driving a spring reverb tank?buffer opamp?

[dfuruta]

I am looking to build a little spring reverb unit to play with, and I've got a question about the driver circuit. I'm thinking of using an Accutronics type 9 (8 ohm input) for the tank. On their website, they have example schematics for the drive circuit. I'm wondering, instead of using transistors to provide enough current to drive the tank, is there a reason I couldn't just use a buffer opamp (LT1010, maybe)?

[The Scum]

Electronically, if it'll fit the system (compatible power rails, bandwidth, etc), there's no reason not to. National used to make some little driver chips that were essentially a totem pole in a DIP.

Cost might be one factor to consider. A discrete totem pole is maybe $.25 of parts. The LT1010 is a $5 chip.

And if you're looking for easy, an Lm386 might be a good compromise - a single part that's got the buffer onboard.

[dfuruta]

Great, thanks! I suspected that, but I'm just getting serious about learning electronics, and wanted to make sure I wasn't overlooking something.

Since I'll just be making, at most, a few boxes, the cost isn't a huge factor. I think, in this case, the lm386 might have too much gain. Shouldn't be too hard to knock something together, anyway.

[Tavvish]

I was scrapping a mixer a little while ago and found a reverb tank inside, I'm definitely going to have some questions in the future when I have enough knowledge to make my own spring reverb unit!

[toothpastefordinner]

While it won't have perfect fidelity, and isn't DIY, a trick you can use (which I have done before) is to set the reverb up on an aux out of a mixer & bring it back in thru a mic preamp.

[dfuruta]

Seems like it also might work for studio use to drive the reverb tank from a headphone amp.

After thinking about it, I'm going to take The Scum's suggestion and use an lm386 to drive the springs. It's as cheap as doing it with discrete parts, and I don't think the relatively high distortion will matter. Once I get something working in a week or two, I'll start a new thread with pictures & a how-to.

My plan is to build the whole thing into a huge (17"x5"x4"), impractical, 9v powered stompbox.

[The Scum]

Seems like it also might work for studio use to drive the reverb tank from a headphone amp.

Not a bad idea at all.

The totem-pole follower also shows up in a number of headphone amps (though it's not usually set up for the current-feedback trick that Accutronics recommended).

[dfuruta]

(though it's not usually set up for the current-feedback trick that Accutronics recommended).

As long as one can eq the send to the reverb driver, that should be ok (?)