pi One ?

[owlsplace]

Anyone have a pi One? I can't even find a photo of one

SteveF was talking about parts-bin speakers and I was wondering if this speaker falls into that category.

As long as we are at the parts bin, can anyone tell me what was the thickness of the wood used for the 3 series cabs?

Roger

[DavidR]

Not a whole lot of info on them out there either. Made 1974 -1975. 12" woofer/1.5" mid/.75" tweeter. No FR given. Same set up as Pie 10 and AR11, apparently. The 11 had the better FR.

[ra.ra]

pi = 3.1415926.....

This speaker model is so obscure that the responses might just barely dribble in - - - it's almost akin to spotting an AR-1x (pink unicorn?) in your neighborhood. Nonetheless, this topic is very timely because tomorrow is in fact pi day - - - or March 14 in the year 2015, more commonly referred to in the U.S. as 3.14.15.

Playing to the nerd in many of us (admission: self included! ), the Massachusetts Institute of Technology (MIT) will tomorrow announce its accepted applicants at precisely 9:26 AM, (or in pi day lingo, 31415926). For you classic speaker enthusiasts who are not familiar with our local geography, present day MIT-owned property includes several original KLH and Advent production sites, and is just spittin' distance from the primary Cambridge AR facility.

http://www.piday.org/

[owlsplace]

Ha, ha, ha, I forgot about pi-day .... I'll have to buy a pie

And if anyone has that thickness dimension of the lumber used on the 3 series, inquiring minds want to know although I suspect somehow π will be a factor

[ar_pro]

Ah, the Pi/One - unobtainium.

[owlsplace]

Well, not a parts-bin speaker then. Looks you will have to bake your own pi to get one of these

Happy pi-day!

Roger

[lakecat]

Wow!....never heard of this speaker. Hmm...improved version of the 3a?.....and what happened to it?

[DavidR]

Wow!....never heard of this speaker. Hmm...improved version of the 3a?.....and what happened to it?

It morphed into the Pi 10 and then an AR11

[Tom H.]

I am celebrating pie day with my AR-10pi's here. I am having a Dylan fest!

[ra.ra]

Thanks, ar_pro, for posting that rare info - - have never seen that before. Interesting to note that as this model morphed into the 10pi, at least they replaced those cheesy-looking switches. Also interesting to see that the LST-2 did not yet have a proper name.

[iso]

The following information was found from 1998 reprint of AR-LST review by late John Grabbe, that appeared first time in August 1973 HiFi News/Record Review. In this review there was also some information about birth of AR International operations. It appears that Frank Jones was supposed to write this review in Hifi News. As AR engaged him to run part of AR International operations John Grabbe actually made AR-LST review. It was decided that it would not be fair to "manufacturer" to review their own product.

Before this there was long discussion between Roy Allison and especially Frank Jones on pages of HFN/RR about design principles of AR3a. It appears that AR actually produced experimental AR-3F pair. The "F" stood for flat and AR-3F did have 6-way spectral balance control on front panel. There was no information how control was made, but most likely similar autotransformer like in AR-LST was used. Despite all their doubts, AR seemed to be toying with the idea of nominally flat response as they did deliver experimental AR-3F pair to Croydon where Jon Crabbe and Frank Jones of HFN/RR could audition it. Crabbe mentions that he and Jones found AR-3F to be very fine speaker. However this model never materialized as AR-3F... but features mentioned seems to be quite similar to pi One mode discussed here, timing was also close enough... so could it be that AR pi One was actually production designation for experimental AR-3F.

Original AR-LST review appeared in August 1973 issue of HFN/RR and I have copy of it. If our staff can handle copyright issues and would like to add this very comprehensive review in library section, I can e-mail scans of this article.

Best Regards

Kimmo

[ra.ra]

From the Library, this may help date the changeover from the Pi/one to the 10/Pi.

[Steve F]

I have to admit, it's a strange mix of unsettling and flattering when a personal communication of yours is cited by someone else as giving credence to an answer to a question from a third person!

The Pi/One to 10 Pi aspect of that letter had actually slipped my mind, so thank you for digging it out.

BTW, AR did send me the 10 Pi lit (the ADD lit in the library) three weeks later, just like Barbara Katsenbaum said they would.

I'd love to know more about that so-called "AR-3F" variant. Obviously the "F" part ("flat") couldn't have been achieved without a Ferro-fluid-cooled tweeter or at the very least, the far more efficient 10 PI/11 tweeter (relative to the first-gen 3a hard black 3/4" dome). You just couldn't drive the 3a tweeter hard enough to achieve "flat" response without danger of mechanical/thermal damage. Well, you could at moderate levels--a 3a with the amp's treble at 2:00 at 'regular' SPLs playing the Brubeck Quartet or Mozart's 40th sounded absolutely great. But play hard rock at high SPLs with the treble turned up and that little black dome was short-lived.

Did the 3F have the WEC also, or was it essentially an 11?

Steve F.

[ra.ra]

I think it was the recent thread about the AR-58s that made me realize that there was still material in the Library that I was unfamiliar with, and then one thing led to another and I stumbled on the Steve F letter from early '75 which had this very specific mention of the Pi/one.

iso/Kimmo may be on to something here - - - I sort of recall once reading something similar about an experimental speaker with a front control that never made it to market, but it does make one wonder what was different between this 'rejected' prototype and the subsequent 'accepted' model which ultimately did reach the retail sales floor as the Pi/one or 10/Pi.