Author Topic: Yet another OC81D thread (Sorry)  (Read 1871 times)

CodeMonk

Yet another OC81D thread (Sorry)
« on: November 14, 2013, 07:47:46 PM »
Since OC81D's seem next to impossible to get anymore (At least from my eBay searches), what are some good equivalents?
I've checked a few cross reference list and have seen several different suggestions.
Like AC128, AC128, 2N406, even NTE102.

Or is there some source of OC81D's I am unaware of?

These well be for Tonebender MkII BTW.

In the collective wisdom of DIYSB, what has been your experiences of the best of these?
Or any others that are obtainable without having to sell a kidney to get a hold of that will give similar performance to an OC81D?
I'm interested in quantities (100+) not just a few.

Thanks.

tonyharker

Re: Yet another OC81D thread (Sorry)
« Reply #1 on: November 15, 2013, 05:09:42 AM »
AC125 is supposed to be an equivalent,  but you can use an AC128.

Electric Warrior

Re: Yet another OC81D thread (Sorry)
« Reply #2 on: November 15, 2013, 07:36:34 AM »
Just build the OC75 version. When set up correctly the differences between transistors aren't all that big. Here's a video comparing vintage units with OC81Ds, S3-1Ts and OC75s:



The Supa Fuzz on the right is the version with the 10µFs and without the cap between input and ground, btw.

Just because a transistor is listed as an OC81D equivalent somewhere, it doesn't mean it will sound and behaves like one, btw. I have some Valvo AC125s that make an excellent substitue for OC75s in a MKII. They would sound way off with the 100k/100k bias setup they used for the OC81D version.
« Last Edit: November 15, 2013, 07:39:03 AM by Electric Warrior »

CodeMonk

Re: Yet another OC81D thread (Sorry)
« Reply #3 on: November 15, 2013, 07:57:36 AM »
Thanks.
And I meant AC128, AC125 in my OP :)