Dt-50 Head Volume Problem In Topology I Only

[Yanitzch]

Hi!  I have been reading this forum for a long time now and now it's my first post.  So a big hello to everybody and thanks for the great infos I found so far.
 
From all the great comments I saw, I decided to buy a DT-50 head with the 412 cab.  It's been 2 months now and I can't get the good sounds you seem to have.  It's my first tube amp, so I don't really know what to expect.
 
But the real problem I have, is with topology I.  The volume is alot lower than the other topologies.  I upgraded the firmware and no changes.  I submit a ticket and they told me it's normal.
 
But I can't understand why the sound is so loud on all the other topologies and not on the first.  There is no way I can stand just in front of the cab with the volume at 12oclock in topo II, III and IV.  But in topo I, I can put the channel and master volume all the way up and it's not breaking my ears.
 
And the things that bother me the most is the volume is louder with the master volume pulled out.....  With volume knob pushed in, there is almost no change in volume level from 5 to 10...  And it's only in topo I.  In the other topologies, if I am in full 50watt operation I can wake up everyone on the street :)
 
I opened the back to check if the lamps where all seated.  I removed and reput the in place.  I saw the left EL-34 looking different than the right.  The filament is not protruding on the top, I don't know if it's ok.  And it's seems to get burn marks inside the tube.  Is it normal?  I used the amp for no more than 6-8 hours since I bought it new.
 
During operation, the right lamp (looking from the back) emit a blue haze but not the left.  This blue haze get brighter with more input from the guitar. Check the video on youtube
http://youtu.be/nbBcwm_9eb8
 
I put another video too where you can see and what I am talking about if I was not clear.  It's start in topo I with knod pulled out.  Check the volume is almost the same with knob pushed in, but only in this topo... http://youtu.be/CWQOmBJhECY
 
Anyway, I would appreciate if you can tell me if the amp is not operating like it should.  In that case, I would submit another ticket.
 
 
In the left tube the heater filament is a lot shorter

 
It's difficult to see, but the glow seems to be better in the right tube

 
Is this normal "burnt" marks?  This amp was on not more than 8 hours in total.

 
The left tube is weird looking, no?  Could it be only a bad tube that is causing my problem?  Or the tube got bad because of an amp trouble?
 

[TheRealZap]

the topology from the front of the amp selects more than just the topology it selects the pre-amp etc...

amps get there sounds from a variety of different approaches.

the basic approach difference you are witnessing is that some amps have a loud preamp fed into a loud poweramp... and others a loud preamp into a quiet poweramp or anywhere inbetween...

 

it is normal that the settings on the front of the amp, are not suitable for every combination that exists....

so yes... if you change power amp or preamp configuration... expect to turn the knobs again...

[Yanitzch]

TheRealZap, thanks for your reply. I absolutely understand that changing topologies changes a lot of things.

 

But I since I did not change the default amp in topology I, it should sound like a Fender Blackface Deluxe, am I right? It should act like it too, no? I just don't understand why I can't get good loud volume with the channel and master volume at max. And why the volume is about the same with pulled or pushed master volume. I thaugt pulling the knod make the amp goes from 50w to 25w, I am wrong?

 

Another thing, sorry for asking again, is it normal that one of the tube is scorched like that? Should I try to inverse them?

 

Sorry to seem so insecure. It's just I never tried the amp before buying it. And it's the first time I spend so much money on musical gear, so I want to be sure it's working like it should. We don't have big music store around here and no one care to carry great amp. I bought it online after reading so many great reviews about it. And since I own a pod hd500, I taught that it will be easy to operate.

 

Thanks for your time!

[TheRealZap]

TheRealZap, thanks for your reply.  I absolutely understand that changing topologies changes a lot of things. 

 

But I since I did not change the default amp in topology I, it should sound like a Fender Blackface Deluxe, am I right?  It should act like it too, no?  I just don't understand why I can't get good loud volume with the channel and master volume at max.  And  why the volume is about the same with pulled or pushed master volume.  I thaugt pulling the knod make the amp goes from 50w to 25w, I am wrong?

 

Another thing, sorry for asking again, is it normal that one of the tube is scorched like that?  Should I try to inverse them?

 

Sorry to seem so insecure.  It's just I never tried the amp before buying it.  We don't have big music store around here and no one care to carry great amp.  I bought it online after reading so many great reviews about it.  And since I own a pod hd500, I taught that it will be easy to operate.

 

Thanks for your time!

 

Sorry, I skipped over some of the questions you had, the root question comes up from time to time and that's what my answer was geared towards.

 

If the volume is the same with LVM (low volume mode) engaged, then something is clearly wrong.

you shouldn't be anywhere near full volume and still be in the same room! 

i would seek out a service center: http://line6.com/service_centers/

although it certainly appears that a tube replacement would be a good idea as well.

[Yanitzch]

No need to be sorry, I am know this question was asked alot... I have read them all before posting:)  I'll try to contact the nearest service center.  It's a shame since it's very far from my place and it's going to cost a bunch to send it by mail.  Oh well, thanks for you patience.  BTW, would you replace both tube to get a so-called match pair or it's just a marketing trick?

[TheRealZap]

I would go with a matched set, but a good amp tech would be able to dial them in to make them work either way...

but the tubes can have their own characteristics which is why i would want a matched set.

[markcockerill]

I agree, something is wrong with your amp. I have a DT50 head and 4x12. I have now configured my amp as a Soldano but prior to that (when it was new) the Topology 1 (Fender clean) would blow the garage doors off at half volume and it certainly is quieter with the master pulled out but I never use that feature.

 

Before you send it back, it might be worth a go hooking up a PodHD500 and re program the amp with midi cc. If the other topologies appear to be working as they should then there is no obvious reason that Top 1 should be behaving badly and I would not necessarily put it down to the valves. I am on the original stock valves and I gig twice a week and have done for well over a year with this amp and it still sings beautifully.

 

I programmed Soldano clean into channel 1 and Soldano Overdrive into channel 2 but I don't use my HD500 for gigging, I use a stomp board in the traditional sense though I do run chorus and delay through the amps FX loop.

 

If this does not work, sent it away for service.

 

Good luck

[Yanitzch]

Hey Markcockerill, 

 

Thanks for the reply.  I loaded a Solo clean on topo 1, channel A and B.  I gives me a little more volume at the same setting (all knobs at 12'o).  But I can still put myself in front of the 4X12 with channel and master volumes at max and my nose is not bleeding :)

 

For the info, the sound is the same with master volume pulled or pushed on all topo.

 

I tried to switch the EL34'S (left for right and right for left).  Curiously, the sound is a little louder.  And more crazy, now the sound is better on topo II and IV at normal volume (knob pushed).  But I can stay in the room (execpt for topo IV !)

 

Any idea?

[markcockerill]

Something is clearly very wrong. I can only advise seeking professional help with it now.

 

Best of luck

[mathojojo]

Hello everybody,

 

I proudly received my DT50 Head and DT50 Cabinet last week. I did not had much time for tests, but I clearly noticed a lack of sound on Topology I as well.

 

To have some idea of the problem, I measured the sound level with an android app. The only problem is that the microphone can get more than 95dB, so I realized the test with this value in mind :)

 

Test are done on Channel A, and Volume Knob to the MAX.

 

TOPO I :

Master Pulled out (Low Volume mode) : rotary MASTER to the MAX : 94 db     -      rotary MASTER to 50% : 77db

Master Pulled in (High Volume mode)   : rotary MASTER to the MAX : 80 db      -     rotary MASTER to 50% : 77 db (the difference is almost inexistant)

 

=> A first weird thing can be noticed : Low Volume mode got Higher Volume than High Volume mode

 

 

TOPO II :

pulled out : Reached 95db with MASTER at 45%

pulled in   : Reached 95db with MASTER at 10%

 

TOPO III :

pulled out : Reached 95db with MASTER at 45%

pulled in : Reached 95db with MASTER at 25%

 

TOPO IV

pulled out : Reached 95db with MASTER at 45%

pulled in : Reached 95db with MASTER at 10%

 

 

Of course I understand that there are adjustment to do on the Master Knob when swithching from a modelled amp and another. But in this case, the Topology I do really have something wrong. It would be great to know where is this problem coming from, if my DT50 Head does only need a Tube replacment, or if it has to be repared in a Service Center (which is really far !!! 250 km).

 

Thank you for your help.

[radatats]

most probably not anything wrong here.  With a standalone DT (no POD) the topology switch actually selects different Pre models, not the physical topology like you would suspect.  So for topo 1 you probably have a Blackface which is relatively much quieter than the Treadplate on topo 2.  The LVM is louder because that switch adds in the modeled power section on top of what is already there to compensate for the lower volume you are searching for.

 

You really need to get a USB midi cable like the M-Audio UNO and a third party editor like DT Edit and see which amp models are loaded in the DT.  You can set 8 different amp models, 4 in channel A and 4 in channel B, one for each topo selection.  While you are connected use Line 6 Monkey to make sure you have the latest firmware installed as well.

 

Once you connect a POD HD by L6 link, the POD takes over all the modeling and effects and tells the DT how to physically configure the tube power section.  In this configuration, the topo switch actually controls the negative feedback loop (NFL) and give you an additional 4 flavors for your particular amp selection.

[geppert]

Yanitzch...

 

Yes the audio output from TOP 1 (Fender Amp) is definitely lower than the others HOWEVER, I noticed that increasing the GAIN for TOP 1 does not significantly increase preamp distortion like it does with other amp models .... so, try having the GAIN up well past 1 o'clock and see if you get a better volume structure. It worked for me. I do like the Fender Amp models (primarily the Twin) and I run them with a significantly higher Gain setting than with other models to compensate for the relative gain differential. The sound is still very clean. What you can also try as an experiment for TOP 1, is to put the Gain all the way up full, lower the Channel Volume so you are not blasting yourself, play some strong chords (with guitar up full) and see if the sound is still clean enough for you, if not, back the Gain down a bit (raising the Channel Vol to compensate) until you find the sweet spot where the Gain setting is still providing the clean tone of a Fender Amp. When you're there, you will probably find the Gain to be past 1 0'clock somewhere which in some of the other amp models will definitely be adding grunge, but not with the Fender amp (or so I've found anyways). Then crank the channel volume up as much as you want (even full out) then the master volume to taste. Once there, ALL the other amp models need to be adjusted (usually via their channel volume) to roughly match that Fender Amp (TOP 1). Then you have a relative comparative gain stage for the other 3 presets.

 

I usually run the Fender Gain very high, and the Fender Channel Volume full up for TOP 1 with Master Vol to taste.

 

I also have a POD 500 and run it the same as described above for the Fender Amp Model into my DT25 via L6 Link.

 

Give it a try, see what happens. Hope this helps you out a a bit?

[mathojojo]

Hi again,

 

so if I understand well, it is normal that in Topo I, "low volume mode" give more power than "high Volume mode" ?  And it is normal as well that we need to push the Master knob to 100 % in Topo I to have 95dB when we reach largly this power in 10% on other Topos ?

 

If everybody has this same behaviour, so I will deal with it... I  just think it's strange, no ??? :)

 

Finally, I think the big problem is the lack of documentation provided by Line6. We don't know what to expect from our product, so if something looks weird, we automatically think that there is a problem with it.

 

In the same idea, upgrading a product without giving the possibility to manage it correctly is again a fail from Line6 (I'm talking about firmware 2.0). Not everybody has an Iphone. An android app, and of course a windows/Mac/Linux app should be availlable as well to control thous new features. (I know about DTedit, but it's a third party developpment, I just find it crazy that Line6 did not this great job!)

 

I would appreciate the answer of a Line6 expert, I need to be sure that Line6 cares their customers.

[mathojojo]

@geppert

 

"What you can also try as an experiment for TOP 1, is to put the Gain all the way up full, lower the Channel Volume so you are not blasting yourself, play some strong chords (with guitar up full) and see if the sound is still clean enough for you, if not, back the Gain down a bit (raising the Channel Vol to compensate) until you find the sweet spot where the Gain setting is still providing the clean tone of a Fender Amp"

 

"Lower the Channel Volume so you are not blasting yourself" : No need to worry....even with the channel Volume raised to the MAX, the sound is easy to support (that's the problem in FACT)

 

"raising the Channel Vol to compensate" : Sorry, I'm already to the Max....

 

When I read your answer, I'm really wondering if our DT50 have the same behaviour (If not, my DT50 (and Yanitzch's DT50) seems to have a problem).

 

:)

 

Hope everybody understand what I mean. And thank you again for the help (from community, and Line6 if possible)

[Brazzy]

When I read your answer, I'm really wondering if our DT50 have the same behaviour (If not, my DT50 (and Yanitzch's DT50) seems to have a problem).

 

:)

 

Hope everybody understand what I mean. And thank you again for the help (from community, and Line6 if possible)

 

You may have a real problem. If you really think you do, you should call line 6 and speak to a tech, might something beyond you. As Clint Eastwood has said "A man's gotta know his limitations." Don't hesitate to to take the time to call them.

[riko77]

Did you guys get your amps checked out? Just curious if there was an identified cause for it?

 

I'm observing the same issue with my DT50 212. Compared to a DT25, my DT50 is *nowhere* near as loud in as it should be in Topology 1. I noticed it seemed roughly 40% louder when I pulled out the master knob for LVM. When I cited the LVM being louder as a symptom, Line 6 tech support assured me that was normal.

 

What the tech didn't think was normal was that I could have the master & channel cranked 100% and all tone settings at 12 o'clock and play the guitar at full volume comfortably with my face in front of the grill. He said it should melt my face off ☺

 

Since I just got the amp today, he suggested I request an exchange.

[velosouk]

I program the DT25 head using the DT Edit software (PC), when connected, and doing changes using the computer everything's fine but, when I re-start the unit all sounds are missed, it looses all the topologies and come back with just clean sounds in both channels.

​Any help ?

[Brazzy]

Did you guys get your amps checked out? Just curious if there was an identified cause for it?

 

I didn't have my amp checked out, there really isn't any qualified repair facilities around me for this amp. I know that sounds strange but it happens. I think that the DT line is too perplexing for the average AMP doctor. How I found out I had issues was by using it. Keep in mind I never owned a tube amp before and I get a DT50 Head to start out, lol.

 

So I read the manuals on it and have experience with a UX2, X3 Pro, HD500 and a Spider Jam. I first noticed in topology III the noise floor was loud enough I could hear it from 10 feet away with my Strat plugged in front.. So I played with it like that thinking maybe that's part of the high gain amp model. It sounded good to me so I jammed away with it for about 4 hours.

 

I had to let it sit for a week or more then fired it back up and noticed a weird noise, but it worked and I played with it 'cause it sounded good to me even with that noise floor on topo III. I played with it for 8 hours straight that day. Most all my sessions with it were for long periods of playing. I continued playing with it for 4 months or so until one day I had weird noise followed by no sound. Looked down at the tubes and no light in the power tubes. I estimated I had close to a hundred hours on the amp at this point. I opened a support ticket and they suggested I take it a service center in the area except that fell short so I continued to find out what I could do to resolve it myself.

 

Then I posted this: Thread

 

I did my homework and found "AMP HEADS" had the instructions and tool for biasing a new set of matched tubes. I knew I would need to retube it in the future so I made the investment and did the tube job with new tubes that the amp came with, 2 x EL34EH and 2 x 12AX7EH. When I went to bias them I was getting a spread of I think 4 millivolts and I think the tubes were supposed to be the same since their matched so both tubes should have been 36mv except I was getting 32 and 36, which didn't seem right to me. So I buttoned it up, it worked, sounded good and I played with it for about 4 hours 'till it went quiet again, looked at the power tubes and no light. I check the all the fuses I could and they were all fine. So I opened a support ticket and got things going. I paid to ship it back to Line 6 in Calabasas,CA., they fixed it up under warranty and sent it back working better than it was when I first fired it up. I'm really very happy with Line 6. :)

 

I suggest if anyone has a question about these amps post a thread and do a support ticket at the same time or you could just call them and ask them.

Edited February 6, 2015 by Brazzy

[Brazzy]

The left tube is weird looking, no?  Could it be only a bad tube that is causing my problem?  Or the tube got bad because of an amp trouble?

 

I didn't see that picture till now. Yep that tube looks like it took some punishment for sure. Time for new ones I think.

[saTa]

I'm afraid this is by design. Bad design. I've used a DT25 for two years and ended up never using Topology I because I would have had to save all my other presets at like 20% volume to match loudness...

[BucF16]

Not a big Fender amp guy here BUT:

 

Isn't it a normal characteristic of these old Fender amps to dime out the GAIN and then bring up the volume?  They stay pretty clean throughout and get much louder.

[TheRealZap]

actually i'm pretty sure that vintage fender amps do not have any gain control on them at all.....

[egkor]

Amps of old didn't have Master volume, only "Volume" or Channel Volume.  In other words those amps act as if, if they had a Master vol, it would be maxed, and the Channel Vol would control everything. An amp like a Fender Twin (at 85 to 100 watts depending) would likely stay clean until REALLY loud.  I think *that* might be the idea behind topo 1, just a clean and potentially clean+loud tone.

 

I have an old (early-mid 60s) tube Ampeg Jet combo amp (1x12) with 3 knobs:  Volume, Tone, and Tremelo (rate).  With 2x6L6 power tubes, its probably 25 watts or so. I have to crank the Volume to get it to break up, and by then it is loud.  You couldn't do this with a Fender Twin at 85-100 watts without bleeding from the ears. They are all about clean, and loud and clean.

 

I don't know if this helps anything, just felt like posting it.

 

:)

[Addictine]

The solution for me, as noted above by geppert, was turning up the Drive on Topology I (Classic American Clean). With the Drive turned up, Topology I is loud like all the others. Unlike the others, though, Drive doesn't add distortion or "overdrive" with Topology I (Classic American Clean). Prior to adjusting the Drive, I had all the volume problems with Topology I that others were mentioning, including LVM being louder than regular mode (but still not loud, by any means).

 

Don't know if this worked for others or not - I post this only because adjusting the Drive setting didn't seem to be acknowledged by others following geppert's comment so I'm unsure if they tried it or not. Subsequent comments still focused on adjusting Volume, LVM, service centers, tubes, etc. (Perhaps some hints at this as a solution with the discussion of whether vintage Fender's have gain/drive/master volume - but not clear to me if others had tried adjust the Drive and succeeded or not). 

 

All worthwhile investigating, but for me simply adjusting the Drive worked to resolve all volume issues with the Classic American Clean model.

 

UPDATE:

Previously my assessment of Topology I being "loud like all the other topologies" when the Drive was turned up was based on my ears - a qualitative assessment only. I have subsequently measured the volume and can state more quantitatively that Topologies I, III, IV (AKA Classic American Clean, Class A Chime, Modern High-Gain) are indeed within a few decibels of each other when I follow the settings on the reference card which comes with the amp, with the important exception of maxing out the Drive on Topology I (which the reference card doesn't do). Topology II (British Crunch) is approximately 8 decibels louder than the other 3 topologies, but the actual decibels of all 4 topologies are still all pretty close as long Drive is turned up for Topology I. Note that I left the amp's Master volume and all guitar settings consistent, changing only the Topology and adjusting the Drive and Volume as per the reference card for each Topology.

[palladinojt]

On 2/8/2015 at 3:10 PM, saTa said:

I'm afraid this is by design. Bad design. I've used a DT25 for two years and ended up never using Topology I because I would have had to save all my other presets at like 20% volume to match loudness...

 

I have a feeling this is correct. Older thread, I know, but one I'm just getting involved in. Let me start by saying I have two DT25s (a head and a 1x12 combo) and they BOTH do the following (I'll provide a bit of background/context):

 

I got the DT25 head about a year and and have been using it as just a power amp (via L6 Link) to power my Helix. I recently decided to experiment with using the DT as my actual guitar amp and the Helix for FX only via 4-cable method (and also as a MIDI controller for the DT). It sounds AWESOME. The first time I gigged with it in this configuration, I noticed that a bunch of my presets/snapshots were not properly level balanced (after seemingly having got them all properly balanced at home). So I did some tweaking before the next gig but had the same problem. Then again at a third gig (which was just this past Friday). What I finally realized was that the only difference between my setup at home and on stage is that Low Volume mode is ON at home and OFF at the gig. Sure enough - I switched to one of my preset/snapshots where I've been having issues, I switched Low Volume mode OFF, and the amp got QUIETER instead of louder. I've also noticed that this seems to only happen with certain preamp models - for example, if I'm using the Treadplate model, the amp behaves exactly as you'd expect it to when switching LVM on and off; however if I use the Tweed B-Man Normal, LVM on is LOUDER than off. So weird...

 

I've been running the amp on Topology I; I don't know if that matters at all since I'm switching preamp models via MIDI from the Helix, but I'm going to switch to one of the other options and see if this still happens. For now my plan is to simply run the amp with Low Volume mode ON all the time. Not only will I get more reliable behavior from my presets in terms of volume, but honestly the amp sounds its best when LVM is on and the Master is around 2-3 o'clock.