PST-100 MKII (SE) SILVER EDITION

About the PST-100 MKII (SE) SILVER EDITION

The Ypsilon Electronics PST-100 MKII (SE) Silver Edition is a high-end vacuum-tube stereo line preamplifier combining transformer-based volume control with switchable passive and active operation. Its active section is a zero-feedback, single-ended Class-A stage using two Siemens C3m pentodes wired as triodes and transformer-coupled to the output; a 6CA4/EZ81 valve rectifier and choke-filtered supply are used. The Silver Edition (SE) upgrades the signal path with custom silver wiring and Ypsilon-made transformers wound with custom enamel-coated silver wire, including the coupling transformers. The volume system uses a 31-tap transformer attenuator, placed after the valve gain stage, rather than a conventional resistive potentiometer. Inputs and XLR connections on this version are unbalanced despite the XLR connector format. The manufacturer currently maintains a PST-100 MK2 product page, although the exact SE Silver Edition configuration may have been superseded in the range by the later PST-100 MK2 SE Anniversary version.