So I’ve just finished building my first DIY project, the CEM3340 VCO on LMNC’s website, using the AS3340 chip.
However, as a beginner I assumed that I would be able to plug this module into a guitar amp and I would hear sound, however after plugging into one, I can’t hear anything. I was wondering if I need a VCA or something to amplify this module before it reaches speakers or I’m being completely stupid and a guitar amp is not compatible with the VCO.
Sorry for what is probably a stupid question, If you could make your responses easy for me to understand that would be great as my knowledge in this is not extensive… yet.
Cheers
hello !
the VCO alone should work
becarefull it’s not a guitar signal, test with a amp not expensive
if you have no sound at all it’s maybe a error on your work. checked and checked again all your circuit.
have you do a symetric alimentation for this module (+12/gnd/-12) ?
If it’s your first project, it may just be some silly build mistake somewhere (we all make them, all the time) but let’s start by assuming it actually works.
First, your synth output (if working) is way hotter than your guitar pickups, so you may want to experiment with something else to verify how things work – do you have some cheap active computer speakers, perhaps? Make sure volume/gain is turned way down before you plug things in, and ramp up very carefully from there. The signal may still be too hot for the amp, depends on how much headroom it has, but if you have signal you should hopefully hear something (possibly distorted).
If you still want to try with the guitar amp, make sure you plug it into aux/line in (if your amp has that). Again, make sure volume/gain is turned way down before you plug things in, and ramp up very carefully from there, otherwise you may blow up your drivers (and/or your ears).
It could also just be that it’s tuned to some ultralow or ultrahigh frequency that’s either outside the range of your amp or outside the range of your hearing. Tinker with the various tuning knobs (again, with the volume near minimum).
If you don’t get anywhere, post a photo of your stripboard/pcb and someone here is likely to help you look for potential issues.
I’ll try an aux in input on the amp, but it is likely that I have made a mistake somewhere, if this doesn’t work I’ll post a picture of the strip board.
Speaking of silly mistakes I just noticed I used a few of these 6A 125
vac instead of the 5A 120vac on something, not sure where. Is that
a deal breaker?
Pretty sure that’s just telling you what current they’ll handle, 5A 120VAC means it’s rated for 5 amps at 120 volts AC while 6A 125 is 6 amps. You’re presumably not going anywhere near its limit and the limit for what you used is higher, so no problem.
These are max ratings, and 6 A > 5 A and 125 VAC > 120 VAC, so probably not an issue
(fwiw, I’m not sure I’d use miniature toggle switches for mains stuff, better stick to small signal use and use rocker switches for mains parts, since they tend to have better specs (more margin) and no user-visible metallic parts)
So I had a thought that the TL072CP dual op amp thing I am using may have been put in the wrong way around in the ic socket, and so turned it around but this lead to my power supply blowing a fuse so I don’t honk it is in the right way around, however, it gets extremely hot when being powered in this way around and so was wondering if any of you guys may know what could cause this, and if this is a potential reason for the module not working.
You probably have a soldering error somewhere that’s connecting a pin on the IC to the wrong voltage. Unfortunately there’s not a quick and easy answer, you just have to check connections and look for something not matching the schematic or layout you’re working from.
I have the same thing going on right now, by the way, with a different circuit. Ugh.
You may have counted the pins the wrong way. You begin at the bottom left and then go to the right and circle the IC counter clockwise. The opamp is probably ruined by now. I would advise you to continue the build with a new one otherwise you keep on doubting it. And maybe afterwards try it again.
Well, try to track down the soldering error, and THEN try running it with a new op amp. Given that it didn’t work before you turned the IC around, there’s presumably an error.
Which pin of the IC is pin number 1, do you think? You need to know the pin numbering to see whether the right components are connected to it. In a circuit diagram you invariably find a mix of the functional part of a component and the physical pins that part of the component can be accessed from. E.g. take a look at an opamp in a circuit. The diagram says not only that a signal must be connected to the minus input of that opamp but also which pin of the IC that minus input is ( and which pin is the output etc. etc).
In order to check your circuit you need to know how to count the pins of your integrated circuits.
As always an image will explain more than a thousand words can:
Start on the bottom left and count upward counter clock wise. The half moon points to the ‘left’ side of the IC, but this may differ from brand to brand.
a little advice if you are really new to electronics, can be started with an APC or something like that before you get started in the modular might be better ? … or not
I’ll just have to persevere with this…