Rat - power supply polarity question

[Ed Boyd]

I have a Rat I bought back in 91 or so. It was a good pedal but it quit about 15 years ago. The op amp chip I guess went bad. It is being repaired. I had always powered it with a battery. Does any one know will the standard power supply connector run it or do I need a polarity reversal adapter for it?

Thanks.

[lefty73]

You should be fine with any power supply that outputs 9VDC. This includes any Boss, Visual Sound, Godlyke, Voodoo Lab, Dunlop, etc. etc. etc.

[GigsbyBoyUK]

I thought Rats needed reverse polarity?

[wrathfuldeity]

Rat is tip positive...reverse of most dano, boss and etc. I use a universal wallwart and you can get some variation by lowering or raising the vdc from 3vdc is kind of loose and grainy at low distortion/gain and tighter when pushed at 12vdc. I'm planning out a mod....lots of mods look to be pretty easy.

[Ed Boyd]

Someone told make that improper polarity can break the op amp chip I don't want blow it up.

I need to figure out a way to rig a 6db boost without buying more stuff. I already have too much stuff.

[s] After I throw the Rat on my board I may see if the OD side of the VS Route 66 can be set to a clean boost. I don't know if it will di it or not. SOMEWHERE I think I have an old EH LPB-2 but I board is out of space and I use the Route 66 for the compressor side. [/s] Forget that. I know what I need to do. I just need to figure out how many db to boost the thing.

[zombiwoof]

The Rats with the 1/8" AC adapter jack use a tip-positive supply. To use it with a Boss-type neg-center supply, just buy a short adapter cable for $3-4 that allows you to use it with the Boss-type adapter. I have these for all of my older American pedals that have tip-positive power jacks on them, a couple of companies sell them. No mods need to be done to the pedals when you use these adapter cables.

Al

[Ed Boyd]

Thanks. I have one of those that came with my power supply stuff. I didn't know if I needed to use the red reversed polarity adapter or the 'normal' ones.

[lefty73]

Originally Posted by wrathfuldeity

Rat is tip positive...reverse of most dano, boss and etc.

I stand corrected! I might derail this thread a bit, but why would a pedal maker want to wander from the de facto standard and use tip positive?

[JoeNeri]

All Rats have always required and still do a positive-center adapter. One-Spot has a 3-inch adapter that works with all negative-center (Boss, etc.) power supplies. Used one for a long time with no issues or hassles.

[zombiwoof]

Originally Posted by lefty73

I stand corrected! I might derail this thread a bit, but why would a pedal maker want to wander from the de facto standard and use tip positive?

Actually, almost all American-made pedals in the early days used tip-positive 1/8" power supply jacks (MXR, DOD, RAT, Cry Baby, etc.). The Japanese (like Boss) pedals came out with the negative-center barrel plug jacks on most of their pedals. After some years passed, and people started using more pedals hooked up at once, the American pedal manufacturers gave in and changed to the Boss-type negative center adapter jacks, in an effort to standardize power supply connections when using multiple pedals. So they didn't deviate from the standard, as there were two different "standards" when pedals started getting adapter jacks (American and Japanese/import).

Al