General pedal building knowledge/ tips please!

lukestace29

Hello guys, 

First post here, so go easy on me please!

I've found myself becoming more and more interested in electronics and I've been enjoying reading Charles Platt's book on the subject over the past few weeks, whilst looking at random schematics to check my knowledge.

I'm going back to my 17 year old self (only 26 still!) and looking at modding and building my own FX pedals. I previously modded my cry baby wah, and 9 years later, it's still going strong and sounds great! From what I've read, a classic fuzz face is an easy project to get started with; I intend to use a breadboard for this first off.

Just a few questions and tips if possible:

1) I'm looking at buying capacitor and resistor kits, however, I'm struggling to find a broad rage of values that are of use to me. Can anyone recommend a kit or two to get me started please?

2) Why am I finding it difficult to locate a 20 uf capacitor? The ones I have seen are over triple the price of other valued capacitors- This isn't much of an issue, because it's still only a couple of quid, but why the jump in price? I am working off of this website's schematic and parts list to get me started: https://www.electrosmash.com/fuzz-face ;

3) I'd like to get into building point to point pedals or use vero board, just out of preference. Are pcb boards not a nightmare to design? How do you go about designing a pcb board as a budding amateur? Not that I'm looking to design any, but for my understanding as I would find it beneficial!

4) How maths heavy should I expect this to be? I would eventually like to look into building my own tube amps too, so would the maths differ much? I’m assuming it would.

Thanks in advance- Please excuse my naivety. Hopefully I'll look back on this in a year or so and find it amusing  

Luke  

m_c

1) With most cap/resistor kits, you usually find you end up with hundreds of bits you'll never use, and never have the value you need. I think it's best to just buy batches as you need certain values.

2) There are certain values that are just more common. There usually is a some theoretical reason behind it, but 22uF is a far more common value (I have no idea why!). 2uF isn't likely to make that much difference to a circuit. If you really want 20uF it would be easier to run two 10uF in parallel.

3) PCBs aren't that hard to design now. My suggestion would be to learn DipTrace (Eagle is the far more common industrial software, but DipTrace is free up to IIRC 300 component pins). Basic steps are input your electrical diagram into the software, assigning the relevant components, then place the key components where you'd like them on the board, hit the auto-placement/auto-router button, and the software magically attempts to place the remaining components along with the circuit tracks, which you can then tweak manually if needed.
Once you have your design, you can either produce the board the old fashioned way using transfer paper and etching it yourself, or exporting all the layers and getting a PCB professionally produced. Get the right deal, and you can get boards done very cheap in china. Check out Seeedstudio Fusion for an idea on pricing (yes, there are three 'e's in Seeedstudio, it's not a typo!)

4) Generally as long as you know the basic electrical equations, you'll be fine. Using the wrong component on low voltage boards shouldn't be too disastrous, however with high voltage and tube amps you probably want to get any calculations double checked, although for most stuff, there are plenty plans around you shouldn't really need to be calculating much.

JD50

Check out some pedal building websites, tons of info & schematics, component advice etc...

http://tagboardeffects.blogspot.com/

http://freestompboxes.org/

http://ilovefuzz.com/viewforum.php?f=151&sid=75cfd62a7ffcdb619f9acb821bca5737

lukestace29

Thank you m_c, that clears things up for me! I did wonder whether I could use a different value resistor, as I did read that this shouldn't make too much of a difference, but I didn't appear to take it literally when looking at schematics. 

JD50- Fantastic, I'll do some digging.

Cheers both,
Luke

springhead

lukestace29 said:

2) Why am I finding it difficult to locate a 20 uf capacitor? The ones I have seen are over triple the price of other valued capacitors- This isn't much of an issue, because it's still only a couple of quid, but why the jump in price? I am working off of this website's schematic and parts list to get me started: https://www.electrosmash.com/fuzz-face ;

Resistor and capacitor values have standardised into series or ranges of values.  22uF is the nearest standard value.  Will make no audible difference.  Electrolytic cap's have a pretty wide tolerance anyway, +/- 10, 20% or more.  If you really want 20uF then buy a few 22's and measure them. 

545454

Would definitely recommend building a basic test box! 
https://tagboardeffects.blogspot.com/2014/09/test-box-20.html

Danny1969

springhead said:

lukestace29 said:

2) Why am I finding it difficult to locate a 20 uf capacitor? The ones I have seen are over triple the price of other valued capacitors- This isn't much of an issue, because it's still only a couple of quid, but why the jump in price? I am working off of this website's schematic and parts list to get me started: https://www.electrosmash.com/fuzz-face ;

Resistor and capacitor values have standardised into series or ranges of values.  22uF is the nearest standard value.  Will make no audible difference.  Electrolytic cap's have a pretty wide tolerance anyway, +/- 10, 20% or more.  If you really want 20uF then buy a few 22's and measure them. 

Back in the day that circuit came out Electrolytic cap tolerances were as much as 50 % higher than the rated value and could be as much as 20% less so yeah not an issue

Replacing the 20uF cap with a 22uF will result in a slightly better low end response (in terms of voltage gain at low frequencies) on paper but as you say won't make any difference to how it sounds in reality 

545454

I found the tagboardeffects site to be a great resource - loads of nice eay circuits to get started with. For components, I think Bitsbox.co.uk is good onestop shop for most of the common stuff. They've also got kits available based on a few of the tagboardeffects layouts:
https://www.bitsbox.co.uk/index.php?main_page=index&cPath=280_281

545454

I found the tagboardeffects site to be a great resource - loads of nice eay circuits to get started with. For components, I think Bitsbox.co.uk is good onestop shop for most of the common stuff. They've also got kits available based on a few of the tagboardeffects layouts:
https://www.bitsbox.co.uk/index.php?main_page=index&cPath=280_281