What’s going on with the inductor in the Bobtavia?

[antonis]

Try placing a cap across the resistor used to connect centre tap to ground

There is no such a resistor, insn't it..??

[soggybag]

Here's the schematic I made. R1 is 100k and connects 9v to the center tap. It's in the original Bobtavia drawing.

[antonis]

That's why I said "there is no resistor connecting the center tap to GROUND"..!!!

[anotherjim]

Can I be cheeky and suggest that 9v is "AC ground"

[soggybag]

Can I be cheeky and suggest that 9v is "AC ground"

Be as cheeky as you like! Thanks for reminding me of this! We amateurs sometimes need these lessons repeated.

[pinkjimiphoton]

its been forever, but if memory serves, grounding or ungrounding it kills the octave effect.

grounded, the signal gets put out of phase to the diodes as its the center tap in the primary.
in the secondary, it induces the connection with the audio signal.

so, grounded,  it splits the signal into pos and neg
ungrounded, its basically an inductor/impedance/dummy load where the signal passes thru the coil of the primary from 1 side to the other.
you only get the octave when the center tap is grounded.. that's what splits the signal and inverts its phase to do the octave cancelling.

i'll see if i can find ya some info i gotta tonne of it but not sure which pc has it all.


god. i'm such a damn...

don't ground it lol

yikes. i gotta find the actual mod. funny, i didn't think i had acid for dinner   

[pinkjimiphoton]

this is what ya want, good luck finding it, maybe aron can?

https://www.aronnelson.com/gallery/main.php/v/Richard-Boop-RLBJR65/Octave/Bobtavia/Bobtavia_OD.gif.html

AHA!!!

found it


this was what i built years ago.

memory. dodgy.. geezer achieved

now, get the hell offa my lawn!!!!