Trying to build a Thor

[trotskyismyniece]

I'm trying to build the perfboard layout version of the Thor and I'm trying to get parts from Small Bear, but I can't find a 20k trimpot.  Would a 25k work?  I'm kind of in the dark about trimpots.

[trotskyismyniece]

also, C7-C8 (100uf) are electrolytic caps right?  Because it doesn't specify which direction it should be facing on the layout.

[B Tremblay]

A larger value trimpot is fine, however anything over 50k will result in needing a very steady hand to dial in the correct bias voltage.

C7 is a 100uF electrolytic cap.  The positive terminal is noted with + on the layout.  C8 is a 100nF or 0.1uF film cap (non-electrolytic) that is non-polarized, so orientation does not matter.

[trotskyismyniece]

OK. so I'm going in circles with the Thor.  Trying to do it on perf was a mess, and there's no way I can etch a pcb for it with the radioshack kit.  I'm thinking of trying to do it on Vero, but I'm totally confused by the wiring.  There's no output, theres only two wires going to each of the switches (the perfboard layout had 3 for each?), there's only one wire going to the volume pot, and only two going to the gain    What am i missing here?  I'm starting to get discouraged, because it seems like I'm having a waaaay harder time than  i should building this.

[B Tremblay]

What layout are you using?  Has it been verified to work?

Remember that some layouts do not reference all the offboard wiring.  Therefore, the one wire going to the Volume pot would connect to lug 3.  Volume Lug 2 is an offboard wire and connects to the switch, while Lug 1 is grounded.

For the Gain pot, grounding Lug 1 may not have been mentioned since it is simply grounded.

[trotskyismyniece]

I'm looking at the Vero layout. though, I still don't understand why there isn't an output on the vero or perf layouts.

[B Tremblay]

Which layout, specifically?  Can you provide a link?

[trotskyismyniece]

http://www.aronnelson.com/gallery/main.php/v/Phils-FXs/ThorFinal.gif.html

[GREEN FUZ]

The output comes from the middle lug of the volume pot.

[B Tremblay]

As I mentioned above, many layouts omit offboard wiring, assuming that the builder understands the conventions of bypass switch and jack wiring.

Remember that a layout is a companion to the schematic, not a replacement.

[trotskyismyniece]

I'm getting close to finally getting this thing working.  When I get engage it I lose a TON of volume, it's only half as loud and the distortion sounds more like a muff than a marshall lead.  I realize that I have no clue how to wire the spdt switches.  It seems like each of them only have two wires going to them from the board.  Which poles get wired to where?  I'm still using the vero layout I posted above.

[B Tremblay]

Wire SPDT switches with one lead connected to the middle lug and the other connected to either outer lug.  The only thing you'll need to worry about is the physical orientation of the toggle when placing them in the enclosure.  That means that you may put the Bright switch in and discover that the up position is off.  All you need to do is rotate the switch 180 degrees if that orientation doesn't work for you.