WADIA 861 versions question

I am posting this to ask a very important question. Have all the 861's been equipped with the "filter choice" feature from the start or have some of them been sent back for retrofitting? I am a second owner of one of these players and the manual came with a separate sheet ( an addendum ) covering the instructions for the cited feature. I tried calling Wadia and wasn't able to connect. I appreciate any info in this matter, as it is very important to me. Thanks in advance

The 861 came with 3 filter settings. You can access these with the sideways arrow button on the upper right of the remote above the phase/polarity button. You then use the up & down buttons (volume) to toggle through A,B & C then the mute button to save.

My used 860 was factory upgraded to an 861 sometime in 2001 & it has the 3 filter choices. They can be accessed exactly as Hifigy wrote. Look @ the bottom of your 861 to find the Wadia sticker & see the manuf date of the unit. If it's post-2001 it seems reasonable to expect the 3 filter choices.
(my *gut* feel of this is that each 86X unit always had the 3 filter choices.)
Congrats on a 'sound' purchase!

Another resource for your question would be Steve at Great Northern Sound - http://www.greatnorthernsound.com/

A search here, or on www.audioasylum.com will give you further information on the 861.
I am not sure if you ever got a confirmation on this question. I used to own a Wadia 861 which came out of the first production batch of the 861. They were without the 3 filer options. Wadia will install the filter chip for free. At least they did it on mine.