data rather than typed in, and the sheet must pass 7 independent checks before it is allowed to build — how many items there are, the order they come in, and the claim in the highlighted box itself. If one fails, there is no file.

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