swing_girl

Thanks for sharing Brazzy.  It is such a heavy amp, it is hard my me to lug it to the service center via public transport on my own.  I am going to replace the 12AX7s and see if that helps.  I like the amp because of the Class A chime ...  I use a HD500X too (with a JTV) and I like the versatility, I hope the tube replacement can fix the problem.

I have the same problem, one day the amp worked, the next there is no sound.  The amp has not moved or anything, just switched off properly (standby off then a minute later, main power off).  There was no issue before the problem, everything lights up as it should, fuses are fine, tubes are securely attached, not loose.  The amp has only been used a few times at home since purchase so the tubes are still quite new.

With what you're reporting, I'm now doubting you bent a pin.  If a person is at all careful, it's next to impossible to bend a pin.  If you are in a coastal area where the air is salty from the sea, your electrical contacts would probably tend to pick up more contaminants and corrosion than average.  when you re-seat your tubes, you are actually cleaning those contacts, so doing what you did would be a good thing, and one that you probably should repeat if you encounter those same symptoms in the future.

You are right, I live right next to the sea.  I am not a technical person who knows about tubes and schematics; I will find someone more knowledgeable to do it if the hiss returns.  Thanks  :)  :)  :)

 Just curious--where is your pentode/triode switch set, and does the amount of hiss change when you switch it?  (this is a power tube thing, not a pre-amp thing, but still...)

The hiss was very loud in both modes and also across all 4 amp types before I re-seat the pre amp tubes.  Like I said, I may have bent some of the pins but I am happy that hiss is almost all gone and the drop in volume is hard to measure, it is not very significant but it seems to be there only.

swing_girl,

 

the only way that re-seating your pre-amp tubes could make any difference would be if there were a bad connection.  It is possible for the pins or their mating contacts to become corroded or tarnished, compromising the electrical connection.  This is rare, though, unless your amp is over 5 years old.  But if you are close to the ocean and your amp is exposed to salty air, then it's much more likely to occur.  

 

However, re-seating the tubes would tend to either eliminate static or other noise, or possibly boost power--if a pin wasn't making contact before and some of the signal was getting lost (can't say if this is even possible, as I'm not fluent in the operation of the pre-amp circuit).  It would not be likely to reduce hiss and volume.  The only scenario where that could happen is if somehow your connections were originally fine, but when you re-seated the tubes you either bent a pin or somehow introduced dirt or other contaminants into the electrical connection(s).

I think you are probably right; I could have bent a pin when I re-seat the tubes.  The tone is still good and I am happy that loud white noise style hiss is mostly gone.

egkor,

I have no idea why removing and inserting the same tubes got rid of the hiss, the tubes were not loose when I removed them.  The tone is still there so I am happy that most of the hiss is gone; even if the trade off is a little bit of volume loss.  I play with clean tones a lot so the hiss was really annoying.

I am in HK and there are two big music shop chains, they both have no stock of any 12AX7, or other tubes for that matter.

I am not going to touch the power tubes, they have a metal cage around them and I know nothing about re-biasing tubes.

Thanks again for advice :-)

Egkor,

Thanks for your reply.  I put the tubes back in and they are secure.  The volume loss is a feeling I have but since I have not measured the volume level pre and post tampering the tubes, I have no idea how much is really lost.  However, I am very happy with the hiss much lowered.

:-)

For the 12AX7 tubes, it is remove & replace.

 

For the EL34 tubes, you would remove, replace, and check/set bias. Bias is best done by trained amp tech.

 

Tubes pull straight out to remove. Their pins are keyed so they can only be inserted one way in the socket.

 

Thier pins can bend & break, so be careful when re-installing.

Thanks.  I could not find any replacement tubes in music shops here; I removed the 12AX7s and plugged them in again, the hiss is mostly gone.  However, I feel that the volume seems to have dropped, could it be that I did not check whether the pins went into the same socket as before?

DT50 212 --- amp went out on me after about 2 months, a quick gurgle as tubes burned out ... then nothing. Thusly, I looked at the tubes ... the EL's were glowing bright, 12AX7's were out. Went to Guitar Ctr and after being assured they'd work, I got the Groove Tube russian brand. I would avoid chinese brands also. Russian just seems better sounding to me. Easy to replace and took about 1 minute of careful pressure to install.  Unplug too ... duh?!  LOL. 

 

I immediately noticed that the factory 'hiss' was nearly gone (like 90%), and the sound was more colorful. I looked online and noticed the EH stock brand was much cheaper than the GT brand.

 

As well, each topology was more defined.  3 and 4 are now my fav's.  Wonder how the sound will be if I replace the EL's with a high quality brand?

 

Bribrew

Hi Bribrew,

I found your post while searching for solutions to DT50 combo amp hiss.  I would like to know if replacing the tubes just a process of unplug and plug in? Do I need to do anything like biasing the tubes? because I do not know how to do this.  Thank you for any advice.

Regarding the Strat 2 & 4 positions, take a look at this thread I started here: http://line6.com/sup...-of-the-quacks/

Thanks, I went there and added my vote to the poll  :D

I prefer a short cable as I play with the pod in front of me.  How much is a 8 feet cable plus shipping to Hong Kong? Thanks.

I know a lot of people who have this opinion, that the semi in the old Variax are great, I just can not understand how a model line 6 worsening rather than improving (I know this is subjective), I also agree that the semi in 2.0 is very thin and weak

This is exactly how I feel.  I hope there will be an update that deal with the Semi and the Spank positions 2/4 soon.  For the time being, I am going to change the semi pickups to the Lester pickups later to see if I can get closer to that 335 sound.

Ater using the HD upgrades for a couple weeks now, I am generally very happy with the improvements in sound.  However, I do find that the Semi models lack the mid-range punch of a semi-hollow guitar like the 335.  I do not remember how the earlier firmware sounded like but I do not recall not liking the models before.  I feel that now the bridge pickup version of the Semi sounds better than the neck pickup.  FYI, I am using same amps before and after the HD upgrade.

Anyone has similar observation?

i thought i was the only one loving the upgraded 400.... man that thing is so sweet....

certainly still a bit of a niche... (ain't gonna be doing many rock tunes on it)

but out standing.

I am primarily a jazz player so the hollowbody models are useful for me.  Before the HD upgrade, I could not use the Super 400 model at all as it was too bassy and percussive and totally unlike an archtop jazz guitar.  With the new update, I can get a workable sound from it and I am very happy about it.  Still, both jazzbox models lack the woody sound from a hollow body.

I have a JTV59, I would like to have an option of using roundwound or flatwound strings for the jazzboxes as well as a L5CES model.  Another wish is a nice nylon string guitar with very little ambiance.  Another wish would be to have more choices of bodies / pickups in the workbench, like a semi hollow telecaster or soapbar pickups.

I have around 35 guitars but since I purchased my MIK 59, I have not taken any other guitars to my gigs.  The JTV is a do-it-all guitar for me.  With the new update, I am even happier with it; so much improvement to the sound, especially the super 400. That's a 5/5.  I hope there will be choices of strings type (round wound, flat wound) and a nice nylon model in future updates.

I'm completely convinced that the acoustic models have been reworked since the last FW update. They sound great to me!

Me too, I find the sound 'tighter' now and it seems that there is less 'ambiance' than before so it is clearer.

I don't know about others, but the HD upgrade improved the models to the point that the guitar seems to feel different to me :-)

Thanks swing_girl.

 

I couldn't find the new information. I'll update this today and re-submit.

Thanks David :-)

The info is here: http://line6.com/jtv-59/features#createcustominstrumentswithvariaxworkbench

Nice poster but according to the info on the variax HD page:

Spank and Lester are 1959

Both Rickenbackers are '66 370

Casino is '64

Jazz box is '54 with P90 pickups

Martin D28/12 is '70

Martin D28 is '59

The Danelectro becomes 1999 Jerry Jones Shorthorn

I recently bought a DT50 112, love the sound and feel but the noise / hum when even nothing is plugged in is very annoying. It is about as loud as a window air conditioner working hard. Since I live in a place where the shops do not do exchange or refund, I have to live with it or sell it, which I don't want to as I like the sound. Is there any way to deal with this noise? I am plugging it in the wall with no other electric appliances nearby.

Thanks for reply. I upgraded from 1.7 so they sound better to me :-)

I am very happy with the improvement in sounds with the hd upgrade and I felt that the acoustics sounded better too (especially the 12 strings); however, someone on this forum said the acoustic models have not been changed at all. Have I been tricked by myself?

Oh I thought the acoustics got the HD upgrade. Silly me :-)

I upgraded from firmware 1.7. I use the low A baritone + Nashville hybrid tuning for the acoustic guitar, before the update, I felt that the low notes were flappy (cannot think of another word) and the high strings were too brittle. I had to use the jazz box body with a single coil pickup to make it work. With the new update (which I thought the acoustics got some upgrades), I can use the jumbo with the said tuning and it seems to sound better to my ears. Also, the 12 strings sound better to me too :-)

Great upgrades. Although I miss the goldtop and the semi hollow telecaster, the quality of the other models are so much higher, especially the acoustics. I can use low A baritone tuning without problems, thank you!!