CRUNCHBOX V2 Question

[giacodav93]

Hi everybody,

I am new here and also new on pedal builds.
I've seen the crunchbox V2 layout and I have a question about this layout, especially about the status LED.

the negative leg goes to the 3PDT switch and the Positive leg is connected to the Veroboard. My question is: do I have to bring it also to power supply? Or does it receive the power from the board?

I am sorry for this stupid question, but I would like to know that.

thanks.
Davide

[Marbles]

Hey there!

No problem, there are no stupid questions, though god knows I try ;)
You're absolutely right, it already gets power from the board. As you can see in the upper right corner, the power goes through the diode, and then up again through the 4K7 resistor to the led.

So you don't have to use a resistor to the led either, it's already on the board.

Happy building!

[giacodav93]

Thankyou thankyou thankyou! :D

[motterpaul]

Just a note. Crunchbox has become my "go-to" build, but I really prefer version 1 with the tone pot - instead of the hidden presence trim pot on the vero.

I just find to be far more useful. It is harder to find (in the blog - because it is from 2011 and doesnt always come up with a search) than V2, but I think you will like it a lot better.

http://tagboardeffects.blogspot.com/2011/04/mi-audio-crunch-box.html

[Muadzin]

The one thing you have to keep in mind with these boards that have an onboard resistor that regulates the amount of power the LED gets, is that they often carry the preferred value of the layouts creator. Which may not be yours. 4K7 seems to be cropping up a lot and I most definitely prefer 1K5. Others may prefer higher or lower values. It would be preferable if these resistors were marked as CLR on all layouts instead, so you know where to put your favorite value. I've ordered quite a few times 4K7 resistors for a build only to discover during soldering that they were the wrong value for my taste.

[motterpaul]

That's really good advice. I use 2.2k current limiting resistors (CLRs) for 3mm LEDs at 9v, but I usually use 5mm LEDs for which I use 580-ohm resistors.  4k7 is pretty high, and I have seen it used in 18v circuits (which crunchbox is not) so I think it would yield a less bright LED.

When I see CLRs in a circuit I always just leave them out and run the LED wires & CLR between the DC jack & the foot switch.

[induction]

LEDs vary widely in efficiency, so it makes more sense to have preferred LED-CLR pairs rather than preferred CLRs in isolation. For a high-efficiency blue LED, you could easily exceed 10k before it's dim enough not to blind you. With  low efficiency red led, anything over 1k might be too dim for some users. LED size doesn't matter so much.

[giacodav93]

Hi guys! thanks for all the tips! will keep them in mind! ;)

[Alex]

I used to write CLR on my layouts but everytime someone was asking what it meant.
After having been asked the same question too many times, I've realized most people were getting confused and I've stopped.