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Restoring Acoustat Monitor 4

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Posted on September 22, 2012 at 13:23:57
LutherG
Audiophile

Posts: 28
Location: Spring, Texas
Joined: September 18, 2010



Mike Savuto pointed me to this forum and so I've done a few searches but haven't come up with anything yet. I wonder if anyone knows of or has a copy of procedures for cleaning the diaphrams of Acoustat Monitors?

The speakers I have went through a flood in 1994. They sat in about 3ft of water for 24 hours. They've been sitting in the garage ever since. I'm now going to attempt to get them back up and running. The outside of the speakers cleaned up well though they could use another pass, and now I need to address the interior.

The interfaces will probably need new transformers. I'll know more after I've disassembled and thoroughly cleaned them.

 

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RE: Restoring Acoustat Monitor 4, posted on September 22, 2012 at 13:25:51
LutherG
Audiophile

Posts: 28
Location: Spring, Texas
Joined: September 18, 2010



This is what they look like after a cursory cleaning. They need more attention but this gave me the incentive to continue the restoration.

 

RE: Restoring Acoustat Monitor 4, posted on September 23, 2012 at 01:26:20
The peleton
Audiophile

Posts: 536
Location: Texas
Joined: July 7, 2010
 welcome

1- Micheal Savuto is one of the most qualified experts in the country, I know him well-great guy
2- I have the same speakers and they are my favorite thing I own. These speakers are amazing
3- You will need to have the amps (tube servo amps?) serviced all caps replaced, tube sockets replaced, power supply replaced, and fuse holder replaced, and thats the minimum. Your looking at lots and lots of cash your going to have to spend just to get them working
4- Im in Houston too.
5- if the mylar is taught you should be fine, if not your done. You can try a hair dryer to tighten up the tension but if its saggy they are done.
6- as far as cleaning them, um I guess a qtip some 409 and lots and lots of time and patience
7- good luck you will need it

 

RE: Restoring Acoustat Monitor 4, posted on September 23, 2012 at 08:13:21
Sondek
Audiophile

Posts: 9632
Location: Fort Worth
Joined: May 17, 2000
Contributor
  Since: April 5, 2002
 You must restore them - you will be so glad you did. I have the same Monitor IV's. Incredible. Although I'm not sure I'd actually do this, but I read one time that Jim Strickland once said those panels were so indestructible that you could spray them down with a garden hose (without being connected of course) and it would not hurt them. Mike Savuto is your man when it comes to the servo amps. Or, you can, if necessary, pickup Medallion interfaces for them off ebay for reasonable money if you watch for them. You really should remove the panels from the frames and assess any warping, etc. to the wooden parts. Will give you much better access to both sides of the panels too. Stay in touch and let us know how you come out.

 

RE: Restoring Acoustat Monitor 4, posted on September 23, 2012 at 09:03:25
LutherG
Audiophile

Posts: 28
Location: Spring, Texas
Joined: September 18, 2010
 You know - someone else said I could probably take a hose to them too. I'll get the grills removed and see what the possibilities of that are. I definately need to hose the grills off. I got most of the dirt out but a good spraying should get the rest of it.

Nothing seems to be warped - I'm amazed they've held up as well as they have! I'm dying to hear these again and watch the glow of the tubes in my amps - so I sure hope this restore works out. I've really missed having a listening system over the years... I'm also looking for another tube cage for my Citations. I know - these are impossible to find but I'd really like to have one so both amps are covered. So if anyone knows of one please contact me...

The Citations were submerged for 24 hours too but these things are like tanks with their potted transformers. I've cleaned them thoroughly and fired one up to 1/2 power on a variac and so far no smoke anywhere... The rest of the system never saw water so those components are good...

Thanks guys for the warm welcome and I look forward to posting my progress...

Cheers,

Luther

 

RE: Restoring Acoustat Monitor 4, posted on September 23, 2012 at 09:07:56
LutherG
Audiophile

Posts: 28
Location: Spring, Texas
Joined: September 18, 2010



Wow - you're in Houston too? What are the odds? I'll pull the speakers out of the garage again in the next few days and remove the grills to see what the condition of the mylar diaphrams is. I sure hope they're still tight... A friend on the West Coast has a pair of acoustat III's and he told me you could use a hair dryer to tighten up the diaphrams. I'd like to find some instruction or a video on that before I try it though...

As for servos - I actually have the MK121 interfaces. What I was driving these with were a pair Harman Kardon Citation IIs strapped for mono - so one amp per channel. The sound was effortless and the headroom seemed limitless... For the front-end I had a simple little Dyna Pas-3 Preamp and the matching FM-3 Tuner. Both of these sounded great! The Pas-3 is somewhat modded but the tuner is stock. I'm embarrassed to say what my turntable is - its an old NAD turntable I got while during the time I worked at Audio Concepts in Houston...

These speakers were left with me by one of the best friends I've ever had who then fell upon hard times and just kinda disappeared... I haven't seen him in over 20 years... When my house flooded everything went out in the trash but I just couldn't bring myself to trash these so they went into the garage... I don't have a listening room any more as the wife says the speakers are too big and ugly - go figure right? But lately, I've had this inner urge - like its time - to see about restoring these.

I'll definately chronicle the restore on this thread.

Regards to all,

Luther

 

RE: Restoring Acoustat Monitor 4, posted on September 23, 2012 at 11:33:00
dogwan
Audiophile

Posts: 871
Joined: December 16, 2004
 Hey Luther,

I also am running my Acoustats from a (heavily) modified PAS3 and also using an FM3 (also modded). In that picture I sent you can see them. Small cases with Rosewood front panels.

I really hope you get these back up and running.

You should be able to remove the individual panels from the rear of the frames without messing with the grill cloth. That is if they're anything like my model X's.

Each panel has 8 plastic screws holding it to the frame. Disconnect the wires of each panel (from the end of the flying lead, not at the panel itself) and label them correctly (should be 3 wires each). To remove the screws I used a power driver with my hand cupped around the tip to keep from slipping. YOU DON"T WANT TO SLIP and pierce the mylar! Back the screws out slowly, they'll squeak and pop because they're plastic but don't let it scare you.

After you get the panels out use a sharpie to outline where the thick felt damping pads are located and peel them off. When it's time to put them back on just get some spray glue (3M super 77 or 90) and dust the felt pad and press back into place.

Once the panels are out and pads are off you should be able to see both sides clearly to inspect and clean. I don't have any experience cleaning them, so proceed cautiously.

You probably could just hose them off? However, I would think the biggest danger is loosening the stator wires which are just glued into place. From what I understand the glue gets old and brittle and is easily dislodged if disturbed. Somewhere out there I found directions for re-gluing a few loose spots, but you don't want to cause anymore. I think it involve laying the panel on sawhorses and working from underneath using superglue. Upside down so you don't risk dripping any glue onto the Mylar.

Whatever you do, I would not use anything with chemicals to clean since you don't know what it would do to the graphite impregnated paint on the mylar (crucial for function). If you just see a thin layer of residue like the ring on a bathtub I would be tempted to just leave it alone. As long as the coating on the mylar is undisturbed and the film is not enough to add signifigant mass to the diaphragm it probably shouldn't affect operation. If you see anything that needs to be washed away, maybe a turkey baster?

As for the re-tensioning the Mylar with a hair dryer. It's easy. I did it with just an average home dryer. I used the HI setting (tried it on medium 1st until I was confident it wasn't too hot), but kept the dryer about 6-8" away. KEEP THE DRYER MOVING! Work across the entire area of the panel, but do a couple laps around the outer perimeter. Most of any sag will be in the corners unless it's really bad (from the info I gathered before attempting).

Hopefully I haven't given you any mis-information. Just adding my experience and 2 cents. If anyone reading this disagrees please chime in!

-Dogwan

 

RE: Restoring Acoustat Monitor 4, posted on September 23, 2012 at 14:28:35
LutherG
Audiophile

Posts: 28
Location: Spring, Texas
Joined: September 18, 2010
 Hello Dogwan,

Thanks for the great information. :D That's cool that you're using vitually the same setup as I am. I've always enjoyed the setup and have only felt my turntble was the weak link in my system.

I haven't received the pictures you sent so would you mind resending when you get a moment? I'm going through the interfaces this afternoon and so far they're cleaning up nicely... I'm a little concerned about the transformers and somewhere in searching for information on the speakers I found a link somewhere to the company that made the original transformers... So I'm actually feeling pretty good about my chances of making these interfaces operational again...

Its really great to talk to you guys about all this. I haven't had anyone I could discuss audio with in 20 years... ha!

Thanks again,

Luther

 

RE: Restoring Acoustat Monitor 4, posted on September 23, 2012 at 15:15:48
VirginVinyl
Audiophile

Posts: 29
Location: Australia
Joined: October 15, 2007
 Please dont hose them down. You may damage them.

Ive read of a couple of people who have damaged panels this way.

You can put them in the bath with water and just a tiny bit of unscented soap (not too much soap you dont want it to be conductive on the panel).

Very safe this way and you wont believe the junk that comes off them.

The mk121 supplies can be massively improved also and then these will compete or beat Martin Logan cl-x and lots of high ende current state of the art stuff.

 

RE: Restoring Acoustat Monitor 4, posted on September 23, 2012 at 15:16:36
The peleton
Audiophile

Posts: 536
Location: Texas
Joined: July 7, 2010
 I bought my first pair of speakers from Audio Concepts. Its a shame the place is gone. There was a guy that worked there with long hair and glasses, I cant remember his name, but he was a great guy. He helped me out a lot. In a way my addiction is all his fault... I miss those magnepan mg12s...

 

Pics of PAS3 and FM3, and Acoustat frame mod, posted on September 23, 2012 at 16:49:51
dogwan
Audiophile

Posts: 871
Joined: December 16, 2004






The Dynaco's have different knobs now, but you can see the new face panels.

The Acoustat's frame have been cut shallower, raised, and given the adjustability in the angle of tilt. Still need to paint the bases, but you get the idea. Tried to make them essentially like the "Monitor" series without giving up the cool Walnut frame.

 

Like the bath idea!, posted on September 23, 2012 at 16:51:34
dogwan
Audiophile

Posts: 871
Joined: December 16, 2004
 You can be very gentle that way. And could do a rinse cycle too.

 

RE: Restoring Acoustat Monitor 4, posted on September 23, 2012 at 18:23:06
LutherG
Audiophile

Posts: 28
Location: Spring, Texas
Joined: September 18, 2010
 Yes - I think the bath idea is a good one! I'm very interested in how the mk121 interfaces can be improved as well. I'll begin searching but if you or anyone else can point me to any resources for this I'd really appreciate it.

regards,

Luther

 

RE: Pics of PAS3 and FM3, and Acoustat frame mod, posted on September 23, 2012 at 18:55:03
LutherG
Audiophile

Posts: 28
Location: Spring, Texas
Joined: September 18, 2010
 Hello Dogwan,

I have to say, the frames around the speakers and stands you made are excellent! The new faceplates for the Pas-3 and FM-3 are outstanding as well. What a simple and elegant solution. They take on very modern and clean lines...

Perhaps some time we can talk about the mods made to the circuits of each... :) I'm very curious to see what you've done to improve them. On my Pas-3, I beefed up the capacitance of the power supply, and bypassed the larger power supply caps with smaller ones. Then I removed the tone circuitry to minimize what's in the signal path. I changed out the mylar caps for polypropylenes and used 1% resistors.

I should have changed out the switches but haven't yet... the volume pot and input selector switch are stock as well... I changed out the output RCAs for gold-plated ones...


Cheers,

Luther

 

While I agree, posted on September 24, 2012 at 06:59:57
E-Stat
Audiophile

Posts: 37666
Joined: May 12, 2000
Contributor
  Since: April 5, 2002
 "hosing them down" is exactly what Jim Strickland said could be done with them. That is when I met him when he and Bob Rieman brought a pair of the Acoustat X to Atlanta for the TAS review.

Especially given their age, I would recommend the gentle bath approach, too. He also spoke of the heat treatment process which I've done for decades.

 

RE: Restoring Acoustat Monitor 4, posted on September 24, 2012 at 07:08:35
Utley1
Audiophile

Posts: 1609
Location: NYC
Joined: July 30, 2010
 Maybe one of the inmates has a schematic of the transformer......That might give you some alternatives....I am excited about your restoration......They are exciting and wonderful speakers compared most favorably to The Quads which are great speakers. Wish you luck on your quest.

 

RE: Like the bath idea!, posted on September 24, 2012 at 07:20:16
VirginVinyl
Audiophile

Posts: 29
Location: Australia
Joined: October 15, 2007
 Ok so apparently you can hose them down. Ive read that also. I also though have read of at least two people who have damaged panels that way. Given the age of the panels and 'hosing down' isnt a very accurate gauge of the pressure you can use safely, i think the bath approach is a safe effective compromise.

I changed the resistor on the bass transfomer with a non magnetic, wirewound, Mundorf Supreme (apparently Alan Wolf from Magico loves these). A nice improvement.

I replaced the .01mf caps in the high voltage supply with 10,000 volt Russian teflons (dramatic improvement but be careful of the metal case ends).

The high frequency wirewound resistor pot i replaced again ith fixed value Mundorf Supremes and tried lots of different combinations. Ended up sounding best with no residtors there (in my system anyway).

Eichmann binding posts were a very great improvement in sound (especislly moreso since my supposedly close to mint 2+2's didnt ven work properly when i got them. Thr binding posts in one channel werent orking and in h other chsnnel were sucking up around an smp of current from the amp before getting to the speakers).

I replaced th high frequency transformers ith he excellent sounding Er Audio ones (5 kg each and a massive improvemen over the stock transformer). Much less distortion. Lots more purity and top end extension.

All the wiiring was changed.

The power supply was basically thron out and replaced with a 12 volt dc supply with adjustable voltage (now adjusted for more juice). Massive gsins here in lowered noise and noise floor, purity and life and dynamics to the sound.

The caps were changed for various types including Durlunds etc and are now a different value of stock.

Frame mods etc.

The panels were all cleaned and retensioned with a hairdryer etc.

A massive massive PITA but the sound is now in a totally different league of when they were new.

Hope some have found this interesting.

LPG.

 

RE: Restoring Acoustat Monitor 4, posted on September 24, 2012 at 08:28:16
Sondek
Audiophile

Posts: 9632
Location: Fort Worth
Joined: May 17, 2000
Contributor
  Since: April 5, 2002
 Hey, Matt. Good to see you chiming in again.

It is a shame that AC didn't make it in Houston. Was in the store there once years ago while in Houston on business. That's where I first heard the Quad 63's. They had a pair of them they'd taken on trade and were kind enough to demo them for me even though they knew I wasn't a buyer. After hearing them there I was so impressed that knew then that some day I'd own ESL's ... little did I know that it'd take more than 20 years for it to come true, but they say good things sometimes take longer. The Audio Concepts here in Dallas is still in business and by all reports doing well. Very glad to hear you hung onto your Acoustats. I am resigned to taking mine to the grave with me.

 

RE: Restoring Acoustat Monitor 4, posted on September 24, 2012 at 20:18:05
The peleton
Audiophile

Posts: 536
Location: Texas
Joined: July 7, 2010
 Sondek! Its nice to see a thread on our favorite speakers...

Im moving to a much smaller place while I list my house on the market. Sure its insane to have 8 foot speakers in a 12x11 room but what else am I going to do ... store them? hell no..

 

RE: Restoring Acoustat Monitor 4, posted on September 24, 2012 at 21:16:51
hella356
Audiophile

Posts: 275
Location: Long Beach, CA
Joined: June 30, 2006



So you kept the Acoustats after all? Sounds like at least the stacked Monitor 4? Your mileage may vary, but I temporarily set up my 2+2 next to my primary speakers, a 3+1 arrangement (the internal 3-panel pod from the model X in a new vertical frame with an additional panel centered above) in my 11'-6 by 16' room to test whether 8 panels per side were too much for the room. The imaging was certainly confused with this setup, but the bass was outstanding and did not overwhelm the room. Strong response to 25Hz & only slightly down at 20Hz; hopefully you'll have similar results.

 

RE: Restoring Acoustat Monitor 4, posted on September 29, 2012 at 14:42:26
LutherG
Audiophile

Posts: 28
Location: Spring, Texas
Joined: September 18, 2010
 I can't imagine having 8' electrostats! That was the only complaint I've ever had for these speakers is that once you stand up, the high-end rolls off a bit... Obviously, that's been corrected! Ha! Did Acoustat actually start selling their speakers this way or did this start out as someone's clever mod?

Cheers,

Luther

 

RE: Restoring Acoustat Monitor 4, posted on October 1, 2012 at 08:25:14
Sondek
Audiophile

Posts: 9632
Location: Fort Worth
Joined: May 17, 2000
Contributor
  Since: April 5, 2002
 Luther, yes, Acoustat made a Model 6 and a Model 8. Don't know that they sold very many of them though. What The Peleton has, among others, is a homebrew set of Monitor 8's. The Monitor series used the tubed servo-amps, and the Model series used the transformer interfaces. I do not believe Acoustat ever made a Monitor 8 or Monitor 6. The only Monitor 8's I've ever heard of were either Model 8's converted to servo power, or homemade Monitor 8's stacking two pair of Monitor 4's.

 

RE: Restoring Acoustat Monitor 4, posted on October 1, 2012 at 11:20:36
hella356
Audiophile

Posts: 275
Location: Long Beach, CA
Joined: June 30, 2006
 Yes, and there were also the transformer interface driven 1+1 & 2+2 models which were also 8' tall, albeit narrower, along with some full-height Spectra models. My ultimate goal is to do a "Monitor 8", essentially two Monitor 4 speakers with the stands removed & stacked, although I'm going to build custom frames tuned to my listening room. These will also have two rebuilt Servo amps per speaker and new electrostatic panels of my own building (basically cloned Acoustat panels, but with some materials upgrades which should improve them) when I can afford such. Hopefully before too long. :)

I find the 8' tall Acoustats to be surprisingly easy to live with visually, and most people don't even recognize them as speakers. I do love the radical, unorthodox look of the original Monitor 4 (which I had and loved many years ago) and every guy who saw mine loved them, too, but most women recoiled from their looks. My pair of 2+2 with blue Spandex covers have received passing grades for their looks by most women, however.

The stirring and magical sound I used to get from the Monitor 4 (and have failed to find in any remotely affordable speaker since) is what has brought me to the point of taking the direct-drive Acoustat method to the extreme. They may not be the end-all in every facet of musical reproduction, but (to me) their overall performance is hard to match, especially when money is taken into account.

 

Well said. Could not agree more with, posted on October 2, 2012 at 13:05:25
Sondek
Audiophile

Posts: 9632
Location: Fort Worth
Joined: May 17, 2000
Contributor
  Since: April 5, 2002
 your assessment of the Acoustat Monitors. Here's a pic of mine in their native habitat ...

Best Regards,

Mike



 

RE: Restoring Acoustat Monitor 4, posted on October 3, 2012 at 17:43:52
atom666
Audiophile

Posts: 33
Location: Etobicoke
Joined: September 13, 2005






Here is my attempt at a Monitor 4/ Spectra 44. There are 4 x 9" panels at a 6 degree angle. 2 panels are 3 wire and 2 panels are 5 wire .I am going to drive them with a MK121C interface initally. I also have a Spectra MK2123 interface that I have to modify to drive the panels in a Spectra 44 type cofiguration
Andy

 

RE: Well said. Could not agree more with, posted on October 3, 2012 at 22:18:24
LutherG
Audiophile

Posts: 28
Location: Spring, Texas
Joined: September 18, 2010
 That's a beautiful system and of course, the speakers are what I hope mine will be again soon... :D

My apologies for lack of responses the last few days. I'm finishing up my parents' house and am about to put it on the market so I'm in my final push to get this done.

I emailed Roy at Sounds Like New and received a response. It'll be $800 to rebuild the interfaces and he was not a fan of all the extra capacitance added... I remember by buddy Ernie telling me he'd once sent them back to Acoustat and one of the guys there really giving him a hard time about the added caps but Ernie always said they sounded better that way and I have to say they sounded awefully good!

Here is what Roy (who apparently used to work for Acoustat) said about the panels: "For the panels, you can take them out of the frames, take off the 3-pin plug and either gently hose the panels down on both sides.... or submerge them for a few minutes in bathtub.

You can use a gently soapy water.... then rinse. Shake out the excess water or use an air compressor ...gently... to blow out the excess. Then they must air dry for two weeks before reinstalling into the frames.

Take care to re-connect the three wires of each panel in the correct order to the 3-pin plug. Washing panels per the above was how we told folks to do it when they asked us at the factory."

Of the interfaces, he had the following to say:

"Your interfaces are easily, the worst I have seen. I would have to rip out everything and start over. Those grotesque capacitors and other ADDED parts must go. I cannot tell from just photos, what else might be needed. The cost will be $800.00 prepaid including return shipping by personal check or MO, included in the shipment if you want me to restore... to much better than new....the pair of interfaces.

All work is by appointment only.

If the two LF transformers are damaged, another 300 dollars will be required to be sent ...later....to cover those. Since flooding occurred in 1994 it is possible all of the transformers have dried out and may be OK.

Your interfaces are the rare elongated box type MK121-1.

We called them Universal Interfaces and very few of them were made. Finding replacement interfaces of this type would be nearly impossible."

I'm very tempted to send the interfaces to him to rebuild. I have found a schematic of these interfaces and so with that, I think I will first put the interfaces on a Variac and slowly bring them up to full voltage and see how things measure to verify the transformers are at least not shorted anywhere... I'd like to see if these will work again before dropping the money to have them rebuilt though I don't doubt what Roy said he could do with these.... I've got to sell this house first before I put that kind of money into these interfaces.

Plus, I want to see how the panels will turn out. I asked Roy if he could do anything to repair or rebuild a damaged panel and am still awaiting a reply...

Anyways, I'll definately be back on this project very soon. If any of you have any thoughts about anything in this post I'd be interested in hearing what you have to say.

I wish you guys all the best, and thanks very much for all of your posts and photos! I'm really jazzed about getting these going again. At least now I know that I have Roy as a resource so, if worse comes to worse, I know he can completely rebuild the interfaces... should the need to do that arise...

So, on to the panels...

Cheers,

Luther


 

RE: Well said. Could not agree more with, posted on October 4, 2012 at 08:20:17
Sondek
Audiophile

Posts: 9632
Location: Fort Worth
Joined: May 17, 2000
Contributor
  Since: April 5, 2002
 Luther,

I am not experienced with the transformer interfaces so take what I say with a grain or two. The panels will work with any of the various MK121 interfaces. If the ones you have are toast, you do not have to rebuild them - although Roy is more than competent to do that work if you go that way. You could buy used versions of either the original MK121's or any of the Medallion versions. The later Medallion versions are said to be better than the earlier ones. The panels come up for sale from time to time on ebay. The 9 inch panels usually go for @ $65 - $70 each, but the 8 inch panels, which are a bit more rare than the 9's, usually go for closer to $100. If you need panels, you might also try Mike Savuto. Last time I saw his cache of goodies he had several.

Best of luck with your restoration. If you really haven't heard them in a very long time I think you'll be gobsmacked with their performance. If you find yourself in the DFW area you are welcome to drop by and audition mine.

Mike

 

The Servo amps are another option if you can locate a pair., posted on October 4, 2012 at 11:59:35
hella356
Audiophile

Posts: 275
Location: Long Beach, CA
Joined: June 30, 2006
 Not easy to find, but the Servos seem to be generally preferred with the wide model Acoustats. There is a certain synergy between them. I definitely fall in that camp. You could offset the cost my selling your current amp. Savuto may be of help. Just an option. Good luck, you've already done some great work.

 

RE: Restoring Acoustat Monitor 4, posted on October 26, 2012 at 06:37:18
tyu
Audiophile

Posts: 963
Joined: April 19, 2011



I have had Acoustat form the 80s ....The Xs were my frist with all stock tube sevos....The Tube sounded good but as with most tube amps left me needing more....i have 8-10 9" panels here with 2pr of the 121 interfaces an have 6-7stock high frc transfourmers if need i may get off a pr.. an bias setup is out boarded so i can set the bias as i need ..from 4-7k...the only way to go to get the best sound out of the Acoustats there worth it,,
The bias is off on all 121s by now.... the 8-10prs i have had here over the years... there all over 30years old by now.......ESL bias is the speaker...
So how is your re-do going...are thay up an runing yet??....i post the 121 just if you or others need it..goodluck

 

RE: Restoring Acoustat Monitor 4, posted on June 16, 2014 at 09:25:46
LutherG
Audiophile

Posts: 28
Location: Spring, Texas
Joined: September 18, 2010
 Wow! I say I'm gonna be busy with whatever for a few weeks and its a couple of years later! Anyways, getting back to attempting to restore the Acoustat Monitor 4's... I'll post progress as it occurs.

Best regards to all,

Luther

 

RE: Restoring Acoustat Monitor 4, posted on June 16, 2014 at 09:29:32
LutherG
Audiophile

Posts: 28
Location: Spring, Texas
Joined: September 18, 2010
 I'm really grateful to have the photos you guys have posted showing how you went about restoring your speakers! Also glad AA left them in the thread. :D Thanks atom666 and all!

Best,

Luther

 

RE: Restoring Acoustat Monitor 4, posted on June 16, 2014 at 09:46:11
LutherG
Audiophile

Posts: 28
Location: Spring, Texas
Joined: September 18, 2010
 I had an interesting experience this weekend when I went to youtube just to see if anyone had any videos of refurbing acoustats and saw sokme speakers I was amazed by. There's a place called Kendrick (sound? speakers? - maybe its Audio?) and its a little shop in Japan. The speakers these guys have in that little room are MASSIVE.

Lots of horn midranges and tweeters - some of which feature the horn itself carved out of wood! It gave me audio fever bad - really bad! ha! There are lots of Altec VOTT speaker videos and it seems they're very collectible in Japan... I remember many years ago, whenever I would attend guitar shows, there'd almost always be someone from Japan who'd rented a booth or several booths just to store all of the old tube amps they'd bought for shipping back to Japan...

It was pretty interersting to see these people with these little listening rooms listening to these MASSIVE speaker systems! It was fun checking that out. Anyways...

Luther

 

RE: Pics of PAS3 and FM3, and Acoustat frame mod, posted on June 16, 2014 at 09:48:57
LutherG
Audiophile

Posts: 28
Location: Spring, Texas
Joined: September 18, 2010
 Really nice work with these Dynacos! I have a replacement lense to put in my FM3 and its ready to be fired up and aligned...

Regards,

Luther

 

RE: Restoring Acoustat Monitor 4, posted on February 16, 2015 at 11:13:30
LutherG
Audiophile

Posts: 28
Location: Spring, Texas
Joined: September 18, 2010
 Is anyone familiar with this? Many years ago, when I worked at Audio Concepts here in Houston, one of the guys made up a little filter network that was mounted on a banana plug. He used them on Magnepan MG-1 speakers. Basically, he inserted these between the speaker cable banana plug and the speakers and it seemed to kick up the bass rather nicely.

I've looked at low pass capacitive/resistive circuits on Google but the way they're set up, being in series, I can't see how you could mount this on a banana plug and insert it between the speaker cable banana plug and the speaker itself... I have a pair of Pioneer CS99-A speakers that I'd like to enhance the bottom end on, and can't seem to figure out how to do this and mount it on a banana plug... These are interim speakers I've been using until I get the Monitors back up. I'm starting on them again now. Just ordered fresh tubes for my Citations and power supply caps for the Dyna preamp and tuner...

Also, since my last post, I've picked up a really nice Linn Axis turntable and it sounds great!

Anyone have any ideas about the little bass enhancing filters?

Also, I'd like to apologize to you all for dropping the ball... You all were so kind to post all of this great information and advice and then I just dropped off... Life gets in the way sometimes and I'm sure you guys understand... anyways, I'll continue to post my progress for anyone who happens upon this thread...

Warm regards to you all,

Luther

 

RE: Restoring Acoustat Monitor 4, posted on February 16, 2015 at 17:24:11
Satie
Audiophile

Posts: 5426
Joined: July 6, 2002
 This is not something you want to do at the speaker level. Do it at line level.
1. you can get an equalizer rather cheaply on the used market, digital or analog. Many good pro audio units are selling at decent prices. You can also get a passive (or active) unit from White Instruments.
2. use EQ on your PC source if you use one
3. If you want a dedicated bass boost device then , or get a simple bass boost circuit and filter box from Marchand. If you are handy with a solder iron then there are plenty of devices to DIY online.

 

RE: Restoring Acoustat Monitor 4, posted on April 4, 2015 at 11:06:20
LutherG
Audiophile

Posts: 28
Location: Spring, Texas
Joined: September 18, 2010



And so it finally begins...

The first thing I notice, is that the mylar itself below the "water line" appears just as clean and shiny as the mylar above the water line. I see slight dust on horizontal surfaces but the mylar itself appears to be surprisingly clean...

Still, I want to remove the grills so that I can do a better cleaning, and would like to inspect the panels outside of the grill. Also, I need to remove the upper and lower wood end caps so that I can refinish them.

The first snag I've run into, is that there are wires going to each panel that appear to be glued in. I say this because there is one wire, that doesn't have the little Styrofoam disc around the wire (see photos) that appears to be a repair and it is located exactly once little block below where it was previously connected... SO, at this point, I'm not sure how to get everything apart? I can mark each wire going to the panel with the "bundle" that it goes to and where it connects to the little acrylic connector block (I'm going to have to remove these wires anyways, to make sure the free ends are clean or else to strip away a little more of the sheathing to expose some "fresh" wire for the reconnection...

Is this what you guys ran into and did you simply leave the tag-end of the wire connected to the panel when removing them?

 

RE: Restoring Acoustat Monitor 4, posted on April 4, 2015 at 11:18:03
LutherG
Audiophile

Posts: 28
Location: Spring, Texas
Joined: September 18, 2010
 Also, its time to fire up the interfaces because without them, I've got nothing - right? I bought a CD packed with Acoustat information from someone on Ebay but there is nothing in there that tells me what voltages I should expect and where in the MK121 Interfaces. So, while I can power them up slowly on a Variac, to see if they'll come up without blowing a fuse, that won't really tell me if they're functioning correctly?

Anyone have any ideas about this?

BTW, I'm also beginning work on my 2 Citation II amps and I'm attaching a link to my dropbox folder for that as well... The last 2 photos are of a Citation that Jim McShane rebuilt for a customer of his. He sent me the photos to show me what can be accomplished if you take them down to the chassis-level. The transformers were sent off to an auto paint shop for painting... They look pretty amazing but not sure that I'll do that. I need to see how expensive that would be...

 

RE: Restoring Acoustat Monitor 4, posted on April 4, 2015 at 12:45:06
LutherG
Audiophile

Posts: 28
Location: Spring, Texas
Joined: September 18, 2010
 Ok- If I'd paid attention to what's already been shared I would have seen the answer to my recent post. So, I'll see what I can do to remove these panels.

Before I remove the individual panels though, I'm going to try to remove the grills if that's possible... If the panels look and feel clean, I'm going to leave them as-is and not bathe them...

BTW, the thick felt damping pads appear to have already been removed by my buddy Ernie before he left them with me.

Best regards to all,

Luther

 

RE: Restoring Acoustat Monitor 4, posted on April 5, 2015 at 16:33:38
LutherG
Audiophile

Posts: 28
Location: Spring, Texas
Joined: September 18, 2010
 Ok - so I've finally managed to come to the conclusion that in order to really clean the grill cloth I am forced to remove the panels. I had hoped I wouldn't need to do this because the diaphragms are indeed nice and taught and appear to be pretty clean...

However, I'm going to go ahead and bite the bullet and remove the panels and put them away somewhere where they'll be safe (hopefully) and then see about cleaning the grills. At this point, if I go through all that, then I'll remove the bases and haul the grills and backs over to an upholstery cleaner of some kind and see if I can have them professionally cleaned. Hopefully there is a method of cleaning that won't involve submersing the wood in water in one fashion or another but I've no idea what is available in cleaning methods on upholstery. There has to at least be steam cleaning and that may be all that's needed... I've tried vacuuming the grills but the remaining dirt just doesn't want to let go...

While I have the bases off the speakers, I'm going to repaint all of the wood black. The bases themselves, have some kind of specks on them I can't seem to get off. I don't know if its the finish that has come off or what but I'm not sure what to do with them other than some of that Krylon paint for plastic lawn furniture... I kind of hate to use that because who knows how long that'll hold up?? Anyone have any suggestions? Is anyone reading this thread any more? ha!

Anyways, I'll keep posting here - maybe someone will have something to gain from my notes and what all has been posted in this thread so far.

Best regards to all,

Luther

 

RE: Restoring Acoustat Monitor 4, posted on April 11, 2015 at 07:01:45
LutherG
Audiophile

Posts: 28
Location: Spring, Texas
Joined: September 18, 2010
 For anyone still reading this thread, the plan at this point is to use Boraxo powdered soap. They make one that is gentle and unscented - 100% biodegradeable so I'll be getting this today. I was thinking I would mix up some boraxo in distilled water, and fill a spray bottle with it. Then, having removed the panels, I could spray them down heavily with this soap mixture, allow them to soak for a bit, then gently hose them down using the "rain" setting on my hose-end nozzle with very low pressure setting... Just enough pressure to rinse the panels well without the pressure pushing on the panels. I could rinse them while they are standing up leaning against the railing of my deck... We'll see how that goes...

Otherwise, I'll have to build some kind of trough to bathe them in which would take longer, require much more water and materials not to mention that I'll have to flip the home made trough over to do a rinse cycle... I think the water bath is a better approach but will take longer and would be more cumbersome to manage... I'm open though if anyone has any thoughts on this...

I've also picked up some black oil-based enamel to paint the frames after I've cleaned them though now I'm wondering if a latex paint might be better... I just don't think latex will hold up over the long haul but on the other hand, I'm hoping there won't be any issues with fumes from the oil based paint reacting with the panels... Maybe I'm over thinking this...

I've talked to the Acoustat Answer Man Andy Szabo and he's going to flesh-out some procedures for testing the interfaces to make sure they're working properly... I hope to hear from him this coming week.

Finally, I was unable to find a professional cleaning service that would clean my grill cloths so I'm going to use the same approach that I'm planning to use on the panels and that is to soak the fabric with a boraxo soap solution from a spray bottle, and then gently rinse the grill cloth using a hose end nozzle set to a gentle spray - but the nozzle is one of those that has a bunch of small holes in it to get a rain-like spray pattern that should be able to push the dirt from the fibers without stretching the fabric...

Wish me luck! I'll post photos here of the process... If all of this works, and I'm able to get the speakers up and running again, then I'm considering replacing the Walnut end caps with Cocobolo end caps. I've already found a couple of exotic hardwood suppliers in Houston that may have slabs large enough for this purpose...

Kind regards to all,

Luther

 

RE: Restoring Acoustat Monitor 4, posted on April 11, 2015 at 08:39:06
JLindborg
Audiophile

Posts: 1037
Location: Uppsala
Joined: April 26, 2010
 Nice reading!

Though, your drop box link doesn't link to Your drop box specifically.

Cheers!


The one who succeeded was the one who didn't know it was impossible.

 

RE: Restoring Acoustat Monitor 4, posted on April 11, 2015 at 14:44:23
LutherG
Audiophile

Posts: 28
Location: Spring, Texas
Joined: September 18, 2010
 Hey JLindborg,

Nice to see a response! ha! Sorry about the link - when I first posted it - it worked for me but now it takes me to the login page so I'll just post some photos here in my next post.

Since there is still someone watching the thread, I'll go on to say that I have indeed discovered that my 8" panels will fit in my bathtub after all. So, that's the route I'm taking and will do 4 panels at a time since there's room in the tub for that many. I'm letting the water sit for a couple of hours which hopefully will allow some of the chlorine to evaporate before I get started...

There is some slight mildew scent either in the bases or grill cloth - or both so I looked online and saw that vinegar and baking soda both help to get rid of mildew and help to deodorize so I'm thinking I'll mix a little of one or the other in some soapy water in a spray bottle in hopes that this will help freshen up the fabric without discoloring it. I sure would have liked to have had these grills professionally steam-cleaned... Drying all day in direct sunlight would also be helpful but not sure how soon I'll have sun like that. Just checked the local weather and I've got rain for the next 7 days... nice...

Best regards to all,

Luther

 

RE: Restoring Acoustat Monitor 4, posted on April 12, 2015 at 21:22:53
LutherG
Audiophile

Posts: 28
Location: Spring, Texas
Joined: September 18, 2010
 Well, I have heard from Mr. Szabo and this is what he had to say about washing the panels:

"It sounds as though your panels are in remarkably good condition, especially considering the abuse they suffered. A good blowing out with compressed air, and/or vacuuming would be a good idea. Although some people have removed their panels and washed them, I don't recommend it. Some folks have had no trouble doing this, but others have destroyed the conductive coating, and I haven't been able to ascertain what makes the difference between success and failure. Therefore, this should be done only as a last resort."

I spent most of the afternoon and evening running around looking for the Boraxo soap I'd decided to use for bathing the panels and ended up having to order it from Amazon. These panels will indeed fit in my bathtub after all. So, for the interim, I begin work on the interfaces. Mr. Szabo sent me some instruction for checking the bias and it looks like I'll need to remove all of the extra capacitance from the interfaces until I have them working properly. I'll also look into the mods that were posted earlier in this thread to see about incorporating them into the MK121 interfaces.

This is all I have to add for now. Until I can come up with some documentation for reconnecting any wires that come free of the panels I'm leaning toward leaving them in the frames because the last thing I want to do is make matters worse than they already are. Plus, as Mr. Szabo recommends above, I should leave washing the panels as a last resort.

For me, once I get the Boraxo, and have secured the proper method for attaching the wires to the panels, then I'm going to give them a bath in the tub using very little soap and, while I have the panels out of the frames, I'll give the grill cloths a good cleaning leaving them to dry in the sun. I won't have sun like that for another week according to local weather reports...

With respect to cleaning the grill cloth, Mr. Szabo recommended simply pulling the fabric from the frames and washing them in Woolite or else simply replace them with new fabric and I'm considering this. My only concern here would be in being able to reinstall the fabric as well as it was originally installed. I'm not sure I can do that - I need to think about how I'd approach this and if anyone has any experience in pulling the fabric and reinstalling it, I'd sure love to hear about your experience and would welcome any tips or suggestions...

More photos to be posted very soon...

Best regards to all,

Luther

 

RE: Restoring Acoustat Monitor 4, posted on April 17, 2015 at 11:14:53
indyhank
Audiophile

Posts: 5
Location: Texas
Joined: August 31, 2006
 Nice project, LutherG. I bought a pair of Model 3's last year and have since procured upgrade parts for all the caps, resistors, diodes, pot and wires and will be overhauling the interfaces. If you want to replace your grill cloth with something more acoustically transparent, consider Spandex. Here's an AVSForum thread comparing the AT qualities of different brands of spandex:
http://www.avsforum.com/forum/110-diy-screen-section/1454505-acoustic-transparency-spandex-truth.html
I've got samples from the top-rated brand. There are some nice dark, elegant colors like burgundy, dark green and dark blue, and others.
Have fun!

 

RE: Restoring Acoustat Monitor 4, posted on November 17, 2017 at 16:41:10
LutherG
Audiophile

Posts: 28
Location: Spring, Texas
Joined: September 18, 2010
 To Everyone who followed this thread and posted your great information and assistance, after having been flooded twice, the last time by hurricane Harvey, I got laid off from a company that I worked for, for 25 years... During this time off, I've taken the time to buy a new house (because I had to have a place to live) and now have a small listening room. I set up a listening system utilizing an old Pioneer tuner and integrated amp. I also picked up a Levinson 38S Preamp, a Levinson CD Transport and a Levinson DAC. I also had the faceplates for my 2 Citation II amps refurbished.

After looking long and hard at my Acoustats, I realized the diaphrams are clean and tight. I contact Roy Savuto and he have me a voltage range to check between the red pin on the 3 way banana plug female receptacle and ground. The voltages checked out so after another cleaning, and making sure both speakers were set at the same angle, I fired them up!

I was blown away at how well these speakers perform!!! It is literally as though I went from the last day they were working to today without skipping a beat!!!

I spent the whole day listening to them. Currently, I'm playing music from my phone into a Pioneer Home Theater Receiver. I'm using it because my Citations need to have the transformers repainted and perform some internal upgrades. In the interim, I'm more than happy to use my Pioneer Receiver and phone or tablet to play MP3 files... The sound is incredible!!! I'll be posting a video on either YouTube or Instagram and when I do, I'll post a link here. I just need to sort out how best to record the audio...

Anyways, I can't thank all of you enough for your kind assistance and I apologize for dropping off like I did... which is why I'm following up on this thread...

To Ernie: these are Your speakers. If you read this thread, message me and let me know how to contact you and I will bring these speakers to you right away and purchase another pair somewhere!! In the meantime, I'm going to really enjoy listening to them! After 23 years, they're running and sound absolutely incredible!

All the best to everyone - Luther


 

RE: Restoring Acoustat Monitor 4, posted on November 17, 2017 at 21:36:06
Satie
Audiophile

Posts: 5426
Joined: July 6, 2002
 Acoustats are survivors. Good luck to you getting back to work.

 

RE: Restoring Acoustat Monitor 4, posted on January 26, 2018 at 14:25:29
LutherG
Audiophile

Posts: 28
Location: Spring, Texas
Joined: September 18, 2010
 To anyone interested,

I've posted several video clips in instagram of the restored Acoustat Monitor IV speakers in action:

https://www.instagram.com/p/BcQ7LAEjp7P/

 

RE: Restoring Acoustat Monitor 4, posted on January 29, 2018 at 09:31:41
LoonyBin
Audiophile

Posts: 1
Location: S.E. Michigan
Joined: September 16, 2012
 Wow LutherG talk about persistence! A long journey to get your Monitor 4 restored indeed. Talk about a bulletproof design. Congrats on getting these awesome panels back up and running, surely them tube Citations will only make them that much better.

I have Spectra 1100s powered by a Sonic Frontiers Power 1 amp, using 4 KT-120s.
DW

 

RE: Restoring Acoustat Monitor 4, posted on January 29, 2018 at 13:00:30
LutherG
Audiophile

Posts: 28
Location: Spring, Texas
Joined: September 18, 2010
 Thanks DW!

The Citations are up next. I have a matched octet of Gold Lyon KT88s and NOS 12BY7As for the front ends...

Once I have them up and running, and have the interconnects and speaker cables in place, I'll post a link of the system up and running.

I need to sort out a better way to record than my phone...

Cheers and thanks for the response!

Luther

 

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