Sound clips:

http://soundclick.com/share?songid=6435261
http://soundclick.com/share?songid=6430994

Here are the final pictures.

Pictures of the amp just after I finished it!

A note on  the overtone layout.  The original Dumble on which the overtone is based had the preamp tube sockets rotated 180 degrees. Where Nik has indicated #1, the Dumble has #6.  The hookup is nearly identical either way.

Just got my extra parts from Niki, and things are moving along. Here are some recent pictures:

I had not seen that site before. Looks like a great on-line reference.

A dumblator kit will be a good idea. I don't use effects in the loop (I put the effects after the mic) but I would get one just to have with my amp, in case I needed it.

January 3rd for me, and nothing yet also...

Fender OT, not MusicMan.

You can tweak the bias of the FET with the 2.7K resistor from "Source." The original had an 8K there.

Niki's is the closest I have seen to an 80s ODS. If you don't consider actual component values, (you said 'layout') and realize Niki's is 50w (50w power supply etc) , whereas the real one was 100w, his layout is nearly exact. The only other things I can think to change would be to add the 50/100 switch and LED and remove the Impedance selector.

Are you thinking about a 90s ODS or a HRM?

Any day...impatiently waiting...

That fourth lead is just a case ground. It's the lower left FET lead on Niki's layout. The FET is not marked but I am expecting a NTE452 when my kit arrives.

I'm using 022699 (Fender Twin) choke, along with Fender Twin output and power transformers. (I'm making the 100w version)

Just heard my parts will be shipping Monday!!

Thanks for the tip. I'm using a Fender Twin output transformer and I found out my schematic was also backwards. I went back and re-drew it so that the side of the phase inverter that is NOT inverted goes to the 6L6s that are connected to the same 'end' (schematic-wise) of the output transformer as the 'ground' speaker lead. I am still waiting on my kit, so I didn't have the opportunity to hear it HOWL like you did.

So, on my schematic, the non-inverted signal from the phase inverter (pin 6) goes to the output tubes that connect to the BROWN wire of the transformer.