I have put together an two loop box . It has an guitar in, amp out, with two loops. All of this switched with an 4066 [ using an radioshack spdt and a 4049 inverter. All I have to do is connect the leds. I must say that I have let this chip befuddle me uptill to now but after  this project I have discoverd this chip is so easy to work with. With all the talk about it popping and clicking, well I am just not hearing it. I put a pedal in each loop and it works perfectly. This a minimal parts count perf. board project. My original intentions was to enable the switch with few as parts as necessary. no caps/noresistors. I have some free web space at geocities and I am going to put it to some good use. I plan on putting together a picture of this project if I could figure out how to do the perf. like runoff groove. I am very well pleased. Anyway one thing that I noticed was there was a minimal click if the unit was left unswitched for awhile but after the first click the noise dissappeared. The dpdt pattern and inverter idea was complimentary of The Tone God / the perf board and wiring is my idea. Stay tuned for more

Hi.  I agree that the 4066 can be almost noise-free.  One design I came up with (a modulator called the Modulatron) used a 4066 to switch between 2 audio signals at rates of 30 to 300Hz.  It had quite a small amount of switching noise.  At 300 clicks per second I'm sure I would have noticed if it was noisey.

cheers

Great Idea to have one of these.
 With all the pedal combinations I like to try, having one of these jobs would make it easier to check them all in/out.  !!!! !!!!

Quote from: brettHi.  I agree that the 4066 can be almost noise-free.  One design I came up with (a modulator called the Modulatron) used a 4066 to switch between 2 audio signals at rates of 30 to 300Hz.  It had quite a small amount of switching noise.  At 300 clicks per second I'm sure I would have noticed if it was noisey.

cheers

Did you try speeding down the slope?  I've done a similiar design with the H11F3 (on the breadboard right now) and I'm sort of frustrated at the amount of clicking I get-not clicking when the guitar is off, but the amount of pop on pop off I get at lower frequencies and the obviousness of it at higher.

-Colin

To get my Modulatron quiet I needed to get the bias on both sides of the switch exactly right.  Also, the noise that I did get was VERY spikey, so a low-pass filter (with fc about 4kHz, I think) got rid of the high transients.  (I'm no expert, so I'm probably using the wromng terms here).

Anyway, it seemed to work ok.

cheers

You cant speed down the control voltage to the 4066, if you do it you'll get bad clicking. You have to make sure the voltages the the switched pins is equal, with a error margin no more than 1mv aprox I think.

I made some experiments with this check my page http://ar.geocities.com/bioroids

I think the amount of voltage difference is the amplitude (peak to peak) of the clicking noise you hear, so I you have a difference of 100mv you get a click of the same level as a plucked note.

I'm playing with choppers also, trying to simulate aliasing without going digital, in this case if you chopp the signal with a freq of 1000hz (say) and you got a voltage difference on the switched pins of 10mv, then you have at the output a 1000hz square wave with 10mv of amplitude not supposed to be there.

My 0.002 cents (of argentinian money)

Luck

Miguel

http://www.maxim-ic.com/appnotes.cfm?appnote_number=638

This app note might help. Apart from getting the DC offsets matched, the other keyword is "charge injection". (I think). I'd be happy to hear from an expert.