RAT Pedal low output

[MstrB]

I have a RAT pedal that seems to have low output, it is distorting but giving no volume boost. Wish it wasnt working because that I could fix. Everything tests okay? I will put a socket in and swap out ICs. Has anyone else had this happen?

[J M Fahey]

*If* you already have high output humbuckers and/or an active guitar , the original pickup level may be the same or even higher than the Rat's output, so you would gain nothing.
It's not an IC problem. What diodes does it use to clip?

[Mark Hammer]

There should be nothing wrong with the IC if you get clipping since the IC has to function properly to push the diodes into clipping. And since the op-amp needs to have a suitable signal fed to it to do that job, then clearly the problem exists after the clipping diodes in the circuit.

There is normally a JFET between the Filter/Tone control and the output control, as well as a 1uf electrolytic cap between the JFET and volume pot. If it is an older pedal, then the electrolytic could have dried out and need replacing. Alternatively, the JFET could be fried, though this is less likely than the cap scenario.

Alternatively, there could be an issue with the volume pot itself, OR with the stompswitch, in that either might have a connection which is high-impedance enough to attenuate the signal, but not enough to totally block it..

[J M Fahey]

I think that MisterB does not really have a broken pedal.
Look at that schematic: there *is* signal and the IC is amplifying, as Mark said, and there's distortion, which amounts to a 700 mV Pk signal, tops. It gets somewhat attenuated after that by a passive filter and buffered either by a Fet or a Bipolar transistor with no voltage gain, so I wouldn't count on a more than 500mV Pk signal . If he has a hot guitar, a heavy hand or both, he can already have that signal level, unassisted, so the "distorting but no volume boost" is about the only option left.
By the way, if your amplifier is already clipping, you may get more distortion, grind or sustain, but not higher volume.

[Mark Hammer]

Actually, I'd disagree. I've built myself a couple of Rat clones, and believe me, they are plenty loud when functioning properly.

[Dirk_Hendrik]

If the TS's pedal has an x-wing switch (it probably does) start off measuring the resistance when it should be in continuity. Good chances you'll read a far larger than 0 ohm value so replacing the switch will cure the problem.

[Mark Hammer]

Stompswitches, be they X-wing, or blue 3PDT can often be rehabilitated by taking them apart, cleaning out the grease, and reassembling them.

The problem is that the free-floating rocker contacts inside are held in place during assembly with a small dab of grease. If you solder leads to them quickly and properly, the heat dissipates in a manner that doesn't interfere with the grease, instead of being conducted to the grease. If too much heat is applied for too long, the grease liquifies and flows along the contacts, effectively turning them into semi-insulated contacts.

As noted, when this happens, you can pry the tabs off the switch a bit, carefully take out the rocker contacts, clean them off of any grease, and place them back in. Done it many times, and it cured the problem.