Turbo rat stacked opamps!?

[garfo]

Guys, I have my Turbo Rat done for a while and I was asking myself: "Is there any reason to not stack two opamps together for a build like a Rat?I was thinking on stacking two op07.
What kind of results would I obtain from this?

[pedalman]

why not stack 3 or 4 different ops ? use a switch to change between them. I have a upcoming build doing this

[jimilee]

You'll poke your eye out!

[pedalman]

lol

[garfo]

Ok, maybe I'm not sure on what stacking is, but I though it was just what the word means, stacking.In my mind I would be running the two opamps in simultanious.Is it ok to run two opamps at the same time(parallel) if i solder them together?please,I dont want to sound rude,but it would be more helpful if the people who are replying would actually answer to the question and not drift away with answers that dont answer the question.Hope You understand.
Big thanks

[pedalman]

read this, it may be useful

http://www.barberelectronics.com/parallelopamps.htm

[jkokura]

Ok, maybe I'm not sure on what stacking is, but I though it was just what the word means, stacking.In my mind I would be running the two opamps in simultanious.Is it ok to run two opamps at the same time(parallel) if i solder them together?please,I dont want to sound rude,but it would be more helpful if the people who are replying would actually answer to the question and not drift away with answers that dont answer the question.Hope You understand.
Big thanks

I totally understand.

Stacked op-amps was a fad that came out of a few 'boutique' builds that featured this. As Dave Barber (who is a smart man and a fine builder) mentions, sometimes it's great, sometimes it isn't. I've only tried it twice, and both times it sucked.

I think the magic in the Rat circuit is the LM308. It's what everyone covets, and I doubt it should be messed with. Not only that, but the LM308, which the circuit is designed around, is a bit different than other single op amps.

So long and short - my recommendation is to try op-amp stacking with a TS type circuit, but leave your poor rat be.

Jacob

[culturejam]

I think the magic in the Rat circuit is the LM308.

The "sweet spot" sound definitely had to do with the op amp type. But I've found a couple other chips besides the 308 that sound great in a Rat: LM301 and CA3140. Others can be made to sound good, usually, as long as they are "externally compensated" and the slew rate is adjusted a bit to taste. Single op amps that take a small cap between pins 1 and 8 are externally compensated. You can adjust the slew rate by changing that cap value. The LM308 is great with 33pf, while the current stock OP07 sounds much better with 47p.

It really escapes me why some boutiquer hasn't made a Rat with adjustable slew rate. All it would take is a small ceamic cap and a trimmer cap in parallel.