Early MXR Phase 90 pics (Data Dump)

[fernieite]

Hey guys. I just took a bunch of photos of my old 1973/74 workhorse Phase 90. I've had this thing for a long time. Hope you dig them.

The pot is dated 137 7346, so the 46th week of 1973. This seems to be a very common pot date for early MXR pedals. They must have bought a ton of them.

The chips are dated the 39th week of 1973.

I replaced the old deteriorated foam, but you can see lots of particles left over on the board. The only thing changed is the battery connector, I think. Oh yeah, and the screws look too new, so are probably replacements...

IMG_0701.JPG (514.5 KiB) Viewed 1273 times

IMG_0702.JPG (540.19 KiB) Viewed 1273 times

IMG_0703.JPG (501.65 KiB) Viewed 1273 times

IMG_0704.JPG (384.97 KiB) Viewed 1273 times

IMG_0705.JPG (420.27 KiB) Viewed 1273 times

IMG_0706.JPG (524.08 KiB) Viewed 1273 times

[fernieite]

IMG_0707.JPG (618.91 KiB) Viewed 1272 times

IMG_0708.JPG (309.64 KiB) Viewed 1272 times

IMG_0709.JPG (337.19 KiB) Viewed 1272 times

IMG_0710.JPG (469.27 KiB) Viewed 1272 times

IMG_0711.JPG (511.13 KiB) Viewed 1272 times

IMG_0712.JPG (434.08 KiB) Viewed 1272 times

[jreeves47]

super awesome! I've only seen a couple earlier than yours. how's it sound?
can you read the revision number on the track side of the circuit board? its P90 followed by a lower case letter

[fernieite]

Cool. It sounds awesome, I love it!

The circuit revision is P90c.

20201025_200450.jpg (418.18 KiB) Viewed 1240 times

Here's another one of the pot. It's not stamped Mxr like some of them are.

20201025_200625.jpg (344.16 KiB) Viewed 1237 times

[jreeves47]

thanks!
here's the earliest pic I've seen of one - serial number 1040 so might be the 40th one made

[fernieite]

Man, the layout is quite different from my revision c.

Is that the first circuit layout? - P90 or P90b? Anymore photos?