Cuterd Posted September 9, 2017 Share Posted September 9, 2017 Hello, today i was practicing at low volume and jumped out of my bench when i heard a loud pop sound coming from the speakers(?), i tested every switch after i heard it, everything seems to works, power valves seem ok, the amp seems to be working fine... But it can't be nothing right? Help? Im kinda worried, spent my savings on the amp secound hand and i don't want to brake it.. Quote Link to comment Share on other sites More sharing options...
psarkissian Posted September 11, 2017 Share Posted September 11, 2017 When was the last time the valves were changed out? Can you see the markings on the valves and tell me what brand they are? Valves need to be changed out and biased once every 18 to 24 months, depending on how much use it gets. And should be done by an authorized service center who knows the product. 1 Quote Link to comment Share on other sites More sharing options...
Cuterd Posted September 12, 2017 Author Share Posted September 12, 2017 Ithe amp has been in my hands for 2 weeks now but the previous owner said he changed the valves arround a year back (when the power transformer died and he sent to line6 to get it fixed) but he said he didnt play much after that.. he probably did the bias himself, the power valves are jj brand and the bias is T1.0Al (if im checking the right thing..) Quote Link to comment Share on other sites More sharing options...
oscarguitar Posted September 12, 2017 Share Posted September 12, 2017 Oh dear, take cover. Probably need a valve change back to the EH originals and a re-bias. Plenty of threads on here about the subject. The DT 25 will pop when changing to Class A but generally if the valves are good it's a pretty quiet amp. 1 Quote Link to comment Share on other sites More sharing options...
psarkissian Posted September 12, 2017 Share Posted September 12, 2017 Get those JJ's out, it may be part of the reason for the transformer failure in the first place. Use the specified Electro-Harmonix. Take it to a Line 6 authorized service center to have the valves change and biased, and the fuses checked for the correct values. These amps are not forgiving of alterations or modifications,... that includes valves. These are not the all analog valve amps of the 1960's and 70's. Amps that come back to me for repair with other than specified valves, failed because they had something other than specified valves in them,... and incorrectly biased. Take it to a Line 6 authorized service center. 1 Quote Link to comment Share on other sites More sharing options...
Cuterd Posted September 12, 2017 Author Share Posted September 12, 2017 Oh right, i forgot to mention that it's a dt50 1x12 combo... Where can i get the original valves, how much will it cost to swap them? Well, the pop sound happened while i was playing so I wasn't messing with the controls, i would say the amp is pretty quiet, there is a low hum that you cannot hear while playing (that hum turns insane with the volume and master full power, but I'm a bedroom player) and there is a tickling of the valves when powered off, that i read was normal (its my first valve amp..) Quote Link to comment Share on other sites More sharing options...
psarkissian Posted September 12, 2017 Share Posted September 12, 2017 Take it to an authorized service center in your area, they can take of all of that. http://line6.com/find/service_center/ 1 Quote Link to comment Share on other sites More sharing options...
Cuterd Posted September 12, 2017 Author Share Posted September 12, 2017 Ok ill do that, how much should i expect to pay? Since im here, the amp has one problem that i noticed when my friend bought him self one too (he got blown away by the sound quality), i noticed my A and B channels dont sound the same, for instance the A channel in the voicing IV sounds as clean as it gets and as metal as it gets on the B channel, in his dt50 it sounds the exact same.. Should i be worried, is it an easy fix? Quote Link to comment Share on other sites More sharing options...
psarkissian Posted September 12, 2017 Share Posted September 12, 2017 Check with the service center for an estimate on that. Hard to tell with a second or third hand product, and I don't have the entire service history available to me, so I can't look that up. I have access to service histories local to me. A & B should sound close to being alike, so you can set each one for different tones and go back and forth between them. All that would be in the manual. http://line6.com/support/manuals/ 1 Quote Link to comment Share on other sites More sharing options...
oscarguitar Posted September 13, 2017 Share Posted September 13, 2017 Try a reset. If the amp was used when you got it, there could be some old settings stored. I'm not sure how to do that on a DT50. And a 50 as a bedroom amp! Unless you blow the doors off you will never hear how good that amp can sound. I Gig regularly with a DT25 combo and extension cab and rarely get it in the sweet spot above 50% master volume. But it sounds stunning when I do. 1 Quote Link to comment Share on other sites More sharing options...
psarkissian Posted September 13, 2017 Share Posted September 13, 2017 There is no factory reset on that amp. It can be re-Flashed thru Line 6 monkey. However, here, this is a hardware issue that won't be solved with software and programming. 1 Quote Link to comment Share on other sites More sharing options...
Cuterd Posted September 13, 2017 Author Share Posted September 13, 2017 I think he is referring to my problem with channel A and B sounding completely diferente, and i think he's right from what have been reading the amp can be programed to have 8 different amps, altho i dont know how to do it... The did have a pod hd 500 for a time and I'm thinking he left the amp like this with it.. Might be wrong. Idk, to me it sounds stunning at bedroom lv x) i read the warnings on the dt50 manual and it didn't warn about changing the valves from time to time or to keep the factory brand, but i will change it back when i can afford to buy the old ones and send the amp to line 6.. I guess ill play it as little as possible untill then Quote Link to comment Share on other sites More sharing options...
Cuterd Posted September 13, 2017 Author Share Posted September 13, 2017 Well i found that there is a factory reset on the amp, u turn the power on and simultaneously press the voices down and the triode/pentode up for 15 sec. Until voicing 1 apears lit. (Dont touch the standby) http://line6.com/support/manuals/dt50212/ As it says on the dt amplifier midi implementation guide Quote Link to comment Share on other sites More sharing options...
psarkissian Posted September 13, 2017 Share Posted September 13, 2017 Cool. Forgot that was there, I've never had to use it myself. Quote Link to comment Share on other sites More sharing options...
oscarguitar Posted September 15, 2017 Share Posted September 15, 2017 That's the one. Same as DT 25 but I wasn't sure about the DT50. Quote Link to comment Share on other sites More sharing options...
JohnWood Posted February 11, 2020 Share Posted February 11, 2020 The DT25 head I own has been performing well for several years now. I have not changed any tubes. Yesterday while playing a loud pop was heard following by no sound and no power. The fuse was verify to be still in god condition as no discoloration. What would you believe to be the problem? 1) Total tube replacement 2) Power Issue? 3) Other Quote Link to comment Share on other sites More sharing options...
psarkissian Posted February 12, 2020 Share Posted February 12, 2020 Any one of the three. Should be taken in to your nearest L6 authorized service. Start with checking the power, and the transformers, then change out the tubes. There is a calibration and test check procedure, post tube change out check list. Have L6 authorized do it. Quote Link to comment Share on other sites More sharing options...
kutsab Posted August 25, 2021 Share Posted August 25, 2021 I just had my DT50 upgraded with a Mercury Magnetics transformer (shout out Bell Audio Lab) and was experiencing a similar pop not long after getting it back. I just tried the reset and seems to have done the trick. I can’t recall what amp settings I updated back when I set this up, but am not too keen on the idea of overhauling my rig after the MM install. As much as part of me would love to go full Helix or Quad Cortex, my 2/3 Dream Rig has been such a fun setup to run (even if I’m only playing 50 watts at home). Next up is trying the 4CM + Helix Stomp… very intrigued Quote Link to comment Share on other sites More sharing options...
psarkissian Posted August 25, 2021 Share Posted August 25, 2021 If it's during power on or power off, then it would be a filter cap discharge cycle, also known as the RC time constant. Might not be as well matched to the transformer as it could be. How long since the tubes were swapped out last? Are they the specified tubes and bias? Tubes choices to use for the DT Series,... DT-50 Series: 12AX7EH Electro-Harmonix approved for the DT50 pre-amps. EL34EH Electro-Harmonix (matched pairs) for the power amps. DT-25 Series: 12AX7B China for pre-amps. EL84EH Electro-Harmonix (matched pairs) for the power amps. Power amp tube choices are crucial, and must be properly biased by a tech or Line 6 authorized service center who knows the product. Don't do this yourself, the shock hazard is too great,... and it hurts when you get electric shock. Leave it to a tech trained who is for this. These valve amps are particular about tubes and tube brands. Do Not use substitutes, No Mesa, Groove Tube, Tung-Sol or JJ or (etc) substitutes. No hot rodding of an already Bogner hot rod. How often do you play it? Gigging musician (once every 12-18 months), weekend warrior (once every 20-22 months), bedroom/closet studio rocker every couple weeks (once every 24 months)? 1 Quote Link to comment Share on other sites More sharing options...
kutsab Posted August 25, 2021 Share Posted August 25, 2021 It would happen mid play actually. Volume is usually relatively low, then the pop, then buzz (like the guitar’s unplugged) without any other sound. The work was done at an L6 service center & they took care of checking/biasing the tubes too. I’ve definitely taken note of how finicky the tube tolerance is with the DT series, so I’ve been very mindful of tune replacement brands. I’m definitely a home office noodler l, so I’m easily into the 24mo timeframe on tubes. It’s definitely a good thing since I want to say I’m at least 2hrs from an L6 service center since I’ve moved to NC. Since my DT was a factory refurb from about 5 years ago, I might end up going rogue and using a local shop if anything else needs to be worked on. Worst comes to worst I end up going the PowerCab route, or getting lured into Neural DSP’s territory… time shall tell thanks so much for the response and the details! Quote Link to comment Share on other sites More sharing options...
psarkissian Posted August 25, 2021 Share Posted August 25, 2021 Hmmm,... mid play, sounds like the tubes. Yeah, it's about that time. 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.