Transistor sockets

[warpie]

I have noticed that some commercial products use transistor sockets. What's the reason behind it? I can understand their usefulness when you prototype but why would you want to use them in a commercial product and most likely run into connectivity issues in the future?

 

[emrr]

I can't say I've seen them in anything remotely recent. I do have a number of 1960's pieces that are all socketed, and none have experienced intermittents on my watch. The only places I'd like to add sockets are all test bed matching scenarios.

 

[Ricardus]

When you build the Hairball 1176s they recommend sockets for 2 different FETs in case you want to audition different ones. I used them. So far no issues.

 

[warpie]

Chandler seem to do it and also I saw a photo form an SSL 4056 G+

 

[Walrus]

Those are not sockets, but spacers. They also shape the leads of the transistors.

 

[warpie]

Those are not sockets, but spacers. They also shape the leads of the transistors.

Ah OK, my bad.

 

[Matt Syson]

Indeed those white pieces shopwn are spacers that form the transistor legs neatly. Transistor sockets were/are often used for transistors/Fets that need to be matched. FETs in particular have very wide tolerances when used in a 'linear' way like for a 'FET compressor' so the boards can be built in bulk and selected matched FETs/ transistors can be fitted at the end. most semiconductors (In well designed circuits) are very reliable so the chances of needing to replace them are slim. It can be prudent to fit ICs/transistors that have 'direct access' to the outside world, like mic amp inputs and assorted outputs that may get zapped by static discharge or phantom power to have sockets most circuitry apart from these 'outside portals' cannot be subjected to anything serious beyond the normal power rails.

 

[Whoops]

I have seen some vintage hifi Power amps and the trasistors were socketed (Pioneer and the likes)

Recently I serviced an 90s NAD power amp, the filters caps blew up and took the output transistors with them. What I can tell you is that I truly wished those were socketed as they were a pain to unsolder and replace, the PCB traces want to come loose with the transistors and break off easily, and I'm not even applying excess heat.
So I guess the reason for gear with transistors in sockets was for making it easier serviceable, probably it stopped being used around the 80s because companies embraced planned obsolescence and they don't want anyone to service their sold products, they want you to buy a new unit