Acoustic Research AR3a Improved

[powerglide]

Hi folks, I have the opportunity to purchase some AR3a improved for a not so bad price, what is the general consensus on the "improved' model? Do they have the same pedigree and following as the first AR3's and AR3a's? 

They need a full Resto as per the 2's I recently finished 

[JKent]

Here's what Roy wrote about them:

"The AR-3a Improved was a non-US model using the European style 3a cabinet. It was equipped with the original AR-3a drivers, had switches instead of pots, and a somewhat different crossover. It showed up for a short while about the same time as the US introduction of the AR-11 (the next generation AR-3a)...around 1975.Do a search over at the Classic Speaker Pages...Lots of info there, including a schematic."

Here are Tom Tyson's comments:

"The AR-3a Improved was a European-export-version only, assembled in England and Holland, and it incorporated some improvements to the original AR-3a that were eventually put in the AR-11 and AR-10Pi over here. The biggest difference in the AR-3a Improved and the AR-3a was the cabinet, as the "Improved" used a slimmer cabinet molding than the original version which improved the appearance and reduced diffraction. The "Improved" speaker had a more elegant, modern look than the original, wide-molding AR-3a. The drivers were the same as the US version, but I think switches were used instead of level controls, much like the AR-11."

[powerglide]

Thanks Kent, 

But i was too slow on the trigger and missed out, not ment to be. 

I was hoping someone would chime in and say they are better or inferior to the 3a's, reading between the lines true enthusiasts would go with either the 3a's or the 11's the improved 3a's seem like a hybrid that didn't really need to happen. Maybe heightened by the fact that they weren't marketed in the US.

happy for someone to correct me

[Steve F]

It is not quite accurate to simply say that the 3a Improved used the same 3a drivers, a Euro-styled cabinet and switches instead of pots and that was it for differences between it and the original 3a. The 'slightly changed crossover' was supposed to deliver a flatter power response than the U.S. 3a. I have a 3a Improved ad that says that and I will endeavor to dig it out.

In any event, the differences weren't that great and the U.S. arm of AR decided against marketing it here, since the ADD's (11's and 10π's) were due at pretty much the same time. One of my "Steve F Letters to AR" in the library covers this and AR's response to me.

Steve F.

[Aadams]

29 minutes ago, Steve F said:

switches instead of pots and that was it for differences between it and the original 3a. The 'slightly changed crossover' was supposed to deliver a flatter power response than the U.S. 3a.

The switches would also make it simpler to keep the mids balanced, a key to the LST sound where all 8 eight mids in a pair are always at matched output.  The improvement in a 3a is noticeable when the mids are at matched output, a state which is almost impossible with old pots but is achievable with LPads , and easy with toggle switches but don't be surprised if you need an an equalizer with those toggles.  That said, I prefer Lpads on the classic mids. 

Adams

[RoyC]

16 hours ago, Steve F said:

It is not quite accurate to simply say that the 3a Improved used the same 3a drivers, a Euro-styled cabinet and switches instead of pots and that was it for differences between it and the original 3a.

Steve F.

Probably not, Steve...but the drivers installed in the Improved's Euro 3a cabinet were the same as the original 3a. The primary differences were changes in the midrange circuit of the crossover and the addition of a parallel inductor on the original 3a tweeter. The similar AR-11 replaced the original 3a type tweeter with the new cloth dome tweeter and, interestingly, went back to a midrange crossover more like the original 3a than the 3a Improved. From a technical point of view both models essentially have 3a crossovers altered to accommodate switches instead of variable level controls. The "improvements" were the result of consistent and more robust level controls, better power handling due to the addition of a parallel inductor for the tweeters, and cabinets with fewer diffraction issues.

It should be noted that the last iteration of the 3a using these drivers, called the "AR-3a Limited",  was equipped with Tonegen made AR-11 replacement drivers, and essentially went back to the original 3a crossover. The primary difference compared to the original 3a was the retention of the parallel inductor to better protect the tweeter, and slight crossover changes to accommodate the differences in the electrical characteristics of 8 ohm L-pads vs the original potentiometers. This iteration of the 3a is my personal preference, as the variable level controls provide a greater number of options compared to 3 position switches...or no level controls at all (ie AR-58).

Roy

[powerglide]

Thanks Roy