Mod completed
I completed the mod last night replacing the stock LF347's with AD713's which are not what was suggested in the original article but spec out similar.
The 347's thd is .01%, the AD713's thd is .003. giving a significantly better overall distortion product. The AD713's have a much lower noise floorthan the 743's so the net result sonically is way better. My 3630 is a "rev d", a late model that already has the THAT chips installed, replacing the original dbx VCA chips . I have about $30 into it for parts and about 2 hrs bench time.I gotta say that this mod is not for folks with limited experience though as it can get tricky when removing the stock IC's . Still well worth doing. Next mod...replacing stock analog IC's in my QV. I'll keep everybody who is interested in the loop.
