reverb tanks

[withmittens]

can anyone confirm that the power supplied to the reverb tank from RM50 & Rm100 is 6volts? AC?

If I wanted to change the tank I would just need to worry about these specs?

tanks for your help

 

[Jaded Faith]

I see what you did there. Clever.

IIRC, it's a 17VDC supply line out to the tank. I'm not sure I've ever seen an aftermarket replacement that works with it. I do have a spare in stock if you need one. Email if needed.

 

[withmittens]

tanks, Rob. I was mainly interested in making an external reverb box and was shopping around for various pans I could use. I'm not crazy about the Randall unit as it really lacks that classic swell.

I appreciate your help

 

[CrunchBunch]

If I wanted to change the tank I would just need to worry about these specs?

Take a look at the model number on your current reverb tank. In my RM80s the tank is an Accutronics 9AB2C1A USA made unit. Amplified Parts has a handy decoder for the model number - https://www.amplifiedparts.com/tech_corner/spring_reverb_tanks_explained_and_compared but basically, the one Randall used in the RM80 combo is as follows:

9 = Long tank (16.75") with 3 transmission springs
A = 10 Ohm input impedance
B = 2,575 Ohm output impedance
2 = medium decay time (1.75 to 3.0s)
C = input insulated, output grounded
1 = no locking mechanism
A = open side up

Belton and Accutronics (Korea) still make compatible tanks and they are supposed to sound different, so you could try one of those.

 

[mThomasDutch]

Reverb tanks on RM 50 and 100? Got a RM100 head and combo and haven't seen anything like a reverb tank. Would love to add one though. What are we talking about here?

 

[Burlo]

I know this is an old thread but…

You do not need to replace like for like when it comes to reverb tanks but you do need to make sure it’s compatible. The coding in the previous post gives the info you need. The most important characters are the two letters which, in this case, are AB.

I can’t understand why Randall installed this particular unit in their amps because 6-spring tanks are recommended for organs and pedal steel guitar. If the point of MTS is to replicate classic amps it would make more sense to use a 4-spring unit as found in classic Fender amps.

It is entirely possible - and fairly simple - to switch units, which is what I’ve done. The number change is from the 9 to a 4 and the decay on the Fender units is 3 not 2. All other letters/digits remain the same.

The Fender-style unit I’ve gone for is 4AB3C1B. But you could use a 4AB2C1B too.

The only work involves unscrewing the tank carefully and removing the PCB and re-attaching it to the new unit. While I was at it I also replaced the fan with a decent 80mm computer fan (Nanoxia, same as I used on my RM100). Oh, and the G12T-75 is being replaced with a Vintage 30.

Cheers!

 

[raimdal76]

I see what you did there. Clever.

IIRC, it's a 17VDC supply line out to the tank. I'm not sure I've ever seen an aftermarket replacement that works with it. I do have a spare in stock if you need one. Email if needed.

the reverb driver powersupply under the randall chassis it's a 17V DC out? I've read in some other post it was a 9V AC. It's 17 DC? Thanks a lot