Hammond reverb tank replacement.

[g1]

56 and 700 ohms for in and out would roughly correspond to the EC in the tank code. So just a matter of figuring out the ground scheme now.
Measure from tank case to each of the 4 wires. One or two of them should measure around 0 ohms to the tank casing. Which ones?

[K.Hogg]

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Hey the pics are compressed they are less than 100kb I'm confused to why it wont allow them.

[K.Hogg]

56 and 700 ohms for in and out would roughly correspond to the EC in the tank code. So just a matter of figuring out the ground scheme now.
Measure from tank case to each of the 4 wires. One or two of them should measure around 0 ohms to the tank casing. Which ones?

Hey so based on the chart if I was looking to replace with a short 3 spring tank with long delay id be looking for an 8EC3........ the original tank part was - 6EC3B if the B stands for the grounding scheme that would be - Connector shield connects to chassis = In Yes/Out No. I will try and measure the grounding now

[g1]

EC does not seem to be common now, but EB is. You can get in 8 or 9 versions. Most of the Mod brand tanks have the ground scheme easily re-configured in need be.

[K.Hogg]

EC does not seem to be common now, but EB is. You can get in 8 or 9 versions. Most of the Mod brand tanks have the ground scheme easily re-configured in need be.

So is it ok substitute an EC for a EB without problems?
Hmmm I don't know if I'm measuring the ground correctly - I'm not getting anything on all 4 wires.....should I be connecting the negative lead of the DMM to the case then touch the tips of all 4 of the wires the with positive lead individually ?

[Enzo]

Hi K

Please don't describe readings as "get nothing" or "no reading". A resistance measurement has two possibilities. One is an open circuit or infinite resistance. The other possibility is a resistance. It can be any amount, even zero ohms, but it will be SOMETHING.

"No reading" for example, means the meter went blank. That is not the same as zero ohms or zero volts. I know, I am being picky, but the name of the game is to accurately convey information between techs here.


You have four wires. It is POSSIBLE one or both transducers are grounded to the housing, but they might not be. SO yes, connect your meter to the box, and probe the four wires individually. If any of them measure like zero ohms, then that wire is grounded to the frame. But it is entirely possible none are.

EB vs EC pans? Changing from B to C is like changing from humbuckers to single coils. It won't hurt anything. The B or C part is the output, so one might match your return circuit "better" but chances are it will work fine. C pans are rare.

[K.Hogg]

Hi K

Please don't describe readings as "get nothing" or "no reading". A resistance measurement has two possibilities. One is an open circuit or infinite resistance. The other possibility is a resistance. It can be any amount, even zero ohms, but it will be SOMETHING.

"No reading" for example, means the meter went blank. That is not the same as zero ohms or zero volts. I know, I am being picky, but the name of the game is to accurately convey information between techs here.


You have four wires. It is POSSIBLE one or both transducers are grounded to the housing, but they might not be. SO yes, connect your meter to the box, and probe the four wires individually. If any of them measure like zero ohms, then that wire is grounded to the frame. But it is entirely possible none are.

EB vs EC pans? Changing from B to C is like changing from humbuckers to single coils. It won't hurt anything. The B or C part is the output, so one might match your return circuit "better" but chances are it will work fine. C pans are rare.

Hey Ok Ill explain exactly what I'm doing. So the reverb tank is completely sealed all the way around and riveted so I don't have access to the inside.
I can only test by touching the outside of the tank case. I have attached the negative lead of the DMM to the outside of the reverb tank , then starting with the IN side I take the Positive lead of the DMM and connect to the green positive tank cable, then I remove and then connect the positive lead of the DMM to the Black negative tank cable.
I then repeat the same process on the OUT tank cables. The display on the meter does not change it stays the same as if I was doing nothing I have tried on the 200, 2k , 20k,200k and 2M ohm settings with the same results.
any Ideas? Thank you

[Enzo]

OK, so open indication or infinite resistance - same thing.

That simly means neither transducer is grounded to the frame. SO you will then need to connect each end to the circuitry. Additionally, once it works, you might also run a wire from the case to the amp chassis, just to help prevent hum.

[K.Hogg]

OK, so open indication or infinite resistance - same thing.

That simly means neither transducer is grounded to the frame. SO you will then need to connect each end to the circuitry. Additionally, once it works, you might also run a wire from the case to the amp chassis, just to help prevent hum.

Hey Thank you!
So the replacement I should be looking for is an 8EB3D1B = Input Insulated/Output Insulated?
The current tank does hum which increases as you turn up the reverb and treble - should the current tank have a wire attached the amp chassis ? I wonder why they did not do this.....
In the regards to the wires that connect to each transducer, is there a reason they are so thin? would thicker wires be advised when I install the new tank? should I used shielded wires ?

[Enzo]

How long would it take you to touch a wire from chassis to the reverb frame? A few seconds? You could find out if it matters a lot faster than we can decide whether it will or won't from out here in the interwebs. It is a possibility, but could easily be other things. Unshielded wires perhaps.

[K.Hogg]

How long would it take you to touch a wire from chassis to the reverb frame? A few seconds? You could find out if it matters a lot faster than we can decide whether it will or won't from out here in the interwebs. It is a possibility, but could easily be other things. Unshielded wires perhaps.

The original reverb tank is not installed as I was testing it so the wires are unsoldered from the PCB, so I can't check it quickly.

So to confirm I'm looking for Input Insulated/Output Insulated? grounding configuration for the replacement ? should I use thicker wires for the replacement or are thin wires used for a reason ? should I use shielded wire ?
Thanks.

[Enzo]

Your pan is designed to be a part of something, inside something, so your wires just trail out of it. The thin green and black wires are what normally comes on a transducer from Accutronics Jut they are usually insied a metal pan, and are only an inch or two long. You are planning to replace this with a real pan, and so the thin wires will already be inside it, and you will instead face a couple RCA jacks. yes, I would use shielded cable. In fact, a simple way is to get a three foot - or however long you need -- RCA cord from somewhere, and cut it in half. That makes two cords that are RCA to bare wires. The RCA males plug into your new pan, and the bare wires get soldered to the amp circuits.

Look at a zillion old Fender amp, and wire it up like they did.

[g1]

So the replacement I should be looking for is an 8EB3D1B = Input Insulated/Output Insulated?

You won't find one. But 8EB3C1B is available. The 'C' may work fine in your amp with the output connector non-insulated. But if you buy the MOD brand tank, you can remove the jumper at the output end so it will become a 'D' ground configuration, or any other ground scheme. Both input and output end are re-configurable to be insulated or non.
So you will be able to find out which way gives least hum in your amp.

[K.Hogg]

You won't find one. But 8EB3C1B is available. The 'C' may work fine in your amp with the output connector non-insulated. But if you buy the MOD brand tank, you can remove the jumper at the output end so it will become a 'D' ground configuration, or any other ground scheme. Both input and output end are re-configurable to be insulated or non.
So you will be able to find out which way gives least hum in your amp.

Hey I've ordered a 8EB3D1B they are able to offer Input Insulated/Output Insulated. Enzo has kindly recommended connecting to outside of the new tank to the amp chassis to reduce hum is that something you would recommend also ?

[g1]

Hey I've ordered a 8EB3D1B they are able to offer Input Insulated/Output Insulated. Enzo has kindly recommended connecting to outside of the new tank to the amp chassis to reduce hum is that something you would recommend also ?

Yes.