18 volt and switching jack question

[pinkjimiphoton]

hi peeps,
i built this cheezy kit i found recently, was surprised at how good it sounds..
http://www.gssteched.com/G-138P.html

but it's in need of a little modification to really be usable..

i wanna add a 3pdt stompswitch for the effect on/off with true bypass and an led, and a second dpdt stompswitch to select fuzz and octave fuzz, with a bi-color led..

but the way it's set up, it has the two 9 volts in series, with a dpdt switch connecting the positive and ground of the two batteries to juice it up.

what i was curious about, is can i use stereo jacks on both the input AND the output jacks, and connect the grounds of the two batteries to the ring connections of the jacks,
or is there a better way to do it? tried googling, but can't seem to find an answer!

i can post a pic of the schematic if that is necessary...

also, when hooking up the led's, do i need to double the values of the current limiting resistors because of the higher voltage, or can i just hack normal values as found on other schematics to use in this instance? do i need to use different values of resistors on the two sides of the led to make it change colors?

i'm just an egg with this stuff, and really appreciate any help on this, and am really grateful for the help i've recieved so far here.

thanks!
jimi

[petemoore]

i wanna add a 3pdt stompswitch for the effect on/off with true bypass and an led, and a second dpdt stompswitch to select fuzz and octave fuzz, with a bi-color led..

but the way it's set up, it has the two 9 volts in series, with a dpdt switch connecting the positive and ground of the two batteries to juice it up.
  True bypass switching schematics and such should apply since circuit switching is 'outside' the circuit [unless the Fuzz Octave need to be separated in order to install the switch] and the LED is completely separate from the audio circuit [except sharing the power supply]
  what i was curious about, is can i use stereo jacks on both the input AND the output jacks, and connect the grounds of the two batteries to the ring connections of the jacks,
  Battery has no ground is the blunt response...I don't understand question exactly, scheamtic demonstration is sometimes easier to visualize.
  or is there a better way to do it? tried googling, but can't seem to find an answer.  i can post a pic of the schematic if that is necessary...
  Tends to optimize and reduce BAForth about what was where, generally remarkable how it reduces thread length.
  also, when hooking up the led's, do i need to double the values of the current limiting resistors because of the higher voltage
  The right "answer lies in Ohms Law". But left yes, doubling the voltage changes the equation.
  Online calculator for LED/CLR's [enter LED foreward voltage...
  http://www.muzique.com/schem/led.htm

  But it's worth it to use that as a 'study cheat' so V/I/R relationships of ohms law can find the right proportions. You'll find it is indespensible to run some equations through the Law and check/compare with online barometer.
  Fairly simple math, just knowing which way and by about how much gets through somost of this stuff, but calculating every last proportion is also an approach that...lets you know, precisely, what is the proportion.
 

[pinkjimiphoton]

thanks for the link! that will make it ALOT easier! i will try and get a decent pic of the schematic (my scanner won't work with this vista laptop...argh) this afternoon.
i really appreciate the help!

i think where i was unclear, is that i thought if i could tap off the power supply in the circuit when the fuzz is "on", the led for the fuzz 1/fuzz 2 wouldn't be on unless the effect
was engaged...just to save a little on the battery life, if that makes any sense. but now i'm thinking maybe i just need to wire the b+ (dunno if that nomenclature applies to solid state stuff like it would with a tube circuit) so that when the effect is on, that powers the second bi-color led on the second switch. i bet that makes no sense either!


anyways, thanks, will post a pic later...peace!

EDIT: the reason i was asking about using the switching jacks was so the b+ would be turned on and off the pedal simply by plugging in like a normal stompbox...
i guess to re-phrase the question,  do you have to switch the batteries on and off individually, or is simply breaking the connection on one side by wiring it to the sleeve of a t/r/s jack enough?

anyways...thanks!

[pinkjimiphoton]

here's the schematic, and layout/bill of materials...






hope this will be easier to explain now...thanks for the help!!

[pinkjimiphoton]

i hope it's ok to bump this, sorry if i'm an idiot, but i really dig this pedal and wanna try and get it right.
thanks!

[R.G.]

The way it's set up, it might well make an ugly thump at turn on if you only switched one battery.

This is the problem I was addressing with the three-transistor power supply section of this:
The three transistors inside the dotted line may look complicated, but they're really simple. The input jack ring contact is grounded by a mono plug. This turns on the middle NPN (2N3904). This conducts current from the base of the 2N3906 and into the base of the second 2N3904, turning them both on like switches, not amplifiers. This lets voltage through from both batteries at the same time, and turns both batteries off when the input plug is removed.

[pinkjimiphoton]

RG, thanks so much...yah, it does look a little complex, but i actually understand it, and have the parts to make it happen..
thanks so much for taking the time to look at my dillema and help me out! again! 

peace,
jimi

[pinkjimiphoton]

as a matter of fact, this is pretty much the exact circuit i believe:

http://www.harpamps.com/schematics/geuoctv.pdf

the eti guitar effects unit octave fuzz...

gonna play with it later and change r8 and r9 to a 50k pot, hopefully that will resolve the volume issues between fuzz 1 and 2.

really nice box, but it EATS batterys alive!!

so...gonna try this question one more time...

with an 18 v fuzz, can i wire the black leads from each battery to the ring connection on two stereo 1/4 " jacks so the b+ will only be turned on when both input and output jacks are plugged in? or am i looking at more trouble than it's worth?

thanks

jimi

[R.G.]

as a matter of fact, this is pretty much the exact circuit i believe:

That brings back memories. Either I or Jamie Heileman drew that schematic for the first effects repository on the internet back in the 90s.

with an 18 v fuzz, can i wire the black leads from each battery to the ring connection on two stereo 1/4 " jacks so the b+ will only be turned on when both input and output jacks are plugged in? or am i looking at more trouble than it's worth?

Yes, you can. But look at what you get.  The circuit is not being properly "supported" by both power supplies as you plug in first one, then the other jack. This will probably result in a big pop when  you plug in the other jack. Whether this is a problem or not depends on your tolerance for it. Notice that it's not an 18V fuzz. It's a +9V/-9V fuzz, with a solid ground in the middle. That's different.

[pinkjimiphoton]

thanks r.g..

i can live with the pop, i guess...usually the last thing i turn on is my amp when i am playing anywhere. i didn't realize it was a +9/-9 power supply!

that's neat that this is a variant of the circuit you guys drew...i was surfing around looking at stuff, and when i found this schem i was like..."wait a minute, that looks an awful lot like that thing i built!!!"...

the tip about raising the gain of fuzz 1 was exactly what i needed, but then looking at it, i was realizing how close the circuits really were.

as always, thanks for the info, sir!

peace
jimi