Recent content by MattG

I didn't vote, because I like 'em both. Slight preference for Slurpee... But I can only print black waterslide decals, and I expect those would show better on the lighter Lilac. So call it a draw for me. Although it's not too different from you standard Tango Green (which is one of my...

Gutshot please :)

So I continued to research on this topic of ideal bias resistors for this electronic switching scheme, and I actually landed on 100k as pretty-good-for-the-generic-case value. Details in this post, but the gist is: Noise: 1M bias resistor has about 18uV or -95dBV of noise (not hifi, but...

I haven't studied ceramic cap datasheets exhaustively, but from what I've gathered, it's generally pretty rare for the manufacturer to actually publish the voltage de-rating specs. That's definitely an option, but not one I really considered for my SMD designs. The main reason is cost: I'm...

Ahh, so good ol' fc = 1/(2piRC). So really anything with a cutoff frequency below 20 Hz ought to be good, right? I'm actually using 1uF coupling caps when I do this with through-hole components, because 1uF film is readily available (and not terribly expensive). But I use 4.7uF in the SMD...

Does that imply something around 100k for 1uF caps? How did you derive these resistor values? Also: what is the effect of making the resistor values too high (as I have previously done)? I've been using the bypass with the "wrong" 1M resistors for quite a while now, and I don't perceive any...

For capacitors, you can go up in voltage rating. The 25v on the PPCB silkscreen can be interpreted as the minimum value. The only issues with going higher are cost and physical size. 1.5x to 2x is a common rule of thumb safety margin for capacitor voltage ratings. You can often get away with...

I mean, you have to give credit to the original creator, but yeah… I’ve always felt the same!

@Animal64 - I think you are exactly right! I asked about this on diystompboxes, and the man himself replied. Looks like I should be using smaller bias resistors.

It's precisely 4.7 seconds, right? I think it's a valid concern, but at least for me, it's always considerably more than five seconds between power-on and when I start playing. But now that you mention it, I should try playing as soon as I power-on just to see.

My first thought was that I was just copying RG Keen directly, see Bypassing and Switching with the CD4053 CMOS Analog MUX. But now that I'm reviewing that page, I see he has two examples, one with 1M bias resistors and another with 510k bias resistors. But that is my short answer: I just...

Thank you! But I wouldn't say I went to any great length - I just did a web search for "old fashioned clip art" and found an image I liked for use on this pedal. I definitely did not design that from scratch! I've checked Mouser and DigiKey several times for the 2n5172, and they've never had...

I use 225F for the drying stage. Just putting a number to it since the “lowest” setting is probably not consistent across ovens.

For the reverse polarity protection, I'm using IRFU5305PBF. The specific mosfet doesn't matter too much, as long as it's p-channel. I picked the IRFU5305 because it had very low RDSon (resistance between drain and source when the transistor is "on"): 65 milliohms, and at the time, was one of...

Thank you! IMO, reducing offboard wiring makes for a cleaner build. The polarity protection and electrical bypass are not proprietary; I credit RG Keen with their design. See Advanced Power Switching and Polarity Protection for Effects, and Bypassing and Switching with the CD4053 CMOS Analog...