Proco Rat version? and mods?

[rosscocean]

Hi all!

A friend has asked me to look into modifying his Rat. He's a bass player, he uses the pedal for it's mid bite but would like a little more bass. He doesn't have the distortion much above 9 o'clock and the filter around 12, 1 o'clock.

I've been looking at schematics and so far I haven't found a schematic for his version. His pedal has an LED, a opo7cp opamp (I think, it's hard to make out), a 2n5458 and a 3PDT switch. Has anyone got a schematic for this version?

Am I right in thinking that changing the input and output caps for higher values would let more low end in and out?

If anyone knows any mods that might fit the bill it would be really handy!

Many thanks

Ross

[rosscocean]

Hi

After doing some more reading online I've realised the IC is a OP07DP. I've just ordered a few LM308Ns, i'll probably put a socket in to A/B them.

I think I'll also try the The Ruetz Rat mod, either on a switch or 1K pot - http://www.diyguitaramp.com/rat.html

Any other ideas?

Cheers Ross

[ppatchmods]

Ross if he keeps the gain turned down that low, you might want to experiment with leds in the clipping section. you might like the result.

[sewage666]

I've modded my Rat2 for bass. Brian Wampler's book How to Modify Guitar Pedals had a list of which caps to replace for more bass content and it worked great. Check out his book for the values. Also, I put the clippers on a switch for stock to LED, and the LEDs make a big difference.

I'd avoid wasting time with the Ruetz mod, especially if you like the mids. I did it to mine on a switch, and I never use it except at home on guitar when I want a really scooped, doomy tone. Which is almost never.

[rosscocean]

Thanks for the input guys!

[rosscocean]

I've socketed the two 0.022uf caps and tried 0.1, 1 and 10uf in their place but I can't really tell a difference. Maybe it's because I was using a harley benton ga15 for testing? I'll have to plug into my mbox another day.

I've snipped the 47ohm resistor for the ruetz mod, I quite like it. I think for the sake of a resistor and a switch it'd be rude not to put it on there.

Ross