Thanks for the detailed explanation ( and historical note ), I think I got most of that.
The video should confirm (or correct) my (mis)understanding.
As for the switches that I had to spread the pins of, I believe it is these ones:
What surprised me is that you didnât use the same pin spacing for the SPDT and DPDT switch footprints.
The SPDT fit fine in the DPDT footprints as they have the same pin spacing as the DPDT.
This is how the SPDT (right) and DPDT compare, with and without spread pins.
ok! well since the brand of switches I usually use do fit into both ( I just checked) I made them different size as the dpdt some of them fit snugger than others which was a bit weird so I adjusted those and never came up against it with the SPST so they stayed snugger⌠from now on ill make the SPDT footprint the same. ill update it. and also if of use ill share the footprints for both.
SoâŚSamâŚone question (or anyone who can answer please) and one request pleaseâŚ
Question⌠If you use 2k resistors instead of 1k then the LEDâs would not be as bright, yes? Is it possible to switch out the 1k resistors to 2k on the daughter board so my LEDâs wonât be as bright or will that screw up something else in the module if I did that? Iâd like them not so bright but wanted to use the ones I have.
Request please⌠Seeing as how I am new to synth DIY and I am a modular idiot, Iâm still trying to figure outâŚ
A) what all of these modules do
B) whether or not I have built them correctly
I wondered if you could make a video for the modules that just shows what happens when a single signal is plugged into each audio jack and another one for each CV jack? For example, what happens when you just have a square wave input to the LFO? What do the knobs do when you turn them with that square wave in? For example, Iâve built the LFO but I donât know if it is working the way it is supposed to because I am not sure what to expect to hear when I turn each knob and/or flip the switches, if that makes any sense. If I had a reference for testing so I knew how to verify that itâs working correctly it would be extremely helpful. I know a lot of people have gotten into synth DIY because of you and I think there are many of us who could benefit from something like this. Just an idea that I thought would be helpful to me and others.
Question⌠If you use 2k resistors instead of 1k then the LEDâs would not be as bright, yes? Is it possible to switch out the 1k resistors to 2k on the daughter board so my LEDâs wonât be as bright or will that screw up something else in the module if I did that? Iâd like them not so bright but wanted to use the ones I have.
yeah 2 things you can do. try a 2k however they wonât turn on lower voltages. the other option is to get less bright LEDâs. which ledâs do you have? if they are standard they are pretty dim anyway! but super brightsl⌠well haha the name suggests.
yep of course! my aim is to do more videos on the modules on the more serious channel. this week im touching on the the 1184, and ill work along from that! hope thats ok.
Okay, so using 2k would make them less bright but it will also not allow them to turn on with lower voltages. Is that what youâre saying? That doesnât sound like that will work then.
I have several different LEDâs, but the ones that I want to use are like yours where they are clear but turn red when in use. I found some that said they were just âbrightâ but not âultra brightâ but they were .49 a piece. So I was hoping that I could use the ultra bright ones that I have, which are .02 a piece, and just use a different resistor to control the brightness.
Yes, starting with the 1184 is absolutely fine. Whatever order you want to do is no problem. I only mentioned it in this thread since you had already commented on making a video about the 1184 and mods for it. Thanks for doing this. It will really help myself and others. Not knowing if I made a mistake in the build process can be frustrating.
There are two sets of LEDs in the #1184 VCA.
The âmuteâ LEDs have a fixed brightness so you can directly control their brightness by changing their current limiting resistors.
The âCV levelâ LEDs vary in brightness with the CV level, they donât actually âturn onâ at a specific voltage, but they have to reach a certain level of brightness before we see that they are lit. If your LEDs are brighter than average (or your environment darker) you will notice them being lit at a lower CV level. Increasing the current limiting resistor to reduce the maximum brightness may just bring the point where you notice the LED being lit back to the same level one would notice it with âless brightâ LEDs or in a brighter environment.
But in fact, the 1k current limiting resistor only controls the maximum brightness that occurs only for high CV levels. At lower CV levels the current through the LED (and thus its brightness) is mostly controlled by the 100k resistor at the base of the transistor.
So you can increase the 1k resistor to limit the maximum brightness and reduce the 100k resistor to increase the brightness at lower CV levels (donât go too low though, down to 33k should still be OK).
You could temporarily solder in pots on wires, or try it on a breadboard to find the brightness level you like.
To quote a wise man (or was he a wiseguy?): âDonât be scared to try it!â
haha I dunno I wouldnât particularly say wise⌠more like too stupid to know better :D! but im gunna keep hammering away till I can fill those bootsâŚ
but yes please let us all know the outcome of your LED messing. they can be pretty darn bright!!! I like how they can pretty much illuminate a room with an ominous red glow. but yes they can startle you!
Try increasing it more, there is no risk to the circuit.
You can also increase the 100k resistor, if the LED is too bright even at low CVs.
Double the values and double them again until you see a change and back down to a level you like, there is nothing critical in that part of the circuit (just donât reduce the values of those resistors excessively, but thatâs not what you want to do anyway).
My guess is the larger resistance was used on the quad VCA mixer because the four VCAs get mixed; attenuating the CVs more helps keep the sum in range. Maybe?
), I think I got most of that.
