Blues Deluxe Mods: A Different Amp Than You Think
Real Fender Blues Deluxe schematic values for the tone stack, presence control and bias trim, and why this amp's actual mod list differs from the Hot Rod Deluxe's.
Tech pages · Electronics
The Bench, Written Down
Long-form write-ups of real repair and design work — measured, not guessed. Every article stands on its own; most come with the math and the schematic.
Searches titles, topics and the full text of every article.
15 articles
Designing a JFET Gain Stage Around a Real Part
How to measure a JFET's IDSS and pinch-off voltage with basic tools, then bias a common-source gain stage around the specific part you have rather than a datasheet typical.
Reading an Amp Schematic
How to read a tube amp schematic from scratch: the symbols that cover almost every circuit, how to trace a signal path stage by stage, and where the four supply nodes are.
The Five Faults Behind Most Amp Repairs
The five most common tube-amp faults from the actual repair bench, what each one sounds like before it fully fails, and roughly how to tell them apart.
What a Tone Stack Actually Does
How the passive Bass/Mid/Treble network in a guitar amp actually works, why Fender, Marshall and Vox sound so different from the same topology, and why turning Mid up turns it down.
What the Presence Knob Really Does
How amplifier negative feedback and the presence control actually work, with schematic-verified feedback amounts for Fender, Marshall and Bassman-family amps.
How to Bias a Fixed‑Bias Push‑Pull Tube Power Amp
Bias a fixed-bias push-pull tube amp accurately using output transformer resistance and voltage drop — no shunt measurement, no oscilloscope, and it reads true plate current.
Taming the Blues Junior: A Blackface‑Flavored Makeover
Blues Junior mods with real component values: the 10k input grid stopper, the 100 pF volume treble bleed, the Twin tone stack swap, and the 1500 pF cap that makes it nasal.
Building Better Pedals: The Real Role of Components in Guitar Tone
A myth-busting guide to resistors, capacitors, diodes, transistors and ICs in guitar pedals — what each one really does to your tone, and where boutique parts stop mattering.
Why Guitar Pedals Sound Different on Batteries vs Power Supplies?
Why battery-powered fuzz pedals really do sound different: rail voltage and bias shift, supply impedance in the signal path, and the positive-ground daisy-chain trap.
Why Reactive Loads Sound Different From Real Cabinets
How speaker impedance turns into frequency response through your amp's output impedance, why reactive loads still don't feel like a real cab, and the IR double-counting trap.
The Ultimate Hot Rod Deluxe Mod
Fix the Hot Rod Deluxe's PCB-cooking dropping resistors, then rework the power amp and preamp for a blackface-style feel and usable drive channels.
Pickup Coils in Parallel: Why Not?
Why humbuckers wired in parallel stay hum-cancelling and sound brighter than a coil split — and the two real reasons the industry never adopted the wiring.
The Pickup Equation: Resistance, Inductance, and Capacitance Demystified
Why DC resistance doesn't equal pickup output, what inductance and capacitance actually do to your tone, and the resonance equation that connects all three.
Plexi Marshall Heresy: "The Grinder" Mod
How replacing a Marshall's cathode follower with a fourth gain stage produces a fatter, higher-gain amp — with the gain staging, attenuators and feedback maths behind it.
