Posted on Feb 13 2020 06:10 PM
Before you take those brass sleeves out and apart, mark the top of the magnets (maybe not so easy), or take a photo, or just turn the brass sleeves after assembling until you get a reverb output, decay and tone to your liking.
In case someone is trying to replace the dampers here's a very important consideration.
A few days ago when I replaced the dampers I didn't put back those ' end caps' (50) that hold the dampers in place.
Those brass caps are really hard to remove. You can see in the photo below how damaged they are from trying to get them out with various kinds of pliers.
A sort of 'hub puller' would be the proper tool but I don't have one that would work on something so small.
I only wanted to put back those end-caps once I was sure the new dampers were working well.
So today I put (pounded) them back in, reassembled the magnets inside and put the brass sleeves back into the plastic holder/bracket, plugged in my guitar and... very little to pretty much no reverb.
Unfortunately, today I also rewound the input coil (again...) with a different gauge wire, so I'm thinking that's where the problem is.
Unwound it and then rewound it with a wire gauge that has worked before.
Plugged in... still no reverb. WTF
I'm thinking maybe the dampers moved in the sleeves when I pounded in those end caps, and maybe the magnet support wire is somehow stuck and can no longer vibrate freely.
I took all 4 apart (again...) but upon inspection they were fine.
I put everything back together and I do notice a little bit more reverb but it's very dark and has a very short decay.
I always just pushed the brass sleeves back into the plastic holder/bracket. I'm not gonna glue them until I'm sure they don't need to come out again.
While plucking the guitar strings with my left hand I started to wiggle the brass sleeves and did notice some improvement.
Then I tried rotating them, as if they were knobs, and wow, it goes from pretty much no reverb to holy-moly-that's-a-lot-of-reverb.
I must have been very lucky a few days ago when I reassembled everything for the first time and got reverb.
So, there seems to be a top and bottom side (or maybe it's left and right) to these cylindrical magnets, making them only function properly when the top and bottom of the magnets are facing the laminations above and below the magnets.
After checking with a compass, the north and south poles of the magnets are not facing the laminations above and below the magnets, but the poles are facing sideways.
Between the two magnets, the north pole of one magnet is facing the south pole of the other.
The interesting thing is that, depending how you position the bottom/top of the magnets towards the lamination, it gives a lot of different kinds of reverb tone: from no reverb, to dark and short decay, to medium, to loud and bright and long decay.
Suddenly I also understand this part of the patent, which until now I didn't know what he was talking about:
The last sentence describes the issue I was having (without realizing it)
Now imagine this:
If the hooks on the springs aren't perfectly in line with the hooks on the magnets, the springs will force/rotate the magnets slightly (or more) out of their ideal position.
The hooks on those springs are clearly made by hand. In some pans (my TAD pans for example) they're really sloppy.
This would mean that it's almost inevitable to have a lot of variation between otherwise seemingly identical pans.
That Chinese (or Korean) worker has 4 chances per pan (2 end hooks on 2 springs) to mess up. He may not even realize how important this little aspect is.
Last edited: Feb 15, 2020 14:49:00