Tube Amp Tech, Reference & Tools

DiMastro

Guitar Tube Amps

Hands-on tools and guides for restoring, building, and biasing vacuum-tube guitar amplifiers — a full bias calculator, an interactive tone stack simulator, a visual oscilloscope and a growing set of must-have calculators, along with diy tools, bench guides and the complete technical manual.

Why DiMastro GTA Exists

This started as my own problem, not a business plan — decades on the bench, a growing pile of scribbled bias calculations and half-remembered resistor codes, and no single place that had it all. Rob Robinette's site came closest, and along with him, I owe a lot to the wider forum and YouTube tech community — creators like Psionic Audio, The Guitologist, and Uncle Doug — that expanded my knowledge on vintage guitar amps — but nothing covered everything I actually needed, day to day, at the bench. So I built the toolkit I wished I'd had, for myself first — and with retirement from my day job getting closer, it's turning into what I do next. I'm glad to finally share it. Read the full story

Tools & Guides

Tube Bias Calculator Pro

Work out safe plate dissipation and dial in idle bias for your power tubes.

Virtual Oscilloscope Pro

Watch the power-stage scope trace live as you turn up volume and tone, with clipping and bias effects modeled.

Tone Stack Simulator Pro

Solve bass/mid/treble response for Fender, Vox, and Marshall circuits.

Tech Manual

The complete engineering, diagnostics & restoration manual — topologies, bench practice, troubleshooting, and bias calibration.

Guides

Biasing, startup, recapping, and safe power-supply discharge.

DIY Tools

Build your own bias probes, current limiter, cap discharge stick, and dummy load.

Mobile Apps

Install the bias, tone stack, resistor, and capacitor tools as mobile apps.

Live Tools

Resistor and capacitor toolkits, tube cross-reference, and a full set of bench calculators.

Amp Restorations

Bringing vintage guitar amplifiers back to life.

Trademark & brand notice: product names, brand names, and model designations referenced in this website — including Fender®, Marshall®, Vox®, Gibson®, Mercury Magnetics®, Fluke®, Apple®, Google®, Microsoft® and others — are the property of their respective owners, used here strictly for identification and technical-reference purposes. This is an independent, unofficial technical reference, not affiliated with or endorsed by any manufacturer named.