AR-10Pi crossover schematic from AR original Drawing sheet

[fedeleluigi]

Here is the AR 10 Pi schematic coming from a copy of an AR original drawing sheet. Unfortunately the copy I have is not complete and a part of the AR drawing sheet is missing.
I couldn't find this schematic in the "AR Drawings" section, so I hope it can be added to the other files somewhere in the Library in order to allow everybody to see it. I think it's a rather rare document even though, unfortunately, not complete.
I have scanned it as TIFF format then I've converted it to JPEG to insert it directly into this post. To get a higher resolution, save the attached file in Tiff format.

Differently from LST, in the AR 10 Pi the auto-transformer and the 3 dB step switches permitted the listener to have more flexibility with a total of 27 different combinations of driver output level (that is 27 different frequency responses) without using any attenuation resistor. The auto-transformer enabled the user to control bass output by a 3 step switch as well. 

Luigi

 

AR10 Pi original schematic TIFF.tif

[KlausDK]

Hi Luigi

Nice work!! Richard from Australia has, helped by a couple of friends here on the forum, previously oploaded a drawing of the 10Pi cross-over schematic, you can take a look to see if they look alike??

BRgds Klaus

 

[fedeleluigi]

Thank you Klaus,

Richard Lowe did an excellent work with the last update (AR10pi-CircuitNotes Version 1.1 Sep2014) and, at first sight, AR original crossover schematic and Richard's seem very similar. I hope to have time to check them more carefully.

 

 

Luigi

[fedeleluigi]

On 7/2/2017 at 11:46 AM, fedeleluigi said:

Differently from LST, in the AR 10 Pi the auto-transformer and the 3 dB step switches permitted the listener to have more flexibility with a total of 27 different combinations of driver output level (that is 27 different frequency responses) without using any attenuation resistor. The auto-transformer enabled the user to control bass output by a 3 step switch as well. 

Luigi

 

AR10 Pi original schematic TIFF.tif

As can be seen by the schematic, differently from midrange and tweeter, the woofer switch (Woofer Environmental Control switch) is actually not a 3 position +/-3dB step switch but a 0dB (4Pi), -5dB (2Pi) and -8dB (Pi) switch.

 

Luigi