Soldering Transistors

[Bellyheart]

If I solder all three poles with one joint will it effect the circuit?

[smallsnd/bigsnd]

what does that actually mean? what are you trying to achieve?

if it means you're going to solder all three legs of a transistor together, you most likely will just end up with the circuit not working.

[Bellyheart]

Okay, thanks. I was worried while soldering the PCB for the TP and wasn't sure if i should be or not.

[Mark]

wait... you should not be soldering any transistors at all! Chances are the PCB has been designed for transistor sockets, so you should use one! It won't actually affect the tone or function at all, but it's safer, because you're not actually heating up the transistor at all, and the socket allows you to swap out transistors later, if you want to experiment.

But to your original question, no, the leads should not be soldered together, at all. They should never touch while actually connected and in the circuit, although if they touch while outside the circuit it's not the end of the world.

[comtrails70]

Unknown.jpeg (1.35 KiB) Viewed 4010 times

i found like 150 of these on ebay for around 5 bucks incl shipping.
they're really expensive on some sites though.

[Bellyheart]

I've already soldered the board and unfortunately the transistors as well, but I shall get these for future builds. SHO next.

[smallsnd/bigsnd]

hmmm transistor sockets are great for certain builds and experimenting, but it's certainly more stable to just solder them in. i've had issues once or twice in the past with transistor legs not being seated in the socket well, making for a faulty/intermittent connection... as long as you're soldering them correctly, it's better practice to NOT use a socket.

just use a soldering iron that's hot enough (between 700-800 degrees is good), be quick about soldering (1-3 seconds per joint), wait a few moments between heating each leg (10-20 seconds or so?) and you should be fine.

[Scruffie]

It's true that it's safer to solder transistors in for stability except... in the case of germaniums where they are more susceptible to heat and at the more expensive cost, I wouldn't suggest soldering them unless you were very confident and the second case being... MOSFETS, they're very static sensitive and even Zachary sockets the BS170 in his S.H.O because they can blow quite easily so I would still socket them in that build even with the diode protection.

Otherwise, yeah, solder them on board, just check your pin-outs before hand, modern silicon transistors take quite a lot of heat to damage really but better safe than sorry.

If you dont want to use those round sockets above, just snip a 6-pin DIP socket in half by the way, 2 cheap transistor sockets, oh and I have seen some people gooping or hot gluing transistors into sockets for more stability.. but I don't see why you'd really want to do that anyway, just an observation.

[Bellyheart]

Man, I hope that geranium is still good. I've gotta wait to finish the Death's Tar, but if it doesn't work I know where I'm going first.

[Scruffie]

Don't worry about it too much, especially if it was one of the newer russian types, it's certainly not reccomended to overheat them but... well it's probably surived and if a pedal doesn't work, checking the transistor isn't necessarily the first place i'd go to debug, in future though i'd put a crocodile clip on them or something to use as heat sink when you solder germaniums.

[smallsnd/bigsnd]

germs should be fine as long as you're quick about the soldering and wait between legs. for the TAFMs, i solder them directly to the board - one leg first, move on to other things while i wait for them to cool, then do the next leg, move on and wait, then the last leg. no problems yet...

+1 on the heatsink

[Mark]

hmmm transistor sockets are great for certain builds and experimenting, but it's certainly more stable to just solder them in. i've had issues once or twice in the past with transistor legs not being seated in the socket well, making for a faulty/intermittent connection... as long as you're soldering them correctly, it's better practice to NOT use a socket.

just use a soldering iron that's hot enough (between 700-800 degrees is good), be quick about soldering (1-3 seconds per joint), wait a few moments between heating each leg (10-20 seconds or so?) and you should be fine.

So don't be a pussy, and push the damn transistor in the socket. There is absolutely no reason why a solder joint would be more stable than a socket. If you are using the socket the way it's supposed to be used, it will be just as stable as soldering it. They are designed that way, and thats how they behave, when used correctly.

The eutectic composition for solder is 362 degrees Fahrenheit. 60/40 rosin-core solder (which is what should be used with this kind of small-electronic PCB) melts between 355-370 degrees. 700-800 degrees will burn traces off the board. Please don't tell people to do wrong things. It's not very nice.

[Scruffie]

So don't be a pussy, and push the damn transistor in the socket. There is absolutely no reason why a solder joint would be more stable than a socket. If you are using the socket the way it's supposed to be used, it will be just as stable as soldering it. They are designed that way, and thats how they behave, when used correctly.

The eutectic composition for solder is 362 degrees Fahrenheit. 60/40 rosin-core solder (which is what should be used with this kind of small-electronic PCB) melts between 355-370 degrees. 700-800 degrees will burn traces off the board. Please don't tell people to do wrong things. It's not very nice.

Transistor sockets are not as permanent as a good solder joint in any way, over time transistors can come loose especially with gigging knocking them about no matter how well you push them in however I have never heard of a solder joint coming loose unless the tracks and board started falling apart.
Even 8-Pin DIP sockets aren't as secure as a board joint, and that's with 8 pins holding it into a socket, also don't forget that the 'springyness' of the socket if you will, will weaken over time from being pushed back, Sockets are mechanical devices and inherintley unreliable and will fail over time.

And good soldering irons are around 340-375oC which is around 700 so he is infact correct... if your iron is lower than this you put your board at more risk as your solder will take longer to melt and your iron will be on the board for long enough to damage it, joints should be swift and efficient, quick heat will not damage a board but leaving a lower temperature iron sat there for 20 seconds to melt the solder will.

The fact is a hotter iron will only affect the surrounding area which is the area that doesn't matter as much as the component itself, the leads and the pad can take heat easily quickly, so using a hotter iron is the right thing to do, if you use lower temperature the heat begins to effect the PCB itself which is not so resiliant as the pad and travels the component lead (which works to slow the heat transfer with a hot iron) and affects the component itself.

So please get your facts correct before insulting others

[veteransdaypoppy]

Just use a heatsink and nuke the fuckin thing. It works.
There, problem solved. Quit yer bickering.



...

[Mark]

So don't be a pussy, and push the damn transistor in the socket. There is absolutely no reason why a solder joint would be more stable than a socket. If you are using the socket the way it's supposed to be used, it will be just as stable as soldering it. They are designed that way, and thats how they behave, when used correctly.

The eutectic composition for solder is 362 degrees Fahrenheit. 60/40 rosin-core solder (which is what should be used with this kind of small-electronic PCB) melts between 355-370 degrees. 700-800 degrees will burn traces off the board. Please don't tell people to do wrong things. It's not very nice.

Transistor sockets are not as permanent as a good solder joint in any way, over time transistors can come loose especially with gigging knocking them about no matter how well you push them in however I have never heard of a solder joint coming loose unless the tracks and board started falling apart.
Even 8-Pin DIP sockets aren't as secure as a board joint, and that's with 8 pins holding it into a socket, also don't forget that the 'springyness' of the socket if you will, will weaken over time from being pushed back, Sockets are mechanical devices and inherintley unreliable and will fail over time.

And good soldering irons are around 340-375oC which is around 700 so he is infact correct... if your iron is lower than this you put your board at more risk as your solder will take longer to melt and your iron will be on the board for long enough to damage it, joints should be swift and efficient, quick heat will not damage a board but leaving a lower temperature iron sat there for 20 seconds to melt the solder will.

The fact is a hotter iron will only affect the surrounding area which is the area that doesn't matter as much as the component itself, the leads and the pad can take heat easily quickly, so using a hotter iron is the right thing to do, if you use lower temperature the heat begins to effect the PCB itself which is not so resiliant as the pad and travels the component lead (which works to slow the heat transfer with a hot iron) and affects the component itself.

So please get your facts correct before insulting others

Well, that's funny... I suppose Wikipedia is wrong then. "60/40: melts between 183–190 °C (361–374 °F)"

Therefor, a soldering iron should be around 450-500 degrees fahrenheit. Higher-than-necessary temperatures are higher than necessary. 700-800 degrees is absolutely wrong. I dare you to set a soldering iron to 800 degrees and try to solder something. If the traces don't come off the board the component will toast. The only thing that needs to get that hot is a stained glass iron, which are usually around 80 watts, as opposed to soldering irons, which are usually around 40 watts.

By your methodology, it's better to bake something at 5000 degrees instead of 350 degrees, because the oven doesn't matter as much as the food itself.

But ya know, I haven't been doing this for 3+ years or built a dozen+ pedals from scratch or anything...

Also, yeah, a heatsink would make soldering transistors much safer, however, most newbies don't usually own soldering heatsinks...