04-05-2026, 01:06 PM
Most older electrolytics are +80% & -20% tolerance and in most applications even wider tolerance is OK. Except valve rectifiers have a maximum loading and best to have about x2 rating vs actual no load voltage.
2, 4, 6.4, 20, 32, 40, 64 and 80 used to be common. See also resistors
Now replaced by
2.2, 4.7, 22, 33, 47, 68 and 100
From
1.0, 1.5, 2.2, 3.3, 4.7, 6.8 (E6)
Only more precise tolerance capacitors use E12
1.0, 1.2, 1.5, 1.8, 2.2, 2.7, 3.3, 3.9, 4.7, 5.6, 6.8, 8.2,
So you'd only replace a non-electrolytic 4uF (maybe in an audio filter) with 3.9 as 4 + 80% = 7.2uF! Otherwise 4.7 is fine.
80uF + 80% = 144 uF, so 100uF is fine
Resistors were first to use E series (History of E series)
2, 4, 6.4, 20, 32, 40, 64 and 80 used to be common. See also resistors
Now replaced by
2.2, 4.7, 22, 33, 47, 68 and 100
From
1.0, 1.5, 2.2, 3.3, 4.7, 6.8 (E6)
Only more precise tolerance capacitors use E12
1.0, 1.2, 1.5, 1.8, 2.2, 2.7, 3.3, 3.9, 4.7, 5.6, 6.8, 8.2,
So you'd only replace a non-electrolytic 4uF (maybe in an audio filter) with 3.9 as 4 + 80% = 7.2uF! Otherwise 4.7 is fine.
80uF + 80% = 144 uF, so 100uF is fine
Resistors were first to use E series (History of E series)
