Yet another thread asking about Shaka Tube

[Merlin81]

Okay, read through *most* of the past threads concerning the Shaka Tube, but I'm still being confused by the layout that Paul Marossy posted on his site... the 12VAC runs through the 10ohm/1W resister then to pins 4 and 5 of the tube socket, yes? Well.. if thats the case, do you then run a wire from pin 5 to ground, after connecting the 12vac to it???

[Merlin81]

Also, could i use a 10ohm 10W wirewound power resistor in place of the 10ohm 1W?

[george]

the 12VAC runs through the 10ohm/1W resister then to pins 4 and 5 of the tube socket, yes?

OK I'm looking at http://www.diyguitarist.com/PDF_Files/ShTube1590BB-PCB.pdf

and the schematic ... http://www.diystompboxes.com/cgi-bin/webbbs_scripts/webbbs_config.pl?read=328

That's not the way I see it - one side of the 12VAC runs directly to pin 4 and also 10ohm resistor

Well.. if thats the case, do you then run a wire from pin 5 to ground, after connecting the 12vac to it???

yes you connect the other side of 12VAC to ground

so:
- one wire from your 12VAC source goes to pin 4 and the 10ohm resistor
- the other wire connects to ground

Looking at the schematic as well as Paul's (excellent!) layout should make this clearer for you

[george]

Also, could i use a 10ohm 10W wirewound power resistor in place of the 10ohm 1W?

yes as long as it fits - it would I think be a fair bit bigger than the 1W though, basically being a square lump of ceramic with wires ...

from an electronic point of view you can use a resistor of same or higher power rating in place of specified resistors.

from a practical point of view using higer rated resistors can cause problems if they are significantly bigger than the specified ones, they also tend to have thicker leads which may not fit the holes in your PCB

hth ....

[Merlin81]

Gotcha, gotcha, i see now. I've leanred alot about this schem in the past 2 days Now its entirely clear to me *knock on wood*.

I don't know where to get myself a 10ohm 1W resistor though.. Small Bear doesnt have them, and thats pretty much the only place I can order from since i need to pay with check or money order... Know of any other places?

[Merlin81]

Oh! Just realised PartsExpress takes M/Os. Disregard that plea for a new place to order from! I got this covered now  

[george]

cool.

I like my (somewhat modded) Shaka Tube!

hope you like yours too

[markr04]

Okay, read through *most* of the past threads concerning the Shaka Tube, but I'm still being confused by the layout that Paul Marossy posted on his site... the 12VAC runs through the 10ohm/1W resister then to pins 4 and 5 of the tube socket, yes? Well.. if thats the case, do you then run a wire from pin 5 to ground, after connecting the 12vac to it???

FWIW: There is a 10 Ohm, 1w resistor mentioned in Paul's build notes also. This one is in addition to the one on the board and is in series with the wall-wart to drop the voltage before going to the power supply board (it's not pictured on the layout). This is the one he used bring his 13.xVAC down to 12.8VAC.