True, but it comes down to the intended use - as part of a filter, there would technically be some nonlinearities although the amount probably wouldn't be enough to effect the output appreciably. For coupling usage, there is no bias present so it wouldn't be an issue. Again, it's a matter of knowing how any parasitics would - or would not - affect the desired outcome. Just about any circuit designer that is at least halfway competent would have already taken into account the impact of the type of capacitor used would have and changing that selection is more likely than not to hurt - or at least not improve -the end performance. Of course, there are always the exceptions but those, IMO, tend to be fairly uncommon.
To be clear, I am not in any way downplaying Mr. Bateman's work - the tests mentioned are extremely well thought out, performed and are very informative. I'm just saying that the results he found only apply to the exact test conditions he used and, more than likely, the conditions found in any given circuit will not match those of his testing. I see all too often someone say "this test showed so and so" and attempt to apply that to all circuits. Electrolytics are frequently demonized in all applications which is very much the wrong thing to do. Like any other dielectric, they have applications that very well suit their characteristics and those that most certainly are not - the trick is to not only know which is which but to know why that is the case.
Well, I think it's safe to say the designers of that vintage tape recorder did not really expect it to be working in 2024.
"For coupling usage, there is no bias present so it wouldn't be an issue."
HUH? If there is NO DC bias, you don't NEED a coupling capacitor at all.
"Just about any circuit designer that is at least halfway competent would have already taken into account the impact of the type of capacitor used would have and changing that selection is more likely than not to hurt - or at least not improve -the end performance. Of course, there are always the exceptions but those, IMO, tend to be fairly uncommon."
Maybe. Until the bean counters got involved and started substituting parts that they could get for the cheapest or from a manufacturer who greased their pockets.
HUH? If there is NO DC bias, you don't NEED a coupling capacitor at all.
"Just about any circuit designer that is at least halfway competent would have already taken into account the impact of the type of capacitor used would have and changing that selection is more likely than not to hurt - or at least not improve -the end performance. Of course, there are always the exceptions but those, IMO, tend to be fairly uncommon."
Maybe. Until the bean counters got involved and started substituting parts that they could get for the cheapest or from a manufacturer who greased their pockets.
Back when that thing was made they didn’t op-amp the hell out of everything. Discrete transistor preamp circuits were chock full of coupling and bypass caps with a couple to a dozen or so volts on them. There may have been some that don‘t have much voltage on them but most of them would. The few that don’t are probably in some filtering circuit, deemphasis network, or tone control.
They also didn’t have bean counters changing everything out with the cheapest parts on the market. Even the best caps of the day just can’t hold a candle to a middle of the road Nichicon made today, that’s all.
They also didn’t have bean counters changing everything out with the cheapest parts on the market. Even the best caps of the day just can’t hold a candle to a middle of the road Nichicon made today, that’s all.
A 'side note' worth mentioning re. electrolytics is when "Designed Obsolescence" (designed to fail)
manufacturing has been implemented, electrolytics have been deliberately mounted next to heatsinks.
manufacturing has been implemented, electrolytics have been deliberately mounted next to heatsinks.
Personally, I don't think there was enough intelligence involved to support the word "Designed."
Rather, it is a very good example of Hanlon's Razor: "Never attribute to malice that which is adequately explained by stupidity."