Alternative for 360pF and 560pF caps. (Matchbox ROG)

[Rockitdog]

Hi there

I'm busy getting all the bits together for a new project. Runoffgrroves Matchbox pedal. The problem is, I live at the tip of Africa, some things are difficult to get down here. I can get hold of everything except the 360pF and 560pF caps.

I can get them off eBay but will wait 3 weeks for shipping, and that's if they even arrive at all.

My question is. What could I substitute them for? I dont really know what I'm talking about (Obviously), I'm sure its a really simple question. But I know with my guitar I can use .022uF - .047uF (Depending on the tone I want) so can I use a slightly different value and get pretty close to the same sound?

And if so, what would be the best values to use?

Posted an image of the schematic below.

Thanks
Richard

 

[ubersam]

You could combine caps to get the value you need, or close to it. Two 180pF caps in parallel will give you 360pF. if you have a 200pF in parallel with the two 180pF, then you'll have 560pF.

check with smallbear/steve daniels http://www.smallbearelec.com/home.html he could probably get the parts to you quicker than ebay

[Rockitdog]

Thanks!!! 
Good idea! Diddnt think of that. 

Easy to do 180pF and 200pF are easy to get hold of.
Shot!

I did order some parts from Small Bear a little while back. He sent off the bits the next day and 3 weeks later arrived in my post box. Really great website and service. Will defiantly order from him again. 

Although unfortunately he doesn't stock either the 360 or the 560. eBay seemed like the only place.

Thanks for the advice. I'll try run them parallel.

[smallbearelec]

I live at the tip of Africa, some things are difficult to get down here. I can get hold of everything except the 360pF and 560pF caps.

360 pf. is available in silver mica, SKU 1301. 560 is available in poly film, SKU 1101, or ceramic, SKU 1311.

NB: Southern Africa is one of the places that my wife and I have on our (Long) list of destinations for a trip. When we do it, I'll be sure to come with an extra suitcase full of chips and such to help pay for our safari.

Regards
SD

[stringsthings]

My question is. What could I substitute them for?

do have any spare 1.2 nF capacitors? .... connect two 1.2nF capacitors in series and you'll have 600pF ... working with capacitors is very much like working with resistors

Good idea! Diddnt think of that. 

....  you don't need to be embarrassed ... no one was born with the knowledge ...

[PRR]

Those cap values are not "magic".

The 10n against the 1Meg volume pot passes "all bass" (down to 20Hz).

The 360pFd shaves about 5 octaves of audio bass, 3 octaves of guitar bass (about 600Hz).

The other four caps are just in-between, roughly 2:1 (octave) ratios.

The 180pFd across 10nFd (10,000pFd) is surely a mistake?

For guitar, it might make more sense to start with 5nFd, go 2.2n 1n 560 360 and 180 on the *last* setting. 10n versus 5n, 20Hz vs 40Hz, isn't much difference for an instrument normally starts at 82Hz. A 180pFd (1,000Hz) setting might (rarely) be useful for a very shrill tone.

360 is an old-scale value. You won't hear a difference with a 330p (new-values) cap, and not a big difference with a 470pFd cap. Likewise the 560 could be 470 or 680 with unimportant change of tonal result.

[Rockitdog]

360 pf. is available in silver mica, SKU 1301. 560 is available in poly film, SKU 1101, or ceramic, SKU 1311.

NB: Southern Africa is one of the places that my wife and I have on our (Long) list of destinations for a trip. When we do it, I'll be sure to come with an extra suitcase full of chips and such to help pay for our safari.

Regards
SD

Oh great! I did a search for 360pF and got nothing. Thanks for reading. Its amazing how tight this community is.

Yeah! If you do come down for a vacation. I will happily grab some stuff from you.
Can also help with the safari.  

Keep me posted.

Oh yeah! I'll be putting in an order for the caps and perhaps some other bits. Thanks SD!

[Rockitdog]

Those cap values are not "magic".

The 10n against the 1Meg volume pot passes "all bass" (down to 20Hz).

The 360pFd shaves about 5 octaves of audio bass, 3 octaves of guitar bass (about 600Hz).

The other four caps are just in-between, roughly 2:1 (octave) ratios.

The 180pFd across 10nFd (10,000pFd) is surely a mistake?

For guitar, it might make more sense to start with 5nFd, go 2.2n 1n 560 360 and 180 on the *last* setting. 10n versus 5n, 20Hz vs 40Hz, isn't much difference for an instrument normally starts at 82Hz. A 180pFd (1,000Hz) setting might (rarely) be useful for a very shrill tone.

360 is an old-scale value. You won't hear a difference with a 330p (new-values) cap, and not a big difference with a 470pFd cap. Likewise the 560 could be 470 or 680 with unimportant change of tonal result.

Wow! Really helpful, thanks so much!

The 180pFd across 10nFd (10,000pFd) is surely a mistake?

I do hope that this isnt a mistake. A lot of people have successfully completed this project since 2004, so I would assume that they would have updated on any errors in the diagram.  But you know what they say about assumptions. Thanks for pointing it out. I will be doing a bit more research before pressing the order button.

Thanks a whole bunch for the help everyone! You guys rule! 

[Rockitdog]

I live at the tip of Africa, some things are difficult to get down here. I can get hold of everything except the 360pF and 560pF caps.

360 pf. is available in silver mica, SKU 1301. 560 is available in poly film, SKU 1101, or ceramic, SKU 1311.

NB: Southern Africa is one of the places that my wife and I have on our (Long) list of destinations for a trip. When we do it, I'll be sure to come with an extra suitcase full of chips and such to help pay for our safari.

Regards
SD

Still cant seem to find the Caps on your site there SD. Need the links to process the order with pay pal. Would you mind posting the links. I'll send you an order.

Thanks again
Richard

[slacker]

The 180pFd across 10nFd (10,000pFd) is surely a mistake?

I do hope that this isnt a mistake.

It will work properly with the 180p in parallel with the 10n. I think what Paul meant is that when capacitors are in parallel you add their values together so a 180p in parallel with 10n (10,000p) gives you 10.18n or 10,180p. The difference is so small it seems like an odd thing to do, especially when most capacitors have a tolerance of at least 5%, meaning your 10n could be anywhere between 9.5n and 10.5n to start with, so you're unlikely to end up with exactly 10.18n.

Looks like the schematics of the actual amp have the 180p cap, so I guess that's why the Runoffgroove boys included it.

[smallbearelec]

Still cant seem to find the Caps on your site
[/quote]

360 pf. silver mica, SKU 1301
http://www.smallbearelec.com/Detail.bok?no=182
Click the dropdown to select the value...

560 is poly film SKU 1101
http://www.smallbearelec.com/Detail.bok?no=162

ceramic SKU 1311
http://www.smallbearelec.com/Detail.bok?no=969

SD

[Rockitdog]

Still cant seem to find the Caps on your site

360 pf. silver mica, SKU 1301
http://www.smallbearelec.com/Detail.bok?no=182
Click the dropdown to select the value...

560 is poly film SKU 1101
http://www.smallbearelec.com/Detail.bok?no=162

ceramic SKU 1311
http://www.smallbearelec.com/Detail.bok?no=969

SD


[/quote]

Wow! That was quick.

Thanks. Order coming your way.

[PRR]

> A lot of people have successfully completed this project

Sure. 10n is 10,000pFd. 10n plus 180pFd is 10,180pFd. As Ian says, "no difference", much less than a semitone lower, and 10n against 1Meg is already way-lower than guitar needs. It works "the same" but costs 15 cents more. A "mistake" that hardly matters.

As for the other values--- as you see, if you are not far from Small Bear, he has scoured the world to find the now-odd values which were used decades ago. Might as well buy from him. But if a Customs Man stands in the way, delaying boxes for weeks and slapping 100% taxes on goods, use what you can get locally. 470 or 680 will replace 560 in any guitar tone-control. Two 270 in parallel is 540 and will surely replace 560 in any audio circuit.

[Rockitdog]

Thanks. That does make a bit more sense now.

I just ordered the caps from Small Bear and some other bits. Rather go with the right components, wait and deal with customs.

Its not too bad down here. For Fedex, DHL or UPS I can expect 45%+. Seems that they like to charge premiums to people that are in a hurry.
But for standard USPS and British Mail it's usually 17% which isn't too bad. But a small hand addressed package usually gets through without charges.
If it fits through the letter slot that is.   

Just have to wait about 3 weeks. Think it sits at the sorting office here for ages. After someone gets round to putting it in the right bin. 

Oh well i cant complain, maybe I should move back to London, get my components pronto and live in a 3X3 concrete box again. Dont think so!
It's way too beautiful down here! 

Thanks to everyone for the help. Much appreciated.