I like to incorporate odd circuits from the past ...
"Odd" isn't odd if you know why they did it. It becomes even less odd if you know
why others didn't do it.
... the Ampeg ET-2b I'm working on has both nfb, and verb drive coming off the Lside spkr. Wondering if anyone has an opinion why that *idea* didn't carry forward?
Search google and this site for "foldback reverb".
Pros:
- You don't need a reverb driver circuit or transformer to get low-impedance drive into the reverb tank; you're already getting that for free from the speaker connection.
Cons:
- Possible positive feedback loop through the reverb circuit if conditions are just-right.
- Changing amp volume may change reverb drive level; could take clever compression circuitry to make this automatic.
I shelved a standalone reverb project (using a Hammond AO-41 as it was intended to be used) for later resurrection, which sources the reverb drive signal from the speaker output of a separate amplifier. The standalone reverb will have its own speaker & cabinet, so it can be mated up to "whatever". The problem I initially encountered with a modern (Korean) Accutronics tank was ridiculously-deep/lengthy reverb no matter what I did with the amp. I did procure a more-correct vintage Gibbs tank to use with the project, but still need to burn some brain cells to figure out a variable-attenuation scheme to control the drive into the tank. I'd prefer to keep the option of the Hammond's bridge-attenuator/compressor using lightbulbs (of course, that attenuator/compressor may be causing part of my problems).
Unfortunately, I can find 20 minutes to type on a forum, but rarely get several uninterrupted hours to think something like this through and test a few variations to know what's going on.
Topic: Odd circuits? (Read 1892 times)