Melissiah 39 Posted January 17, 2014 according to this http://line6.com/supportarchivenew/thread/75238 DT25 multimeter to DCV 200m AB mode and you should get a reading close to 25.0. If it's off, turn the adjustment screw with a small screwdriver until it is at 25 +- 3 Like one guy in previous post I'd like to try JJ el844 who have 25% less power cause my DT25 is still very loud. Should I bias -25% (18.75) like I read on other amp site or I stay at 25? thanks 1 Quote Share this post Link to post Share on other sites
boyce89976 18 Posted January 18, 2014 Your best bet is to contact Eurotubes and ask them. They are the importer for JJ's and really know their stuff. 1 Quote Share this post Link to post Share on other sites
marco3253 4 Posted March 17, 2017 my EL844 bias around 14 Quote Share this post Link to post Share on other sites
Krontab 62 Posted August 13, 2017 Take care as EL844 may not cathode bias correctly in Class A mode. As I recall it may require a resistor swap in that case. Quote Share this post Link to post Share on other sites
psarkissian 350 Posted August 14, 2017 Use the specified valves from EH. That's what these amps are designed for. These amps are not like the all analog amps of the 1960's and 70's. They are not forgiving of modifications, or even of valves. The difference in the characteristic curve between valve brands can cause problems. This is not an all analog amp, the digital and analog sections have expectations of one another. Mess with that and problems occur. Use the specified EH valves. Quote Share this post Link to post Share on other sites
marco3253 4 Posted August 14, 2017 I went back to el84 biased around 24 and 27 Quote Share this post Link to post Share on other sites
psarkissian 350 Posted August 14, 2017 Very good. Quote Share this post Link to post Share on other sites
