The PRC-2 audio choke from One Electron was designed for shunt-feed single-ended output applications, but is also useful where quality inductive loads are needed or as high-quality filter chokes. It uses the same high quality M6 laminations as the UBT transfomers. Has two identical windings allowing series and parallel combinations. It is not recommended for use as a transformer.
The table shows the maximum recommended load impedances when used as a shunt-feed choke. As with traditional class-A triode amplifiers, the driving impedance is about 1/2 the load impedance. The recommended load impedances are based on a -1dB response at 20Hz; for better low frequency response, use a choke with higher recommended load(higher inductance).