Capacitors and service components: document why and what was replaced

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.