From the Bench

A reissue Deluxe Reverb and a genuine AB763 Super Reverb, on the bench together. What tighter tolerances and forty years of ageing actually change, and what they don't.

No paperwork, just a guess at '67. Three transformer date codes, cross-checked against each other, confirmed a genuine late-1967 build. A tube chart discrepancy turned out to be nothing to worry about.

A leaked 9V battery in an electro-acoustic preamp: the corrosion had travelled along a wire to fail at the output jack, well away from the battery itself.

An Ampeg M-15, fresh from an auction win and a mains voltage mishap, as a real illustration of what gets replaced, what gets left alone, and why. Evidence over instinct, every time.

Completely dead: no output at all, effect on or off. Power's the first thing to check, and the DC input jack gave up the answer fast: a dry solder joint. Reflowed, back in service.

A faulty PROGRAM encoder sending presets in the wrong direction: missed counts and reversals traced to aged solder joints and contaminated contacts. No parts required.

A squeal that changed pitch with the Color knob: traced through a wrong-value pot and an out-of-spec clock, two faults stacked on top of each other and disguising one another.

A practical guide to finding someone who'll fix your valve amp properly: what to check first, what filters a repairer needs to pass, and what to ask before you hand it over.

No fault notes, just the unit. An intermittent mains cable fault on a 1980s TC Electronic SCF, one of the most copied effect circuits ever made, still all-original inside.

In for a clean-up. Left with a loud mains hum, scratchy pots, and a pulsing on both channels: diagnosed and resolved, the culprit a dry joint hiding on the underside of the board.

RCA socket failures, filter cap degradation, and a tremolo hiss: what started as a reverb job became a full service.

A £4 LM386 kit, a scrap enclosure, and an afternoon. The bench amp that exists so the real amp doesn't have to.

Sounding thin and weak: a saturated Q1 transistor, still passing a bench diode test, tracked down through DC bias voltage measurement and confirmed by substitution.

An intermittent Speakon input on a well-used bass cabinet: worn contacts confirmed, discontinued green Neutrik replaced with the current black NL4.

A completely dead ESQ-1: no display, no sound. Heat damage from a failing transistor had destroyed solder joints on the display board above it. Display restored, audio recovered.

A dead power circuit, two failed surface-mount ICs. Removed under magnification, pads cleaned, fresh components reflowed. A piece of Moog history back in action.

A seized Speed pot and scratchy controls on a boutique Korean chorus. Opened to find a resin-potted circuit. Some controls cleaned and restored; the Speed pot remains inoperative.

Someone stomped the Hot Tubes indicator LED clean off the board. PCB intact, pads cleaned up, matched LED soldered back in. Both channels confirmed working.

A vicious crackle every time the gain knob moved. Contact cleaner wasn't going to cut it: the pot was too far gone. Correct replacement sourced and fitted, clean sweep restored.

A loose screw shorted the supply rail, a BD677 transistor failed open, and 50V ran into a board designed for 30V. Taking out four TL074 op-amps in the process.

A power button that was sticking and a CD drive that had stopped reading discs. Two separate faults with a common cause: age and lack of movement. No parts required.