Thanks to
@Megii and a @marauder I'm now in business to build a Rat clone, so if I may be a late entry I'd like to get in on this challenge business.
From Marauder I got an old LM308N op amp, and then from Megii I got a Fuzz Dog Rodent kit. LM308s are hard to get now, hence my buying Marauders, but actually Megii's kit has one, so if this goes well I'll be looking at building something else LM308-based. Maybe a Rat 2—I was interested by ICBM's comments that he prefers the Rat 2, so perhaps I'll compare them. I'd have to do that on veroboard though, because I'm not aware of anyone who makes a Rat 2 PCB.
If successful, this will be my first completed build. Years ago I bought an OCD kit off a fellow forumite (back in the MusicRadar days, I think) and I got most of the way through the (vero) circuit board before running into trouble with my soldering iron and getting a tech to finish it off. Hoping to manage the whole thing this time.
Question: I've got a 4-pot kit for incorporating the Ruetz mod into the pedal. I wouldn't have chosen this, and I'm thinking about just leaving it out (assuming I can find something not-unsightly to block the fourth hole in the enclosure). Does anyone know if there's anywhere on the Ruetz pot's travel that replicates a stock Rat? I've seen forum posts claiming that with a 1k pot, there's no way to get exactly the classic Rat sound. I only want the pedal for the Rat tone. If I can get the stock Rat tone AND some others, I might as well include the pot, but if I can't I'll leave it alone.
Here's a picture of my highly organised workspace, where I am currently re-learning how to read resistor codes while I wait for my Amazon Prime soldering mat to arrive. Pretty excited about the black case and neon orange knobs (don't know why my camera makes them yellow) —should be a cool looking pedal as long as you don't open up the case!
My YouTube channel,
Half Speed Solos: classic guitar solos demonstrated at half speed with scrolling tab and no waffle.
Comments
The first component goes on... great success!
Then I did all the resistors except R4, which relates to the Ruetz mod and I haven't decided about it yet. I also added the IC socket since it had resistors either side and I was worried it might be fiddly.
... and the back, which... looks like a circuit board.
Alright! So far this is highly rewarding and very moreish. Time for a lunch break (and to research how to to identify capacitors and diodes!). This is also much easier than making cables or replacing pickups, the soldering jobs I've attempted in the past.
If you got the vertical mount pots that go straight into the board, mount them to the chassis before soldering them into the board otherwise they might be a bit wonky.
Got some de-wonking to do later
Good luck, mine sounds excellent and may even be knocking the 90s LM308 turbo rat off my board
Later...
OK, diode out. I think there's just enough length left on the legs but I can't get the holes in the board clear enough of solder to push them back through. Do I need to get some flux to put on my soldering braid? So far it seems very adept at soaking up the solder from the tinned tip of the iron but much less enthusiastic about taking it off the board.
Here's what the back of those joints look like now (sorry, couldn't get my phone camera to focus any better than this). Is it likely to be fried?
https://www.amazon.co.uk/Quality-Innovative-Silicone-Nozzle-Engineer/dp/B002MJMXD4/ref=mp_s_a_1_2?ie=UTF8&qid=1538836392&sr=8-2&pi=AC_SX236_SY340_QL65&keywords=engineer+solder+sucker&dpPl=1&dpID=41by8CVXglL&ref=plSrch
If you want to try and MacGyver it today heat the pads until the solder melts then push a toothpick in the hole which should open it wide enough for you to get your diode in.
Out of interest, @roberty, how come you're not using D2 or D3? Did you just build a Turbo Rat?
EDIT: I DID IT!!!!!! D3 is just about in situ now.
I have four original rats of different varieties and a deucetone with LM308 mod
I'll be gutted if I end up preferring the new op amp :-)
Pots on board, mounted in case (cheers @roberty, I can see this would've been a pain if I hadn't done it your way!)
See?
Testing time! Regret not doing this in the enclosure. Wiring this was a faff.
And... it's dead. I then realise that I had initially forgot to put the IC in the socket, and I hoped that would do it. Nope. It passes a signal, but the signal is about the same as going straight into the amp, possibly a little quieter and crappier sounding. Pots don't seem to have any effect (I tested it with gain and volume on max). I've (attempted to) wire the mini toggle for LED clipping and regular diode clipping; sound is the same in both toggle positions.
So, off to google pedal troubleshooting I guess!
Here's the full size image if anyone wants to play spot-the-noobie-error:
Check the orientation of the op amp and polarised parts
Also make sure the knobs are turned up!
Sorry if you've already tried these
Here's mine for reference:
I said maybe.....