BOM lists 1 470R, but build pic and board call for 2?
Would stacking 1/8W in series be fine? I don't have anymore 470R and only ordered one, might have a few 1/8W that would add up to around 470R...
Wow, yeah that's a mistake. Should be two 470R, not one. Sorry about that. Yes, you can put a couple in series. Or, put two 1k in parallel.
I'll get that fixed on the doc.
It supposed to be 2 of them.
Those resistors are parts in a couple of high pass (low cut) filters in the clipping stage. The Alpha Dog has slightly different values than the stock Rat.
The way RC filters work is that the values combine to equal the cutoff frequency. So if you dont have a 470 R you can use a different value AND change the Cap value to get the same cutoff frequency. You can use a bunch of different combinations of R and C that will equal the same frequency. This is where filter calculators come in handy.
R4 and C5 = 1539 Hz
R5 and C6 = 60 Hz
Check this out too:
https://www.electrosmash.com/proco-rat
Quote from: madbean on November 13, 2021, 12:22:32 AM
Wow, yeah that's a mistake. Should be two 470R, not one. Sorry about that. Yes, you can put a couple in series. Or, put two 1k in parallel.
I'll get that fixed on the doc.
I have two 1/8W 1k, Just to make sure in parallel it will be fine?
Quote from: Aentons on November 13, 2021, 12:27:51 AM
It supposed to be 2 of them.
Those resistors are parts in a couple of high pass (low cut) filters in the clipping stage. The Alpha Dog has slightly different values than the stock Rat.
The way RC filters work is that the values combine to equal the cutoff frequency. So if you dont have a 470 R you can use a different value AND change the Cap value to get the same cutoff frequency. You can use a bunch of different combinations of R and C that will equal the same frequency. This is where filter calculators come in handy.
R4 and C5 = 1539 Hz
R5 and C6 = 60 Hz
Check this out too:
https://www.electrosmash.com/proco-rat
Trying to keep it stock, but this I guess will have to be close enough if parallel 1/8W works fine.
I've just recently come to grips with parallel resistors. Sorry, I just need to admit this...
I'm still sorting it out gordo, the way caps and resistors work are opposite, but I remember from speakers parallel divides and series adds on resistor, reverse for caps.
I do have a couple 220R 1/4W I could series if need be.
Went with the 1k 1/8W, ended up at 495R. Close enough.
Quote from: madbean on November 13, 2021, 12:22:32 AM
Wow, yeah that's a mistake. Should be two 470R, not one. Sorry about that. Yes, you can put a couple in series. Or, put two 1k in parallel.
I'll get that fixed on the doc.
Two 1k 1/8W in parallel seem to be working perfectly fine.
Also my cleanest build yet and it sounds pretty cool, but I've already noticed it can really get huge and hairy (yes I know the switch is huge, ordered the switch before I ordered the box and rest of the parts, I'll live with it).
Probably should call it the Big Rat or Rat Muff because it sounds exactly like them put together to me. XD