SFT337 and OC76 (or SFT363E) - where?

andershp · Post by **andershp** » Tue May 03, 2011 10:20 am

Hi

I've been looking for the germanium resistors SFT337 and OC76 (or SFT363E), since I need them for a VOX Tone Bender clone. However they are pretty difficult to find anywhere. I've seen the OC76 on ebay, but not the SFT337 ?

Can one find these anywhere or what would be a replacement that would fit in the VOX ToneBender?

Thanks

h8mtv · Post by **h8mtv** » Tue May 03, 2011 10:44 am

You are going to find hfe more important than make.

andershp · Post by **andershp** » Tue May 03, 2011 11:21 am

Okay, so how do I actually do this?
And is the HFE the only difference between germanium transistors, since you only mention that?

h8mtv · Post by **h8mtv** » Tue May 03, 2011 9:37 pm

Are you making it PNP or NPN? If you go NPN it will play with other pedals more happily. Smallbear sells sets. I could make you a set of NPN's. Usually you want q1 around 70 and others around 90 in my experience.

andershp · Post by **andershp** » Thu May 05, 2011 10:17 am

Are you making it PNP or NPN? If you go NPN it will play with other pedals more happily. Smallbear sells sets. I could make you a set of NPN's. Usually you want q1 around 70 and others around 90 in my experience.

I'm not really sure about the difference, but as far I know, the original was PNP and since I want to recreate the original early VOX ToneBender sound, I think I would make it PNP.

On the other hand, why would I want to make it NPN and does it make a difference besides the transistors?

Do smallbear have sets similar to the original ones that I mentioned, and which would this be?

h8mtv · Post by **h8mtv** » Thu May 05, 2011 10:44 am

NPN and PNP versions sound the same, or so close it would be nearly impossible to know the difference. These may help you.

http://www.generalguitargadgets.com/ind ... &Itemid=26

http://www.smallbearelec.com/Categories ... ransistors

Any pnp circuit can be made npn by using npn trans and also reversing the polarity of polarity sensitive components like diodes, polarized caps, etc and also reversing the battery and ground.
Personally, I hate pnp circuits.