Problem with Pearl. Please Help

[cviller]

and now did the third 2SK389 decide to retire...
Of a different lot/date.
I have triple-checked all voltages, they are within 0,5V of Mr. Pass specs. All other parts are matched, exept zeners & electrolytic caps...

Any hint of what is killing them?
My stock of 2SK389 is running low...

Arne K

So approximately how many hours does a pair of 2sk389 last?

Are they running hot?

You could try a matched pair of 2sk170's instead of a 2sk389, I don't think it's hard to mount them...

 

[steenoe]

So approximately how many hours does a pair of 2sk389 last?

Mine has so far been working for nearly 3 years. Never fried any, so far.

Steen

 

[cviller]

Mine has so far been working for nearly 3 years. Never fried any, so far.

Steen

Great! Good news for me, since I guess those you gave me were from the same batch!