Next project on the table: A Proco Rat.

[gtech]

Ok, I know I should finish what I started before I begin something new. But I like to do many things at the same time.

I'm waiting for a few parts to finish my Tube Reamer, and a Mini-Booster that  I am fitting inside an Effect Loop Box.

Yesterday, I listened to a few clips of the Rat. It sounded so good that I decided to build one... I ordered Jack Orman's article on the Rat to make sure I would do it right...    Very nice article btw.

I like a smooth creamy distortion, a woman tone, a little sustain. Something bluesy...

Any suggestions or comments about the Proco Rat? Any good or bad experiences?

Btw, it all started with the tone control that I added to the Mini-Booster. It's a Rat style tone-control, as used by  Doug Hammond in his Shaka IV and BBQ.

I check how it was used in the Rat, and then BAM!... I wanted to build one.

[RDV]

I built a "Rodent" recently for my son. I like it a lot, it's definitely not a hard distortion to my ears, but more a soft fuzz aproaching a Neil Young sort of thing.

RDV

[Vincent Volta]

I built a Rat clone on my protoboard and really liked the tone, very warm dist. with a lot of attack and definition. BUT the output level was just a bit above the direct, something I hate on fuzz boxes. I used a different opamp, a TL072 since the LM308 costs about 10 times the price of a normal chip on my country. I tried to add a second stage on the second OA to make things louder- no luck yet.
I dismantled and built it again with a whole new set of components to see if this was the problem but got same results.
The filter knob just made things worse since it took even more of the output level. And the action is too "extreme" for my ears, tell me, are all of these things normal on a Rat? Is it SUPPOSED to be so low on the output and is the filter so extreme? Anything to do with the weird opamp( the 308)? Thanx a lot!

[RDV]

It seems to have a lot to do with the weird opamp, which is why I sprung for one from Smallbear. If you do that volume recovery stage right it will work though:


RDV

[ocelot]

I have a Keely modded RAT which because of the high gain I reckon the output /distorion and filter pots are anything but usable. I need to be able to lower the gain. I changed the output pot but it didn't do much.

[gtech]

Well, in the article from AMZ about the Big Muff and the Rat, Jack gives a few (many...) mods to do to the original circuit to correct the problems you guys are talking about.

I'll try to find where I saw a pcb layout for the Rat and will tell you  more about how it sounds with the mods.

I also don't want a Fizzy Fuzzy Fuzz, but a warmer distortion for the times where I want more than just overdrive.

I also want some kind of a woman tone.

The sound should be closer to this than an original Rat.

http://www.muzique.com/gnat.htm

Maybe a bit smoother.

Haaaa!... Santana.  Ha....! The Guest Who.  

But I'm also taking note of your suggestions because I would like to play with this circuit a bit until I find a sound that I like.

Gilles.

[RDV]

The Rodent is very smooth IMO, very overdrivish, not a lot of fizz.

RDV

[gtech]

I just found the pcb layout I remembered seeing.

...It's the Rodent on GGG site.    What a coincidence

With this schematic

http://www.generalguitargadgets.com/diagrams/rodentsc.gif

Gilles C

Added:

More info about modding the Rat.

http://www.diyguitaramp.com/rat.html

http://www.vintageamps.com/PlexiPalaceUBBcgi/ultimatebb.cgi?ubb=get_topic;f=6;t=001502

[RDV]

I just found the pcb layout I remembered seeing.

...It's the Rodent on GGG site.    What a coincidence

With this schematic

http://www.generalguitargadgets.com/diagrams/rodentsc.gif

Gilles C

I actually expected something more hard rock/metallish, but it wasn't at all. I dug the the Millenium+ in it so much that I bought a bunch of cheap X-wing switches, some 2N5485 JFets and I've been adding it to quite a few pedals.

RDV