Does anybody here know the pinout + other uses for Mullard OC81D please?

[luap77]

Hi all,

I've just managed to dig up some Mullard OC81D transistors (metal case version) and am thinking tonebender. I'm not sure of the pinout.....could anybody here help with this please?

Thank you

P.S. Do any other stompboxes use OC81 transistors?

Paul E

[Toney]

 

  Looks like the OC81"D" suffix is a very low HFE variant. Up to 25.. that seems awfully low!
If this is what you have... they may not be very useful.
Here's a link http://vintageradio.me.uk/info/germanium.htm
Having said that, there are no rules with Ge's -test them and see!

[King Tubby]

  Looks like the OC81"D" suffix is a very low HFE variant. Up to 25.. that seems awfully low!
If this is what you have... they may not be very useful.
Here's a link http://vintageradio.me.uk/info/germanium.htm
Having said that, there are no rules with Ge's -test them and see!

The > before the 25 actually means "greater than" :*)

Sometimes there's a white or red dot on transistors like these which usually indicates the collector.

[luap77]

THank you. What about the order of the pins on OC81D please? Collector (red dot) then which is B and E? These are rare transistors and I don't want to damage them. I've extra, so am wondering if any other pedals specifically used OC81 germaniums?

BTW I have a collection of about 3000 Ge transistors, so I am aware of substituion based solely on hFE (and no other characteristic) and also the mojo aspect, however, several people here have commented in the past that OC81D has a specific sound in the tonebender that isn't quite matched by others.

Cheers.

Paul E

[King Tubby]

It should go C (indicated by a dot) then B E, this is what i've found it to be on other OCXX transistors but search for a datasheet just to confirm!

I dont recall any other pedal specifically using OC81Ds

They should be alright to use in most germanium PNP pedals like the fuzz face and the Rangemaster and their numerous variations.



Use sockets, less chance of heat damage from your iron 

[SISKO]

To all the OCxx Ive got the pinout was C red dot, then B and E

Hope it helps

[luap77]

Yes, this does help. Thanks very much to everybody that replied.

Paul E

[momiel]

The TONE BENDE MK II uses the OC81D!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! The devices with them are said to be the best ones....