Splashy reverb

[whammy64]

The reverb in my SFDR sounds too splashy, the lightest notes seem to drive the springs way too much and they sound like they're flopping around in there like a king mackerel in a big washtub. The effect is not pleasing to my ears when playing alone but in a band situation, it is more tolerable. Even then, setting the reverb knob to 2 is about all I can stand.
As an experiment, I removed the reverb tank from the cabinet to see if cab vibration was causing the problem but no difference. Are the springs just stretched out from dragging the amp around for 30 years? Time for a new tank?

[Enzo]

Did you look inside the pan? Are all four little corner springs intact? Are all the long springs OK?

And it could be time for a new pan, yes.

[whammy64]

Yep, everything's intact, but very loose as if the springs have lost tension from bouncing around for so long. I think that's the problem, just wondering if others have experienced/corrected the same issue. The amp was about 10 years old and well used when I got it in the late 80s and I have gigged with it pretty steady ever since. Tank was never in a bag as long as I've had the amp, so the prior owner must have pulled the tank out for a reason I can't explain. He just screwed it to the bottom of the cab with the little cardboard insulator underneath. I only discovered it was supposed to be in a bag when I looked in the back of another DR years after buying this one.

[Marc]

Whammy,
Before you replace the tank you can try a couple of things:

1) a differnt tube in the driver position 12AU7 will drop the drive and splash a bit. some folks like it, some don't, but you will certainly be able to go past '2'

2) If you're comfortable with pan surgery you can do a couple of things to tighten up the pan. If the reverb crashes from floor vibrations a bag helps a bit, but so will adjusting the spring crade springs. There are 4 springs that float the spring cradle inside the pan, if you relocate where they are attached so they are tighter it will stiffen up the cradles play and make it less bouncy.

3) the other surgey that can help is a bit more delicate; you can shim the spring transducers and epoxy them so they are tight in the laminate frame attached to the cradle. If you have more than one thumb on each hand this may be dangerous.

4) I heard ~but not tried ~ that a small dab of silicone at the center rivet joint of the springs can add a bit of damping. It might not work worth a crap especially if it kills the springs vibrations entirely.

5) of course when all else fails you can always replace the tank.

Marc

[whammy64]

Those are some interesting solutions, Marc. No. 1 sounds easiest but No. 3 produced the biggest grin. Regarding No. 2, I had wondered about some way of tightening the springs but reckoned the cradle springs had less to do with the problem than the pan springs. No. 4 sounds fairly reversible, unless I get carried away with the goo.

[Paleo Pete]

Try the tube first, I put a weaker tube in mine for the same reason, I like a light reverb anyway, rarely turning it past 3 or so. The weaker tube makes a difference, and I'm thinking about doing some internal surgery too, but to use the reverb section to tweak it for a little gain. It also lowers reverb response, but I don't mind turning the knob a bit higher for the same effect, I use it very light anyway. Haven't decided on that one yet, it's a Super Reverb and sounds great, I'm not sure if I really want to tweak anything...so for now I'm leaving it alone.

I would stay away from the silicone, if it has to be removed I would be afraid of damaging the spring. A dab of hot melt glue should do the same thing, but again I'd be afraid of damaging the spring trying to remove it.

[imo]

I had a couple of things that i employed to help tame my vibrolux reverb. I was having a similar problem. It was suggested on this forum that i raise the cathode resistor on the driver tube. This helped a bit. The biggest change was moving from a 12at7 to a 12au7. I really like it, much more usable and musical to my ears. At this point if its still too splashy i would look into a new tank unless you are a surgeon. Working on those things is really challenging, at least to me, and this is one case where a new tank, especially a 3 spring, will probably give you the results you want.
Ian

[J Martin]

Tanks are cheap. Don't knock yourself out unless you enjoy the experimentation.

[Rob Mercure]

Whammy, I couldn't tell if someone else recommended but you can just shorten/tighten the signal spring by clipping a section out of it and making a new loop where the springs join (I'm assuming you have a 17" two spring pan). I've had great luck with this in the past and if you're considering buying another one then what do you have to lose? I refer this to using any type of glue, etc. inside the pan. If you've got some "needle nose" vice grips these are some of the best tools to grip the spring ends - once you separate the ends keep tension on the spring you're not shortening at the moment so you don't have to fool with reattaching the transducer end. I've replaced almost every part on a reverb pan over the years even changing impedances as desired. And if you wind up replacing your unit keep the pan as it makes a great chassis for many types of projects from whole amps to stomp boxes.

Rob

[TD_Madden]

Tanks ARE pretty cheap, but I'v found that the Accutronics tanks being made today just don't sound quite "right"...not sure why.

[whammy64]

New tank did the trick but I kept the old one since I'm a pack rat anyway so I may experiment in the future with it. Thanks all for the input.