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Mullard OCx transistors from radios?

Posted: Thu Nov 01, 2012 6:21 pm
by Ben79
Hi all, I'm new here. Been building a few kits and now getting into putting together some vero fuzzes.

I've got a couple of old 60s transistor radios. One has 2 oc81 and 1 oc81d transistors in it. I know these are desirable trannies for tonebenders but am I right in thinking there's only a minute chance of these 3 actually being right for a pedal?

Re: Mullard OCx transistors from radios?

Posted: Thu Nov 01, 2012 7:23 pm
by nbabmf
They'll probably work. It might not be HOLY GRAIL OMFG sounding, but it will probably sound good.

Re: Mullard OCx transistors from radios?

Posted: Thu Nov 01, 2012 7:52 pm
by devnulljp
get some hfe readings off em.
Or punt them on fleabay for sillymoney

Re: Mullard OCx transistors from radios?

Posted: Thu Nov 01, 2012 9:24 pm
by Scruffie
If the radio works then yeah they'll probably do fine for a MkII, my favourite MkII actually has that combo of trannies... although that doesn't mean anything, with that circuit you really need to swap transistors round to get the best sound.

Thankfully the MkII is forgiving of gains and leakage, you'll get different sounds with those variances but they can usually make a nice fuzz, although perhaps not a 'true' MkII sound.

If the radio is working though i'd check its value first, tbh... I really don't think the OC81Ds are that special IMO, I tried a MkII with lots of them (real mullard ones, not the unbranded ones) and it was too... loose? The 81 and 81D combo worked from the correct balance of gains and leakage.

I've actually had good luck with OC44s and 71s and lower gain 45s can make a great fuzz with a higher gain tran somewhere in there.

Re: Mullard OCx transistors from radios?

Posted: Fri Nov 02, 2012 6:06 am
by Ben79
Cheers, I'll take the radios off ebay!

All the radios work. I've got various OCs - 71, 45, 44, etc. in these 3 60s radios I bought from car boot sales. I've put together a Marshall Supa Fuzz with sockets so I'll rip them out the radios and give them a try. Seems a shame cos the radios are lovely but I'm never gonna use them and I only paid a few quid.