3 ms·
> The sine-wave shaper appears to be inspired by the similar circuit in the HP 3300A Function Generator, introduced in 1965. The schematic below shows the HP 33
by formerly_proven 5y ago
> The sine-wave shaper appears to be inspired by the similar circuit in the HP 3300A Function Generator, introduced in 1965. The schematic below shows the HP 3300A's sine-wave shaper; the breadboard's network is similar. The resistances are carefully chosen to achieve the sine wave.
In some Philips FGs they had sine shaping ASICs (presumably with a ton of taps and good matching) and managed to get distortion down to 0.1 % iirc (which for the 70s or early 80s would have meant that you don't really need a proper RC oscillator any more for testing audio amplifiers).