1222 Tuner VCO Triangle Waveform Output Volume

[KevinG]

Hello,
I’ve recently built the 1222 VCO and whilst everything appears to be working fine, the triangle output seems a lot quieter than PW or sawtooth.

I couldn’t find much info on this, and I’m just wondering if this is expected due to the nature of that waveform or if there is something else down to calibration that I’m missing?

Apologies if there is an obvious answer, I’m fairly new to this!
Thanks

[CTorp]

Hi Kevin, welcome here.

The short answer is yes it’s normal.

the triangle and saw are made from the square with parts of the wave removed so it does get noticeably quieter

Discussed more here:

Calibrating output signal amplitudes

If I don’t say stupidity, all the waveforms come from the Square, and the more they are “rounded / cut” the more they lose in dynamics. It is therefore normal to have a Sine more low than a Triangle and this one than a Square. Most people just leave it that way I think. Otherwise it would be better to increase the low values, rather than lower the dynamics of Square. I adjust them after in my mixer

And:

@analogoutput

It is also true the perceived loudness depends on the wave shape as well as the amplitude. A sine wave sounds quieter than a square wave of the same height.

[KevinG]

Ah fab, thanks a lot! I’ll have a read through these

[analogoutput]

@CTorp

the triangle and saw are made from the square with parts of the wave removed so it does get noticeably quieter

Actually the 3340 is a triangle core oscillator, so the saw and pulse are made from the triangle. Saw I think by switching between original triangle and inverted, and pulse by using a comparator. Result (from the datasheet):

(Not sure why the saw amplitude is double the triangle, the linked tri to saw method gets you the same amplitude.)