Tube DIY Asylum Do It Yourself (DIY) paradise for tube and SET project builders.

---

[ Follow Ups ] [ Post Followup ] Thread: [ Display  All  Email ] [ Tube DIY Asylum ]

---

[ Alert Moderator ]

---

Advice on Substituting Western Electric 412A for 6X4?

Posted by Jim Hodgson (A) on May 26, 2017 at 15:43:59

I'd like to try a different rectifier in my phono preamp in place of the originally specified 6X4 (or EZ90). I can't ask the original builder, so here I am...

I seems that the Western Electric 412A -- with a pin adapter, of course -- is a near substitute for the 6X4. That said, I understand that the 412A draws more heater current ... specifically, 412A = 1 A while 6X4 = 600 mA [edited].

Thinking that this might present a problem, I called the manufacturer of the phono preamp's power transformer (DeYoung outside of Seattle) and asked. The company's design engineer told me that the PT's 6.4-volt tap is rated for 2 A. So, his message to me was that even the 412A's higher current draw is still well under limits. He also clued me into the fact that, in general, the designer/builder always over-specified his PTs.

So, I'm fairly confident. I guess I just want, as a double-check, to get a consensus recommendation on whether this is safe and reasonable. I always try to stay within an "original" tube's limits ... and my proposal entails a 65% [edited] increase in rectifier heater current draw. And maybe this isn't even the only potential pitfall?

Thanks for your help!

Edits: 05/27/17

This post is made possible by the generous support of people like you and our sponsors:

VH Audio

---

[ Top of Page ] [ Contact Us ] [ Support/Wish List ] [ Copyright © 2024, Audio Asylum, all rights reserved ]

---

[ General ] [ Speakers ] [ Tubes ] [ Vinyl ] [ Digital ] [ Hi-Rez ] [ Video Asylum ] [ Cables ] [ Tweaks/DIY ] [ Music ] [ Films ]

---