[sdiy] Vox continental - one other thing...

[Dave Manley]

Dave Manley wrote:
> Tom Wiltshire wrote:
>> Sorry, there's one other question I've got about the Continental.
>>
>> Why do the OC71 germanium transistors have *four* legs?!
>>
>> http://www.electricdruid.com/continental.gif
>>
>> It looks like a basic transistor flip flop, but I don't get the 
>> four-legged transistors drawn as a black box. What's going on?
>>
> According to this they don't: 
> http://homepages.nildram.co.uk/~wylie/Mullard/Mullard.htm
> (scroll down to find a pic of an OC71).
>
> I think whoever drew the schematic just took a short cut, similar to 
> how you often find multiple transistors all controlled by the same 
> base connection, with all the bases tied together, with the schematic 
> showing a 'lead' on the same side as the collector and emitter.  If 
> you look at the OC71's on the left side, they only have three leads.
>
For example, compare how the same basic circuit is drawn here (upper left):

http://www.voxamps.com/downloads/circuits/continl2.jpg

-Dave