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2X12 DT-50 Power Transformer
by broadfca on 2012-06-07 04:18:19.0910

Hi, I was playing along on my DT-50 and it JUST DIED !!! So.... I grap my trusty meter and find that the secondary side of my Power Transformer is reading only about 8 ohms resistance.

Can someone tell me if I can just replace the Power Transformer? How would I get this repaired. It's practically NEW, but I can't find a reciept. Please help me (sad face).



Re: 2X12 DT-50 Power Transformer
by DarthHollis on 2012-06-07 06:58:57.6410

Where did you buy it?  If you purchased online you should be able to look up your purchase history there.  You can still register your gear here:

If you bought it at a physical store they probably can give you a copy of your reciept too.  I don't thing you need to be exact on your date and price, anyway.

You should still be covered by the warranty.  Go here for warranty info:

And here for a service center near you:

Good luck!

Re: 2X12 DT-50 Power Transformer
by broadfca on 2012-06-29 02:49:59.7680

Thanks. I want to let everyone know about the great experience I just had with Line 6 Customer Service. After explaining my situation to Ashley, she offered me a very fair and reasonable solution. Thank you Line 6, this is the kind of Customer Service one would expect when purchasing a $1,400.00 Amp. I have been phasing over to All Line 6 equipment, and it's good to know that Line 6 takes care of their customers.

Thanks again everyone, and thanks again Line 6.


Re: 2X12 DT-50 Power Transformer
by whiteop on 2013-02-11 19:44:13.5840

I have had my power transformer go bad 3 times on my DT-50 within 14 months! Each time sent in for repairs. Each time it came back working after it was diagnosed with a power transformer that went bad. The amp would work for a few months then would either just suddenly die or wouldn't power on. All tubes were checked; even replaced them with other tubes I had that I know are good to see if that was the problem. It wasn't the tubes; all glowing in their sockets. This last Sunday my amp dies right in the middle of playing a song while at church! Mind you I only play the amp twice a week for 30 mins each time and I don't lug it around so it still looks brand new. I put it in Standby before powering it down like I've done all my tube amps in the past. I do leave it hooked up through the XLR jack out into the sound system and it does pop through the sound system when you turn it off and I've heard that there's an output transformer that the XLR is tapped off of but I don't know if that has anything to do with it; probably not. I'm thinking it's just cheap power transformers or a part of the circuit that was designed poorly that overloads it as that's how you kill transformers usually (I went to study to become an electronic tech years ago). None of my other worship team players that are using amps are having any problems on the same circuit so I would guess it's my amp.

Today I called up Line 6 customer support and spoke with a gal named Ashley that may have been the same one. I told her my situation that my amp had just gone out of warrantly including the extended one I had bought which I though started AFTER the Line 6 one year warranty expired. Anyway that was what the GC employee who sold me the amp told me (I had a talk with the manager today about it; he said he would check to see what the GC employees are telling their customers about their extended warrranties; I know the manager personally so he knows I'm not trying to pull a fast one on him). Otherwise I would have bought a longer extended warranty; I figured two years would be plenty of time for whatever would go wrong to go wrong.

Ashley didn't miss a beat (sounds like she's heard this a lot before) and told me to send the amp in and they would take a look at it and see why it kept blowing the transformer. Of course I had to shell out $55 to mail the amp to them but that's better than having an oversized doorstop that cost $1300 that only worked a few months at a time for 14 months before breaking down each time. BTW - I have a Rivera M100, a Fender SRD that I've NEVER had to have serviced and a Mesa Stiletto that has only had to be looked at once in 6 years.  Seriously I wish they would just send a new one after what all I've had to deal with on that amp, especially if they've made any revisions to the design or replaced the bad power transformers with newer ones just so I would have some peace of mind not anticipating the same thing happening again. Also in the event that some other circuit board is also causing the power transformer to go bad; I know on most amps like that they just simply swap out the cards / circuit boards and replace it instead of repairing separate components. I had to drive it 40 miles to a service center the first time and wait 3 weeks. 2nd time I had to drive it 25 miles to the nearest UPS facility to mail it to Baltimore, MD (Protech) and had to wait about a month; now this.

If I were Line 6 I'd definitely being giving Reinhold Bogner a piece of my mind for not market testing the amp for durablity and problems like this. Hoping I will get it back and it will be the end of this problem. Ashley if you're out there, thanks for at least trying to make a Line 6 customer happy. That's how you get repeat customers for life.

Re: 2X12 DT-50 Power Transformer
by hzpyzs on 2013-02-13 21:19:25.3970

hmm, just a call from the shop and yep, blown tranformer. I was given the offer of a used one or wait for a new one, with no eta. $128 w/shipping. Seems they are on back order, must be in demand :-(  I would wait months for a improved part that didn't need to be replaced in short order .... another part that I can't rely in is of little use ....

Re: 2X12 DT-50 Power Transformer
by jeffwatt on 2013-02-14 10:38:53.4760

+1 This is EXACTLY what I'm afraid of as far as owning my DT-50 long-term. I've only had the power transformer blow once, so far... but why do I feel like it won't be the last time?

Re: 2X12 DT-50 Power Transformer
by hzpyzs on 2013-02-14 17:32:16.7930

It is tough not to worry about the long term future of the DT50. Not because it is a bad amp of coarse, mostly because it is a great sounding amp. A better amp then I am a player. Possible the last 2X12 combo I would ever need to buy, if it holds up. A amp that seems to be having some issues with transformers. Since I have no idea of what that that issue is, one can't but wonder, will it continue to happen?  Is it a bad batch of tranformers ? Has the problem been addressed ? Can it be ? Is the design somehow tough on tranformers ? Mine was used daily in a bedroom at low volume for the past 7 months. Does using it at low volume hurt the life of the transformer ? Reading about people being on their second or third transformer is a little scary. Should I buy a spare tranformer ? or even spares ? 5-10 years from now will I even be able to find one ? Apparently I can get a used one this week, but not a new one. Personally, I think I will just put the DT50 in the practice space and hope for the best. If it eats another tranformer, I will have to see how long it took to do so. Then decide if I need look for a different amp or stockpile some transformers.

Re: 2X12 DT-50 Power Transformer
by PDKTDK on 2013-02-15 09:20:31.5710

I started using mine at consistently high volume recently (since I got my attenuator).  Master at 1-2:00.  I wonder if the opposite is true.

such a bummer.

Re: 2X12 DT-50 Power Transformer
by hzpyzs on 2013-02-27 20:46:34.0950

3 months. That is what I have been told it will take for my replacement transformer to be at my service center.

Re: 2X12 DT-50 Power Transformer
by whiteop on 2013-03-02 16:41:39.2620

Better hope they don't do to your amp what they did to mine. Basically put a ding in the front facing of the amp, left one of the screws unscrewed, and stripped some of the paint off some the screws. It works but I don't like the ding or defaced screws. It was repaired at one of their facilities in California. Never had damage to my amp when repaired in Texas or New Jersey. Probably a young guy or someone that was high (it is in CA). Go figure.

Re: 2X12 DT-50 Power Transformer
by whiteop on 2013-03-04 13:03:55.5430

Bad news again. The power transformer blew the day after I got it back from repair! Mind you I've been using numerous other amps on the same circuit for 6 years with no problems. It's clearly the amp. If you have an enemy you clearly despise the DT-50 will make a wonderful gift...;)

Re: 2X12 DT-50 Power Transformer
by spaceatl on 2013-03-04 13:21:29.9900

I think your enemy is the Service Center...When a power tranny blows, it nearly always takes other components with it...Methinks your amp has other broken components...grid resistors maybe...It's the equivelent of replacing a fuse...My DT50 is 4 years old...same power tranny...

Re: 2X12 DT-50 Power Transformer
by PDKTDK on 2013-03-04 13:28:30.2220

Can you elaborate on things that need to be checked?  I need mine working as well as the replacement that arrives Thursday.

This dude's story is getting very discouraging.

Re: 2X12 DT-50 Power Transformer
by spaceatl on 2013-03-04 13:58:45.8950

One of the obvious ones would be input voltage selection...I don't know this for certain, but a lot of times these power trannys can do 220 or 110...DT50 seems hardset...but if the wrong primary is wired in, that leads to all sorts of problems....Bad B+....grid resistors...the solid state rectifers...Really hard to know without actually seeing the damaged amp firsthand...My suspicion is something solid-state...Regulators and other transistor like devices tend to have the behavior of pulling more current with voltage drop...tubes are self limited so I find it more difficult to see a problem there...If there was one, methinks you would lose the output tranny first...But power supply is always the first question...And saying I have never had a problem in x number of years tells me nothing...Measuring it over time tells me more...better yet...use an AVR so you are "insured" the gear is seeing within 5% of 120 volts...My AVR switches all the time...everytime the fridge swtiches on, HVAC and my wife or daughter's hair dryers...and that is just at home...gigs are always worse...once you actually run your gear on one for while and see how often it is in regulation is scare the crap out of you...

I really don't know how well these amps fare on attenuators...I will not use one on my amplifiers...I have seen too many amplifiers fry on hotplates in my time to ever trust any of them...The Weber is the only one that I would even consider...

I do know that Marshall Powerbrakes have a bit of a rep these days...But that is just scuttle butt...nothing more...

I have run my DT50 and DT25 for extended periods of time with the master at around 2 oclock at outdoor gigs....Running these at 2 oclock on an attenutor is NOT the same thing...Weber would be close to what a cab would do...The cab affects reactance and amplifiers are generally designed with that reactance in mind...

Re: 2X12 DT-50 Power Transformer
by PDKTDK on 2013-03-04 14:02:07.9520

I meant to ask:

How could an attenuator negatively impact an amp?  It's just effecting sound output to speaker.

Also: "Running these at 2 oclock on an attenutor is NOT the same thing" ?

Re: 2X12 DT-50 Power Transformer
by spaceatl on 2013-03-04 14:17:50.1610

That isn't exactly right bro...A lot more going on than that...The higher you run any amplifer, the more current the amplifier will draw...If you run full output then your tubes, power tranny and every compenent in the power amp is running at capacity...Attenuators disapate power in the form of heat...With the Weber is is actually a motor like a real speaker...Anyway, load resistors heat up underload...guess what? the resistance of the load a resistor generally drops as it heats up...It depends on the make the temp coeficient rating, but it does happen...They can even go full short to 0 ohms...They can fail open which can be a no load condition...Anyway, attenuators wear your amp out faster...Especially the tubes...Some amps can deal with them...some can't...

Reactive voltage is a voltage that is generated by the speaker as a result of it's movement...If you put a meter on a speaker, push the cone in and let it go, you can measure a little bit of AC voltage...a speaker is an electric can also generate's same principal as a microphone...diaphram, coil and magnet...same thing...just bigger and designed to go the other way...

Here is one I know of...

If you run a pignose at full volume too long, you will blow the power tranny...You have to wire a resistor in it to get the voltage right...I think the power tranny is japanese or something...Anyway, if you put the new tranny in without the resistor, the new one blows right away...Only thing I have ever heard of that is similar...

Re: 2X12 DT-50 Power Transformer
by PDKTDK on 2013-03-04 14:46:39.3320

I found this thread regarding attenuators.  The main posters are amp makers.

They tend to agree that it's not so much attenuators, but people misusing their amps that damatges them.

Check it out:

Love to know your thoughts.

I personally look for good sound without attenuation.  Then I apply it as needed.

I love my DT50 and baby the hell out of it.  Despite recent events, I ordered a backup unit arriving Thursday.

I am very dependant upon my L6 setup.

Re: 2X12 DT-50 Power Transformer
by spaceatl on 2013-03-04 18:55:31.6310

That's a good thread...I tend to agree with most of what they are saying...There are a lot of factors that play into this and it is all about getting the tone you're after...Some amps really have some cool tone they can help you get at without killing yourself...For some folks it's a tonal tool...

Anything I write here is just my own opinion. I am happy to share it, but what works for me might not be right someone else...I have my own paranoia, hence AVRs...

I would not expect power tranny failures...output tranny is more of what I would expect with attenuator funkiness...But with a Class and Mode switching amp...I don't really know...switching high current stuff...hmmm...I honestly don't have much to compare it to with these amps...I do watch the threads the trailblazers post...

I have had a few Boogies, but Simul-Class was on the back I generally set it and left it...I would love to get my hands on a Mark V for a while...But I am not sure that it changes negative feedback and mode as well...DT50 seems to have some fairly boutique features in the power section...

My problem is that I do not trust load resistors...I don't like using my amp with single speaker, but sometimes you just have to...That's more a safety thing...If I have 2 or 3 speakers wired in parallel, odds are my amp will always see a load even if I lose one...

In the end, with Line 6 amps I think stable power is of the utmost importance...Mainly because if the power drops low enough, the digital modeler can reset....But it is also because it increases the lifetime of any gear attached...So my advice to anyone gigging these amps is invest in an AVR.

I changed the speaker in my DT50 112 to a 16 ohm Jenson Jet Tornado...That knocks the volume down about -3db...So I can kick the master up a bit more to get the same volume that I would with the stock GH-90. It's a form of attenuation as the Jenson is a bit high impedance which reduces power a little bit and it is slightly less efficient (SPL)...

My own personal opinion is that the DT50 112 sound better running at 16 ohms than 8 ohms...I have tried a lot of speakers in it...The other reason I went 16 ohm is that I use a 212 cab with it when needed and I did not want to add a matching tranny...3x16 ohm makes for a 5.3 ohm load. It's just a tad brighter than running the amp with a 4 ohm load on the 4 ohm tap...kinda close to the clarity of 16 ohms...I love the 5.3 ohm mismatch on the 4 ohm tap...

Sorry, this was a little ramblin'...

Re: 2X12 DT-50 Power Transformer
by Zhorell on 2013-03-04 22:09:13.4910

Wow! good thing I did not buy DT50, very tempted almost bought one.. Maybe MkII will fix all the Tranny problems?

Re: 2X12 DT-50 Power Transformer
by whiteop on 2013-03-05 04:50:42.7290

Well Line 6 has been helpful in that they are willing to take a look at it even after the warranty period given the fact that the power transformer has blown 4 times in 14 months which is very unusual but I think spaceatl is right; the service centers have been missing something and probably just replaced the power transformer and nothing else. After getting it back dinged from the Calabasas facility I'd rather just have a new one given the fact that the old one may just come back from being repaired and blow another power tranny. I'm sorry for the ranting but I'm just frstrated. If it had been once or twice I'd be a little perturbed but 4 times. If Line 6 does me right I'll also let everyone know just the same.

Re: 2X12 DT-50 Power Transformer
by spaceatl on 2013-03-05 04:58:45.5550

I hope Line 6 makes it right for you. .I think they will...

Don't worry about venting bro. That is what the forum is for...

This type of thing is not limited to Line 6 amps...A few interesting tidbits in here for you...">">

The information above may not be current, and you should direct questions to the current forum or review the manual.