transistor sockets

[sneakers563]

So, I've got it into my head to put together an "Umble" pedal for my guitar. I'd like to put the J201 transistors in sockets, but I can't seem to find any TO-92 sockets at Digikey or Mouser (or anywhere else really). Does anyone know where I can find some? Am I looking for the wrong thing; do people use something else as sockets for these things?

[Nigel Goodwin]

Basically people haven't used transistor sockets for many decades, and for a guitar pedal it would be a VERY bad idea.

[jackinnj]

AllElectronics has them.

http://www.allelectronics.com/make-a...OCKET/-/1.html

[sneakers563]

Originally posted by Nigel Goodwin
Basically people haven't used transistor sockets for many decades, and for a guitar pedal it would be a VERY bad idea.

Really? I'm a complete noob here. Why would it be a very bad idea? I read somewhere that the transistors can/will fail eventually and so putting them in sockets is a good idea. What's the disadvantage?

Thanks for the advice!

[Conrad Hoffman]

Transistors in a properly designed circuit should have a very long lifetime, probably longer than ours. Sockets reduce reliability- they can oxidize and the parts can vibrate free. They reduce high frequency performance. Commercial equipment almost never uses sockets, and not for cost reasons. OTOH, I've been known to use the nice Augat Teflon sockets for front end transistors where the frequencies are low and I want to play with careful matching. I've also been known to cut off a strip of 3 machined contact sockets from a break-away strip, and use them for TO-92 devices. I have a radio where static can blow the input device, and I keep that in a socket for easy replacement. I wouldn't say nobody ever uses sockets, but it's less and less common, especially since SMT is taking over everything anyway.

BTW, it's little known, but gold sockets are a waste of time unless you have gold leads. High pressure tin leaf types are best for tin IC leads.

[jackinnj]

Conrad -- good idea on the snippable machined sockets -- I use them when matching resistors for gain stages. DK carries them.

[sneakers563]

I'll take a look at the break-away sockets, but probably just solder the jfets directly to the circuit board.

Thanks for the advice, that's a big help.

[teemuk]

Just buy a 6-pin DIL and split it in half: Two transistors sockets.

[Nigel Goodwin]

Originally posted by sneakers563


Really? I'm a complete noob here. Why would it be a very bad idea? I read somewhere that the transistors can/will fail eventually and so putting them in sockets is a good idea. What's the disadvantage?

Sorry for the slow reply, but basically what others have said.

The transistor socket is going to be a LOT less reliable than the transistor that's plugged in it - it's adding an unreliable part to a part which will most probably last longer than you need it to. Transistors are VERY, VERY reliable - small signal ones as used in an effect pedal will almost never fail.

When transistors do fail, it's usually because something nasty has been done to them - like plugging too many speakers on the output of an amplifier.

An effect pedal is a device that gets a LOT of abuse, thrown around, dropped, all this is going to make the transistor work loose from the socket and cause problems.

[Minion]

The reason why DIY Pedal builders use sockets in there pedals is so they can easilly change out different Transistors for getting a different sound and/or to mod the pedal.... Many Pedal builders do this.....And if they find a transistor they like then they have the option of Soldering them to the board....

What I use for transistor sockets are regular DIP opamp sockets and I just cut them down with a Pair of Nail clippers so there are 3 Pins in a row...

Cheers

PS: With that Curcuit , it would be a good Idea to use Sockets at first, at least till you get the Pedal working properly..why?? Because that curcuit uses JFets (J201) which are nortorious for haveing wide rangeing specs which can make curtain Fets practicly un-Biasable so you might have to try several fets before you can get the curcuit working optimally.... (I had to try about 20 J201 fets to get 4 that would Bias correctly in my DR.Boogie build)...