Transistor selection

[tegendemuur]

I need to place an order because I fried some transistors that came with a kit, so I thought it best to buy a bunch of different types that are commonly used in effect pedals, so I can start play around myself eventually. I came across this page. A good idea to buy, let's say, a bunch of the top 10? Or have things shifted since this list was compiled? Not looking for high priced "stuff of legend". Just the highly useful, for someone who has no idea yet what most of these even do.

1 J201
2 2N5088
3 BC549C
4 2N3904
5 BS170
6 2N5089
7 MPSA18
8 2N3906
9 BC548
10 MPF4393
11 2N7000
12 2N5457
13 BC550C
14 2SC1815
15 2N4125
16 2N1308
17 2N2222
18 BC549
19 PF5102
20 2N5485
21 OC71
22 2N5087
23 2N5133
24 2N5458
25 BC109C



Source: https://diyeffectspedals.com/common-diy-guitar-effects-pedal-components/
Info on individual transistors for pedal use: https://www.gerlttechnologies.com/index.php/more-info/components/168-transistors

 

[DeadAirMD]

J201
2N5088
2N3904
BS170
MPSA18
2N3906
2N7000
2N5457
2N2222

These will take you almost everywhere. I'm sure other people here will have a better list and/or better explanation of why you need what you need. Also, J201 smd is majorly cost effective and waaay easier to get ahold of.

 

[spi]

@DeadAirMD's list is a lot more focused on what you'll actually encounter.

And there's many viable substitutes (for example, if you need BC549 or a BC109, a 2n5088 will work). If you have the most common 10 or so, then usually one of them will sub in if you encounter something different.

Another example: bs170 and 2n7000 are often interchangeable in guitar circuits (just reverse the orientation), so you don't need both.

Also, be very careful ordering j201 and 2n5457 (anything that is a is a jfet). Lots of them are fakes, and many that work are out of spec (so they work as jfets but perhaps not in the circuit they were intended for). Safer to buy these as SMDs from a reputable dealer.

 

[tegendemuur]

@spi Funny that you should mention 2n5457, because I need two of these. Ah well, good lessons are being learned about scarcity, alternatives, et cetera from here on.

Edit: Found a small pedal DIY shop somewhat nearby, please don't be scam.

10 x​	2N5457	€12.50​
5 x​	2N5458	€7.50​
10 x​	BS170	€4.00​
10 x​	2N3904	€1.50​
10 x​	MPSA18	€10.00​
10 x​	2N3906	€1.50​
10 x​	2N7000	€4.00​
10 x​	2N2222A	€2.50​
5 x​	J201 Siliconix	€9.75​
10 x​	2N5089	€8.00​
10 x​	2N5087	€4.50​

 

[Feral Feline]

What I do sometimes is do a global search of my computer's HD for something I'm considering purchasing.
Say you've got a build that asks for PF5102, I'll search my HD for it and all the build docs that include that will come up — then I have a rough idea of how many I need to buy after checking the relevant build docs.
At the same time, I'll check the build docs for alternatives.
Ex: A 2N5088 and 2N5089 are pretty much interchangeable, but the '89 has a wee bit more gain and lower noise than the '88 — which brings me to datasheets.

During that global search, I can also check to see if I have the relevant Datasheet for that transistor.
You can never have too many datasheets for the same part as they may differ slightly between old, new, different manufacturers — they may have different pinouts or other attributes.
So it's good to get the Intersil datasheet if what you ordered is delivered and says Intersil on it; Fairchild/ON-Semi; STMicro; Toshiba; Motorola; Infineon; Philips; etc...

Example 2N5306 pinouts:
Fairchild is EBC, Central is ECB

...

10 x​	2N5457	JFET SDG & DSG so check pinout! N-Channel	€12.50​
5 x​	2N5458	JFET SDG & DSG N-Channel — check pinout!	€7.50​
10 x​	BS170	MOSFET SGD N-Channel	€4.00​
10 x​	2N3904	BJT NPN CBE/EBC check pinout	€1.50​
10 x​	MPSA18	BJT NPN (unlike most other MPSA, this is NOT a Darlington!)	€10.00​
10 x​	2N3906	BJT PNP CBE/EBC	€1.50​
10 x​	2N7000	MOSFET SGD N-Channel	€4.00​
10 x​	2N2222A	NPN EBC (check pinout; PN2222A & 2N2222A vs P2N2222A)	€2.50​
5 x​	J201 Siliconix	JFET DSG N-channel	€9.75​
10 x​	2N5089	BJT NPN CBE/EBC pinout!	€8.00​
10 x​	2N5087	BJT PNP CBE/EBC pinout!	€4.50​

In my transistor inventory doc, I also have listed the gain ranges and a "notes" area where I can include additional info such as alternatives and also list builds specific to that part.

Ex:

NAME	TYPE	PINOUT	GAIN RANGE	Additional Notes	Quantity In Stock
2N4401	NPN	EBC	40-500 hFE	TO-92 case, Motorola DOD280, Glass Hole, IVP, Astrotone, DuoPhase, Muff, Krampus 808, GK-Rails, Retrograde and MANY others…	40

How 'bout that. I didn't have the Datasheet for my 2N4401s before posting this missive. Now I have it.
2N4401 also available from NXP, CDIL, SeCoS and other manufacturers...

 

[tegendemuur]

@Feral Feline Thanks man! Sounds like a good plan for me to start with right away. For now it's just the codes I am seeing in the kits I am building, but if the kits are going to be stepping stones towards my own creations, some effort is going to be needed!

 

[HamishR]

I don't know if they still have any but I've had good luck finding 2N5457s and other similar JFETs at Mouser. I just used a 2N5457 today from my Mouser stash. I know they don't have any J201s, only the surface mount equivalents.

The BS170 MOSFET is indeed very similar to the 2N7000 but is noticeably beefier sounding, ie more powerful.