clearly, i'm doing something incorrect

[boog]

newest 'way too big, let's just hope i finish it' project: 1 box, 6 fuzz.  the fuzz selector is a rotary switch; fr various reasons i only have 2p6t rotaries, meaning that i can't have status LED's.  that stinks.  but i had a wondrous idea to fix that: since this box is just for noise and play (and to see if i can do it), and since (in my experience) LED's generally don't alter the signal AS MUCH as other diodes, i'll just put a pair of clipping LED's at the end of each circuit. boom. fixed. mostly. one of the fuzz circuits is escobedo's tripple fuzz. now, while they might be altering the signal (tough to say, i've built 3 tripple fuzzes and each sounds a lil different) they're not doing their intended purpose, which is to flash when clipping.

i remember being told something about forward voltage before, and i'm wondering if this is an instance when their isn't 'enough' left at the end of the circuit? i've tried putting the led's in at different places in the circuit (at the gain control and at the coupling cap in the center of the circuit) and while they did 'work' there, they were noisy as hell. am i just outta luck on this one or is their a parallel set of components i could put in earlier the circuit to tame that noise?

[petemoore]

  Not sure I follow and suspect whether it'll work like that.
  Can suggest RG's Millenium Bypass articles for status indication when an extra Pole/Throw doesn't happen to be open after standard bypass [like when using less than 3pdt for bypass or 'selection'.
  LED's do light up in certain audio circuits, Keeley seeing eye mod being example of distortion with light-up when you play LED, it requires gain be set so the diodes threshold is met.
  Suggest blindfold testing for choosing/setting diode thresholds in distortion circuit though, choosing the clipping elements by sound only [or re-work the circuits to see if the LED that lights also can be preferred for sound].
 

[slacker]

i remember being told something about forward voltage before, and i'm wondering if this is an instance when their isn't 'enough' left at the end of the circuit?

Yes that's exactly it, the triple fuzz has clipping diodes on the end of it , so they limit the output to about +- 0.6 volts, where as the LEDs need about 1.5 volts or more to light up.
What you could try is put a 1k - 10k resistor in series between the output cap and the diodes. Then connect your clipping LEDs straight after the output cap. The resistor will isolate the LEDS and diodes and hopefully there will be enough voltage to turn the LEDS on.

Another option would be stick a buffer in front of the whole thing with the output connected to the inputs of all the fuzzes, then use one set of throws on your switch to select between the outputs of the fuzzes and use the other set of throws for status LEDs.

[boog]

@petemoore, i thought about the millenium, but couldn't wrap my head around it with the rotary (i've used it with success on regular dpdt stomps) i'll have to look into the seeing eye mod, i think that's what i'm trying to do.

@slacker, i'm using the led's in place of the 'regular' clippers in the tripple fuzz (which is why i was surprised when it didn't work), but the idea of a buffer never really occurred to me.

thanks to both of you! (there's no 'thumbs up' icon, but if there were, it'd be here 

[PRR]

If you are trying to sense the output of a 0.6V (common diode) clipper, with a 1.6V LED, no it won't work. A "120V" incandescent lamp will glow dim at 45V, but an LED is just dead below 1.2V-1.4v, and pretty dim at that.

You can use LEDs for clipping. You get maybe 1.5V clip level, so you have to have a bit more gain in front and a bit more turn-down belind it. Even then, you may not see anything. LEDs need roughly 1mA to "light" so you can see them in a non-dark room. Many clippers feed the clip-diodes through large resistors, get maybe 0.1mA flowing at MAXimum crunch. You don't want to have to shield the box with your hand to know what's happening.

(Also LEDs are slightly light-sensitive. If exposed, they will clip a little different in a dark bar than a mid-day beach party.)

> fr various reasons i only have 2p6t

Yes, the standard deck has 12 outside contacts. You can get 1P12T, 2P6T, 3P4T, 4P3T. You can no longer readily get multi-deck switches (my 1981 Allied catalog lists a 24-deck switch as a standard stock part, but logic-switching made that old-hat).

The "too much stuff in one box!" solution would be six DPST relays (one per effect) and one 1P6T (you can use half a 2P6T) switch. The switch feeds power to the selected relay. An LED+resistor across the relay will indicate which is active.

_IF_ these fuzzes all work with buffered inputs (some only work well from naked guitar) and you don't mind a little cross-hash, buffer the input to all 6 effects, let them all roar. Now use one pole to select the output you want (plus whatever leaks from the other 5 going-nuts effects). The other pole lights LEDs.

[Mark Hammer]

A 2P6T rotary can work as desired.  What you need to do is simply include an active splitter that feeds the 6 individual circuits.  Then, one pole of the rotary can select between the 6 different fuzz/distortion outputs, and the other can select different LEDs.

Alternatively, why use LEDs?  A rotary switch will require some type of pointer knob, like a chickenhead.  Why not just let the knob do the indicating, and use a master 3PDT bypass stompswitch to tell you that the circuit being pointed to is in or out of the signal path?

[petemoore]

  A knob with an LED window in it could be used, leave all the LED's on, only the one in the window [which is underneath the switch-skirt-window and lines up in the window when the switch is turned to it's setting] will be seen.

[boog]

methinks i'm gonna go with the buffered input try; as i said the point is really just to do it, there's no practical application i can foresee. thanks to PRR, tho, for exploding my brain a little bit more with the voltage stuff. someday i'll learn! to answer the question about why led's: simple, one of the most basic pleasures of pedals (for me) is knobs and lights. so it's all part of the fun!

[Mark Hammer]

This may be a little advanced, and involve more than you want, but it will do the switching for you, in round robin fashion, with an indicator LED, using a single momentary push button.  That is, push once to move to the next station in the sequence. The article illustrates 6 stations, but can be easily extended to 5-8 if you add another 4066 chip, the indicator components, and wire up the reset pin accordingly.

http://hammer.ampage.org/files/quadsequentialswitch.pdf