Substitutions for a couple of Rat components?

[DangerDigits]

I’m starting to build a screamer/rat 2 in 1 with boards from Pedalpcb and the lil switcharoonie board too. While gathering components I realized I was short on a couple of things.

R3 calls for a 560R closest I have would be 510 or 680

C6 calls for 30p I’ve got a couple 33p floating around

When I was sourcing parts I couldn’t find any LM308 but I do have LM386l, TL061, and TL072 laying around.

I figure swapping a 30p and a 33p isn’t a crazy jump and should be ok right? I’ve read that these ICs are pretty comparable and I’m going to socket it anyway so that should be fine. Would those resistor values be ok to sub out?

I’m just trying to avoid making any orders right now because shipping and impatience.

 

[Betty Wont]

510r and 33pf are close enough for rock and roll. OP07 is the modern replacement for LM308 in the rat.

 

[vigilante398]

The general rule I like to follow is if a component is within 10% of the intended value then it's fine. So 33p instead of 30p is fine, and I would go 510R in place of 560R.

As for the op-amp it will need to be a single op-amp, and TL061 should work. TL072 is a dual op-amp, LM386 is the wrong pinout.

 

[jesuscrisp]

As the others have said, 33p is fine, 510R is fine, but I'd say 680R also sounds close enough, that gain filter isn't so picky.

For the op amp try to source either an OP07 or LM301. You can also try different ones like NE5534, TL071 (or TL071 which you have), LM/uA741 etc. but for those I'd leave the 33p cap out.

 

[DangerDigits]

I do have an OP07 in a bass brutalist I could cannibalize for the time being. I need to put together a parts list for odds and ends on some upcoming builds I could always replace it later.

Thanks for the advice everyone! I’ll start on the tube screamer side of this and work my way over to the rat

 

[Stonezero]

I have a few LM308’s Cans if you wanted to sort some trade?

 

[Mike52]

The last I looked, Jameco had LM308Ns. But you should definitely take him up on the offer of cans. (Cans just look super cool inside a Rat.)