Lyle, so when a customer comes in off their world tour bus and they say "Put some sizzle on the reverb" Don't just parts swap out for the mod tank huh? BIg fan, thanks

Very cool. I always thought there were only 2 kinds of reverb. One kind works and one kind doesn't. I definitely learned something today Lyle thank you for the lesson

I always found it odd that people so much time on tubes and speakers but rarely talk about tanks in terms of the resulting sound. Some models definitely sound better than others. Less tinny. More room-like. Sometimes 3 springs sound worse than 2.

I am surprised that these tanks are not repairable. Is it simply too expensive to fix vs just replace?

Are the

Nifty. I've just shortened them for exactly that reason & was hard pressed to tell a difference, with no mods.

U will never get that sound from a pedal. Listen to a ,,YES. Song. Or. Like old ELO. They have that ending pichy sound

I just bought a short decay MOD to try for the first time and it is still longer and darker with more low frequency content than the two 60's Gibbs tanks I have. Its definitely the best sounding MOD tank I've tried but still not nearly as pleasing to listen to, especially in a Tube Reverb or Surfy Bear unit.

My ‘74 DR has the reverb sizzle issue, especially when I hit bass notes. Looks like it’s time for a new tank, unfortunately. As always, thanks for your help, Lyle.

Heighth? Seriously?

I had the exact same problem in my mid-70s vibrolux reverb. I couldn’t figure out why it was extra splashy and sensitive to just walking around the room compared to all of my other amps with spring reverb. Every other reverb failure had to do with connections or the reverb circuit. After going through everything in the circuit, I finally stumbled onto a forum posting about the spring sag and bit the bullet and replaced the tank. You’re absolutely right about the new tanks. Thanks for highlighting this failure mode!

I think Lyle's comment on "tuning the reverb send circuit and recovery to taste" is spot on. Much easier than finessing with springs. Fender's PR and "ultralinear pro reverb" schematics both show 0.002 mfd parallel the 220k reverb recovery grid leak. That cap shunts the tank output and may be reduced to brighten the tone. The UL pro reverb 12AT7 driver has a 560 pf between grid and plate that might also be tuned -- although I wouldn't without a scope.

Just a trick. U can zip tie to make the springs tighter

I still have an original Hammond-Gibbs tank from the early 60s. Pure surf wetness.

Especially if you amp is a clone, not a vintage gem, it is often very simple to add a on-off-on or rotary switch to change the coupling cap value of the reverb driver stage input line. I normally use good quality 630V styroflex caps which give for example 270pF, 700pF and 1930 pF using on-off-on switch to parallel connect 2 of those caps if wanted. That's all you need to get the amount of low end to the driver stage that sounds best.

I think it's grate buddy

Good to know which tanks are good. Which circuit designs are good to go with them? Any good stand alone reverb units? Thanks!

Lyle, have you tried one of the new “custom” reverb tanks that Surfy Bear is having made?

I just tried an Accutronics 3 spring medium decay tank in my '65 PRRI and it still has way too long of a decay. I am going to try a Mod 8AB1A1B, Short Decay, 3-Spring and hope it comes in around 2 seconds. The original Ruby that came with the amp is supposed to be short decay and it's crazy long.

is it possible to get a set of replacement springs?