new article: 4016 vs 4066 some results

[bioroids]

Hi, I've run some little experiments on both chips for switching and found  interesting results (at least for me, I found the cause of my 4066 popping)

If you want to check them out, they're at my site:

http://ar.geocities.com/bioroids

on the Challenge of the switches section

Luck

Miguel

[Tim Escobedo]

Nice article. Thanks.

[Gringo]

Muy bueno Miguel, me quedo esperando los resultados de las pruebas de distorsion, aunque con lo baratos que son estos bichos, creo que voy a hacer un par de pruebas a ver si me puedo deshacer de esos switches pedorros que estoy usando ahora.

[gez]

Thanks Miguel, that's really useful stuff!

[Gilles C]

If you ever feel like trying another IC for switching, may I suggest that you try the CD4053.

I would be curious to know how you compare it to the 4066/4016 famly.

I tried the CD4053 and found out it was popping. The circuit I built is still laying somewhere, waiting for me to solve this problem.

Gilles

[Peter Snowberg]

Nice job, thank you for the info.

Take care,
-Peter

[R.G.]

I tried the CD4053 and found out it was popping. The circuit I built is still laying somewhere, waiting for me to solve this problem.

Every danelectro pedal of recent manufacture uses the CD4053, so we know that non-popping switching with the CD4053 is possible.

[toneman]

Hola Miguel,

google and
check out the Axe Grinder and the Motion Filter by PAiA.

Both use 4066 in/out switching that is pop free.

i think it's how U bias the ins and outs.
Something about not switching between hot and gnd,
but rather to a mid point of the supply voltage.

tone

[Transmogrifox]

Just another thought about the CMOS switch as a variable resistor:

The MXR envelope filter has inspired me in this way.  They use a high-frequency pulse-width modulation technique, which is a much less finickey way of adjusting the equivalent 'resistance' of a CMOS switch.

The only catch is that the signal IS sampled, so the capacitive charge and discharge (of the filter) happens in steps.  It basically allows you to adjust the discharge time of the capacitor with the pulse width.

In terms of volume/amplitude control, the on/off ratio adjusts the amount of total signal power that passes through the switch...then if filtered, the high frequency content is removed, leaving the audio range signal.

I haven't tried this "tremolo" idea with the CMOS switch.  I have used the JFET-diode setup found in the common stompbox active bypass scheme, and found a significant amount of resulting distortion when the signal level is attenuated (ie, the pulse is at it's most narrow 'on' time).  I have just ordered some CD4066's and intend to try this with them to see if the CMOS switches produce better results...

[gez]

I haven't tried this "tremolo" idea with the CMOS switch

If you do, the 4053 is the better chip to use.  Each switch of the 4016, when wired as an inverter, has current flowing through it when input is high, so one switch is always conducting when wired as a square-wave oscillator.   You can wire a 4053 so that this doesn't occur, resulting in lower current consumption.  It also gives you the option of stereo panning (auto-hocketing anyone?).

I've only just started messing around with this idea, but so far things are going well.

[bioroids]

Thanks for the replies, there's still much more to be tested, the 4053 may be the way to go. At least we know that if worked correctly is possible to use many different switch possibilities.

Now I'm learning a lot on this and found an interesting application of the switches. I'll post as soon as I can get consistent results.

Luck

Miguel

[Gilles C]

>>>Every danelectro pedal of recent manufacture uses the CD4053, so we know that non-popping switching with the CD4053 is possible.<<<

Right, I know it's possible.

That's the problem... it should work. It works in another circuit I saw in a mag, etc...

But everything I tried with my 4053 circuit produced some popping when switched.

After a year now, there should be no more voltage left in the caps  :wink:  I should try it again, this time with a fresh mind.

But that will wait until I'm back from vacation.

Gilles

[bioroids]

Hi

I just checked out my little danelectro hash browns. It uses indeed the 4053 for the switching. It uses also the 4013 for the latch driving it.
I havent traced it all but seems to be very similar to the 4053 switch on geofex, the main difference being the different setup for the momentary switch (no transistor).

I must say I never noticed this pedal popping.

But I did notice the switch sometimes does not switch, if you press it in certain way. I dont know if this is a mechanical problem or is due to the 4013 flip flop (i have had the same problem with other effects I made using the 4013 this way)

Luck

Miguel