Original MXR Blue Box Schematic

[tcarr]

Trying to build a clone of the original, not reissue. The only schematics I can find are for the current PCB. Can't seem to find clear pictures of the trace side of the board or original schematic anywhere. Attached is where I am at. Circled are my three trouble areas where I can't clearly see the traces. If you happen to have a clear shot of the traces on an original board or a schematic of the original I would really appreciate it.

[J M Fahey]

Do you have data on the reissue?
If so, what's the problem with the reisue vs. the original one?
Do you have both schematics to compare? (If so, post them)

[tcarr]

Nothing wrong with the reissue. I am just trying to build a fairly accurate clone of the original and can find no schematics of the original - so have been trying to do it from whatever pictures i can scrounge up and try to follow the traces. Unfortunately, the best picture of the trace side of the board I have found has a few places blocked by the off-board wiring. If I had an original schematic I would be good to go.

[Mark Black]

Not an actual factory schematic, but has some good notes/info. Might help get you there...

tonepad -- file information

[oc disorder]

Thanks to Cjlectronics via the "Wayback Machine"
http://web.archive.org/web/200510141...ms/bluebox.jpg

ahaa I had one lying around uncollected repair..
The novelty soon wears off with this....
One of the pictures is reversed like yours

[Mark Black]

Thanks to Cjlectronics via the "Wayback Machine"
http://web.archive.org/web/200510141...ms/bluebox.jpg

Web ninja! Way to go...

[J M Fahey]

Brings old memories:
1) Bishop Graphics crepe black tape used to draw the board
2) Carbon composition resistors
3) Fully tinned tracks and pads, no solder mask
By the way, the solder side picture is inverted so you can superimpose it on the parts side (Photoshop) and easily "reverse engineer" (copy) it.
4) Clearly, no reissue here.
5) I forgot: a 741 Op Amp used as a state of the art audio gain block.

[tcarr]

Much thanks oc disorder. I may love it or hate it once it's done, won't know 'til I try it out. Thanks again!