[Build] Dannysound - Cali Oscillator (258 clone)

[dannysound]

Waz
V/oct works from 0V to 10V. Middle C on most keyboards with 88 notes is 5V. You can use the master tune trimpot to set the Oscillator to middle C when the coarse and fine tune controls point to 12 o’clock or whatever position you prefer. Ensure the LFO switch is out!

The master tune trimpot also functions to tune multiple Cali Oscillators to each other if you’re playing polyphonicly.

With nothing plugged into the v/oct input it is normalled to around 4V via a switch in the socket. If you’re running v/oct in a lower range say 0V to 5V you can plug the v/oct out from you’re Controller to the log input of the Cali and turn the control up full. That should give you better range from the frequency controls.

The quickest way to tune v/oct trimpot is to play an arpeggio over 3 octaves then tune it by ear. If you can’t get it tune then send us an email.

[Waz]

If I set both tuning pots to 12 oclock, tune the module to middle c via the trim, I am unable to follow the 1vo tuning procedure. My module can't go down to C2? Am I setting pitch with a dummy cable in 1v/o?

Also there is some erratic behavior with module, Only when I am handling it, sometimes it knocks out of tune and "wobbles" pitch until I physically tap the module then it goes back into tune. I checked all of the solder joints under a microscope and nothing was fishy there. Is this the nature of the tempco and those 2 transistors? It only happens when I am holding the module.

Thank you for your help.

[Waz]

I think i got it...I think?

However, it seems like something is off. I set the pitch controls to noon, then I took 5v from Ornaments and Crime, plugged it into the 1vo and tuned the oscillator to middle c from the trim. Then I followed the calibration procedure. Everything kinda locked into tune and it sounds great. I have one small issue tho. The coarse frequency ranges from LFO territory to around D5 as a max frequency.

If this doesn't sound right, I might have to take you up on the email.

*edit
I didn't get it. I need some guidance on how to do this.

[devinw1]

When you have the LFO switch on or off?

[Waz]

When you have the LFO switch on or off?

Off. When it's on the module is a super slow LFO.

[devinw1]

Hmm that does seem off. And no CV source is plugged in?

[four_corners]

Just finished my build, and seems like it partially works but I can tell some off things are happening...

First, should the SINE_SHAPE trimpot change the pitch at all while turning? When I turn it, it does seems to go between a triangle and a sine wave, but also the pitch is changing some, is that normal?

Secondly, the O/P_LVL trimmer doesn't seem to do much of anything on mine. I'm assuming this should be changing the output level globally? I'm getting about 3V peak to peak with the switch both up and down on the main output, and exactly 10V from the PWM output. These values don't change while turning the O/P_LVL trimmer.

Lastly, I must have some sort of grounding issue, because when the switch is at the middle setting, everything seems to go a bit bonkers. The signal usually drops out, and touching the front panel I can hear obvious grounding on/off sounds. Any specific area I should check if this only seems to be happening with the switch at the middle position?

Thanks for the help!


EDIT:
I actually think it may not be as messed up as I originally thought after watching DivKids video and after super super carefully calibrating via listening and an oscilloscope.

I'm able to find the "pure" sine wave tone, as well as the point where the WS_trim starts to distort. At this point, the oscillator seems to almost work well, but if I use the waveshaper knob on the front, it only will shape/fold about half way from a sine wave to either the square or saw shape. At fully clockwise, the shape looks about half way to what DivKid gets, so about 50% on his video. I thought maybe I had too small of a value pot there, maybe 10k instead of the 100k needed, but that isn't the case. I'll go through and check all my resistors. Are there specific ones I should look around first before just checking every single one? Thanks!

EDIT #2:

Fixed! Turns out it was the 220p cap next to the O/P_LVL trimmer. Turns out, there was a 2.2nf cap inside the same bag as all my 220p caps, and I magically picked that one out of the bag. So the lesson is, check the actual marking even if you have a bag labelled a specific value.

[sisyphus]

Finished my build as well. Luckily I ordered a bunch of kits prior to thonk stopping shipping. Now that I have a bunch of free time I've been going through them... but I digress.

I think I sucessfully completed the calibration procedure (using a scope) until I got to that last step with the switch in the middle position. All I get is noise at -10V and the trim does nothing.

Mine is also displaying a similar issue to four_corners in that the middle switch position does nothing when the wave shape is at 0 (part of the calibration procedure). Additionally, when I touch the switch's metal I get a blip of noise like it is a grounding issue or something. I checked the cap that four_corners mentioned and it seems to be the correct value (B221k).

When sweeping the wave shape knob with the switch in the middle position I get nothing until around 9 o'clock where it shows some waves, then cuts out again around noon or 1 o'clock. Definitely not getting a square wave at 0 and the PW knob does nothing (unlike what it shown in the Divkid video).

I've gone back through the build guide a verified all my components (to the best of my ability ). Just about done double checking the resistors. The switch seems to be doing what it is shown to do on the schematics. I checked the pins on the board connector with the switch in the three positions to verify.

I'm all out of ideas at this point. Maybe a fried transistor or something? I figured if that was the case I wouldn't get any sound, or some earlier step in the calibration would have been off. Maybe a bad solder? I looked at them all and nothing was obvious (unlike another build I did ) and no obvious solder bridges or anything.

Anyone have any advice? I'd appreciate even some hints. I guess I'll go through the build guide again

Take care all, hope modular is providing at least a little solace in these crazy times!

[sisyphus]

Spent a few hours and went back through the build guide and verified each resistor (at least the band colors) and the rest of the components. Re-ran the calibration procedure and everything seems ok up until I get to the middle switch positions.

Same issue, although now touching the switch body no longer "blips" some sound. I found that when barely touching pin 4 I get continuous sound. Seems like a grounding issue or a bad cap or something? Under normal operation when going from either the up or down position to the middle position I get some sound for a split second then it trails off to nothing. Lower frequencies seems to last longer. I'm imaging a cap discharging or something, but I don't know enough about electronics, sadly.

At this point I'm thinking a bad component. Maybe a transistor or cap? I figured if it were that the calibration would have failed and the up and down switch position wouldn't be working.

Any advice would be appreciated

[Drgreen]

Is Sine Trim supposed to affect pitch? Mine does.

Having a little trouble calibrating my V/Oct and wondering if this has anything to do with it.

[dannysound]

Yeah the Sine trim will affect pitch but it won’t affect the V/Oct tracking. If you’re still having problems please email me, don’t seem to be getting notifications from MW anymore!

[Drgreen]

Yeah the Sine trim will affect pitch but it won’t affect the V/Oct tracking. If you’re still having problems please email me, don’t seem to be getting notifications from MW anymore!

Thanks for that. I re-centered all of my trimmers and started again and got both tracking well.

They sound great!

[adwer]

Waveshaping doesn't work on my build. What should I check first? Solders look good.

[adwer]

Waveshaping doesn't work on my build. What should I check first? Solders look good.

Solved.

[hflink]

Recently completed building this oscillator (Thonk DIY kit ) and at the point of calibration, I noticed an output frequency of roughly 50 kHz and that turning the TUNE pot does not have much effect until the signal suddenly dies when tune is at 75% or so. Also, the shape is in no way near to a sine or saw, but I consider that another issue for later ;-)

With the switch at saw, the OUTPUT signal with TUNE at 50% and MASTER_TUNE fully CW, is 2.6Vpp with a DC offset of +480mV:

IMAG001.png

Switching LFO in has a small effect:

IMAG002.png

Checked the soldering, component values, types and orientation and all seem ok. All voltages (+12V, -12V, +9V and -9V) are all ok at the relevant spots.

I am at a point where I could use some insights in the core of the oscillator and the voltages that control it.

Following are my measurements at the core:
@IC1 (CA3080) pin 2: 1.8Vpp Vdc+480mV:

IMAG003.png

@IC2 (LF356N) pin 6: 15Vpp Vdc 0mV, see:

IMAG004.png

Following DC voltages measured with TUNE going from 0% to 50% to 100%

	0%	50%	100%
@U1Q2Q2 (2N3906) base	-26mV	-80mV	-150mV
@IC3 (TL074) pin 7	-28mV	-90mV	-157mV
@IC1 (CA3080) pin 5	-11.9V		-11.5V

If anyone can shed some light on where and how to debug further, I would be really grateful: been banging my head on this for a couple of days now

[dannysound]

Hi can you post some pics of the PCBs? Is the kit all from Thonk? As there are quite a few fake 3080 chips knocking about, could be causing these types of issues. The ones from Thonk should be fine though.

[hflink]

Thanks Danny!

Pics of PCB's:

DSC_0007.JPG

DSC_0006.JPG

Not all parts are Thonk, I remember the CA3080 is from Aliexpress. This would be the second time for me cheap China IC's turn out bad, had some bad luck with other opamps as well. I'll replace this IC with a decent one.

regards,
Herm