Mosfet colour dot on package

[alayn91]

Hello,

I am trying to fix my Pioneer A-109 amplifier.
This one uses Mosfet IRF530 & 9530 in the final stage.
But these ones have a color dot on the package.
Green for the IRF530 and orange for the IRF9530.

I didn't find any information on the data-sheet.

Are you aware of these colour dots ?
Do you know the meaning of these colours ?

Are they linked to some parameter, maybe Vgs.
As for the gain of BJT.

Regards.
Alain.

[Mooly]

They are probably selected in some way by Pioneer, as you say, quite possibly Vgs.

I would be confident that any reputably sourced replacements would work just fine providing any bias adjustment was correctly adjusted following replacement.

Japanese manufacturers often marked devices in some way, Sony for one.

It will be fine

[ATAUDIO]

I have at home several IRF530 original from the old IR brand and none of them is marked, So I must think that Mooly is correct.
BTW I would love to have an ampli schematic using them (I was using them for a PID controller, not for audio).
can you provide me it? A PM will do if you do as well.

[alayn91]

Hello,

Thanks for your answers.

The SM for the Pioneer A-109 could be found here:
ElektroTanya | Service manuals and repair tips for electronics experts

Type in brand: pioneer & model: A-109.
You are allowed 2 free downloads a day.

Regards.
Alain.