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ESS AMT3 Heil Sickness-Continuing Saga Of Changes And Improvements

I'm thinking you have a early 3 coil crossover. They may have been playing with the values-or (more likely) using the remaining stock from the 4 coil crossovers-as those values (20uf;55uf) were used in the 4 coil Zobel AMT3 crossover.
Axom poly's are just fine.
Ok-I know this will be a pain, but you should really replace those resistors, and check the traces underneath. Overheating is no good. In fact you really need to check, and re do all the solder connections, even without the overheated resistor. Reinstall the resistors with a air gap between the pc board and the resistor body-ESS wasn't always good at doing this.
I'm sure the circuit board is attached with silicone-if it's black-it's silicone.
Using a heat gun on the 'board" side (not the pc board) and a razor blade, you should be able to remove this. Pry very gently.
If it's hot glue (I kind of doubt this) then the same applies.
I see the woofer inductor has silicone-so I bet the PC board does to.
I managed to remove my 3 coil, and 4 coil with no damage to the traces.
However-if I was to do it again, I would use the silicone remover.
To use this, I would take the coils/switch/terminal board off ( a thin layer of silicone attach's this), and just leave the caps and resistors, as you should be replacing these.
Then soak the board till the silicone is loose, the separate the board and pc.
Remove the remain silicone traces be rubbing them off-if they don;t come off easily-soak them longer. This stuff won't corrode or damage the pc board, copper-etc. Expensive-but good, and a real time saver.
Make yourself a new mounting board, and drill a couple holes for standoffs-and skip the silicone. The silicone works well for the coils, and woofer cap. Use something like Permatex Ultra Black (auto parts store) as it doesn't have any corrosive properties -the vinegar smelling stuff does at least till it dries.
Make sure you check all the traces, and re flow, or repair as necessary.
This is a lot more work-but I would hate to see you go to all the work recapping, and find you have a problem-and a overheated board IMHO means a through checkout, and redo is needed. In fact, I would also replace all of the internal wiring-the NTE hook up wire @ Parts Express will be fine, and is relatively inexpensive.
Be patient, and spend some time on this one. The end result will be more then worth the time spent on the refurb, I guarantee it!:thmbsp:
Believe me, these speakers are well worth the extra effort-don't short change yourself, or waste your time.
 
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I would like to do it right.

Basically you are saying sacrifice the press board main board (my board looks like the same material as used in the 4 choke) and create a new one as I doubt I can get it out of the cabinet in one piece.

The part I am worried about is the metal rear plate. That would be pretty irreplaceable.

Can that safely be freed from the main board using the silicon solvent (something like this http://www.silicone-remover.com/)?

Thanks

BTW, why did they change crossover design from the Zobel configuration?
 
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I removed all mine by applying some pressure to the back side, and gently working something like a butter knife underneath the metal plate from the front.
You could just use another wood board, or look at iplasticsupply.com for some ABS sheets.
Parts Express also has some sheeting that make work well if you are re-using the stock coils.
The eyelet nylon ties are also fairly inexpensive and work great for securing the coils and caps-but you need to use some silicone as well. In this way-the ties are more or less the back up. One the silicone is dry-they are very solid. I find it better then hot glue-which can over time dry out, and the component just falls off.
In my custom crossover, I'm using a large gauge custom wound inductor coil for the woofer (2.4mh) that must weigh 2-3 lbs-so the P.E. ABS sheets were a little to flimsy for this application-but should be fine for stock coils.
Amazon has inexpensive felt sheets for the gasket.
You won't need to cut out a square relief with the sheets-but you will need to drill 3 holes-2 for the input terminals and one for the switch. These will keep the metal plate attached to the ABS sheet-so you wont' need any glue/adhesive.
I can forward the Digakey parts I used-stand offs, screws etc. I also replaced my fuse holders and input terminals with new-these are easy to find-Digakey etc.
All these can sourced from a number of different outlets, and IMHO is part of the fun as well, and good reference for future projects.
 
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iplasticsupply.com is great, they have a 1/8" G-10 glass epoxy board which would work well IMO.

Did the silicone remover I referenced look good?

Yes, please forward your part numbers, especially for the binding posts and fuse holders, knowing which ones are known to work would be nice.


Thanks
 
Ok-Digakey part numbers:
8413K-ND (standoff)
H157-ND (screws)
H220-ND (nuts)
F004-ND (fuse holder)
I also found a switch from Digakey that will work for the brightness switch. The terminals are reversed from the O.E.-but the direction is the same-so it works-just reverse the connections from left to right.
 
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I would go with that silicone remover if it looks good. It's much less expensive.
This was recommended to me by a electronics repair shop. Not sure what they mean by corrosive as it doesn't appear to be, and was made for electronic pc boards among other things-but I would try the other stuff first.
That switch is the same as Digakey #360-2350-ND.
 
automojo said:
I would go with that silicone remover if it looks good. It's much less expensive.
This was recommended to me by a electronics repair shop. Not sure what they mean by corrosive as it doesn't appear to be, and was made for electronic pc boards among other things-but I would try the other stuff first.
That switch is the same as Digakey #360-2350-ND.
Click to expand...

Yep and the Digikey piece is cheaper, thanks.

Going to get all my parts ordered and do the rework the first free weekend I have.
 
automojo said:
Great!
Keep us posted please.:thmbsp:
Click to expand...

Will do. All parts ordered, really adds up :nerd:

Another couple of differences on my crossover. The brilliance switch operates in the opposite direction from all the other crossovers I have seen posted. This makes sense since the power resistors are also reversed left to right on the circuit board.

Also my back panel calls out a 1.5A fuse. The others I have seen specify 2A.
 
automojo said:
I would go with that silicone remover if it looks good. It's much less expensive.
This was recommended to me by a electronics repair shop. Not sure what they mean by corrosive as it doesn't appear to be, and was made for electronic pc boards among other things-but I would try the other stuff first.
Click to expand...

Yeah if it works it would be useful for many purposes around the house so I ordered the 1 quart spray bottle. "If it works" being the important bit here. Only one way to find out. You definitely use this product differently from the SU100. Rather than bathe the parts you want to separate you spray it on a putty knife and then work the putty knife in between, the liquid breaks the adhesion and you continue on. Then when you get the pieces apart you can spray it and wipe off.

I'll report back on this too when I get done, looks like around mid-August so all the stuff arrives and I have enough free time :music:
 
Very impressive, looks like a huge amount of work went into those, would love to hear them!

How did you measure the frequency response of your bass section? I measured mine with my RTA and I get a pretty substantial peak at 100Hz. I suspect the woofers the previous owner put in, while nice units, are not well matched to the cabinet. They are "no name" so I can't even get TS for them. I wouldn't imagine anyone has TS for the original woofers? Also is polyfill as good as it gets for increasing effective cabinet volume?

This site sure is a great resource.

One thing I am going to need to at some point is pull my diaphragms and check them. They were replaced by a previous owner and I have heard that there were knock-off diaphragms produced.

automojo said:
Some new pics of my "Super AMT3" project.
http://www.audiokarma.org/forums/showthread.php?p=5922821#post5922821
Click to expand...
 
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You could utilize a Zobel if you want to stick with the current woofers.
The Dayton St255-8 was the only woofer I ran across that had no peaks in it's response with the AMT 3 cabinet volume-'its more or less ruler flat.
It's made for relatively small boxes.
It's 8db down @ 34hz-which isn't too bad IMHO, as you have to count in room reinforcement on top of that.
 
automojo said:
You could utilize a Zobel if you want to stick with the current woofers.
The Dayton St255-8 was the only woofer I ran across that had no peaks in it's response with the AMT 3 cabinet volume-'its more or less ruler flat.
It's made for relatively small boxes.
It's 8db down @ 34hz-which isn't too bad IMHO, as you have to count in room reinforcement on top of that.
Click to expand...

Edit: Looks like the Daytons are the way to go. If I am spending $200 on the crossovers I may as well get the bass tuned in also.
Do the Daytons just drop into the baffles?

Thanks
 
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I like the way it sounds overall better- and more importantly (to me) doesn't require a additional Zobel to smooth it's response.
It's heavy, so you need to add the front brace and (8) Hurricane Nuts (P.E).
You also should also give it more port then stock.
You could experiment with the stock port first.
I just decided up front I was going to get the best possible performance with this upgrade-time consuming-but I want this one the 'final edition'.
I didn't have a problem with cutting the ports, once I established how they would perform.
To me modification that makes something truly better, is fine.
Some people get too worried about varying from stock.
This isn't Antiques Road Show-they made quite a few of these-my pairs are both in good shape-but the potential for me out weighed deviating from stock.
DIY
 
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automojo said:
I like the way it sounds overall better- and more importantly (to me) doesn't require a additional Zobel to smooth it's response.
It's heavy, so you need to add the front brace and (8) Hurricane Nuts (P.E).
You also should also give it more port then stock.
You could experiment with the stock port first.
I just decided up front I was going to get the best possible performance with this upgrade-time consuming-but I want this one the 'final edition'.
I didn't have a problem with cutting the ports, once I established how they would perform.
To me modification that makes something truly better, is fine.
Some people get too worried about varying from stock.
This isn't Antiques Road Show-they made quite a few of these-my pairs are both in good shape-but the potential for me out weighed deviating from stock.
DIY
Click to expand...

Hopefully all this discussion is of interest to someone other than me :D

I really appreciate the assitance.

Modifying the boxes is of concern for me, not because of originality but because my woodworking skills are primitive at best. Destroying a cabinet would leave me in a very bad place.

I may end up using the Daytons but want to explore all the options.

Will the ESS driver drop in, if you connnect them in series? I am guessing that the rim won't fit in the stock cutout.

Did I see in a thread that the box volume is 2.7ft3?

Thanks again
 
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Th ESS driver should work.
I'm not all that good at wood working either.
I just thought out the brace-2 "C" shapes, and one board from side to side.
The holes were a hole saw, slightly undersized, and a sanding drum to fine tune the size-epoxy to hold them in.
I got the tubes from P.E.-closeout, and had a exhaust/muffler guy cut them for me as a favor-so they would be straight.
I will have to check- but the volume actually calculates to around 2.4 cu. ft(with mid tube/woofers)-so this is why the Dayton works well-smallish enclosures.
 
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