Every circuit oscillates?!

[vid.sicious]

Hey guys!

So I'm still quite new to this and I've only built  a few circuits so far but it feels like I've hit a brick wall... I've made 5 circuits so far and every single one of them does nothing but oscillate like crazy. I spent a couple of weeks breadboarding, socketing different transistors and every time it just ends up oscillating and I don't get what is it wrong that I am doing. I had a Proco Rat clone working once but tried again a couple of days later and oscillation has infected that too. I've built the Colorsound One Knob Fuzz 3 times and each time I believe there was some misbias issue which causes oscillation with the transistors, same with the DAM Meathead. I've spent hours and hours of socketing different value transistors, resistors and etc and nothing seems to help. Kind of losing my motivation in doing this unfortunately. I don't know how you guys can do it all the time haha.
I hope you can help or inspire me to keep on trying...

[Synsound]

If it happening with every build it must be something that you are doing consistently with each. Being that the thing that they all share is the off board wiring, I would recommend verifying that it is double checked. My best guess is that there is a consistent grounding mistake. I'm sure whatever it is will seem silly once you can put your eyes on it.  If you can post a couple detailed pics I'm sure someone could help you track it down.

[vid.sicious]

Yes, it was lack of ground loops I believe. I hooked up 3 circuits that oscillated like mad earlier and now they kind of work. So I've got 3 projects at the moment and I think I might need some help with each one of them.

First, I'll explain how I do it. I simply populate the board and solder in the wires onto the board at the same time. Then I simply connect everything with alligator clips leaving out the 3PDT and running it with a battery.

I've got a Proco Rat which is the only pedal that works properly. The only problem I've got with it is that when using high gain pickups (Les Paul for example) and have the gain knob above 12 o'clock, it starts oscillating. It's not that much of a deal but can get annoying. But as I said, this one's kind of fine, I've got more issues with the other 2 circuits.

Next up is the Colorsound One Knob Fuzz. Now, I'm on my third circuit and I'm starting to get there but it's still giving me a huge headache. For this one, I socketed the transistors and the bias resistors too. At first it was oscillating due to huge misbias as I had BC109C as Q1. I ordered a bunch of new BC108s and BC109s and they all are close in hFe (270-310). First, I tried different bias resistor values but I either got really loud oscillation or extreme gating. I figured, I could try using 100k pots I had lying around instead of the resistors, find good resistance for both transistors and then put appropriate value resistors in there. Well, I've worked out that it works best with having 7.64K (6.8k and 820R in series) for Q1 and 4.4K for Q2 while Q1 (BC109) being 317hFe and Q2 (BC108) being 273hFe. It doesn't oscillate and does sustain for a little longer than it used to with these bias resistors but it still is pretty much impossible to use the effect as it fizzes the guitar signal out after a few seconds of sustain. And it completely ruins palm muting (very bad gating) or makes it impossible to play guitar with volume knob on it rolled down... I should get some lower value pots to maybe do a more precise job at measuring bias settings or simply find different value transistors but I really have no idea what hFe I should be looking at. If you have any suggestions then it'd be great!

Now, the last project is DAM Meathead. I've made the one with switchable caps but excluded them from testing as the circuit does a similar thing to Colorsound One Knob Fuzz - the effect is terribly gated. I socketed the transistors and it seems that my hFe's got messed up all over again. All the ones for Q1 I received are close to 500hFe and for the Q2 are under 300hFe. I tried swapping them over (pinout considered) but it still sounded all out of bias. For this one I didn't socket the bias resistors and therefore cannot do anything about it. I'll be rebuilding this circuit and probably do the same thing as with colorsound one knob - socket the bias resistors and find the correct value with a pot.

Is there anything else you guys could suggest? I'm having a really bad time matching transistors and biasing. I really don't understand how it should be done. It's kind of annoying as I've been stuck with this issue for weeks now. I've just became so desperate now after rebuilding circuits and still having same issues...

[nocentelli]

Are you sure you are hooking all the grounds up correctly to test these veros? That is, the guitar input ground from the cable is connected to the output ground going to the amp (or next pedal), AND the battery negative AND the vero ground AND lug 1 of the volume pot? I am surprised there is oscillation with the Colorsound, pretty much any npn silicon should work ok with no need to bias or trim anything. Some transistors might be a bit more gatey than others, but the treble caps between C and B should remove and high gain squeal. It would piss me off no end to spend the time making a vero only to have it not work, let alone five, so look carefully at what you're doing to hook up the circuits before you assume they are all not functioning correctly. I'd sacrifice a 3PDT and make a bypass looper box (guitar input jack to 3PDT, out to an amp output jack, link the in and out grounds and have three flying leads for the send/return/board ground connected to croc clips, include an LED if you feel fancy) and use this to test the boards. You can then check that you can get a solid clean bypass when you just connect the send and return clips straight to each other, then move to inserting your OKF in the loop.

If this doesn't identify the problem with one of your boards, go simpler: get a small breadboard and hook up a set of parts to replicate the OKF/meathead circuit; they're only like 10 parts so it's hard to go wrong: use your looper box to test and see if you can get the basic circuit working with the transistors you have to hand (BC108 should be fine) without diddling with the bias. This way you won't commit anymore parts to solder without knowing if it's going to work.

[vid.sicious]

Thanks for your advice! I'll definitely try playing around with a breadboard more and I'll probably have to build a test box of sorts maybe something similar to beavis audio test board.

The way my grounds go are:
9v negative -> circuit -> pots -> output sleeve -> input sleeve -> 9v negative

I had weird oscillations before I connected the input ground back to 9v with default layout components. Now I only get that when I push bias resistors to extreme. With stock values I have to strum strings pretty hard to get any effect and it just gates it in less than a second (that's with both meathead and colorsound circuits). I've seen in the comments other people having similar issues but couldn't find any solution. Do you think I should get some lower gain transistors maybe?

EDIT: I just discovered the glory of ordering stuff on Tayda. Just went there, spent about $30 and holy crap how much crap you can get for that price! So yeah, I'll be building the Test Box 2.0 and hookup my circuits this way to avoid any problems I've been facing up till now.