1222 Tuner VCO Module

[Farabide]

Fair point. "Unbranded? "
Sam uses the term legit, knock off, and cheapo to describe some of the nanos he uses. Perhaps he has access to some illicit stockpile for YouTubers?

[WesleyV]

Hey all, I’m kinda sad that the triangle wave is so quiet compared to the other waves - has anyone experimented with some different resistor values to boost it up a bit? I’m about ready to do a lil clip and kludge on my VCO’s so I can actually use that wave form without it getting drown out by everything else.

[analogoutput]

What resistors? There’s just a voltage follower between the pin and the output jack.

[Bitnik]

Can’t you just put it through an amp? There’s no rule saying you can’t add a tl072 and a couple of resistors to the triangle output.

[Tachi]

I found that my triangle wave is super quiet like a lot of others have said but if i half unplug the cable and the tip touches the ring connection i get a full volume triangle!? Could I have put something in backwards to reverse the socket polarity? It’s odd because I have two of the VCO’s and both display the same thing.

[fredrik]

What are you plugging it into, and what does “full volume” mean?

(The triangle output from the 3340 is 4 Vpp (VCC/3), which is about half of the ramp (2×VCC/3) and pulse (~VCC−2) signals, but still about +3.5 dBu – so something that expects a consumer line-in signal at −6 dBu will find it rather loud, while something that expects professional levels will probably be quite ok with it. It’s still less than ramp/pulse, though, and won’t sound as loud unless you amplify it.)

[WesleyV]

Thanks AnalogOutput,
I hadn’t yet consulted the schematic so I was kinda shooting from the hip there. Anyway, based on my understanding I think the following is true:
If I cut the trace connecting pin 14 to pin 13 and replace it with a resistor, then add a resistor of equal value from pin 13 to ground, I will end up with a gain of 2, boosting the triangle output from 4vpp to 8vpp, roughly the same as the other waves. Is that correct?

[WesleyV]

Tachi,
I can’t say for certain but it sounds to me like your signal might be connected to the switched tip pin instead of the usual tip pin, so you get signal when the cable isn’t plugged in far enough to throw the switch, then when you plug it in all the way, the switched tip pin separates and is floating, so you get nothing. I could totally be wrong though, I’m just speculating here.

[stmllr]

Weird values on LED display. Reg/green tuner LEDs also weird. What’s wrong here?

Using the tuner code from https://github.com/josbouten/Tune-O-Matic

[heckseven]

Yeah. That’s what I got when I used that code. I switched to LMNC’s code and it worked like a charm.

[stmllr]

Opened a github issue for that

[fredrik]

The SC56-11EWA you link to is common cathode (“Gemeinsamer Anschluss: Kathode”) but @Jos code has:

//
// SET YOUR DISPLAY TYPE HERE
//
const int LED_DISPLAY_TYPE = COMMON_ANODE;

so looks like everyone who uses Sam’s BOM with the alternative implementation will run into issues, unless they edit the file.

[Bitnik]

Oh yes, I thought it might be another occurrence of the “common cathode but software assumes common anode” problem (or vice versa). Didn’t the alternative implementation get changed last time so the code could be compiled to work either way?

[twinturbo]

Yep I hit that, probably in this thread somewhere

was a 5 second fix in the code.

Rob

[stmllr]

Thanks for the pointer.

Changing the type to cathode works like a charm:

const int LED_DISPLAY_TYPE = COMMON_CATHODE;

[Jos]

Ha, I see this got resolved even before I needed to step in. Nice ! Yes, I included a switch in the software to make it easier to switch between common cathode and common anode some time ago.

At the top of the code I defined 2 constants. Pick the one that fits your hardware and compile and upload it to the nano.

const int COMMON_CATHODE = 1;
const int COMMON_ANODE   = 2;
//
// SET YOUR DISPLAY TYPE HERE
//
const int LED_DISPLAY_TYPE = COMMON_ANODE;

As I am using common anode that is what ended up chosen in the repository.

B.t.w I hope you like the LED test for the display’s segments and other LEDs which is run when the tuner starts up.

[h3lloko]

Great work. Please can you tell me they sizes of PCB and front panel? I want to make My own VCO 1222 .

Thankyou

[twinturbo]

well the panel is 200mm by 100mm, the pcb not entirely sure but the general rule of thumb would be (using the forums design guidelines) 175mm by 95mm but it’s a split level PCB for the jacks.

[h3lloko]

Thank You!! This is a great group. !!

[stmllr]

Have a look at this thread for specifications: Kosmo Specification