Another ESS AMT-1a pyramid rebuild thread

But why oh why does every ****ing thing on this planet need to be turned digital?
That's an easy question with regard to photography. Far more pictures are being snapped, shared and enjoyed thanks to the digital age. EVERYONE has a camera on them at all times, some feeding directly into their social media accounts (I didn't say it was ALWAYS a GOOD thing) for everyone to pick up real time.
I wouldn't say EVERYthing on this planet needs to be digitized..................or WOULD I??

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The matching sub was only available with the second-generation Transar. Mine are the first. The "low-freq" AMT plays 150hz-799, and the mid-range AMT plays from 800-2x,000. I'll look for a sub some other time once these are set up. For now, I'm working on acquiring a passive crossover from ESS. Should the active crossover and cables come up on eBay, then I'll be all over it. I've got the daily-search emails saved. Due to the proprietary 5-pin XLR cable, I can't just use any old after-market or pro active crossover. We've been down this road on my Transar rebuild thread, linked above.
Actually, you could just use any old after market active crossover. It's just a matter of tweaking the settings to the right levels and having the correct protective capacitors in place. You could have a couple of MiniDSPs and four electrolytic caps at your door for under $250.
 
How did you decide on the name "PorkLoin", if I may ask?
1. It's a combination of two words just cram packed with innuendo.
2. It's a thing of beauty on the barbeque.
By the way, that photo of me up above was snapped at CUM-Con in Vegas. That nerd in the purple shirt wouldn't keep his hands off of me.

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So. Well. Uhm. Yeah, I'm on vacation right now. Can't wait to get home and listen to my finished AMT-1a speakers!
 
This weekend I took out my custom 1a crossovers and replaced them with a pair of AMT Monitor bi-amp'able crossovers that I bought on eBay. Though the two speakers use the same drivers, same passive radiators, same AMTs, the specs are just a touch different.

IIRC, the monitor was 93db sensitive, and the AMT-1a was 91db sensitive. Also, the other main difference was frequency response--the Monitors were 30hz-20-23khz, and the AMT-1a were 35hz-20-23khz. I assume the low freq differences were related to the Monitor having the taller, deeper cabinet.

First off, despite having the same size board, it wasn't a direct fit because the knobs on the Monitor crossovers hit the upper wall. So I screwed in the original crossover plate--minus tiny holes for the mid- and high-freq controls, which is how I routed blue/pink wires to the AMT, and the driver wires (brown and green) to the Monitor crossover board resting externally, on top, of the cabinet. As an experiment, it works and sounds great.

When I get more time, I'll fabricate a new crossover board and mount it properly inside.

Oh yeah, and I'm also bi-amped with the ESS electronic, active crossover. Using a DIY Decware SET el84 tube amp for the AMT and an Emotiva XPA-2 (gen2) for the drivers.

Loving it.
 
While very interesting and at times I had a better you than me attitude you certainly have sticktoittiveness .Never a mention about the freaking hoods like on Ohm Walsh 2, 2xo and others that are huge dust collectors. Are you going to use the hoods or go w/ gratuitous audio nudity ... They look great and back in the day were my favorite speaker but you need a huge room because of their footprint.
 
Greetings! First time post and I am happy to have stumbled upon this thread!

I also grew up with Ess in the house and had to have a pair upon buying my first house. My old man has a pair of amt 1b's & I was able to find a pair of 1a's for a reasonable price and in respectable condition with new foam surrounds and radiators, but otherwise original.

Unfortunately, the sound is not quite as sweet as I remember. The Heil seems quite a bit loud compared with the bass. Particularly in the mid range and the mid sounds a bit off. Kind of overly filtered and tinny. Vocals can sound a bit naisaly or raspy depending upon the source. The best sound I can dial up is with the brilliance dial at about 9:00 (far outside the optimum range) and a 3db cut to the mid on my preamp.

Also, one of the brilliance dials crackles and cuts out while adjusting, and if the midrange selector switches are functioning, it's so subtle I can't notice.

Ess will refurbish the xovers, but they only test and replace anything off factory specs. They're maybe 40 years old, so I'm considering replacing them all myself.

It looks like some of the values are hard to find and I would need to place multiple caps in parallel to get proper values. Also, I wasn't sure if I should "upgrade" to polypropylene or stick with electrolytic. Any suggestions?
 
I've always thought the main appeal of those was the cool pyramid look and the cool looking heil driver. I've always wanted a pair, still do, but in truth I'e never thought they sounded very good, other than the tweeter. If a locsl set ever came up for cheap I wouldbe tempted to try something to fixbthe sound. Planar mid maybe, dsp. I'm enjoying the thread.
 
I've always thought the main appeal of those was the cool pyramid look and the cool looking heil driver. I've always wanted a pair, still do, but in truth I'e never thought they sounded very good, other than the tweeter. If a locsl set ever came up for cheap I wouldbe tempted to try something to fixbthe sound. Planar mid maybe, dsp. I'm enjoying the thread.

I'd really like to get a dsp for these. I've tried them in different rooms and was blown away with the huge difference in performance. They worked best in the bedroom along the short wall with carpet, and a mattress. Much tighter bass. I've added a rug and some furniture to the front room where I have them now, but it's not quite as good as the bedroom. I'm hoping the dsp can make even more improvement and possibly bypass the xover and go active in the future.
 
I'd really like to get a dsp for these. I've tried them in different rooms and was blown away with the huge difference in performance. They worked best in the bedroom along the short wall with carpet, and a mattress. Much tighter bass. I've added a rug and some furniture to the front room where I have them now, but it's not quite as good as the bedroom. I'm hoping the dsp can make even more improvement and possibly bypass the xover and go active in the future.
If you ever do keep us informed. I've thought an L pad for the tweeter might help.
 
Greetings! First time post and I am happy to have stumbled upon this thread!

I also grew up with Ess in the house and had to have a pair upon buying my first house. My old man has a pair of amt 1b's & I was able to find a pair of 1a's for a reasonable price and in respectable condition with new foam surrounds and radiators, but otherwise original.

Unfortunately, the sound is not quite as sweet as I remember. The Heil seems quite a bit loud compared with the bass. Particularly in the mid range and the mid sounds a bit off. Kind of overly filtered and tinny. Vocals can sound a bit naisaly or raspy depending upon the source. The best sound I can dial up is with the brilliance dial at about 9:00 (far outside the optimum range) and a 3db cut to the mid on my preamp.

Also, one of the brilliance dials crackles and cuts out while adjusting, and if the midrange selector switches are functioning, it's so subtle I can't notice.

Ess will refurbish the xovers, but they only test and replace anything off factory specs. They're maybe 40 years old, so I'm considering replacing them all myself.

It looks like some of the values are hard to find and I would need to place multiple caps in parallel to get proper values. Also, I wasn't sure if I should "upgrade" to polypropylene or stick with electrolytic. Any suggestions?

Welcome!

You've touched on two of the biggest complaints against the AMT, that it runs faster than the low frequency driver, and that it has no mids. I'd recommend leaving the mid cranked up full blast for psychological reasons, but I leave my high frequency knob in the just a little bit more than barely-on on. I also listen to two-channel in Direct mode with no other tone controls.

Something I've noticed a lot in the past few months with my basically new speakers is that they sound like crap for a good 15 minutes if I haven't listened to them in a while. This was apparent to me recently when I plugged them back in after listening to a "crap" brand of speakers that I've been refurbing and which have a completely different style and approach to sound. But after that 15 minutes, there comes a time when I stop thinking about the sound and the music just seems to float in, and when the AMT better blends with the low frequency driver. So, give it a few minutes to warm up.

Next, get some De-Oxit and clean up the L-Pads.

If you've gone through this whole thread, you'll see my rebuilt crossovers. They're basically factory spec with new Dayton caps, but I had to fabricate a new board to make it all fit. And by that point I just went crazy with new terminal barriers and custom-braided wiring. Now that I'm running the AMT Monitor crossover, I'm going to make these 1a crossovers available on the sale site, but hey, this isn't a marketplace thread, so just saying that I think this crossover is worth the effort and cost. If you can solder, you can do it yourself.

You can find 50+ pages of schematics here, though there is some model variance even between speakers with the same name: http://esslabsusa.com/download/

I'd really like to get a dsp for these. I've tried them in different rooms and was blown away with the huge difference in performance. They worked best in the bedroom along the short wall with carpet, and a mattress. Much tighter bass. I've added a rug and some furniture to the front room where I have them now, but it's not quite as good as the bedroom. I'm hoping the dsp can make even more improvement and possibly bypass the xover and go active in the future.

With a rear-firing passive radiator, you will get bigger, boomier bass closer to the wall. The bass will lean out the further from the wall you get. As one who successfully went active with this speaker and the ESS 2241 Active Electronic Crossover, I can say that that is a fine idea.

If you ever do keep us informed. I've thought an L pad for the tweeter might help.

It has two already.
 
Greetings! First time post and I am happy to have stumbled upon this thread!

I also grew up with Ess in the house and had to have a pair upon buying my first house. My old man has a pair of amt 1b's & I was able to find a pair of 1a's for a reasonable price and in respectable condition with new foam surrounds and radiators, but otherwise original.

Unfortunately, the sound is not quite as sweet as I remember. The Heil seems quite a bit loud compared with the bass. Particularly in the mid range and the mid sounds a bit off. Kind of overly filtered and tinny. Vocals can sound a bit naisaly or raspy depending upon the source. The best sound I can dial up is with the brilliance dial at about 9:00 (far outside the optimum range) and a 3db cut to the mid on my preamp.

Also, one of the brilliance dials crackles and cuts out while adjusting, and if the midrange selector switches are functioning, it's so subtle I can't notice.

Ess will refurbish the xovers, but they only test and replace anything off factory specs. They're maybe 40 years old, so I'm considering replacing them all myself.

It looks like some of the values are hard to find and I would need to place multiple caps in parallel to get proper values. Also, I wasn't sure if I should "upgrade" to polypropylene or stick with electrolytic. Any suggestions?

This is a dramatic demonstration of the subjective nature of this hobby. My ear finds the great Heil to be smoother and more organic than anything else, including my famed (ADS) sticky domes - what could be more natural than half of a silk sphere with a fresh coat of goop on them?
Other than a mylar accordian so light that I can make them undulate just thinking about it.
ESS did Oskar Heil's brain child no favors with what they put beneath it. One only has to look at the output graphs of an AMT and those big woofers below to see that there's not enough overlap to overcome the mid dip that everyone complains about.
Unfortunately, if you get a sensitive woofer that goes up another octave, the low end tends to climb and necessitate those horrible subwoofers. As most dig the out of place blob of bass phenomena, I'm surprised that no one is veering toward pro woofers augmented with a separate subwoofer.
I've enjoyed the poly caps in both of the projects that I've done with them. Whether they were worth it or not is relative to your wallet thickness. You could probably shave some bucks off if you have any caps NOT involved with the tweeter, which is difficult with ESS speakers as that big fat one that parallels the woofer could very well be doing double duty in the high pass circuitry for the tweeter as well. I could've saved about 40 bucks on my AMT-3's if I'd have thought of it then.

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Sent my original grilles to Ricky at ESS few weeks ago. He said the frames were done and grille cloth will be done shortly and shipped on Tuesday.

Also, since my last update (I think), I have sold my modified AMT-1a crossovers and bought and installed original, un-restored AMT Monitor crossovers. My Scott LK-150 tube amp should be ready very, very soon and then I'll have biamp Emotiva SS watts for the lows and Scott tubey goodness for the AMT.

::fingerscrossed::
 
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