Man you have no idea how much you helped me through your videos, especially this one !! I hope you are doing well and that we will have a chance to see you here again !!
I would love to see a vid on the topic of how to create control voltage resistors with the OTA ICs. There's a whole world of DIY modular synth enthusiasts that I'm sure will find this very useful for implementing CV on parameters that only have potentiometers such as filter resonance.
For other people looking for that information: A voltage controlled resistor circuit is in the LM13700 datasheet! Single-ended and floating versions included.
Probably the best expo so far of lm13700. Ever. And I’ve looked and seen and read. I’m glad you pointed out the “keep voltage low at the input “ concept. I’m hoping to reduce popping on sharp changes in control voltage. Also no luck with onboard Darlington.. arrangement
Great video and empirical method for setting up the right bias conditions! Would love to see a video on use of the OTA as four quadrant multiplier, how that works and how to set up correct bias for that.
finalmente un video con una spiegazione semplice.... ed estremamente conciso... BRAVO! finally a video with a simple explanation .... and extremely concise ... GREAT VIDEO
Thanks a bunch! I'm currently trying to design and build some audio filters for a DIY synth setup. I just got my head around the concept of the op-amp but I saw the OTA popping up in loads of designs. I found some schematics but no explanation to them and as a layman, I'm quite lost. It helps to get the basics down before trying to understand a whole schematic but I'd love to see more explanations regarding audio devices.
There may be an issue with a multi meter used in current mode in order to determine the correct resistor values for the current inputs. Standard MM in current measure mode cause a voltage drop across the MM itself. Depending on your supply voltage and the quality of the device, this may effect your results in an undesirable way. The drop should be less than a volt but bad contacts and low quality meters in combination may turn out to be worse.
Yep, I did come across this when researching input impedance of instruments, but for breadboard work and with the meters I have, it seems to be negligible. Of course, for making a proper commercial product with real tolerances, I'd be more careful.
Regarding your comments on the malfunctioning darlington buffer: I recently ordered 10 LM13700's on Ebay, but I received 80 for the price of 10?? I also don't use the onboard buffer, I use op amps. The OTA's work very much the way you describe in your video, c.w. the d.c. biases. I wonder if the onboard Darlington buffers work in the batch that I ordered?
How would you approach the calculation when using feedback loops? In my case i am trying to build a Filter circuit where the diff. voltage = Uin - Uout? However i don't know how much phase i will have on my output..
8:00 So if you have 2 inputs that are exact oposites + noise (differential signal) and you voltage divide both the same way then they are impedance matched, right?
I've only just started scratching the surface with it, but so far it's behaved wonderfully. It's just super fiddly to configure, but once you do it seems pretty nice. I haven't been able to figure out the on-chip darlington emitter follower buffers yet, though, but I find op-amp buffers to be much easier to work with anyway.
According to the datasheet for the LM13700 I use, the Iabc (Ibias in the datasheet) pin is two diode drops above the negative rail, so you'd have to put almost the full negative voltage on that pin to draw current out, and doing so probably would make the OTA not work right, so it's pretty much always going to be current going into Iabc, not out of it.
Wow so so helpful. As you mention before on a previous vid . OTA are very overlooked this has blown my mind open !!!👊🏿 Much respect to you.
OK, that is way the best explanation I've ever seen!
Man you have no idea how much you helped me through your videos, especially this one !! I hope you are doing well and that we will have a chance to see you here again !!
I would love to see a vid on the topic of how to create control voltage resistors with the OTA ICs. There's a whole world of DIY modular synth enthusiasts that I'm sure will find this very useful for implementing CV on parameters that only have potentiometers such as filter resonance.
+ 1 please !
For other people looking for that information: A voltage controlled resistor circuit is in the LM13700 datasheet! Single-ended and floating versions included.
Probably the best expo so far of lm13700. Ever. And I’ve looked and seen and read. I’m glad you pointed out the “keep voltage low at the input “ concept. I’m hoping to reduce popping on sharp changes in control voltage.
Also no luck with onboard Darlington.. arrangement
Great video and empirical method for setting up the right bias conditions! Would love to see a video on use of the OTA as four quadrant multiplier, how that works and how to set up correct bias for that.
finalmente un video con una spiegazione semplice.... ed estremamente conciso... BRAVO!
finally a video with a simple explanation .... and extremely concise ... GREAT VIDEO
Good, practical information.
Awesome videos man! Would be great if you could run through utilizing the LM13700 to create voltage controlled resistors!
I have no idea when I'll get to that particular topic, but it's on my list!
Thanks a bunch! I'm currently trying to design and build some audio filters for a DIY synth setup. I just got my head around the concept of the op-amp but I saw the OTA popping up in loads of designs. I found some schematics but no explanation to them and as a layman, I'm quite lost. It helps to get the basics down before trying to understand a whole schematic but I'd love to see more explanations regarding audio devices.
Such a good video.. 👏👏
Thanks bro!
U have a way of simplifying things
Good explanation like your tips and tricks very useful and informative. Keep them comming
Thank you big guy that was awesome
Great video thanks for the explanation 👍
another great explanation,thank you.
There may be an issue with a multi meter used in current mode in order to determine the correct resistor values for the current inputs. Standard MM in current measure mode cause a voltage drop across the MM itself. Depending on your supply voltage and the quality of the device, this may effect your results in an undesirable way. The drop should be less than a volt but bad contacts and low quality meters in combination may turn out to be worse.
Yep, I did come across this when researching input impedance of instruments, but for breadboard work and with the meters I have, it seems to be negligible. Of course, for making a proper commercial product with real tolerances, I'd be more careful.
Great Video!
Thanks a lot! You are awesome!
Fckin awesome explanation !!!👍👍👍 Finally I can understand ans apply ! Thank you ...channel subscribed
Awesome! TY
Regarding your comments on the malfunctioning darlington buffer:
I recently ordered 10 LM13700's on Ebay, but I received 80 for the price of 10?? I also don't use the onboard buffer, I use op amps. The OTA's work very much the way you describe in your video, c.w. the d.c. biases. I wonder if the onboard Darlington buffers work in the batch that I ordered?
thank You sir
How would you approach the calculation when using feedback loops? In my case i am trying to build a Filter circuit where the diff. voltage = Uin - Uout? However i don't know how much phase i will have on my output..
8:00 So if you have 2 inputs that are exact oposites + noise (differential signal) and you voltage divide both the same way then they are impedance matched, right?
Great video, thanks! I've always gotten poor results using the LM13700. Probably user error.. :)
I've only just started scratching the surface with it, but so far it's behaved wonderfully. It's just super fiddly to configure, but once you do it seems pretty nice. I haven't been able to figure out the on-chip darlington emitter follower buffers yet, though, but I find op-amp buffers to be much easier to work with anyway.
10:20 with negative supply on volume knobe it is possible to draw current out of Iabc, will OTA be current sink in this situation?
According to the datasheet for the LM13700 I use, the Iabc (Ibias in the datasheet) pin is two diode drops above the negative rail, so you'd have to put almost the full negative voltage on that pin to draw current out, and doing so probably would make the OTA not work right, so it's pretty much always going to be current going into Iabc, not out of it.
Mmm, smart guy. :/
It’s too bad you play the Millennial Freak game. You could be good.
What the fuck