a bit of a novice here, but learning. I am trying to find a replacement for a Hitachi 1SS84 diode, which is no longer manufactured. The specs are here: https://pdf.dzsc.com/88889/22732.pdf

Hitachi 1SS84

The 1N4148 is seen as a replacement. However, if I look at the specs for those, I am met with different values. Like these: https://uk.farnell.com/w/c/semiconductors-discretes/diodes-rectifiers/small-signal-diodes?diode-mounting=through-hole&product-range=1n4148&range=inc-in-stock

The forward V max available is 1V, not 0.8V. Peak reverse voltage is 100V, there is the recovery time. Some things are not listed. Any help would be appreciated.

  • \$\begingroup\$ You choose a replacement based on the circuit it is used in. \$\endgroup\$
    – Andy aka
    Jul 29, 2023 at 11:54

1 Answer 1


It's possible none of those numbers are particularly important, and a look at the application schematic might clear that up, but if I was totally uninformed of the circuit design, lacked knowledge of the operating principles and had to pick something, the Vishay, Onsemi etc. BAV19 is very close including the sluggish recovery time (suggesting a lack of gold doping compared to the ubiquitous 1N4148).

If that doesn't work as a drop-in, chances are it also might not work with another randomly picked sample of 1SS84.

Added schematic with presumed diodes:

enter image description here

I don't think those two diodes are particularly critical, 1N4148 should work there.

  • \$\begingroup\$ It is for a power board on a synthesizer. Here is the schematic of the Korg M1 if it helps.: The diode is used on the KLM 1267 power board (also on other boards). Page 10: synthxl.com/wp-content/uploads/2018/01/… \$\endgroup\$
    – cakebot
    Jul 29, 2023 at 14:11
  • \$\begingroup\$ I see. I will get hold of the 1N4148 diode with the closest specifications to the 1SS84 then. \$\endgroup\$
    – cakebot
    Jul 29, 2023 at 15:47

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