ilovefuzz.com

I'm sure most DIY people know about the whole, LM308 chip thing with the Rat. I have a few questions I haven't been able to get answered about it though. First, is the chip the only difference (other than LED/enclosure) between a vintage Rat, and a Rat2? Second, are there different LM308's, and does it matter? I've seen both LM308N's and LM308AN's. If anyone can answer these questions for me I'll be really

After doing a quick google search...

http://www.happybob.com/rstrand/rat/rat_versions.htm

Some say that the new Rat2s sound even worse. Plus Keeley has stopped modding the new ones, saying that the parts may not even be worth it. I can't find gutshot comparisons right now, but there are probably some out there.

Ah, very cool page. Pretty much answer's my question too. I have an older Rat2 with an LM308AN chip and have been trying to figure how to mod it to sound better considering it already has an LM308 type chip. I think I will give up on it now and try and find an older Rat. Might just mod the shit out of it.

I kicked up the value of the I/O caps and the 2 in the filter circuit, then removed the clipping diodes. Much better sounding, more bass (always a good thing) and more volume (also always good).

Over on one of the effects boards, there are a lot of mods written up.
Any one remember the name of that board.

MM

Superfuzz wrote:Ah, very cool page. Pretty much answer's my question too. I have an older Rat2 with an LM308AN chip and have been trying to figure how to mod it to sound better considering it already has an LM308 type chip. I think I will give up on it now and try and find an older Rat. Might just mod the shit out of it.

Modding it yourself is for the real winners.
Vintage rats sound really awesome. I think my friend has one of the cheapo Rat2s, but it did sound pretty good on low settings (if there are any real "low" settings on it).

The main issue people have with the new ones is the clipping in it.. change the clipping diodes (they made be 1N914/1N4148 Diodes or LEDs, swap them to the opposite, you can also add a switch to change between the 2)

The LM308 chip isn't for everyone, you can desolder it, stick a socket in and try several Op-Amps, I liked the NE5334AP best when I tried but some people like the LM741 chip and others like other Op Amps.

Another problem is some newer models have Rev Log pots in them, changing them back the 100k Log of the originals can apparently make them alot more useful.

Swapping all the components back to value of the original shouldn't be too hard to mod, here's some useful mods you can try
http://www.beavisaudio.com/projects/FKR ... rMouse.gif

I saw a guy using one of the small body rats from the early 80's at a show and it was the exact sound I'm looking for. I'll probably shell out for one of those and then just go mod crazy with the one I have. I definitely want to add a knob to starve the voltage and probably do the ruetz mod.