Adding a spring tank to a speaker cab

[johnS]

I didn't realize spring reverb tanks were so cheap, but you can get a new Accutronics for well under 30 clams on the 'bay.

http://search.ebay.com/search/search...&fsop=1&fsoo=1

But what would you do with it once you got it? I'm thinking of wiring one into my speaker cabinet, but I have no idea what this entails. Does anybody have any ideas?

[smopo24]

no idea, but it does look neat! i have a cheap pratice amp that i've kept because of the spring reverb; it masks the inherent crappiness.

[GearJunkie]

mounting it in a cabinet wont do anything. the reverb needs to go through the amp circuit. there's mods that can be done, and i'm not sure, but you might actually be able to run it through an effects loop. I may be wrong, but who knows, give it a shot.

[johnS]

Originally Posted by GearJunkie

mounting it in a cabinet wont do anything. the reverb needs to go through the amp circuit. there's mods that can be done, and i'm not sure, but you might actually be able to run it through an effects loop. I may be wrong, but who knows, give it a shot.

You mean there are wires involved!?!?

I guess what I'm asking is where in the amp circuit would I have to tap the signal (the amp has no effects loop--but I am willing to drill holes and solder in some wires). Also, where would I put the pot that controls the amount of signal that gets routed through the tank, etc.

[Nubus]

I'm sure it is different on different amps but this Fender puts it before the 12AX7s and 6L6s. Interesting that it goes through the spring first and then gets switched on or off at the output.
http://www.ampwares.com/ffg/schem/su...a763_schem.gif

[dagosto]

From that schematic it looks like it needs to come after some initial gain stage (in this case there is one tube going to the reverb). So what you may need to do is set up a parrallel circuit coming off your input with a gain stage and then a summing stage after the preamp section. The level control can be either before or after the unit. My guess is that it is usually on the output right before the summing stage so that the reverb is more uniform at all level. It would be cool to control the level going to the reverb unit as well because then you could get shorter or longer times as well as overdrivr the springs.

edit: sp

[smopo24]

Originally Posted by dagosto

From that schematic it looks like it needs to come after some initial gain stage (in this case there is one tube going to the reverb). So what you may need to do is set up a parrallel circuit coming off your input with a gain stage and then a summing stage after the preamp section. The level control can be either before or after the unit. My guess is that it is usually on the output right before the summing stage so that the reverb is more uniform at all level. It would be cool to control the level going to the reverb unit as well because then you could get shorter or longer times as well as overdrivr the springs.

edit: sp

boy! with all that hassle, no wonder they go so cheap on ebay!

[Nubus]

I opened up a Carvin PA I got last weekend and noticed that the tank in there is made by Accutronics and made in Cary Illinois. I'd bet you can find a lot of old spring reverbs like this one just waiting to be salvaged out of broken amps.

[smopo24]

Originally Posted by Nubus

I opened up a Carvin PA I got last weekend and noticed that the tank in there is made by Accutronics and made in Cary Illinois. I'd bet you can find a lot of old spring reverbs like this one just waiting to be salvaged out of broken amps.

true, it beats paying a few hundered for a tube reverb unit (not to mention another peice of heavy equipment to lug):

http://cgi.ebay.com/Guyatone-FR-3000...QQcmdZViewItem

[Nubus]

Originally Posted by smopo24

true, it beats paying a few hundered for a tube reverb unit (not to mention another peice of heavy equipment to lug):

http://cgi.ebay.com/Guyatone-FR-3000...QQcmdZViewItem

These are cool.

The problem with building spring reverb units your self is it isn't easy to get the noise floor down. Even on something mass-manufactured like say, the one on my Squier PA the noise is there and bugs me to the point of not using it.

Still though I'd love a stand alone, noise and all. I know a guy who just got a weird old pioneer... wonder how that sounds..
edit-brand name