Reverb Tanks

[boots]

I need some advice on reverb tanks. I have to admit I've never built an amp with reverb, and I don't know a lot about it, other than it sounds cool.

I have a Vibrolux Reverb on my bench right now and the owner wants maintenance done on it. It is missing the reverb tank and he wants a new one.

Which tank to buy? I assume the long ones sound better than short. Do I want 2 springs or 3? What reverb tank is going to bring this Vibrolux back to its full glory?

Thanks guys!

[sluckey]

https://www.tubesandmore.com/products/P-RK-4AB3C1B

[Leo_Gnardo]

In general long's better than short HOWEVER in some cases I've found the short tank is the choice. Long 3-spring tanks (sometimes referred to as 6-spring because there's 2 springs hooked end to end to make each long one) take way too long to settle down for my taste & the reverb schmears over the "new" notes way too much. Like playing in an indoor arena, the echo just keeps building until it's annoying. For the tech minded, the RT60 is excessive. Also, good luck finding short 2-spring tanks. Short 3-spring tanks don't have the problem I mentioned the long ones do. Although listed in the catalogs somehow 2-spring shorties always out of stock. Lately I've been getting MOD labeled tanks from Antique/CE or Ruby labeled tanks from Magic Parts - they look to be identical. Belton is your other choice, I'm sure they're OK but I don't go out of my way to source them.

Another factor is tanks sound different one to the next even though presumably identical. I used to buy a dozen at a time in the days when Accutronics was the going brand, a couple sounded prime, most were OK, maybe one out of the bunch was a real dog.

DO cover the tank's open side with some corrugated cardboard or a slice of thin plywood as Fender did, and DO cover the tank with a "sock" of Tolex or similar material & fix each end down to the amp's floor with a screw or two. I find the rubbery grommets supplied with tanks these days don't do much good. Just pry 'em out and put 'em in your grommet collection, they may turn out useful for something else someday.

[Phil_S]

A bit of history learned when researching this for a reverb build I never did.

Gibbs was bought by Accutronics. Those brands were THE brands to get. They are now unobtainium except used on eBay where the seller typically will not be able to give you the model number, so that's not where to buy. Accutronics was acquired by Belton, a Korean company. On-line reading suggests they are OK, but not the same. Belton uses the same part numbering system as Gibbs/Accutronics, so at least they took that much.

The MOD tanks Leo mentions are also made off shore, probably somewhere else in the Pacific rim. At the time I was doing the research, my general unscientific impression, based only on what was written by others, was that the MOD tank is a better sounding tank. Whether it is, I don't really know. IIRC, MOD has a different numbering system, but they publish an equivalency table to the old Gibbs numbers we've all come to know and dislike for it's cryptic nature (though it is not a secret; you just need the chart.)

+1 on using the tolex bag and screwing it to the cab. Same for covering the open side with cardboard or something.

[Gaz]

I actually like the ambiance of the long 3 spring, but if I were repairing an old Fender, I would use 2 spring like in sluckey's link just to keep it legit. I've had good experience with MOD tanks from AES.

[Stevem]

First make sure the reverb circuit itself works !
Take a 470k resistor and clip lead it inbetween the tips of both RCA Jacks and then play and turn up the reverb , you should hear a good volume boost if all is well.

[The Ballzz]

First, I've had VERY good results with several MOD tanks, seemingly better than the OEM. For example, on my JTM30, I rarely used the reverb, as it sounded only kinda so-so. After the original crapped out, I put in an MOD and now use it a lot!

Second, the informational links on the page linked by sluckey are a pretty good read!

Just Sayin'
Gene

[boots]

Thanks everyone! The article in sluckey's link was especially good. I had been poking around on the AES site, but did not notice that article until I clicked on the link.

[Stevem]

Even on new tanks no less old ones doing this mod will make them sound better.
Take a sliver of a tooth pick and wedge the coil to its layered iron core passing thru each one and the set it in place with dribbling super glue into and around the gap.
For better tank life take a dab of silicone sealer and or hot glue a put some on the connection points of each wire to the rca jack, and if the new tank does not have slip on connectors at each coil, then do that same thing to help strain relef the wires.
And yes, the fold over wire hold downs near each Jack seem to do nothing in regards to stopping the wires from snapping off with age!

Please note that if any of you have high value vintage tanks that have failed by having the spring hook snap off at either end of the springs, do not toss out those tanks, I can fix them for Ya!

[Leo_Gnardo]

Even on new tanks no less old ones doing this mod will make them sound better.
Take a sliver of a tooth pick and wedge the coil to its layered iron core passing thru each one and the set it in place with dribbling super glue into and around the gap.
For better tank life take a dab of silicone sealer and or hot glue a put some on the connection points of each wire to the rca jack, and if the new tank does not have slip on connectors at each coil, then do that same thing to help strain relef the wires.
And yes, the fold over wire hold downs near each Jack seem to do nothing in regards to stopping the wires from snapping off with age!

True 'nuff ^^^ esp. in Accutronics tanks. I take squares of sticky-back weatherstrip foam and make bumpers to cushion the aluminum spring carrier at each end, also between carrier back and box. Put 'em on the steel box not the aluminum carrier. Seems to help, gotta use appropriate thickness foam. Funny I've not (yet) seen the MOD or RUBY tanks fail from lead-in wires pulling loose or coils mysteriously going open circuit.

[Stevem]

Yes, good point Leo, the less slap / flex distance the springs have the less strain there is on the hook ends!