simple transformer octave gets overheated

[scoop]

I found this online

I wanted to put it into the same box footswitchable with a silicon fuzz face, I didn't need the octave knob so I stream lined it:


also added resistors before and after to adjust the volumes...
this all sounded perfect on breadboard, however when I finally boxed it up , all three resistors, 50R, 1M & 100k resistors, get VERY hot, like cooking, almost too hot to touch, I think it was starting to smell too, no good. Caps and 2n7000 actually seemed fine but warmed from the resistors. The fuzz face side of the circuit is completely fine not heated.

Do you see anything wrong with this? I can post the entire schematic if that helps.

Thanks for any help!

[mookyj]

Are you sure that heat is coming from the larger value resistors? To break this down, if you dead shorted 9V across a 1M or 100K you will not get enough heat to notice 90uW for the 100K, 9uW for the 1 meg, However across the 50ohm, you could draw as much as 1.6W. You have a short possibly on the 100uf cap (bad cap or solder short, or a physical solder short on the non-supply side of the 50 ohm.

[bmxguitarsbmx]

I would encourage you to chose a bigger load than 50 Ohms. Usually you don't choose a load that will burn out your active device if saturated. the 2n7000 is capable of 350mW continuous.

Using Ohms Law: R = (9v^2)/0.35W= 231 Ohms. Easily drive your 42TM022 transformer- I am assuming you are driving the 600ohm secondary. I have no idea why your 100k or 1M would be getting hot, but I would guess it is being heated by your 50 Ohm.

You may want to experiment with loading the transformer with different resistor values, it will have drastic effects on the frequency response and distortion of the OPT. Though I do understand if this particular arrangement is part of the tone.

[scoop]

Thanks for replies, your assessments are correct. I meant to update this thread I actually found that on my breadboard I used a 500R resistor even though my notes said 50R. 500R works perfectly.