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Re: Way Huge - Purple Platypus

Posted: 25 Jan 2018, 04:06
by digi2t
Sorry for the nerco-bump.

Found another gutshot. This one without the 27K/47K resistor installed. As you can see, this unit came off the line in 1998, whereas the other unit is a 1997.

Leads me to believe that the 27K that is shown on the other unit does indeed go nowhere.

Considering the position, it might have been an idea to create some sort of switchable hi/lo gain circuit. Anyway, looks like the idea was dropped, and this unit carries diodes resembling 1n4148's as well.

Re: Way Huge - Purple Platypus

Posted: 27 Jan 2018, 02:32
by digi2t
Just noodling with Paint. Maybe this was what they had in mind for the Drive? Though, you would have to flip the outside lugs.

Image

Re: Way Huge - Purple Platypus

Posted: 18 Feb 2018, 21:44
by digi2t
Been on the breadboard for a while now, and I'm pretty happy with it. Added my own tweaks; octave on/off (with LED), octave intensity control, and Mill 2 bypass. I upped the base gain resistor to 68K because I was getting a bit of a step in the gain at the low end of the pot. 68K smoothed that right out. The russian D9V diodes in the octave section are the cat's ass. They offer a vF very close to silicon, but with a very gentle knee of germanium. The higher vF seems to allow chords to sound less ring-modish, while still allowing a fairly decent octave bloom on single notes. The transistors are also the result of lots of trials. They work really well together, but anything similar will work too. Socket and swap is the name of the game. Also upped the filtering, 100uF right at the power, and 470uF for the unused pins, which help tame any possibility of oscillation or poor decay from the 4049.

PCB is on it's way, but here's a schematic and vero for the vero/perf freaks.

Image

Image

Enjoy!

Re: Way Huge - Purple Platypus

Posted: 19 Feb 2018, 14:52
by phibes
Yeah I think I came to that same conclusion on the drive pot when I was drawing up the schematic. Was so damn long ago I can't remember exactly though.

Re: Way Huge - Purple Platypus

Posted: 07 Nov 2018, 08:16
by Seiche
hey Folks, they are reissuing the Purple Platypus. Maybe a chance to get a peak under the hood. I'm still wondering how they did the Red Llama 25th anniversary high cut control, assuming they kept it the same in the PP.

Re: Way Huge - Purple Platypus

Posted: 07 Nov 2018, 15:01
by phibes
Definitely won't be mind blowing.

Re: Way Huge - Purple Platypus

Posted: 13 Nov 2018, 05:53
by Seiche
No of course not, but here's a gutshot from their instagram