Strange Rat

[oldrocker]

I had built a Rat a while back and used a 741 since I didn't have a 308 at the time.  Sounded OK.  I replaced the 741 with the 308 now and it sounds a little better.  My problem is I can't put any effects before or after the Rat.  This includes boosters and compressors.  If I do the signal just goes nuts.  Anyone else have this problem?  The reason I ask is I needed more volume out of it so I thought I would just put something in the signal chain to increase the loudness.  The Rat by itself sounds pretty good.

[George Giblet]

Can't say I've seen one of those.  It could be tat someone modded it.

Does your rat have a cap across pins 1 and 8 of the I?.  If not find the rat schematic and add the cap.

What could be happening is the IC is oscillating.   When the 741 was put in the cap may have been removed.

[petemoore]

  Rats usually have lots of boost.
  If you want more volume try a boost after it?

[oldrocker]

The Rat is one I did myself. Yes after I replaced the 741 and put in the 308 I put the cap btwn pins 1 & 8.  I can't put a boost after the Rat because it starts making weird noises.  Even though it sounds good I'm thinking I have something wrong.  When I get the chance I'm going to have go over the circuit and see where I messed up I guess.  I had a feeling it should be a loud pedal and I haven't read that anyone else complained about the problems I'm having with it.

[Bernardduur]

Never had any problems with it, and I build a lot......

which schem / layout did you use?

[oldrocker]

I used the one in Tonepad.  I'm going to take a look at the board to see if I screwed up on a cap or resistor value.  Once I get the MXR Noise Gate working (which I can't get working and is driving me nuts) I'll go back to it and see if I did something wrong there.  How many of these did you build?  I have a friend who wants me to build him oneand he has friends who would like one too.  I want to make sure mine works good first before I offer to make one for him though.