April 13, 2014 Leave a comment
How big are the boards?
- Line stage: 2.15″ x 3.90″ (app. 55 x 99 mm)
- RIAA: 3.0″ x 3.875″ (app. 76 x 98 mm)
What is the status of the boards?
The boards are both in version 1.1. Version 1.0 has been prototyped and version 1.1 incorporates some minor tweaks and fixes to the layouts.
Does it use any special/expensive/hard-to-find parts?
Not really. The 6J5 tubes should be possible to find on ebay and similar places. There is also a 12J5 version which, apart from needing a 12VDC filament voltage, should be identical to the 6J5. As for other substitutes, please search online. The caps in the line stage and the RIAA are Mundorf standard MKP types (the white ones).
Anything else I need to know?
Not really, no. The boards take a +37VDC (or thereabouts) main power supply and draw very little power – you can easily use one of the regulated PSUs I have posted here on the site. The Line Stage additionally needs a +6.3VDC filament supply. Current draw depends on the type of tube chosen, but you can use one of the regulated PSU designs as well as long as you use a 6 or 7VAC transformer.
Download design files here
Note: Always read the “intro post” for additional important information about my designs.
Link to the original design/build article (in Danish) is here (20MB scanned pdf).