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

---

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

---

[ Alert Moderator ]

---

Re: Why are 6DJ8 so hum prone

Posted by fatbottle on December 21, 2004 at 11:46:57

In Reply to: Why are 6DJ8 so hum prone posted by Gusser on December 21, 2004 at 11:18:20:

Hello ,
I recetly tested 38 Bugleboy (Dutch Philips) scope pulls which all tested within +/- 5% of target spec for NOS . Tested miles better than all that crap being touted on Audiogon at the moment , only 5 made the grade for noise and hum . Russian 6H23 weren't bad , more modern Pinnacle branded Rusian (thick glass) terrible . I was using AC heating , no problem whatsoever for NOS Mullard ECC88 . Even using DC heaters , sometimes hum is still a problem , I'm almost convinced that some hum problems with this type are down to microphony due to proximity to transformers and chokes and perhaps even loose Chinese sockets . Adding Viton 'O' rings to the valves often helps , you could always go one further and try screening cans . Watch your layout , keep leads short and ensure gridstoppers are always used but some brands are still pretty noisy and useless . I can't comment on new production but have heard from a friend that current JJ's are pretty quiet . For the record I'm using mine in a Hedge circuit driving trioded EL822 (similar to Allen Wright's PP1C driver) with 95dB/1w speakers . Hope this helps :)

cheers

...FB

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 © 2013, Audio Asylum, all rights reserved ] [ Take5 ]

---

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

---