Reverb Tank Question: Accutronics vs. Belton vs. Mod

[oc disorder]

I had a 135w Fender Twin recently with the tank missing but luckily an empty bag remained.
Thought I'd take a punt and try the mod tank equivalent.
I pulled the rubber stoppers off and taped the standard issue piece of cardboard across the bottom.
After fitting, with master vol full and reverb vol about 5 it would develop acoustic feedback about C# above middle C !
I tried all manner of tightening/loosening the bag and rearranging the leads to no avail.
So I pulled the tank and re-arranged the 4 suspension springs to make it sloppier (ie not so taut)
although the reverb springs were nearly touching the bottom cardboard there was still clearance.
Then I wrapped the tank in thin foam and with the help of a partner in crime forced the whole lot
back in the bag (yes the stitching held up) .
Bingo no feedback!
The tone seemed to me a little more mid-rangey than I remembered from the Accutronics but had no
original tank to A/B compare it.
I suspect the two Celestions fitted may have also contributed to the midrange which exacerbated
the feedback problem.
However there was more than enough reverb to drown in and I doubt the owner would ever have the
reverb vol above 3.

[Raybob]

I started building amps with Belton, then Accutronics, then switched to MOD. MOD tanks seemed to sound more like the old Accutronics then the new ones. I've probably gone through about 40 MOD tanks, but just today, got a report from a tech in NY about a Deluxe I built, telling me the MOD tank failed. Here's what he said:
"Hi I have one of your deluxe amps here and frankly for the most part it’s a work of art except? Well the reverb tank literally fell apart, both springs severed the solder points on the ends." "im telling you all 4 points went, the springs were loose"

I built that amp April 2011. I'm suspecting that amp was dropped hard for all 4 ends to break loose, but no idea what really happened. One bad out of 40 isn't good, but will there be another?

[Chuck H]

For all four end to go, I'm of like mind. It was probably dropped or swung into a door casing or some such. The old Accutronics pans would take this abuse most of the time. That doesn't mean that it should be expected from another product. It's a pretty delicate mechanism.

[Bruce / Mission Amps]

...but just today, got a report from a tech in NY about a Deluxe I built, telling me the MOD tank failed. Here's what he said:
"Hi I have one of your deluxe amps here and frankly for the most part it’s a work of art except? Well the reverb tank literally fell apart, both springs severed the solder points on the ends." "im telling you all 4 points went, the springs were loose"

I built that amp April 2011. I'm suspecting that amp was dropped hard for all 4 ends to break loose, but no idea what really happened. One bad out of 40 isn't good, but will there be another?

Does he want it repaired under your warranty? Sounds more like carelessness and falls into that nebulous realm of abuse.

[Prairie Dawg]

Damaged in shipping or handling methinks. That seems to be where most of the reverb problems I fix seem to originate with. Chalk it up to good will and send out another. I worked on a Rivera recently, an old one, and although the amp was 13 years old Rivera sent the guy a new tank gratis. That's customer service.