Hi, in general, when replacing capacitors, which values (be it capacitance, voltage, ripple current, leak current, ESR, e.t.c.) must be followed and which ones are ok to be different? This mostly depends on the particular circuit. However, if the part will fit physically, a higher voltage rating will be ok. and lower leakage is ok.
If there is, then the capacitor should be replaced. If you’re replacing capacitors with higher values than the originals, then it’s important to check for other components that may be affected by the change. This is especially true when it comes to voltage and current ratings.
Generally speaking, you should always replace like-for-like when it comes to capacitors – meaning if your capacitor has a capacitance rating of 10μF, you should select a new one with the same value. However, there are times where it may be necessary to replace with a higher or lower capacitance rating.
For electrolytic caps (and really all caps), there are testers that check "equivalent series resistance" (ESR), and leakage (or dielectric strength). Then it becomes a pretty clear result of pass/fail instead of "replace on general principle". ... Other than capacitors what parts within an amp need replacing because of age?
Replacing a capacitor is a straightforward process when approached methodically. Here’s a step-by-step guide to help you navigate through the replacement procedure: Prepare Your Workspace: Select a clean, well-lit area with ample space to work comfortably. Ensure proper ventilation and access to necessary tools and materials.
Generally its only electrolytic capacitors that need replacing, the most critical being the ones serving as filters in the power supply. Occasionally resistors that are stressed (like ones near the power tubes) can fail, and in some designs its a good idea to replace some of these with higher tolerance ones before they fail.