The problem is these are not real Reticon chips & I have no idea is these guys are making a true quality knock off, or simply a weak facsimile. A company called DigChip, who sells a ton of all kinds of ICs & related, claiming ED*GE is the company manufacturing these new SAD512D chips. So I've went down the path along these lines and ended up with my current problem:ġ) I found a source in Hong Kong claiming to be making & selling brand new made SAD512D & bought (3) $6 each to see if I could resurrect the chorus. Just couldn't bring myself to modify the old girl from the stock circuit w/o hopes of a SAD512D falling out of the sky someday to solve my problem, so I could resurrect the old girl. If fact, the schematic and other info from that thread were the backbone of support for this latest repair effort for this pedal. So I had resigned myself to convert the pedal to the MN3007 version posted elsewhere on this site, a very good post, great info & a lot of details/dialog, that I've been following for years now. Been on the hunt for a new chip for many years, but alas, they're either totally unavailable, or some scheister is asking $50-$100 for one, and 9X's out of ten, what you receive doesn't work anyway, because either A) the guy's a scheister, or B) in the process of removing and/or packaging, the guy fried the chip. The Chorus broke down years ago when the the SAD512D BBD chip failed.

So my hope is the same will happen with my postĪnyway, I've got a 1978 MXR Micro Chorus I've had since 1978 when I bought as a teen rock guitarist, along with my MXR Phase 90 (1977), Phase 100 (1975), Micro Amp (1978), Flanger (1977), 6-band EQ (can't remember what year I picked it up), and Noise Gate (1978).

It always seems that great dialog, awesome tech info, & good people jump in on these posts to help out & support guys like us who have a ton of old pedals and do all their own tech work, mods, repairs, builds, etc. I realize this thread is a couple years old, but I've watched these threads on this site for a long time, but it matches my problem description fairly close, so I figured it to be most relevant.

Mxr phase 90 mod schematic