Checks by gear type

On guitars and basses, inspect finish, woods, joints, neck, headstock and cavities separately.

Scratches and wear may be consistent with age; refinishing, structural repairs or routing instead change material and configuration. Look for colour differences, overspray, added holes, enlarged cavities and signs of glue work or breaks.

Do not conclude from one photograph alone: finishes can age unevenly and older repairs may be difficult to detect.

For important items, photograph uncertain areas before disassembly and limit disassembly to what you can do safely.

In vintage amplifiers, transformers and speakers can carry significant technical and historical importance.

Check codes, labels, mounting holes, wiring and period consistency. A replacement may improve reliability or operation, but it should be described precisely.

Do not open or work on an amplifier unless you are qualified: dangerous voltages may remain even when the unit is unplugged.

For a serious assessment, combine external documentation with inspection by a competent technician when internal access is required.

Many pedals and effects go through production revisions without a major change in commercial name.

Before comparing two examples, check the enclosure, graphics, jack layout, power arrangement, PCB, chips and other identifying components where they can be inspected safely.

Do not assume an earlier or rarer revision is automatically “better”; demand, sound characteristics and availability also matter.

Document the revision as a plausible range if the evidence does not support a more exact classification.

On vintage synths and keyboards, identify hardware revision, installed boards and significant replaced components when documentation is available.

Models with the same name may contain meaningful production changes. A replacement board may be correct and fully functional without being original to the unit.

Keep invoices and workshop notes, especially when scarce components are replaced.

Avoid irreversible updates or modifications before understanding compatibility, backup options and the possibility of returning to the previous configuration.

An older amplifier may require replacement of deteriorated components. This does not automatically make it less interesting, but it changes how its originality should be described.

Ask for or retain a list of replaced parts, the reason for the work and, where appropriate, the removed components. Avoid indiscriminate “preventive” modification unless supported by diagnosis and safety needs.

Separate necessary service from work intended to change tone or response.

The quality of the work and documentation is often more useful than a generic “fully serviced” claim.

On an older effect unit, switches, jacks, potentiometers and power connections may have been repaired after years of use.

Inspect soldering, wiring, components and signs of replacement, but also ask whether the intervention is consistent with normal maintenance.

A documented professional repair may be preferable to an intermittent original component. From a collector perspective, however, the replacement should still be disclosed.

If the circuit has been modified to alter gain, EQ or bypass behaviour, describe that separately from maintenance.

Pickups, potentiometers, capacitors, switches and wiring can provide many clues. Compare codes, materials, wire colours, soldering style and layout with documented examples.

A disturbed solder joint may indicate service or replacement, but it does not by itself explain when or why. Conversely, old-looking solder does not automatically authenticate a component.

Record which parts are consistent, which are known replacements and which cannot be verified without invasive work.

Avoid desoldering components merely to “check more closely” when the operation could destroy useful historical evidence.

Keybeds, membranes, displays, encoders, sliders and buttons are wear-prone parts. Replacement may make the instrument far more usable without necessarily changing its primary sonic identity.

Record which components were replaced, whether replacements are original, compatible or modern, and whether the original parts remain.

Also check key consistency, display readability and control response, because good cosmetics do not guarantee full functionality.

For collectors, documented maintenance and transparency are often more useful than a generic “never opened” claim.

In pedal collecting, external appearance can matter greatly: paint, graphics, labels, screws, knobs and baseplates help identify period and preservation.

However, a correct enclosure can contain a modified circuit, just as an original circuit can sit inside a restored enclosure.

Assess external and internal originality as connected but separate sets of evidence.

When cosmetic parts are reproduced or touched up, disclose that even if the visual result is very faithful.

Cabinets, coverings, grilles, handles, feet and panels can be restored independently from the circuit.

Look for added holes, inconsistent materials, reproduction panels, replaced logos and differences in wear. A new grille is not equivalent to replacing a transformer, but both should be disclosed.

When cosmetic restoration has been performed well, document which materials were original and which are new.

Separating cosmetics, structure and circuit makes the assessment much clearer.