Microstatic supertweeter rescue mod

[JKent]

The MicroStatic tweeter array has been discussed in these pages several times. I'm a fan. I think Frank is too. Some other members not so much.

I've owned and refurbished several but sold my last working pair. All I had was one working orphan and a pair I'd foolishly bought "not working". I thought maybe it was a crossover component but it turned out all 8 drivers were fried. 

The MS-1 had Peerless tweeters. The very earliest ones had 2 sizes: Larger diameter on the outside and smaller in the center. Later ones had all 2" drivers. The drivers were Peerless, maybe MT-225 (?) I dunno. Those are no longer available and I seem to recall someone on these pages offering Mitsubishi replacements.

So. This pair of MS-1s had Mitsubishi drivers. I guess someone fried all the Peerless tweets and replaced them with Mitsus, then fried those. Searching around for 2" Peerless tweets I found some at $25 each, so $200 for the pair of MS-1s 🙁 That ain't happenin.

Then I found these Buyouts at PE: https://www.parts-express.com/JZ2-678H-2-Paper-Cone-Pressfit-Mount-Tweeter-6-Ohms-69-289-2358?quantity=1. I bought 10 for $13.30 total 😊

They fit the 2" holes in the MS-1s perfectly but had no mounting tabs so I glued them in with E-6000. This is a permanent thing so it has to be right. The xo wires were attached to the original drivers with Sta-Kon type quick connectors but I found those won't work on the PE drivers. The terminal tabs are inconveniently placed. You can't reach them after the drivers are glued in and if you attach them before pushing the driver through the hole they get hung up. The best (only) way to do it is to solder the wires to the drivers. And, the little terminal tabs are precariously close to the magnet so I used heat shrink tubing to protect them from shorting (sorry I didn't take photos).

The PE drivers are 6 ohms and the original Peerless were, I believe, 8 ohms but in my brief listening tests I did not hear a significant difference between the new modded MS-1 and an original I had on hand.

Next up will be replacing the grille cloth. The original linen-like fabric was glued to a cardboard backing so removing it is a challenge. I'll post more on that when/if I get the grilles finished.

Here are some pics of the almost-finished MS-1 being tested and side-by-side comparison of the PE and Mitsu drivers.

 

[JKent]

Earlier MS-1 grilles were lightweight linen, wrapped on all 4 sides of the cardboard backing. Later ones were a thicker fabric wrapped only on the narrow ends leaving raw edges on the top and bottom. They were stapled on and the staples eventually rust.

I had some small pieces of the wichelt 18-count linen left. I glued them to the cardboard, wrapping on all 4 sides and attached the grilles to the speakers with Alene's Tacky Glue.

The backs were screwed on, on the early models but glued on later ones. These had been glued but I used screws to reattach. Also added some DakaWare knobs to match my ARs and to be able to easily see where the pots are set.

 

 

[Aadams]

Are you using them above 3.5k or 7k?

[JKent]

1 hour ago, Aadams said:

Are you using them above 3.5k or 7k?

I tried 3.5k, thinking my old ears won't hear above 7k but I was mistaken so now I have them set at 7k with the pots at about 50%

[frankmarsi]

"The MicroStatic tweeter array has been discussed in these pages several times. I'm a fan. I think Frank is too. Some other members not so much".

Hi Kent,  yes I am a proponent of these little guys and have been since 1974. When I had no recourse as what to do about constantly blowing AR tweeters I was at my wits end. In fact I may not have become a continuing AR-3a fan all these years if those little guys didn't come to my rescue. 

Since my first blown AR tweeter in late 1971 I became a regular in talking to AR offices and sending out and receiving new replacements from them  for about a 3 year period.

Of course, that had to stop because AR and myself were growing more and more distraught by the issue. They even asked about my amplifier a Dynaco ST-120 which itself was another problematic piece of equipment and I went through the same situation with Dynaco with sending back forth their driver-board and power transistors.

In 1974 I had to make a decision as what to do. I couldn't go on with constantly failing tweeters and, I had to have my music. After much soul-searching and the saving money each week, I bought my first pair of Micro-statics for $78.00. And, even though AR-3a's and the Dynaco amplifiers were the darling pairing of components back then and a very popular favorite if you were an avid fan such as my self.

Fast forward to later 1974 and I had already straightened out the AR tweeter problem by using the Micro-Static array but, I was also past feeling devoted to Dynaco SS amps and had to move on to another amplifier.  In that period, the most cost effective and highest wattage rating amps at the time were the Phase Linear 400 and 700 anything was more money or ultimately had less positive reviews. I couldn't afford the 700 which at the time was an unheard of amount of power, I purchased the PL-400. And as they say, I never looked back. 

With the Micro-Statics absorbing enormous amounts of power without failing and the amp supplying them without flinching the least bit, I was finally content and once more never looked back except viewing those first few years as a learning-experience. I also learned because of the changes I made was that AR's midrange and woofer were able to handle such high wattage without damage.  From that point on, I have never accepted anything less than high wattage and crystal-clear and realistic amounts of high frequencies in my listening pleasures. For me, this is what I consider realistic and accurate sound and high power was the path I took. Listeners holding onto low wattage systems just don't know what they're missing.

FM

P.S. AR tweeters are excellent in all areas except power-handling as most would agree. Their degree of sound spread and accuracy are hard to match yet, they just don't put-out enough of it. Beyond all of their testing, the large amount of public-acceptance and popularity, for me and as generally most would agree, cymbals, note-edges, transient nuances, and other high-frequency information is not as limited in real-life as the AR tweeter portrays in most cases. Don't get me wrong there have been times where they can be surprising and as AR intended I trust the tweeter's rendition of high-frequencies but, that would be the exception, not the rule.

I'm so firmly planted in this opinion as I've said above, if I didn't discover and happily use the Micro-Statics all these years I'd be listening to who knows what. Maybe Advents, KLH's, anyone's guess in that league or, I would have many high-end greats that have come and come already in the last 50 years but, that's another discussion. But, in the end, even I find it amazing that I believed in this speaker for 52 years-geez!

P.S. II the newer ferrofluid AR-9 tweeters have improved things substantially however, their power handling is not a great as the Micro-Statics. 

The Micro-Statics were and still are very attractive, their price was/is affordable for the masses whereas other offerings were/are outrageously priced. Names like Ohm, ESS Heil Air Motion Transformer, the Janszen l-30, the Pioneer versions plus older variants from the late '50s and '60s are still available used. Numbed by so much advertising of components through out the decades that I've forgot many but, the list goes on. Additionally, the current market is vastly different than my formative years were of absorbing all I could, there's just too much to retain mentally.

Ultimately, for me, my experiences reflect well on how I've set-up my system and my approach to critical listening. I've set-up a glorious sounding system solely with vintage components except, phono-cartridges, record cleaning and cables as I feel those areas have improved through-out the years and are easily affordable and do make obvious differences.

They've certainly gone up in price since I purchased my first pair'  back during the "Golden-Age".      

  https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2047675.m570.l1313&_nkw=Micro+Acoustics+MS-1+Speakers+Microstatic+Tweeter&_sacat=0

FM

 

 

 

 

 

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[genek]

I have two pairs of these (used to have three, sold one to one of our members a while back). I question whether they really added all that much to the higher end AR speakers back in the day, but considering that those old speakers' tweeters are now operating at less than optimal performance, for what I paid for the Microstatics ($50 and $75/pair), they're an obvious alternative to having to rebuild or replace all the old tweeters.