AR-MST

[Guest AR-MST-PICCO]

I owned 2 pairs of AR-MST loudspeaker. My MST is the earlier model. The speaker box contained 4 units tweeters and 8 inches woofer. I learn some MST information from this forum. AR discovered that the earlier MST model have technical problem occured. For example, impendance issue. They released a new improved model and named MST-1.

The new model contained 3 tweeters and 8 inches woofer. I like the MST speaker.

Information provided from Steve F.

The MST was introduced in March 1975 along with the 11 and 10Pi as part of AR's new ADD (Advanced Development Division). The cabinet was shaped like a smaller version of the LST, with three radiating cabinet panels--one forward facing, and two angled away to the left and right of the front panel.

It used an 8" woofer and three 1 1/4" cone tweeters (similar to the tweeter in the AR-6 and -7), not the 3/4" dome. The speakers were mirror-imaged, with two of the tweeters side by side above the woofer on the front panel, and the third tweeter on the side panel. One side panel was blank. AR's instructions were to orient the speakers with the tweeters on the inner panels for a more tighly-focused stereo image, and to place the speakers with the tweeters facing out for a more diffuse, spacious effect.

The forward-facing tweeters crossed over from the woofer at 1600Hz; the outer tweeter handled frequencies above 5000Hz.

There apparently were some response irregularities in early-production MST's due to measurement inconsistencies between AR's different testing facillities, but this was straightened out in due course.

It was actually quite a nice sounding speaker, but the relatively high price ($159 ea. in 1976) for a speaker with a 3dB down point no better than an AR-6 and the difficult-to-place LST-type cabinet limited its commercial success."

[Guest AR-MST-PICCO]

AR designer found that installed the High Pass capacitor filter from the negative circuit will improve the phase shift problem. MST using a 6db octive crossover design. For more detail, please see below:

[Guest AR-MST-PICCO]

It is easy to reconize the original AR-MST Tweeter. The Tweeter designed from Roy Alision. The tweeter look like a nipple.

This is a slow response tweeter (compare with AR 3/4 tweeter "with magnet liquid cool design"). I used solen cap. It improves the sound quality.

[dynaco_dan]

>It is easy to reconize the original AR-MST Tweeter. The

>Tweeter designed from Roy Alision. The tweeter look like a

>nipple.

.

.

>This is a slow response tweeter (compare with AR 3/4 tweeter

>"with magnet liquid cool design").

I used solen cap.

It

>improves the sound quality.

>

Hi Picco;

This is another example of a Solen capacitor being used with tweeters and with sound satisfaction.

Recent writings here would have made me believe that Solen caps were not so great.

How confusing.

How long have you had your Solen Caps installed?

How long did it take for you to appreciate the sound difference?

Nice photo.

[Guest AR-MST-PICCO]

The different in between AR-MST and AR3 tweeter. A big difference from Magnet component. AR-3 installed huge volume of Alnico V magnet.

From 1970's Roy Allison design a new AR tweeter. The sound is great.

[mluong303]

Could you post close up pictures of the the AR-MST and AR-MST1 logo pictures for us? Thanks.

ML

[Guest AR-MST-PICCO]

I would like to share my experiences.

I found that the original crossover from AR 3 and 3a using the oil cap or Bi polar Electrolytic capacitor. It is talking about 60's. There is no CD player. Actucally the original AR 3a tweeter can provide a wide frequency response. The tweeter is very sentitive.

It must working with fast response capacitor. It is hard to find from 60's. Do you remember the tolerence of the capacitor?

From technical point of view, the response time for oil cap and bipolar Electrolytic capacitor are slow.

I replaced a solen cap from Tweeter, it improved the sound quality.

To be continue.....

[Guest AR-MST-PICCO]

Hello mluong303,

Thanks for your interest from my AR-MST topic. I apologized that I do not have AR-MST-1. I visited the classicspeakerpage web page. It got a AR-MST-1 picture. As you know, the different in between AR-MST and MST-1 model is the total units of tweeters. Yes, there is a different from Crossover.I purchased a AR-MST cabinet from ebay last year. This MST unit is under construction. I try to collecting and install the original MST-tweeters. The project is in progress. I will post the picture to this forum once project complete.I like the alnio magnet AR 8 inches woofer. Therefore I installed a pair of Alnico woofer from this cabinet.

I like AR speakers and JBL speakers. From my personal point of view, AR mid-range and JBL 2441 horn driver is the State of the art device.

Please find attached photo for reference.

[Guest AR-MST-PICCO]

Vintage AR speakers and driver devices are under value. I purchased few AR alnico speaker devices. Paid expensive delivery cost. Take a closer look for my photo (see attached photo). Huge alnico magnet, very high quality.

I used solen cap replaced the original capacitor, especially for AR-2ax and AR-3. It sounds great and improved the tweeter efficency.

[dynaco_dan]

Hi there;

Nice closeup photo.

What value and voltage rating of Solen caps did you use for the 2 series and 3 series?

Thank you.

[Guest AR-MST-PICCO]

Hi Vern,

For AR-2ax, the solen cap are 6uf and 4uf.

I like vintage AR speaker very much, my collection included AR-98Ls. I replaced few capacitors from the crossover. Put the sponge from Tweeter area (Dual Dome) and replace the binding post. I am not going to modify the crossover design. AR-98LS installed a very good design crossover.I treat with respect.There are AR Fans bypass the switch from the crossover. Do you like vintage AR speaker.

[Guest AR-MST-PICCO]

I put the sponge tape to the tweeter area. It improved the sound stage. Do you want to try this solution?

My amp is a intergated tube amp. The tubes are using EL-34.

[Guest AR-MST-PICCO]

Dear vintage AR fans. Do you remember AR-1ms? A excellent quality mini loudspeaker from mid 1980's. My personal collection included AR-1ms.

[Guest AR-MST-PICCO]

I opened the AR1-ms metal cabinet and found that the dual-dome device not similar to AR-98LS. The tweeter and Mid range from AR98LS sharing the Magnet device. The magnet size is huge.

AR-1ms using standalone speaker unit (tweeter and woofer). From technical point of view, it is 100% equivalent. It emulating a single point source design concept.

[Guest AR-MST-PICCO]

The closer look for the AR TSW liquid cool tweeter.

http://img.photobucket.com/albums/v704/cha...tic-fluid-2.jpg

[Guest AR-MST-PICCO]

The magnet fluid running in between magnet and voice coil.

http://img.photobucket.com/albums/v704/cha...tic-fluid-1.jpg

[Guest AR-MST-PICCO]

I like vintage AR speaker. I do concern with my amplifier. I used tube amp (Conrad Johnson and ARC)to drive my AR speaker. Does anybody else using tube amp (Pre + Power amp) working with your AR?

Please see attached pictures (my AR MST collection).

http://img.photobucket.com/albums/v704/cha...o/AR-MST-S2.jpg

http://img.photobucket.com/albums/v704/cha...o/AR-MST-S1.jpg

[Guest AR-MST-PICCO]

From technical point of view, the end-users will use high power, high current solid state power amp driving vintage AR speakers.

The vintage AR speakers including AR3, AR3a, AR-LST, AR-MST and Teledyne Group (AR38s to AR9Ls).

However my opinon is different. Regarding to my experience, I prefer to use Vaccum tube power amp instead of solid state high power, high current power amp. My equipments setup are shown as below:

Source

Turnable:

DP-55K plus SME-3009SII improved + Decca Super gold cartridge

CD Player NAD

Conrad Johnson PV-2

Conrad Johnson MV-75-a-1

Speaker AR-98LS , AR3, ARMST, AR38s

I noticed that there is a integrated tube amp which can providing a excellence performance. The selling price is HK$(5300)- equal to US$700. The brand name is Melody and the model no is SP3.

This amp contained 4 6L6GC tube. This amp also contained a line amp (10 times). I found that there are few integrated tube amp do not contain line amp. However they claimed that this is a integrated amp.

This SP3 is manufactured from China. However it installed high quality components. For example volume control (manual made-soldering resistors by hand), Dual C core output transformer.

High Quality case.

I am comfortable to use this integrated amp to drive my AR3.

The signal source is NAD CD player.

The AR3 loudspeaker+Melody SP3 do the best. No matter you are listening Jazz, Classic, Female vocal voice. They can provide a deep sound stage and 3D effect. The sound is warm.

http://img.photobucket.com/albums/v704/chanpicco/AR3SP3.jpg

[Guest AR-MST-PICCO]

From technical point of view, the end-users will use high power, high current solid state power amp driving vintage AR speakers.

The vintage AR speakers including AR3, AR3a, AR-LST, AR-MST and Teledyne Group (AR38s to AR9Ls).

However my opinon is different. Regarding to my experience, I prefer to use Vaccum tube power amp instead of solid state high power, high current power amp. My equipments setup are shown as below:

Source

Turnable:

DP-55K plus SME-3009SII improved + Decca Super gold cartridge

CD Player NAD

Conrad Johnson PV-2

Conrad Johnson MV-75-a-1

Speaker AR-98LS , AR3, ARMST, AR38s

I noticed that there is a integrated tube amp which can providing a excellence performance. The selling price is HK$(5300)- equal to US$700. The brand name is Melody and the model no is SP3.

This amp contained 4 6L6GC tube. This amp also contained a line amp (10 times). I found that there are few integrated tube amp do not contain line amp. However they claimed that this is a integrated amp.

This SP3 is manufactured from China. However it installed high quality components. For example volume control (manual made-soldering resistors by hand), Dual C core output transformer.

High Quality case.

I am comfortable to use this integrated amp to drive my AR3.

The signal source is NAD CD player.

The AR3 loudspeaker+Melody SP3 do the best. No matter you are listening Jazz, Classic, Female vocal voice. They can provide a deep sound stage and 3D effect. The sound is warm.

http://img.photobucket.com/albums/v704/cha...3Hofner1959.jpg

[Guest AR-MST-PICCO]

I still remember, I replaced the edge of my AR 12 inches woofer.

The edge material is make use of sponge. However i found that this material not suitable for high humidity weather (like Hong Kong - Asia country). Then I use rubber edge replace the original sponge edge. The diameter of the 12 inches woofer using 11 inches edge.

At that time, it is hard to find original AR parts in Hong Kong.

I modified the rubber edge(non-AR) and make use in the woofer.

Attached is the photos for reference.

http://img.photobucket.com/albums/v704/chanpicco/AR-12-1.jpg

[Guest AR-MST-PICCO]

I still remember, I replaced the edge of my AR 12 inches woofer.

The edge material is make use of sponge. However i found that this material not suitable for high humidity weather (like Hong Kong - Asia country). Then I use rubber edge replace the original sponge edge. The diameter of the 12 inches woofer using 11 inches edge.

At that time, it is hard to find original AR parts in Hong Kong.

I modified the rubber edge(non-AR) and make use in the woofer.

Attached is the photos for reference.

http://img.photobucket.com/albums/v704/chanpicco/AR-12-2.jpg

[Guest AR-MST-PICCO]

I still remember, I replaced the edge of my AR 12 inches woofer.

The edge material is make use of sponge. However i found that this material not suitable for high humidity weather (like Hong Kong - Asia country). Then I use rubber edge replace the original sponge edge. The diameter of the 12 inches woofer using 11 inches edge.

At that time, it is hard to find original AR parts in Hong Kong.

I modified the rubber edge(non-AR) and make use in the woofer.

Attached is the photos for reference.

http://img.photobucket.com/albums/v704/chanpicco/AR-12-4.jpg

[dynaco_dan]

Hi there;

Does anyone here know if there is a schematic of the 3 tweeter version of the AR-MST posted on this web site?

I saw the 4 tweeter version schematic.

Is there a drawing of the cabinetry on this web site for the 3 or 4 tweeter version?

Has anyone attempted to make a similar speaker system from scratch?

[Mexicomike]

I have to say this site is really interesting. I never heard of at least half of the AR speakers that were made! After the LST, I pretty much lost track of what AR was doing, having sold my 3As and 2Axs in the mid 70's and moved on to "better" speakers. I never heard of MSTs or virtually any AR after say, 1973-4. The ARs I was familiar with were 3As, 2Axs, 4xs, 5s, and LSTs (LSTs only by ads, never saw or heard one at the time). I did audition a pair of what I now think were AR 9s in the mid 80's but I didn't buy them, opting for Nestorovic 5AS's.