datasheet of the cd4066 states on the first line: 15-VDigital or ±7.5-VPeak-to-PeakSwitching people use them in Synthesizers aswel and that's 10 V.p.p. for many signals.
Any active element you put in the signal path adds distortion. I believe that, if your intention is to make an active audio selector, it is better to have a selector that short-circuits the signals you don't want, and leaves the signal you want to hear loud. That is very easy to do using bipolar transistors and does not add any distortion to the signal. If instead of bipolar transistors you use CMOS, much better. A CMOS transistor can go from several MΩ to a few tenths of an Ω when turned on.
Cool dude! I'm building an equalizer/chorus/reverb unit to put into my amplifier's fx loop and my idea is to make it all switchable, turn on and off the eq or reverb or chorus bypassing it out of the signal chain by footswitch, I thought the most practical way would be using relays, but then I would get a loud pop, so I was thinking in using some kind of analog switch but I don't have push buttons for the footswitch, just SPST/SPDT switches. For the IC I think it would work better with a DG419 or some similar , any suggestions?
The DG419 actually sounds like a better alternative since it can cope with audio signals better and handle split supplies if you have them. With a trimmed split supply, you should be able to couple the signals in directly without the caps or resistors. The loud electrical pop sound could still happen even with a solid-state switch. It usually comes from charge built up in the cables from static or from small differences in DC voltage from different devices getting discharged when switched in. If you had no caps to be charged and discharged in the switching network, it might really help the popping issue. Unfortunately, the DG419 is a break-before-make type switch. This means charge can accumulate for a split second before it makes the new connection. As far as relays go, dual-coil latching relays would be best and would have lower distortion than any CMOS switch. Since it's a guitar amp though, a little more distortion probably won't matter. Also, slide switches or toggle switches will make the circuit easier to make, I just used pushbutton switches in the video to make it useful for that situation.
I think that DC coupling capacitors can be ceramic. And also for bipolar signals it is better to use DG4** switches or even MAX series (if you want something hi-end). I've digged into CMOS multiplexers a bit and a forum tells that they need a lot of additional "addons" to the circuitry if you don't want different "side effects". DG4** works with a minimum set of components and do the job great because they are designed to switch audio signals (not digital primarily).
Interesting, I was wondering if there were higher-end switches made for audio. I've just never found them until now. In Hi-Fi applications I would usually use relays but those MAX chips seem like they'd make fairly low distortion.
@@thetuberoaster8321 I know that bistable relays can be used for this, but I don't know, maybe some distortion can be applied due to relay construction and physical properties? Or this is appropriate way, what you think?
@@switlle If latching relays are what you mean, yes you could totally use those and the distortion shouldn't be any worse. Sometimes, it can be hard to get those relays in the right contact arrangements or coil voltages you want. I thought about using them but instead decided to use a circuit that would accommodate more widely available parts. The MAX switch I'm referring to is the MAX312L.
ty for the vid am trying to build something like this for my home automation using replay to turn on and off. I have the codes already just looking how to integrate the sources and the outputs
The HEF4053 would be interesting because it contains one more switch than the 4066. I think it still has the problem of the input voltage not being able to to less than -0.5 V which is what I accidentally discovered with the 4066. After carefully reading the datasheet, I discovered why when I turned the switch off it wouldn't stop the signal but clip it.
I'll have to wait until I get my oscilloscope back (channel 1 is faulty somehow) so I can experiment with that. Would be interesting to see how it copes with these negative voltages.
Sorry might be dumb question but i am new to this and trying one project, can this be used for video too? I have requirement where i have 3 video input and 1 output to screen. I want decide which video source to be shown based on Push button, i didn't find any suitable thing so far... Will this work? if not do you know any other options?
You can use this for video, but be aware that there will be some loss. The 4066 doesn't quite have the bandwidth so the video may not be perfect. Also, play around with the values of the capacitors and resistors, the video cable has a 75 ohm impedance (I think) and if you can maintain that through to the TV, the video will still look good. I haven't tried it though so I have no idea what works best.
@@thetuberoaster8321 Thanks, i won't be connecting this to TV my plan is to connect it with car rear view camera and screen. I saw another option 3 Channel Video Switcher Module 3 online but this one is for FPV so not sure how i can switch it with push button.
I successfully use 4066 chip to switch video signals, despite its noticeable resistance in on state. No perceivable video degradation so far. But it's better to use MAX4547 or NJM2235D for such purposes.
You can make a peak detector or some type of comparator. When a signal appears on the input, it will charge up the peak detector or trigger the comparator. The voltage on the output can be used to flip the switch for the opposite channel. If you want both inputs to automatically switch, just use two comparators/peak detectors. The output of each of the comparators/peak detectors would have to couple up to where the pushbutton switches would normally go. This way, the latch circuit can latch normally.
I'm guessing you're an audiophile or at least an "audio aficionado", so my question is can you notice any distortion or difference in audio while using the 4066?
I haven't used this exact circuit extensively, but from what I have heard, there is a difference depending on how the 4066 is operated. For signals that have a very large dynamic range (clipping of peaks) or loads that draw more than a few mA of current (or draw current unevenly at different frequencies), the distortion might become quite noticeable. For most applications, it's quite subtle and it would work just fine. (The datasheet claims 0.4% THD under ideal conditions. Around 0.7 - 1% THD is where it becomes noticeable at least for odd harmonic distortion.) For Hi-Fi designs though, I still use mechanical relays because they are more transparent sounding and aren't as restricted by voltage and power.
If you click on the About page on my channel, you should be able to find an email address "for business inquiries" or something like that. Use that one and send me the details.
Yes but increase the input resistors to 2.2M or buffer it with another pedal to avoid loading the guitar. With 2.2M resistors you can use 0.1uF caps for input and output.
Normally, the coupling capacitors are calculated for the low end of the audio frequencies to around 10-20Hz. For example, for 16Hz, you could use 0.1μF with a 100kΩ input impedance, 1μF with 10kΩ, and 10μF with 1kΩ. Using a larger value would simply extend the lower end without having significant negative effect on the circuit. So, you could actually use 10-47μF if you're not sure what's the impedance in your circuit.
It's a low powered chip designed for line level signals. The maximum input current is only +/- 10 mA which means it can only take about 200mW before burning up the MOSFETs. It can switch the input signal to a 100w amp but not the actual speaker output. For that you'll need something heavy duty like a relay.
You'd have to find a circuit that latches with only one button. You can make one, but they are a bit more complicated and more finicky than a two button circuit. One type is very similar to the latch described here. You can search "single button latch" and you'll get a circuit that looks a lot like this one but with some changes. It's not the most reliable but it is probably the simplest out there.
yes the crosstalk is in the cmos switch if you wire a second cmos switch between the first cmos switch output to ground or your half rail reference voltage & put a series resistor of a few kilo ohms at the junction of the 2 cmos switches at the output & connect opposing voltages to the control pins so one cmos is switched on & the other off this will work much better then 1 cmos switch & give much better isolation & you will have no crosstalk, the alternate is to use a 4053 which is a 3 channel double pole cmos switch & tie the off state pins to ground. its 3 pole double throw .@@thetuberoaster8321
They are basically the same chip except for one small detail. The 4053 has both a Vss and a Vee pin. One for 0V and one for a negative power supply. Like I showed in my video, the input cannot go below the negative supply rail. I showed how to compensate for it using a resistor network. For some applications, it's best to have a clean channel with no extra voltages or impedances. Actually, it seems that the 405X series is more geared to audio applications. The datasheet markets the device differently than the 4066.
The 4066 OUT and CNTRL pins are reversed on your schematic - might be important for someone who doesn't know. Cheers, good vid.
Thanks for pointing that out! I have no idea how that happened.
A DPDT switch would achieve the same effect, but thanks for explaining how to do it with CMOS. Next, how to do it with just one switch.....
Now I know what is "CMOS" a bit better :) Never seen these diagrams.
datasheet of the cd4066 states on the first line: 15-VDigital or ±7.5-VPeak-to-PeakSwitching
people use them in Synthesizers aswel and that's 10 V.p.p. for many signals.
Thanks man, that explained a lot!
I think you could get better results with an op amp buffer stage on both sides of the switch.
Any active element you put in the signal path adds distortion.
I believe that, if your intention is to make an active audio selector, it is better to have a selector that short-circuits the signals you don't want, and leaves the signal you want to hear loud.
That is very easy to do using bipolar transistors and does not add any distortion to the signal. If instead of bipolar transistors you use CMOS, much better. A CMOS transistor can go from several MΩ to a few tenths of an Ω when turned on.
The pinout of 4066 as shown in video is different from the datasheet.
Cool dude!
I'm building an equalizer/chorus/reverb unit to put into my amplifier's fx loop and my idea is to make it all switchable, turn on and off the eq or reverb or chorus bypassing it out of the signal chain by footswitch, I thought the most practical way would be using relays, but then I would get a loud pop, so I was thinking in using some kind of analog switch but I don't have push buttons for the footswitch, just SPST/SPDT switches. For the IC I think it would work better with a DG419 or some similar , any suggestions?
The DG419 actually sounds like a better alternative since it can cope with audio signals better and handle split supplies if you have them. With a trimmed split supply, you should be able to couple the signals in directly without the caps or resistors. The loud electrical pop sound could still happen even with a solid-state switch. It usually comes from charge built up in the cables from static or from small differences in DC voltage from different devices getting discharged when switched in. If you had no caps to be charged and discharged in the switching network, it might really help the popping issue. Unfortunately, the DG419 is a break-before-make type switch. This means charge can accumulate for a split second before it makes the new connection. As far as relays go, dual-coil latching relays would be best and would have lower distortion than any CMOS switch. Since it's a guitar amp though, a little more distortion probably won't matter. Also, slide switches or toggle switches will make the circuit easier to make, I just used pushbutton switches in the video to make it useful for that situation.
Thanks for the reply. I am looking to switch an audio signal which you identify in the video. So the capacitance would be as you stated. Thank you.
I think that DC coupling capacitors can be ceramic. And also for bipolar signals it is better to use DG4** switches or even MAX series (if you want something hi-end). I've digged into CMOS multiplexers a bit and a forum tells that they need a lot of additional "addons" to the circuitry if you don't want different "side effects". DG4** works with a minimum set of components and do the job great because they are designed to switch audio signals (not digital primarily).
Interesting, I was wondering if there were higher-end switches made for audio. I've just never found them until now. In Hi-Fi applications I would usually use relays but those MAX chips seem like they'd make fairly low distortion.
Which switch from the MAX series are you referring to? Please give me example
@@thetuberoaster8321 I know that bistable relays can be used for this, but I don't know, maybe some distortion can be applied due to relay construction and physical properties? Or this is appropriate way, what you think?
@@switlle If latching relays are what you mean, yes you could totally use those and the distortion shouldn't be any worse. Sometimes, it can be hard to get those relays in the right contact arrangements or coil voltages you want. I thought about using them but instead decided to use a circuit that would accommodate more widely available parts.
The MAX switch I'm referring to is the MAX312L.
ty for the vid am trying to build something like this for my home automation using replay to turn on and off. I have the codes already just looking how to integrate the sources and the outputs
Excellent video. I have a HEF4053 which also has these switches. I'm going to try if I can use that to switch audio signals. :)
The HEF4053 would be interesting because it contains one more switch than the 4066. I think it still has the problem of the input voltage not being able to to less than -0.5 V which is what I accidentally discovered with the 4066. After carefully reading the datasheet, I discovered why when I turned the switch off it wouldn't stop the signal but clip it.
I'll have to wait until I get my oscilloscope back (channel 1 is faulty somehow) so I can experiment with that. Would be interesting to see how it copes with these negative voltages.
use pulldown resistors.
The 4066 has 4 SPST switches, and the 4053 has 3 SPDT switches.
How do I connect a relay to an FM radio output so that it can turn on a light?
Sorry might be dumb question but i am new to this and trying one project, can this be used for video too? I have requirement where i have 3 video input and 1 output to screen. I want decide which video source to be shown based on Push button, i didn't find any suitable thing so far... Will this work? if not do you know any other options?
You can use this for video, but be aware that there will be some loss. The 4066 doesn't quite have the bandwidth so the video may not be perfect. Also, play around with the values of the capacitors and resistors, the video cable has a 75 ohm impedance (I think) and if you can maintain that through to the TV, the video will still look good. I haven't tried it though so I have no idea what works best.
@@thetuberoaster8321 Thanks, i won't be connecting this to TV my plan is to connect it with car rear view camera and screen. I saw another option 3 Channel Video Switcher Module 3 online but this one is for FPV so not sure how i can switch it with push button.
I successfully use 4066 chip to switch video signals, despite its noticeable resistance in on state. No perceivable video degradation so far. But it's better to use MAX4547 or NJM2235D for such purposes.
@@WRXMSK Do you have any video which i can refer? Did you use resistor or capacitor? What voltage did you pass?
Awesome, Thanks.
Your understanding of the 4066 is wrong. And you need a pull down resistor in the ctrl input.
Is there any way to make it automatic so when the second input has signal it will cancel out the first input so the second input will play thanks
You can make a peak detector or some type of comparator. When a signal appears on the input, it will charge up the peak detector or trigger the comparator. The voltage on the output can be used to flip the switch for the opposite channel. If you want both inputs to automatically switch, just use two comparators/peak detectors. The output of each of the comparators/peak detectors would have to couple up to where the pushbutton switches would normally go. This way, the latch circuit can latch normally.
I'm guessing you're an audiophile or at least an "audio aficionado", so my question is can you notice any distortion or difference in audio while using the 4066?
I haven't used this exact circuit extensively, but from what I have heard, there is a difference depending on how the 4066 is operated. For signals that have a very large dynamic range (clipping of peaks) or loads that draw more than a few mA of current (or draw current unevenly at different frequencies), the distortion might become quite noticeable. For most applications, it's quite subtle and it would work just fine. (The datasheet claims 0.4% THD under ideal conditions. Around 0.7 - 1% THD is where it becomes noticeable at least for odd harmonic distortion.) For Hi-Fi designs though, I still use mechanical relays because they are more transparent sounding and aren't as restricted by voltage and power.
I have a project I need help with, I think you could help. How do I get in touch?
If you click on the About page on my channel, you should be able to find an email address "for business inquiries" or something like that. Use that one and send me the details.
Sir can i ise it for guitar pedal switcher?
Yes but increase the input resistors to 2.2M or buffer it with another pedal to avoid loading the guitar. With 2.2M resistors you can use 0.1uF caps for input and output.
What size coupling capacitors are you using ?
5.6 uF but the value is not critical. It depends on the impedance of the circuit it is connected to.
Normally, the coupling capacitors are calculated for the low end of the audio frequencies to around 10-20Hz. For example, for 16Hz, you could use 0.1μF with a 100kΩ input impedance, 1μF with 10kΩ, and 10μF with 1kΩ. Using a larger value would simply extend the lower end without having significant negative effect on the circuit. So, you could actually use 10-47μF if you're not sure what's the impedance in your circuit.
Use for hitachi HTD-G2 problem ic hcf 4066
Can we switch two audio source of 100w using this chip?
It's a low powered chip designed for line level signals. The maximum input current is only +/- 10 mA which means it can only take about 200mW before burning up the MOSFETs. It can switch the input signal to a 100w amp but not the actual speaker output. For that you'll need something heavy duty like a relay.
Thank you sir.
How to make it with one button?
You'd have to find a circuit that latches with only one button. You can make one, but they are a bit more complicated and more finicky than a two button circuit. One type is very similar to the latch described here. You can search "single button latch" and you'll get a circuit that looks a lot like this one but with some changes. It's not the most reliable but it is probably the simplest out there.
Still some cross talk I think you need another switch in series with the output to ground or half rail voltage, good effort though.
Is it crosstalk between channels or feedthrough from input to output?
yes the crosstalk is in the cmos switch if you wire a second cmos switch between the first cmos switch output to ground or your half rail reference voltage & put a series resistor of a few kilo ohms at the junction of the 2 cmos switches at the output & connect opposing voltages to the control pins so one cmos is switched on & the other off this will work much better then 1 cmos switch & give much better isolation & you will have no crosstalk, the alternate is to use a 4053 which is a 3 channel double pole cmos switch & tie the off state pins to ground. its 3 pole double throw .@@thetuberoaster8321
Just use 2 poles 3 position switch instead
4066 vs 4053?
They are basically the same chip except for one small detail. The 4053 has both a Vss and a Vee pin. One for 0V and one for a negative power supply. Like I showed in my video, the input cannot go below the negative supply rail. I showed how to compensate for it using a resistor network. For some applications, it's best to have a clean channel with no extra voltages or impedances. Actually, it seems that the 405X series is more geared to audio applications. The datasheet markets the device differently than the 4066.
@@thetuberoaster8321 Thank for reply