New at this! Gunna need help!

[FartInhaler]

I've been wanting a Randall RG 100 forever but I've never found one for a good price and I came across this preamp pedal diagram and figured what the heck I want to give it a try. I've soldered some guitar pots and Pickups but that's about it but I feel like I can do this the problem is I'm not familiar with any of these components. I was hoping somebody could just look at this diagram and then just give me a shopping list a grocery list and I'll go buy everything I need! I would really appreciate some help on this if it's not too much of a bother thanks everyone.

[GibsonGM]

Hi bud - pic is too small to read. Do you have a link to the site the diagram came from?  I'd use a "known good" layout rather than work hard at something we don't know is verified working or not!!    Once you've got that together, we'd be glad to help you! Welcome to the forum.

[antonis]

IMHO, 4V Zener (3%) is overkill, from cost point of view..
(3V9 or 4V3 could be just fine..)

[Mark Hammer]

I hate veroboard, mostly because the layouts are generally hard to follow and take up way too much space.  And unless one is absolutely scrupulous about things, all of that flipping over and back, and the sheer number of cuts to be made, is likely to result in error/s.

My recommendation is to get hold of some perfboard or pad-per-hole board, and build it on that.  You can build it a stage at a time, and confirm that it functions as it should.  For example, build everythng from the input jack up to the gain pot, straddled by the 22k/.005uf network, and then check to see that the output at the wiper is both higher than input and varies with the setting of the Gain pot.  THEN, you can add the next section, with the pair of FETs, and confirm its functioning on the negative side of that 1uf cap.  And so on.  MUCH much better than building something on vero that's hard to follow and requires a full build before firing up and testing.

[FartInhaler]

Hey thanks everyone for the fast responses! You guys rock!

@gibsonGM sorry about the small picture, I got it from this here website https://dirtboxlayouts.blogspot.com/2019/07/pre-amp-from-hell-randall-rg100es-pre.html?m=1
And there's a video on YouTube of a guy who's playing a pedal made from this diagram, sounded killer!
https://youtu.be/bs7oS3TaF5A

@antonis hey that diagram definitely looks alot clearer and cleaner, I'm looking at it tryna figure out what it all means haha i have alot to learn!

@mark hammer you're probably right, my only thing is when I look at that diagram I posted I can kinda see how I'd go about building it, when I look at the more professional looking diagrams my half retarded brain can't hardly tell what I'm lookin at.

[antonis]

@antonis hey that diagram definitely looks alot clearer and cleaner, I'm looking at it tryna figure out what it all means haha i have alot to learn!

I'm sure there are many willing guys here..

P.S.
Welcome, also..

[idy]

And you can sometimes mix and match the advice: go ahead and try the strip board layout you chose, but do one stage at a time. Get the first transistor working, then the second, etc. So you are never looking at a big mess that doesn't work, you are looking at like seven components that don't work...

[ElectricDruid]

And you can sometimes mix and match the advice: go ahead and try the strip board layout you chose, but do one stage at a time. Get the first transistor working, then the second, etc. So you are never looking at a big mess that doesn't work, you are looking at like seven components that don't work...

+1 absolutely this.

I rarely build a whole veroboard circuit and then test it, and when I do, I regret it. It's far better to build one bit, check it, get it working, then build the next bit. I usually *plan* the whole thing on squared paper first, so that I know I've got space and so I don't paint myself into a corner later on, but I don't *build* it like that - always section by section wherever possible.

[Phend]

Another way is to put it on a breadboard and get it working.
Breadboard first or you will be solder suckin.
Then transfer it to a solder able bread board like this.
They come in different sizes, best have the plus minus rows.
(Some have the rows and columns connected together internally)
IMHO, space is cheap. However those 1590A builds are some impressive.!



(First on my grocery list is Harpoon ipa)

[Mark Hammer]

And you can sometimes mix and match the advice: go ahead and try the strip board layout you chose, but do one stage at a time. Get the first transistor working, then the second, etc. So you are never looking at a big mess that doesn't work, you are looking at like seven components that don't work...

+1 absolutely this.

I rarely build a whole veroboard circuit and then test it, and when I do, I regret it. It's far better to build one bit, check it, get it working, then build the next bit. I usually *plan* the whole thing on squared paper first, so that I know I've got space and so I don't paint myself into a corner later on, but I don't *build* it like that - always section by section wherever possible.

Thing is, if it doesn't work right off the bat, your troubleshooting strategy is going to be checking the functioning of each stage anyway.  So why not do the troubleshooting as you build, by assembling one section at a time?

[antonis]

go ahead and try the strip board layout you chose, but do one stage at a time. Get the first transistor working, then the second, etc.

Well said idy but don't you think the above presupposes some degree of circuit understanding (in distinct building blocks) as well as their depiction on board..??

[GibsonGM]

I build everything on perf.  It's not always easy or fun, but it does 'train' you to follow good habits, check subcircuits, and pay attention to what you're doing!

[FartInhaler]

Thanks to everyone for all of the advice! This seems like a very great and knowledgeable community!
My problem is I don't know exactly what components to get! I went to a website called teyda electronics and have been typing in the numbers and letters on the little doodads but nothing is coming up!  Like 2n5484 and stuff just says nothing found?

[antonis]

Like 2n5484 and stuff just says nothing found?

Then search for J113, BF245A, 2N3819, 2N4416 or PN4416..

Should a particular item can't be found, search for equivalent..

e.g. " 2n5484 equivalent" goes to https://www.google.com/search?client=avast-a-2&q=2n5484+equivalent&oq=2N54&aqs=avast.0.69i59j69i57j0l6.5075j0j15&ie=UTF-8

[FartInhaler]

Like 2n5484 and stuff just says nothing found?

Then search for J113, BF245A, 2N3819, 2N4416 or PN4416..

Should a particular item can't be found, search for equivalent..

e.g. " 2n5484 equivalent" goes to https://www.google.com/search?client=avast-a-2&q=2n5484+equivalent&oq=2N54&aqs=avast.0.69i59j69i57j0l6.5075j0j15&ie=UTF-8

That's great advice!! Thanks! I should be able to get all my components now 😁

[antonis]

Just beware of the spacing (distance between legs) of film caps and voltage rating of electolytic ones..

[amptramp]

If you choose substitute transistors, check that the pinout is the same as you have on the diagram or you may have a problem that makes no sense until you understand what is happening.

[duck_arse]

if I might make a suggestion - while you are at tayda, find one or some of their printed circuit boards. forget about your randall from hell, start with a sillicon fuzz face or a rangemaster or a tube screamer - somethings simple. make some mistakes, order some wrong parts, build some stuff, then start on the project from hell.

is that worth $0.02?

[idy]

Good advice to start smaller.
And a warning that your project uses JFETs, which are not in production in through-hole devices anymore. You would have to:
1) go to a place that caters to hobbyists and has a good reputation
2) buy SMD parts and itty bitty adapters.

[Mark Hammer]

There are still plenty of thru-hole FETs available.  You just might have to hunt a little more, pay a little more, and consider a functional substitute for whatever the schematic says.