Stripboard build - first question

[Paul_C]

So, because I was very taken with @BetterOfShred's Noise Swash, I thought I'd have a go at making something on a stripboard.

I'm (reasonably) aware of my limitations (I can follow instructions, but I don't have a great depth of knowledge of electronics) so I thought I'd start with something simple to get started.

I've chosen to start with one of the simplest layouts I could find on Guitar FX Layouts, a Devi Ever OK (I could go for a couple of the other layouts, but the question is still the same).

Now, so far I've ordered a load of parts from both ebay and Bitsbox, and the first bits arrived this morning.

What struck me while sorting things out, measuring and labeling a starter kit of resistors and generally making sure I got what I ordered, is that the layout lists two types of transistors - 2x MPSA18 and 1x 2N2907.

Those of you who know way more than me will no doubt already have said to yourselves:

NPN and PNP on one board?
What will Paul make of that? (he's not sure it's a good idea)
Does he have any idea what the difference is ? (sort of, but not completely, if I'm honest)

So, I'm currently thinking I ought to find an NPN equivalent of the 2N2907 (Google suggests a 2N2222 should do), but I'm open to suggestions from all of you who know way better than me.

TIA

[BetterOffShred]

Yeah man, I would drop some money on a variety of stuff from Tayda to get started. Build a Hyperion or Sodameiser that actually sound "good". Tayda has good strip board too. Buy a couple of 1590B boxes and a couple stomps and you're off to the races.

Mouser, small bear, Love my switches to name a few are all great as well. I buy from all four, with the bulk of my caps and resistors and transistors coming from Tayda.

A few paint by numbers builds (well you won't stop there) and you'll start to see common themes. Devi builds are not really the best for circuit theory as most of them feature at least one "hmmm really?" Thing that still works though. That being said I think I've built just about everything she ever produced

I'd be happy to elaborate on a beginning order though it would probably be an excel spreadsheet

[Paul_C]

Tayda being in the US makes things too much of a hassle for me (as I'm in the UK ).

I started with the OK (over the LP or Electric Brown) because I liked the ridiculousness of it - though by the looks of things I could build the Hyperion 2 from what I've ordered.

If I do, the question is still the same - should I swap the 2N2907A (PNP) for a 2N2222A (NPN) ?

[crochambeau]

NPN and PNP on one board?

There are many circuits that utilize both PNP and NPN, and while I didn't see any schematics that were definitively labeled as the OK I do see a lot of conjoined NPN/PNP pairs in Devi's work. I'd say build it as instructed, use sockets on the transistors, and substitute parts only if needed.

Have fun!

[DRodriguez]

Most of the time you can not just swap out a pnp for an npn and vice versa. There are plenty of circuits that use both transistors. From standards like harmonic percolators, to wild noise machines.

That said, you,re building fuzz. so try wrong things out anyways and see if you like how it sounds.

[BetterOffShred]

Tayda being in the US makes things too much of a hassle for me (as I'm in the UK ).

I started with the OK (over the LP or Electric Brown) because I liked the ridiculousness of it - though by the looks of things I could build the Hyperion 2 from what I've ordered.

If I do, the question is still the same - should I swap the 2N2907A (PNP) for a 2N2222A (NPN) ?

My response was meant to be more of a "get more parts, swapping won't always (usually) work"

Tayda comes from Thailand.. they must not import to the UK easily

There's UK parts suppliers for sure. Bunch of guys on DIYSB's are from UK I'm sure they could be of more help there.

[Paul_C]

I see

I can see myself acquiring lots of parts before long (for one thing, some of the sellers on eBay sell 100 of some things for the price of 10 elsewhere, so it would be foolish to only have 10 ) but I thought starting slow might have been a good idea, even though it doesn't usually take long before a simple four pedal board becomes 30 or buying one weird looking Yamaha bass finished with me owning 16 (all gone now) so I ought to have known from the start it would get crazy pretty quickly.

[BetterOffShred]

It's not that expensive dude. Another option is having a USA bro get you a Tayda order and ship it to UK.

I have 12"x9" tackle boxes full of components and I probably have 15 full, plus many larger ones for switches and pots and other electromechanical devices.

Yes it does spiral, and it's a gateway to hoarding

[Paul_C]

I fix guitars for a living, so I already have boxes of guitar bits all over the place - at least resistors etc. take up very little space

My first idea was to learn electronics first, but this way (hopefully) adds to my pedal pile while I learn

[Jero]

If something doesn't seem wrong with a DE circuit, it probably is :wink:

She used the npn/pnp combo really often, and in various ways. The stutter from the LP is made by adding a pnp (2907) in a crude feedback loop from the input to the second mpsa18...if you lifted it (or just its Emitter connection on the input) you'd end up with the Electric Brown. Lots of DE circuits were just minor tweaks off of a couple base ideas...Goes to show you how much difference one or two parts + some haphazard experimentation can have.

[adamajah]

I'm building my 3rd and 4th pcb builds right now and am def curious about doing a stripboard/tagboard one soon. I'll be watching this thread.

[Paul_C]

A follow up question - I realised just now that what I thought was a 2N2907 is actually a 2N2907A - how much difference does that make ?

If I went for the Hyperion 2 instead of the other three I would appear to be ok as the A version is listed for it.

[BetterOffShred]

If you go to Mouser and look at 2n2907 there is like 20 part numbers. A lot of them are just manufacturers call outs.

Edit: the 2907A can handle slightly higher voltage.. but for our 9v purposes we don't care.

That being said some stuff like BC548/9 are sorted by gain characteristics with A being the lowest and C being the highest. (BC549C etc.) I think 2N2907 is only offered in the one range if memory serves

Edit 2.0: Hyperion is sick. I removed the ground starve because I thought it sounded like ass, otherwise it's meaty AF. I definitely recommend trying different transistors in it when you get it working.. also she made a combo box with a dark boost after the Hyperion.. that's what I did with mine. It sounds pretty choice

[Bartimaeus]

Not sure if things are different for folks in the UK, but I'm in the US and some of my Tayda orders were only $1 for shipping. The wait is a little long (two weeks) but it always arrives safely. I'm curious if other countries don't have that option?

One bit of advice I wish I'd realized earlier is that if you buy strips of sockets (https://www.taydaelectronics.com/30-pin ... -type.html) and cut them up, you can make a socket for any component you want. Perfect for swapping transistors on a fuzz until you get it sounding just right.

[Jero]

Not sure if things are different for folks in the UK, but I'm in the US and some of my Tayda orders were only $1 for shipping. The wait is a little long (two weeks) but it always arrives safely. I'm curious if other countries don't have that option?

One bit of advice I wish I'd realized earlier is that if you buy strips of sockets (https://www.taydaelectronics.com/30-pin ... -type.html) and cut them up, you can make a socket for any component you want. Perfect for swapping transistors on a fuzz until you get it sounding just right.

I've built boards with literally every part socketed before