madbeanpedals::forum

Projects => General Questions => Topic started by: MikeM on February 22, 2012, 05:16:41 PM

Title: Weener Trannies
Post by: MikeM on February 22, 2012, 05:16:41 PM
Hey folks

I don't have a very good understanding of SS goodies, and I am planning to try my hand at a wah as a first pedal soon.

Can get most of the goodies I need here in South Africa, but transistors are relatively limited..

The pdf calls for a 2n3565, BC549C, 2N5457. I can get a hold of the 2N5457. But not the others. It also mentions that the 2N5088 is an alternative. Would that work for both of the others? I can also get BC107s, and actually quite a few others which I have just spotted here (http://www.rabtron.co.za/transistor) if anyone has the time to scope a page or 2 out for me.

What would the difference be between these though? Aren't they all little amplifying goodies?

Thanks very much folks!
Mike
Title: Re: Weener Trannies
Post by: jkokura on February 22, 2012, 05:28:52 PM
You can use pretty much any NPN that has a similar sort of function to the ones listed. I don't know about the BC107 off hand, but if it fits in that range also you can. Check the datasheet. I know that using BC108 or 109 transistors is quite popular in Vox Wah Mods.

Check the pinout on any transistor you want to swap in. A safe bet is to buy extras of different kinds and 'auditioning' various trannies for what sounds best to you.

As for the differences, as I mentioned there may be a different sound that you get using different kinds. Yes they all amplify, but they amplify with different strengths and flavours. Does that make sense?

Jacob
Title: Re: Weener Trannies
Post by: MikeM on February 22, 2012, 05:31:47 PM
Ahhh alright that makes sense, so pretty much tube rolling  ;D

Can also get the 108 and 109.

Just confirming, can I use the same transistor for both needed in the actual wah?

Thanks very much Jacob
Title: Re: Weener Trannies
Post by: jkokura on February 22, 2012, 05:33:08 PM
Yes, but you can use different ones as well. There are few hard and fast rules in DIY building.

Jacob
Title: Re: Weener Trannies
Post by: Haberdasher on February 22, 2012, 06:46:34 PM
I think my dunlop came with mpsa18's in it which are pretty high gain.
If you wanted to approximate the gains of the ones in the build doc, I think bc549c's are about 550hfe.  So 2n5088 would go great right there but the pins are the other way around so just face it the other way.  The 2n3565 is about 250hfe i think?  So a similar gain range could be found in a 2n3904 or 2n4401.

But there are probably hundreds of npn trannies you could use in there and they would sound fine.
Title: Re: Weener Trannies
Post by: MikeM on February 22, 2012, 07:09:36 PM
Thanks guys!

Going to get

BC108B
BC108C
2N4401
BC549B
BC547C

2N5459 (Can't find the 5457 as this supplier, and this is supposedly just a lower gain equivalent?)
2N3819
2SK0163
BF245C

Should keep me busy for a long while!
Title: Re: Weener Trannies
Post by: Haberdasher on February 22, 2012, 07:27:30 PM
I used a 2sk117 jfet in mine.  It looks like the jfet in the circuit is there for the switchable buffer so it probably won't make much difference which one you use.  the 5459 ought to be fine, just check the data sheet to make sure you get the legs in the right order.  I had to make the 2sk117 do a little bit of "ballet".
Title: Re: Weener Trannies
Post by: MikeM on February 22, 2012, 07:29:46 PM
Yea, I figured it'd be as easy as checking where the base, emitter and collector would be and just comparing it to what would have been stock. Think I'll be able to figure it out :)

Now just to order the pcb, whipple and pot!
Title: Re: Weener Trannies
Post by: gtr2 on February 22, 2012, 08:46:36 PM
um..this topic subject is disturbing...  ;)
Title: Re: Weener Trannies
Post by: MikeM on February 22, 2012, 08:47:44 PM
It'd be even more so if it was swapped around  :D
Title: Re: Weener Trannies
Post by: TNblueshawk on February 22, 2012, 09:05:44 PM
Has anyone found a source for the 2n3565? I have some 3904's but I have to place an order for some stuff so I'd like to order up the 3565's but the usual suspects don't have it.

Title: Re: Weener Trannies
Post by: DutchMF on February 22, 2012, 09:09:01 PM
Banzaimusic.com has the 2N3565, I'd drop them an e-mail before ordering, as they don't list availability on their site

Paul
Title: Re: Weener Trannies
Post by: Haberdasher on February 23, 2012, 02:46:29 AM
Quote from: TNblueshawk on February 22, 2012, 09:05:44 PM
Has anyone found a source for the 2n3565? I have some 3904's but I have to place an order for some stuff so I'd like to order up the 3565's but the usual suspects don't have it.


smallbear dude.
http://www.smallbearelec.com/Detail.bok?no=282
Title: Re: Weener Trannies
Post by: TNblueshawk on February 23, 2012, 12:23:07 PM
Quote from: Haberdasher on February 23, 2012, 02:46:29 AM
Quote from: TNblueshawk on February 22, 2012, 09:05:44 PM
Has anyone found a source for the 2n3565? I have some 3904's but I have to place an order for some stuff so I'd like to order up the 3565's but the usual suspects don't have it.


smallbear dude.
http://www.smallbearelec.com/Detail.bok?no=282

WTF! I simply missed it. Dang. I ordered from them a few weeks ago and didn't see them! Just overlooked it I guess. Thanks.
Title: Re: Weener Trannies
Post by: Haberdasher on February 25, 2012, 06:47:47 PM
well crap, I just noticed someone went in & bought all the 2n3565's.  I needed 3 or 4 of them, too. :(
Title: Re: Weener Trannies
Post by: TNblueshawk on February 26, 2012, 12:31:35 AM
Wasn't me. I'm in Florida drinking beer and eating Italian food  ;D