These capacitors are commonly used in synthesizers in both filter and oscillator circuits.
A good indication that these may be failing is if a filter is intermittent. This is especially common in the Prophet 5. If the filters cannot be calibrated, or the self oscillation is intermittent, these capacitors are almost always to blame.
Other common synthesizer specific failures caused by faulty polystyrenes:
– Disappearing Oscillator in Oberheim SEM
– Unstable tuning of Oberheim OB8
– Filter loss in Prophet 5 Rev 3
This listing is for value 150pf, or .15nf