Anybody know where I can find a schematic for the old Roto Tone 1 from Maxon?
The closest thing I could dig up was the 909 but that's not quite the same.
I'd wager its closer to Ibanez's "Phase Tone" (either PT-900 or PT-999). They are also 1-knob affairs and have the same Maxon black-boxed interior. Even uses similar wording in their descriptions.
Still digging for a schematic but I'd bet its an almost carbon copy of MXR's Phase 90 of the same era.
(https://i.imgur.com/UYL36YH.jpg)
That's the 900. The 999 appears to be similar with a second trimmer inside for what I think is depth adjustment.
Yeah, definitely the same thing as the 999. I'm guessing it's pretty close to the 909 which I did find a schematic for. Just wanna make sure I've got the right one in case there are more than a couple basic tweaks.
Found a schematic for the 999 - https://i.imgur.com/v5nkGKT.jpg
from this thread: http://www.freestompboxes.org/viewtopic.php?f=19&t=9424
There is another version of it floating around that I believe is for the re-issue which uses jfet switching. The original unit looked like it was true bypass, hence this fan traced version.