More Equalizer Stuff
I figured that since two of the three pairs of electrolytic caps were bypassed with PP, why not the last pair. So I bypassed the two 1000uF Panasonic FM caps with 1uF Solen PP caps that were in my spares box. There just so happened to be two holes in the board already predrilled through the traces next to each of the FMs, so I used them to install the bypasses - a snap!
Below are two pictures of the power supply bypasses. The first shows the 4.7uF bypasses on the 4700uF caps, and the second shows the 1uF bypasses on the 1000uF caps. With the two sets of power supply bypasses in place, I can say that the sound is a bit snappier, especially on transients. I think I'm going to repeat the opamp faceoff now that the bypasses are in place - perhaps I'll hear more differences.
I also ordered one more set of opamps to compare, Burr-Brown OPA2107, and they should arrive in a couple of days. So I'll be comparing the LF353N ($0.40 each), the OPA2134 ($2.45 each) and the OPA2107 ($12.25 each).
From what I've read the 2107 is supposed to have better definition in the bass and mid-bass than the 2134 - we'll see soon enough. :yes:
P.S. 06/22/09: I also ordered a full set of PRP metal film resistors (plus 2 Shinkohs) to replace the stock carbon film resistors, at double the stock wattage ratings. That ought to bring the background noise level down! So once I install the 30+ new resistors I'll go ahead with the opamp showdown - should be very interesting...
