this project / page is under construction
Current status of the project (2019/09/16) :
– XOno circuit diagram created
– XOno PCB design created
– Controller circuit diagram created
– 2 XOno circuit board supplied (prototyping)
Table of Contents
Since 2008 I provide printed circuit boards for a Pass Labs XOno replica and over the years unexpectedly many have been built. Unfortunately the gold dust – the outstanding 2SK170 JFETs from Toshiba – are running out. The supplier I always recommended can’t offer any more. So it becomes difficult to impossible to build an original XOno.
At the end of 2018 I decided to build a MC-prepreamplifier based on the XOno topology with the 2SK2145 JFET’s from Toshiba as a plug-in card for my DPV1 phono preamplifier. It should serve as a test setup for a new XOno to be designed. I put this plug-in card into operation at the beginning of 2019 with great success and thus nothing stood in the way of a redesign of the XOno.
The design should still be as close as possible to the original XOno design, but with a few useful improvements from the design of the XP-15 and my own experience of many years. I have written the following points into my personal specifications:
- Optionally assembled with 2SK170 / LSK170 or 2SK2145.
- Reference voltage source instead of the simple LED for the current sources of the RIAA amplifier.
- Modern design of the inverter (XP-15).
- Optionally assembled with DIP switches or relays.
- Optional AC or DC coupling at the outputs of the RIAA stage and the inverter.
- DC power supply input with CLC filter.
- Discrete power supply regulation with a modified Jung regulator.
- Extension Board with additional Equalization Characteristics (Columbia, Decca, EMI & Teldec)
- Microcontroller PCB for the relay operation.
- Use of mainly through-hole components.