mystery transistors & capacitors

trad3mark · Post by **trad3mark** » 06 Apr 2009, 10:58

hey
i was recently clearing out my room and came across a box of parts from aaaaaaaages ago, when i tried before to make a small amp. Anyway there's a couple of mystery transistors here that i'd love to know what they're used for, the code on them is ZTX500.

i also have a bunch of massive capacitors, like the size of a 2c coin lol. i think they're ceramic disc of some sort. Their code is 104S5. I've also about 400 loose resistors, but the chances of me going through them is mighty slim.

ALSO (and finally) hit the jackpot when i came across a small bag containing not 1, not 2, but 20 2N3904.

so, any info on the ZTX500's or the mental capacitors would be great. I've googled them both, but pedal wise, what could i use them for?

Fuzzed · Post by **Fuzzed** » 06 Apr 2009, 14:48

The capacitors are probably .1uf, about the voltage i don't now.

P1NkY · Post by **P1NkY** » 06 Apr 2009, 21:40

Hi trad3mark.
The ZTX500 is a PNP small signal transistor similar to the 2N3906. So now you have PNP and NPN trannies for your experimenting pleasure!

Here is the ZTX500 datasheet. http://www.datasheetcatalog.org/datashe ... ztx500.pdf
Like Fuzzed said, the caps are .1uF, but I also have no idea about the tolerance/voltage designation.

trad3mark · Post by **trad3mark** » 06 Apr 2009, 22:08

P1NkY wrote:Hi trad3mark.
The ZTX500 is a PNP small signal transistor similar to the 2N3906. So now you have PNP and NPN trannies for your experimenting pleasure!
Here is the ZTX500 datasheet. http://www.datasheetcatalog.org/datashe ... ztx500.pdf
Like Fuzzed said, the caps are .1uF, but I also have no idea about the tolerance/voltage designation.

thanks P1NKY

so that ZTX500 could be interesting in, for example, a Fuzz circuit?

sorry, i'm a bit of a noob when it comes to electronics, i'm building my first pedal at the mo, and the extent of my experience is a bit of work trying to make an amp (which is why i can read schems etc) and wiring countless guitars.

edit:
but i am learning

P1NkY · Post by **P1NkY** » 07 Apr 2009, 01:02

trad3mark wrote:so that ZTX500 could be interesting in, for example, a Fuzz circuit?

Sure thing. For a quick example, check out the second schematic on this page: http://www.geocities.com/teleman28056/f ... atics.html
Just substitute the 2N3906s for your ZTX500s. I cant vouch for the quality of it's sound, however, because:
1- I'm not very "into" fuzzes. My real interests range from light to heavily overdriven sounds or Metal-type distortions.

So I wouldn't be able to speak from experience.

Any Fuzz fans reading this wanna help a brother out?

2- From what I've read, the better sounding - vintage type fuzzes use germanium transistors (ZTX500 is silicon, which is said to produce a harsher sound). It'll still work, though, and it's still a great learning experience. It's always good when you can say "I built it myself!".

trad3mark wrote:sorry, i'm a bit of a noob when it comes to electronics, i'm building my first pedal at the mo, and the extent of my experience is a bit of work trying to make an amp (which is why i can read schems etc) and wiring countless guitars.

Ahh, don't sweat it, bro! We were all noobs once, and we're ALL noobs at SOMETHING! You're in luck, though. I'm new in this forum, but in the short time I've been here, I've noticed it's a great spot on the web! There's TONS of stuff to learn, and lots of good people willing to help ya out, so stick around!

trad3mark wrote:edit:
but i am learning

So am I, buddy, so am I

trad3mark · Post by **trad3mark** » 07 Apr 2009, 14:32

cool. it'll be worth a go. the next pedal i plan on doing uses a 2N3904. So it might be worth swapping that for the ZTX500 to see how that turns out.... <3 sillicon fuzz! so messy like!

P1NkY · Post by **P1NkY** » 07 Apr 2009, 22:12

trad3mark wrote:cool. it'll be worth a go. the next pedal i plan on doing uses a 2N3904. So it might be worth swapping that for the ZTX500 to see how that turns out.... <3 sillicon fuzz! so messy like!

I hope you meant 2N3906!

trad3mark · Post by **trad3mark** » 08 Apr 2009, 11:01

no the schem says 2N3904, BC549C etc.

I don't really understand transistor numbers etc...

Fuzzer · Post by **Fuzzer** » 08 Apr 2009, 14:36

The thing is, you can't just replace a transistor like the 2N3904 with your ZTX500. Because the 3904 is NPN, and the ZTX is PNP, you would have to make more changes to make it work.

As Pinky noted, the second schematic in the link he posted is a possible ground for you to put the ZTX without problem (because 3906 are NPN).

P1NkY · Post by **P1NkY** » 08 Apr 2009, 19:05

Fuzzer wrote:The thing is, you can't just replace a transistor like the 2N3904 with your ZTX500. Because the 3904 is NPN, and the ZTX is PNP, you would have to make more changes to make it work.

As Pinky noted, the second schematic in the link he posted is a possible ground for you to put the ZTX without problem (because 3906 are NPN).

Thanks Fuzzer! Good explanation

except for the typo at the end, 3906 are PNP!

2N3904 = NPN
2N3906 = PNP
ZTX500 = PNP

Therefore, ZTX500 is compatible with 2N3906
and ZTX500 is NOT compatible with 2N3904

But wait.......... You already HAVE 2N3904!!!

trad3mark wrote:ALSO (and finally) hit the jackpot when i came across a small bag containing not 1, not 2, but 20 2N3904.

trad3mark wrote:the next pedal i plan on doing uses a 2N3904. So it might be worth swapping that for the ZTX500 to see how that turns out....

If you have 20 pcs. of 2N3904, you already have the trans you need! So why try and swap it out for a ZTX500?
(besides the fact that it won't work as they're incompatible!)............... Oh, no.... I've gone crosseyed!!!

I guess I'm not the only one who needs a vacation, huh guys?

trad3mark wrote:I don't really understand transistor numbers etc...

Nobody really understands them, except maybe the manufacturers! (or über geeks!)
Sometimes, as on your ZTX500, ZTX is the abbreviation for Zetex; the "brand" name, but that's not always the case for other transistors.
Sometimes they have a date code, or a logo or whatever... I don't bother trying to decipher them much.
I usually think of the numbers/letters as that particular transistor's name, just as a person can be named Ralph or John.
Takes some of the stress out, saves more neurons for troubleshooting!

trad3mark · Post by **trad3mark** » 08 Apr 2009, 19:43

ok.... i kinda get it..... So then if the schem had a PNP, could i replace it with any other PNP?

i also came across a few 2N2222's and BC107's, but they're both NPN.

P1NkY · Post by **P1NkY** » 09 Apr 2009, 00:40

trad3mark wrote:ok.... i kinda get it..... So then if the schem had a PNP, could i replace it with any other PNP?

For the most part? Yep.
There's lots more transistor variables to consider, like gain, voltage ratings, types (small-signal, power, switching, etc) and so on....
But experimentation is key!
I'm a believer in that you just may "accidentally" discover a unique sounding circuit by using parts intended for another purpose, or just combining them in new ways!
Sometimes there will be differences in the sound of two identical parts, due to manufacturing tolerances, etc.
Get a breadboard if you don't own one and plug away. Try proven circuits first, and when you've got 'em working, change one part at a time and note any differences.
Most importantly, have fun!

Fuzzer · Post by **Fuzzer** » 09 Apr 2009, 01:48

P1NkY wrote:Thanks Fuzzer! Good explanation except for the typo at the end, 3906 are PNP!

Yes, I'm sorry

. thanks for pointing it out.