Reverbetank Q

[ganzonimx]

Hy folks,

I'v got a 5F6a with a wedged in reverbe circuit like the one described here: http://www.el34world.com/charts/reverbmod.htm but no tank.

Somebody offers me a Type-8 Accutronics 3 spring tank. It has a 10 Ohm input impedance. I can't try it out before buying, would that work in the circuit ore should I get a long tank with the 1750 ohm impedance?

Thanks, Chris.

[sluckey]

10Ω will work fine on the tank input. The tank output needs to be around 2KΩ.

[eleventeen]

For reference:

PART NUMBERING SPECIFICATIONS FOR TYPE 1 & TYPE 4

EXAMPLE: 4EB2C1B

DIGIT #1 - REVERB TYPE
1 for Type 1 or 4 for Type 4

DIGIT #2 - INPUT IMPEDANCE
A = 8 Ohm
B = 150 Ohm
C = 200 Ohm
D = 250 Ohm
E = 600 Ohm
F = 1475 Ohm

DIGIT #3 - OUTPUT IMPEDANCE
A = 500 Ohm
B = 2250 Ohm
C = 10000 Ohm

DIGIT #4 - DECAY TIME
1 = Short (1.2 to 2.0 sec)
2 = Medium (1.75 to 3.0 sec)
3 = Long (2.75 to 4.0 sec)

DIGIT #5 - CONNECTORS
A = Input Grounded / Output Grounded
B = Input Grounded / Output Insulated
C = Input Insulated / Output Grounded
D = Input Insulated / Output Insulated
E = No Outer Channel

DIGIT #6 - LOCKING DEVICES
1 = No Lock

DIGIT #7 - MOUNTING PLANE
A = Horizontal Open Side Up
B = Horizontal Open Side Down
C = Vertical Connectors Up
D = Vertical Connectors Down
E = On End Input Up
F = On End Output Up


My question is: I often get dead Peavey amps, etc; that have (based upon the above code) 600 ohm input impedance reverb tanks.
What's the best strategy to use such in a Fender reverb circuit driven by the usual little SE output tranny? If it's possible.

I assume the 8 ohm output would massively overdrive the 600 ohm tank, by roughly a 100:1 factor.

One thought would be to build a 100:1 voltage divider, say, a a 10 ohm resistor in series with a .22 ohm (which is about 45:1) and assume that a 12AU7 goes in for the reverb driver tube, then drive the tank from across the .22 ohm. Or, an 18 ohm or a 22 ohm in series with the .22 ohm, obviously the voltage divider would have to be massaged to provide a usable reverb-knob-rotation range. I'd be happy to swap in a 12AU7 for the normal 12AT7 driver, then I would perhaps stop having my negative view of 12AU7s as usable items.

Anyone ever successfully tried such a thing? Or have an opinion?

I will likely be trying such a schema on an experimental basis, just wondering if anyone has done it before.

[ganzonimx]

Thank you sluckey! Chris

[shooter]

as long as the thread is here.....what is the proper method to hang a tank?  can it be vertical, upside-down?  The one I just bought from doug has "rubber washers".  Should it be mounted "loose"?  thanks

[sluckey]

as long as the thread is here.....what is the proper method to hang a tank?  can it be vertical, upside-down?  The one I just bought from doug has "rubber washers".  Should it be mounted "loose"?  thanks

The tanks that Doug sells were designed to be mounted open side facing down. Example, Fender Twin Reverb with the tank mounted in the bottom of the combo cab.

You can put screws through the rubber grommets. But just snug the screws down enough to hold the tank. The grommets act as shock absorbers.

[shooter]

Thanks, I have an old fender cab so that's where it'll go, @the bottom!