john_rut Posted September 29, 2017 Share Posted September 29, 2017 I was playing at band practice and all of a sudden no sound. Power is on and all switches are responding so I figured it had to be a tube. I changed out to my backup set and still no sound. I can see the tubes powering up but still nothing at all. I tried resetting the amp as suggested in the manual and still nothing. Any suggestions on troubleshooting the preamp section or the digital section? Quote Link to comment Share on other sites More sharing options...
psarkissian Posted September 29, 2017 Share Posted September 29, 2017 Have it checked by a Line 6 authorized service center near you,... http://line6.com/find/service_center/ Keep your fingers out of the innards of the amp, shock hazard is significant, and that hurts. Quote Link to comment Share on other sites More sharing options...
oscarguitar Posted September 30, 2017 Share Posted September 30, 2017 Check the tube protection fuse before you get it checked by a tech. If the tubes go they often take the fuse out. Mine certainly has/ does. It's a weird fuse so be prepared to search around for it. Remember to have it re-biased as well. Otherwise the tube will just go again. Quote Link to comment Share on other sites More sharing options...
psarkissian Posted October 2, 2017 Share Posted October 2, 2017 Unless you have experience dealing with valve amps, keep you fingers out of the insides. Touch a line the wrong way and you get zapped,... even if it's unplugged. One good capacitor discharge into you and you're done. And if you're prone to heart conditions, it's worse. It hurts when you get zapped by a capacitor. Leave it to the techs with the experience. Quote Link to comment Share on other sites More sharing options...
john_rut Posted November 6, 2017 Author Share Posted November 6, 2017 Update: took it in to get it worked on and the first update was it was not showing any plate voltage on he power tubes. Root cause is still unknown... Will post more info as it comes in. Quote Link to comment Share on other sites More sharing options...
psarkissian Posted November 6, 2017 Share Posted November 6, 2017 Log a support ticket. If there is no plate-volts, then something wrong and should be looked at by an Line 6 authorized tech who knows the product. Quote Link to comment Share on other sites More sharing options...
john_rut Posted December 21, 2017 Author Share Posted December 21, 2017 After taking it in to a Line 6 authorized repair place it turned out to be the power supply connector to the digital board was heating up and failed. The tech informed me this also happens to the DT50 as well. He also confirmed the need for the EHX tubes based on the way the digital board interacts with the power section of the amp. If you are looking for a backup set the EHX mid duet is the specific ones needed. Going forward I won't be trying to bias myself after hearing about the intensive burn in protocol for new tubes. I have to say after fixing it and the new tubes it sounds better than it ever has... Hope this helps! 1 Quote Link to comment Share on other sites More sharing options...
Brazzy Posted December 21, 2017 Share Posted December 21, 2017 After taking it in to a Line 6 authorized repair place it turned out to be the power supply connector to the digital board was heating up and failed. The tech informed me this also happens to the DT50 as well. He also confirmed the need for the EHX tubes based on the way the digital board interacts with the power section of the amp. If you are looking for a backup set the EHX mid duet is the specific ones needed. Going forward I won't be trying to bias myself after hearing about the intensive burn in protocol for new tubes. I have to say after fixing it and the new tubes it sounds better than it ever has... Hope this helps! Interesting about the power supply connector being the cause. Thanks for sharing. Enjoy your amp man. Quote Link to comment Share on other sites More sharing options...
psarkissian Posted December 21, 2017 Share Posted December 21, 2017 There is a whole set of signal checks and tests done after putting new tubes (valves) in, sp that it runs stable with the new tubes (valves). For the DT50, EL34EH matched pairs from Electro-Harmonix for the power tubes (valves), 12AX7EH low microphonics for the pre-amp tubes (valves). For the DT25, use the EL84EH Electro-Harmonix (matched pairs) for the power tubes (valves), and 12AX7B China for pre-amps. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.