MOD® Reverb Tanks

DC resistance is unfortunately not much to go off since it can vary so much from the impedance. If you have model numbers I can look to see if there is any information on these amps and their reverbs.

It might not harm the amp but it will not work correctly.

We don't have anything compatible with that one. It's a pretty uncommon tank code. You might want to reach out to the manufacturer of the amp to see if they could supply one for one.

I think you might like the sound of Mod tanks given your description. Check out this video comparing 4AB3C1B reverb tanks from different manufacturers to get an idea of the tonal differences: https://youtu.be/c1IIiv89Qoc They're using the 4AB3C1B which is the stock tank in a Princeton Reverb like an Accutronics in your amp. I think you might also be interested in the 3 spring version which is a 9AB3C1B. This video compares the three spring with the two spring: https://youtu.be/Wg8hBVHEAqo

There isn't a lot of info on this amp available. It might be worth contacting the manufacturer. I know Peavey used the 8EB2C1B a lot but that is only a guess and a confirmed answer from them would be preferable.

A search online shows the 8DB2C1D as a compatible tank for that amp. I would still recommend checking the old tank for any markings to be sure since a schematic is not readily available to confirm this.

The schematic found online lists an input impedance of 1475 and an output impedance of 2250 so the FB tanks will be the compatible ones. It also looks like the input needs to be insulated and the output is grounded. The 8FB3C1B looks like it should be compatible as long as the schematic is accurate. If it has room for a longer tank the 4FB3D1B might work but the output jack might need to be modified to be grounded on this tank. This would require jumpering two solder pads on the output jack inside of the tank.

The AC15C1 uses an 8EB2C1B.

There is not much out there on this one, not even a proper schematic. Are there any marking on the original tank?

The schematic lists the 4AB3C1B as the tank used in the T50C.

Is there a letter after the 2 on your code ie 9AB2_1B?

There isn't much to go off on this one. I would guess that it is not going to be an AB type since these are more common to transformer driven circuits. BB, DB, EB, or FB would be more likely. Solid state circuits often use a higher impedance input. Looking at a schematic on the GX amps, the input probably needs to be insulated and the output sleeve is likely grounded.

Thanks MichaelT, I'll carry on with my research if i get it working i'll come back and update. Have fun during the holidays.

I don't have any way to verify this but there is a guy on Youtube with one of these. He put a full sized 9AB3C1B in his but mentioned the original was a short tank. The short version of this would be the 8AB3C1B.

The service manual says the stock tank is an 8EB2C1B. I always recommend double checking these against the one in your amp in case there have been any changes. The 8EB2C1B is a short 3-spring medium-decay tank. For the same specs but with a long decay you could use the 8EB3C1B. I'm not sure if there is room in that amp for a full sized tank but if there is, the 4EB3C1B would be a good choice. This is a 16.75" 2-spring long-decay tank that can work in place of the 8EB2C1B. Be sure to check the dimensions inside your amp though!

Reverb tanks need specific circuitry to function in an amplifier. Without modding the amp or using external equipment, a reverb tank will not function with that amp.

There is a schematic online that lists the following models: L5 Model 308A, L7 Model 309A, L9 Model 312A, and the L11 Model 313A. You might want to check yours against this schematic to make sure it is the same L11. This schematic lists the tank's input impedance as 8 ohms and the output as 2250 ohms. The 4AB3C1B might be a compatible tank. We have no way to verify it but if you have a Fender amp or a friend with one, many of them use the 4AB3C1B so you might be able to test it out.

Unless the amp already has the drive and recovery circuits needed, a spring reverb tank is not compatible without heavy modifications.

The 4FB2D1B is compatible with the Type C tanks that were commonly used in the tube driven Ampeg reverb circuits. The version we carry has the long decay and is the 4FB3D1B.

The schematic from 2009 for the Supersonic 60 shows a 4AB3C1B tank.

The stock tank is a 4EB2C1B. If you would like a compatible tank with a longer decay time, the 4EB3C1B would work. The 9EB2C1B is the three spring version of the stock tank. We also have the three spring version with the long decay time which is the 9EB3C1B. Check out the videos linked below for some sound comparisons of the variations listed here. Decay length comparison: https://www.youtube.com/watch?v=ZNHZEQRDOOI 2 vs 3 spring: https://www.youtube.com/watch?v=Wg8hBVHEAqo

A 9AB3C1B will likely work in its place but I would suggest testing before fully installing to be sure.

You should be good to install it flush to the bottom of the cabinet. There shouldn't be any noticeable difference in the sound or functionality with it tilted back.

We don't have a tank that is compatible without potential modifications to the grounding scheme. You might have better luck finding an 8AB3C1B. That tank only differs in that the decay length and won't require any modifications for use.

That one does not have the outside chassis like most tanks so I'm not sure if anyone will be selling them as a retail product. You might be able to use a tank with similar impedances to replace it. Some people modify that amp for RCA jacks to use common tanks. Another way would be to modify the tank by removing it from the chassis and rewiring it so it can mount internally.

The schematic for that amp shows part number 064063 which is the 4AB3C1B.

The stock tank in a Twin Reverb is the 4AB3C1B. A three spring version of that tank with a medium decay would be a 9AB2C1B.

It's not listed in the schematic so I don't have any way to confirm this but a few posts online point to the 4DB3C1D.

The schematic for that amp does not list any impedances or tank code. If you can locate a schematic for the older unit that you know the tank code for, you could compare the circuits. Amp manufacturers often use the same reverb circuits in different amps.

It probably won't harm the amp but it is very unlikely to produce any usable effect. We would recommend using a tank with the correct impedances.

The 8EB2C1B is the tank used in the Blues Junior.

The YGL-3 mkIII service manual lists a 4FB2B1C. The YSR-1 schematic lists a Gibbs type C which is equivalent to a 4FB2A1C. We're unsure of any reverb changes that might have occurred in the manufacturing of these two amplifiers so please double check your amps against schematics to confirm compatibility.

We're not sure of which tank is used in the Avenger 30. It be be worth asking the manufacturer to see if they could help you out.

There isn't much info out on which tank in used in that amp. Are there any marking on the original tank? Thanks!

The Deluxe Reverb II uses a 4AB3C1B.

Yes. That is used to keep the springs in place when shipping but needs to be removed before installing the reverb tank.

The 4AB3C1C is the stock tank for that unit.

The 9EB3C1B works with the AC30C2.

The Champion 30 uses a small internal reverb unit and would require modifications to the amp or the tank to work with a MOD tank. We can't find any specs listed on the tank but if you could provide more information we might be able to make some suggestions.

The Deluxe Reverb uses a 4AB3C1B.

Hey Michel. Are there any markings on the tank? Matching the impedance is important when replacing reverb tanks.

We don't have a way to verify this but the 8EB2C1B is mentioned online as the stock tank by users of this amp.

We couldn't find too much on it either. Most transistor driven circuits use a higher input impedance such as the E types or F types but there are exceptions.

The Hot Rod Deville uses a 4EB3C1B.

The input impedance is 10 ohms on the 9AB2A1B. The DC resistance measures roughly 1 ohm but keep in mind that this will not be consistent across different brands of tanks.

We only have complete tanks.