Wet tantalum capacitors - how good are they?

[japlytic]

In a distortion and noise meter from the mid-70s, it had wet tantalum capacitors for signal coupling.
How good are wet tantalum capacitors from the 70s as well as modern wet tantalum capacitors?

[redwire]

Re: Wet tantalum capacitors - how good are they?

I've only seen aerospace/military grade wet tantalums, which are hermetically (glass not rubber) end sealed. They are highly reliable and last decades (assuming they did not get any reverse-voltage).

For an audio distortion meter, tantalums measure low in THD but do poorly in listening tests. I don't think electrolytics in the 1970's had good ESR above say 10kHz, and tantalums seem better than electrolytics for tolerances and dielectric absorbtion.

Source: Tantalum Capacitor Benchmark in Portable Audio Applications pdf
"Picking Capacitors" Walter G. Jung and Richard Marsh, Audio Magazine, February and March, 1980