I used to have one of the '70s ones with the 14-pin chip and I thought it was great. I got it for $15 (!!) years ago and sold it for $350 back in 2010 when I needed money. Does it sound better than the later ones with the standard 4558 op amp? Yes and No. It depends on your needs. If you mainly play thru a clean amp, the 70s one sounds better because it has a more balanced tone. The later one is very midrange focused and has a lot less bass. It's good for adding a focused lead sound to an overdriven Marshall master volume type amp.
If you want the more balanced tone of the older one, all you have to do is replace 4 capacitors. Like everyone else, I thought it was all about that 14-pin chip but nope, Boss changed capacitor values and that's what makes them sound so different. I thought I was all set with my SD-1 but now the modded OD-1 is my favorite. It's especially nice placed before my BD-2. It makes my little Roland Cube 60 sound and feel like real amp
I took screen shots of a thread a while back.. I forget where. Anyway, give it a shot if you have a 4558 OD-1 that you neglect. You might like it!
Re: the location of the .0047uF, the description is correct. It's to the right of the 4558. The red Wima caps are the new .1uF caps that replace the original green .047 uF caps. I didn't use Wima, I used those maroon 104k caps that come with Fender replacement pots that thankfully I saved.
