Acoustat Model 2 Full Restoration Thread!

Hey guys!

Just picked up a set of Acoustat Model 2s from LA and drove them back to Oakland. They look pretty ratty, the interfaces are completely rusted, battered cloths, and chipped wood bases (which I helped worsen moving them into my station wagon and back home). So I've decided to do a full overhaul!

Day 1

Transformers removed from unit. I used Liquid Wrench (not WD40) on all the rusted screws and banged them with a rubber mallet. The interfaces came apart pretty easily afterwards:

Fi4ioFJ.jpg


Vinegar bath for the rusted lids and other parts, and soaking some vingear soaked paper towels on the interfaces to try to remove any surface rust:

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Removed chipped laminate from speakers using a metal scraper and a hair dryer (these were not as bad as the ones on the other speaker). Just work patiently and they come off in one piece:

1fLDWM6.jpg


Cleaned, sanded, and prepared the bases for veneering. I'm contacting several laminate vendors to send them a sample and get a perfect match:
X12T3Lh.jpg


Also ordered a new Acoustat badge from ebay (even one of the badges was rusted!), and 4 new Acoustat replacement feet as they were rusted as well.

Stay tuned!
 
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Another long time Acoustat owner here. Looking good so far. When you're done with the restoration I'm sure you'll be happy with the sound.

If the actual panels appear to be dirty and/or stained you can soak them in a solution of dish soap and warm water. Thoroughly rinse them and let air dry. You can also use a hair dryer to tighten the diaphragms. Since you're going to replace the grills using the hair dryer is a good idea. IME using a heat gun instead of a hair dryer is a bad idea.
 
I know of no one who replaces Acoustat diaphragms. If you know of someone who does I'd like to know. I have an MK-131 interface that needs a transformer. Maybe they/he could be helpful.

One good thing about Acoustats is that the stator wires are well insulated and a burn through ala Quad is pretty much a non-issue.
 
Does anyone who has replaced the laminate on Acoustats have an idea of what the original color was called? Is it by Formica?
 
Additionally, how safe is it to fully disassemble the electronics out of the interfaces? There's quite a big warning sticker on these guys. It turns out they might have to come apart completely to get all the rust off, I was going to take them to a powdercoating place.
 
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Additionally, how safe is it to fully disassemble the electronics out of the interfaces? There's quite a big warning sticker on these guys.
What Joe said.

Here is one of my Roy Esposito modified interfaces with the "Air Mod" that switch bypasses the large HF resistor altogether.

airmod.jpg
 
Day 2

Matching original laminate. I have the lighter wood on my Acoustats, there are two from Wilsonart that are really close, Solar Oak and Castle Oak.

A3Yfo1I.png


Solar Oak in different lighting:
HiIubNS.png
 
I know of no one who replaces Acoustat diaphragms. If you know of someone who does I'd like to know. I have an MK-131 interface that needs a transformer. Maybe they/he could be helpful.

One good thing about Acoustats is that the stator wires are well insulated and a burn through ala Quad is pretty much a non-issue.
If you hunt for panels, it shouldn't be too long before you find some. They're not rare. Stator wires tend to detach from their mounts at the ends of the panels, easy to re-glue.
 
More samples of laminate coming in, this time from Formica. Wilsonart Solar Oak was dead close (if not original, considering the laminate may have faded after 30 years). Fingers crossed!
 
Day 3

Over on DIYAudio, I got confirmation from one of the ex-Acoustat managers, that they indeed used Wilsonart for the laminate.

On the other hand, it's been near impossible to source replacement grill cloths for these. Through some efforts of googling, I was able to find this for Acoustat grill cloths:

From http://www.audiocircuit.com/Home-Audio/Acoustat:
[Tony Fasola (July 27, 2016): The Upholstery Shop in Arizona no longer supplies replacement socks for the Acoustats. Through Soundlab in Utah I found their source of speaker cloth to be "Guilford of Maine". Guilford recommends their DMD line and there is a selection of 15 colors if so desired. Very helpful customer service. The DMD line is available by the yard and 60" wide.
Good luck!

Guilford does not appear to carry the DMD line any longer, but I found them here: https://www.acoustimac.com/dmd-acoustic-fabric

The Stone colorway appears to be closest to the original "white" option, in both color and texture, I ordered 4 yards for two speakers:
dmd_0000_stone.jpg
 
Acoustat panel disassembly:

After the interfaces have been removed, unscrew the trim bracket cover from the top of the speakers and then unfasten the staples holding fabric (I used a small flathead screwdriver and pliers):
FNKWRfI.jpg


Lay the speakers down flat on a soft work surface (I used drop cloths), and remove the two black screws going into the base:
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Remove one screw from each side of the bottom, below the feet of the bases:
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After removing any dust or cobwebs, using a long screwdriver remove the four silver screws attaching the bases to the panels:
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Afterwards, the bases will slide off without effort. Be extra careful with the wiring to not damage it during removal. Roll up the unstapled fabric from the top of the panel and lean the speaker against a wall or work surface:
ihwEXbI.jpg


Remove the staples from the bottom of the fabric using the same methods as before:
R7Y7CPD.jpg


The grill cloth will now pull off the speakers with little effort, the existing fabric can now be used as a template to make new grill cloths. Clean and vacuum the panels:
L87ZxRE.jpg
 
Congratulations, on your choice of transducers, your work ethic, and your quality standards!

You should have a lovely pair of 'stats when you finish.

:)
 
Day 4, 5, 6

Tape off the interfaces and components, you don't want to introduce rust bits inside the interfaces.

Rust dissolver, steel wool, repeat, repeat and repeat.

This is tiring and time consuming but needs doing so just power through it.
 

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