HP201C Audio Oscilator ,the whole manual can be found here : http://www.hparchive.com/Manuals/HP-201C-Manual.pdf

VCO article by A.Lazzari and R.Monti published in 1979 issue of italian Selezione Radio .

 

Electronic Synthesizer ,series of articles by D.Avramov and V.Veleva published in Bulgarian magazine Радио, телевизия, електроника 1981

 

 

 

 

Low Frequency Function Generator by  Emil Novakov and Nikolai Mudrov featured in '82 September issue of Bulgarian - Radio ,Televija ,Elektronika

Parts of EAI Model TR-20 desktop analog computer 

  

HP3300 Function generator Oscillator section

Krohn Hite TM-9
The Models 3200 and 3202, illustrated in Figure 1, are solid state variable electronic Filters with cutoff frequencies
continuously adjustable over the frequency range from 20 Hz to 2 MHz. The pass-band gain is unity (0 db), with an
attenuation rate of 24 db per octave outside the pass-band. Maximum attenuation is greater than 80 db and the output
hum and noise is less than 100 microvolts.
The Model 3200 can function as either a High-Pass or Low-Pass Filter. In the High-Pass mode of operation the maximum
input signal is 3 volts rms and the upper 3 db point occurs at approximately 10 MHz. In the Low-Pass mode the Filter is
direct-coupled and the combined ac plus dc input signal should not exceed 4.2 volts peak.

Nine channel Stereo Equalizer by Gary Kay featured in Popular Electronics 1974

 

 

     

Farnell LFM2 Sine/Square Oscillator

PAiA VCO remade by Federico Cancarini for 1976 issue of  Selezione Radio magazine .

Drum machine article from Radiorama magazine September 1976

 

Radio Elettronica 1978 Sequencer article by Dl Irvi Cervellini