Деки NAKAMICHI, Настройка и обсуждение (Part 2)

"Ясный пень", А бывает пасмурный пень? Или туманный пень? ... Борцы за чистоту языка)) Япона мать))

Глупостей не надо писать, можно просто погуглить, если чо.

Tantalum capacitors are reliable on the same very high level as other electronic components with very low failure rates. However, they have a single unique failure mode called “field crystallization".[9] Field crystallization is the major reason for degradation and catastrophic failures of solid tantalum capacitors.[13] More than 90% of the today's rare failures in tantalum solid-state electrolytic capacitors are caused by shorts or increased leakage current due to this failure mode.[68]

The extremely thin oxide film of a tantalum electrolytic capacitor, the dielectric layer, must be formed in an amorphous structure. Changing the amorphous structure into a crystallized structure is reported to increase the conductivity by 1000 times, combined with an enlargement of the oxide volume.[11] The field crystallization followed by a dielectric breakdown is characterized by a sudden rise in leakage current within a few milliseconds, fr om nanoamp magnitude to amp magnitude in low-impedance circuits. Increasing current flow can accelerate in an "avalanche effect" and rapidly spread through the metal/oxide. This can result in various degrees of destruction fr om rather small, burned areas on the oxide to zigzag burned streaks covering large areas of the pellet or complete oxidation of the metal.[6] If the current source is unlimited a field crystallization may cause a capacitor short circuit. In this circumstance, the failure can be catastrophic if there is nothing to lim it the available current, as the series resistance of the capacitor can become very low.

If the current is limited in tantalum electrolytic capacitors with solid MnO2electrolyte, a self-healing process can take place, reducing MnO2 into insulating Mn2O3

Impurities, tiny mechanical damages, or imperfections in the dielectric can affect the structure, changing it from amorphous to crystalline structure and thus lowering the dielectric strength. The purity of the tantalum powder is one of the most important parameters for defining its risk of crystallization. Since the mid-1980s, manufactured tantalum powders have exhibited an increase in purity.

Surge currents after soldering-induced stresses may start crystallization, leading to insulation breakdown.[69] The only way to avoid catastrophic failures is to lim it the current which can flow from the source in order to reduce the breakdown to a limited area. Current flowing through the crystallized area causes heating in the manganese dioxide cathode near the fault. At increased temperatures a chemical reaction then reduces the surrounding conductive manganese dioxide to the insulating manganese(III) oxide (Mn2O3) and insulates the crystallized oxide in the tantalum oxide layer, stopping local current flow.[6][66]

и что дальше?
Это все давно известно и без перевода

тантал коротнуть может если

-резкий перепад температуры совпал с приличным броском тока через него (переход из холодного в рабочее состояние совпал с броском тока через обсуждаемый девайс)

-токовая нагрузка в сочетании с неправильной полярностью пост. напряжения. (т.е. включен наоборот по постоянке)

-бросок тока с прямыми фронтами (мгновенное нарастание)
- и еще совсем редкие страхи

где такое сочетание факторов встречается в аудио аппаратуре, и конкретно в кассетниках?


а может не коротнуть,  ...зависит от фазы луны и погоды в Новой Гвинее
за 20 лет - ни разу.

вердикт - страхи из разряда ОБС

Нет смысла категоричить, потому как опыт и статистика говорят об обратном. Да, они выходят из строя реже, но выходят и не только в гвинеях и не только при полнолунии. Как не совсем давнее от Тандберга - коротышом в питании (ну или в управлении питанием каналов записи)