[Slade01]

Yes I really enjoy the dt1990 pros with my darkvoice 336se, I'm using the twin 6j5 tung-sol tubes with Chatham electronic 6AS7 power tube. I also have the hd600, hd6xx & hd660s2 which are also great but not quite as detailed as the dt1990 pro with dekoni hybrid pads. I tried the dt1990 pros with the velour pads but it was a little to much base. Pad rolling makes a big difference with beyerdynamic headphones.
I bought my dt1990 pros off a guy that owns both the T1-2nd gen, T1-3rd gen & he swears by the 600ohm T1-2nd gen which he won't part with. Lol
So I though I would ask about them on here before I buy. Thanks for the reply.

The only thing I would add here that may or may not be useful is that I’ve heard DV users who did run 600ohm headphones got better results using them with a 7236 power tube. Might have a bit more juice that could be more optimal for them. I personally don’t know, and never went down that rabbit hole myself but I came close once to also trying a 600ohm T1 once upon a time.

 

[Lightspeed12]

The only thing I would add here that may or may not be useful is that I’ve heard DV users who did run 600ohm headphones got better results using them with a 7236 power tube. Might have a bit more juice that could be more optimal for them. I personally don’t know, and never went down that rabbit hole myself but I came close once to also trying a 600ohm T1 once upon a time.

Thanks for that bit of information, I would imagine that the 6as7 should be ok as I have heard the T1 600ohm cans have worked well on lesser tube amps but if not I can run both my darkvoice 336se together that may make a difference with power not sure but the volume does increase when I do.

 

[Slade01]

Thanks for that bit of information, I would imagine that the 6as7 should be ok as I have heard the T1 600ohm cans have worked well on lesser tube amps but if not I can run both my darkvoice 336se together that may make a difference with power not sure but the volume does increase when I do.

Should work ok with 6as7 for sure. I think that some recommended 7236 came when some might have experienced clipping at higher volumes. Others just like the sound better. lol. But these were just the notes I had when I was looking to get 600ohm headphones. Let us know how you make out!

 

[Lightspeed12]

Will do. Thanks

 

[SHIMACM]

I own the Chatham 6as7g and a pair of Tung-Sol 6j5g and 6j5gt. This combination sounds great on my Crack with Dt1990 and it sounded great on my old Darkvoice with T1 600ohms.

 

[Lightspeed12]

I own the Chatham 6as7g and a pair of Tung-Sol 6j5g and 6j5gt. This combination sounds great on my Crack with Dt1990 and it sounded great on my old Darkvoice with T1 600ohms.

Ok thanks for your response.

 

[matts19]

My Darkvoice lost volume in one channel. It started to lose volume gradually for an hour or so until becoming totally silent in one channel. One thing I've been doing with this DV is that I use it for many hours every day.

What could have happened ? I can tell you it is not tubes - I swapped tubes and the problem persists. I suspect caps are dead due to overheating ? But would tube amps not be able to handle all-day use ? Has anyone used DV for extended time, like 10-12 hours daily?

I opened the case to see inside, but visually there is nothing wrong in components - no bulges, discoloration, burn marks etc.

 

[HTSkywalker]

My Darkvoice lost volume in one channel. It started to lose volume gradually for an hour or so until becoming totally silent in one channel. One thing I've been doing with this DV is that I use it for many hours every day.

What could have happened ? I can tell you it is not tubes - I swapped tubes and the problem persists. I suspect caps are dead due to overheating ? But would tube amps not be able to handle all-day use ? Has anyone used DV for extended time, like 10-12 hours daily?

I opened the case to see inside, but visually there is nothing wrong in components - no bulges, discoloration, burn marks etc.

The DV produce excessive heat especially if left on for long hours.
10-12 hours daily is not a regular practice for any non industrial component especially when not well ventilated or in a hot climate.

 

[Slade01]

My Darkvoice lost volume in one channel. It started to lose volume gradually for an hour or so until becoming totally silent in one channel. One thing I've been doing with this DV is that I use it for many hours every day.

What could have happened ? I can tell you it is not tubes - I swapped tubes and the problem persists. I suspect caps are dead due to overheating ? But would tube amps not be able to handle all-day use ? Has anyone used DV for extended time, like 10-12 hours daily?

I opened the case to see inside, but visually there is nothing wrong in components - no bulges, discoloration, burn marks etc.

When you swapped tubes…you swapped both input and power tubes? Or if you couldn’t see anything internally, did you check the headphone jack itself and connections there?

 

[HTSkywalker]

When you swapped tubes…you swapped both input and power tubes? Or if you couldn’t see anything internally, did you check the headphone jack itself and connections there?

Indeed sound fading gradually could be due to the power tube failure

 

[matts19]

When you swapped tubes…you swapped both input and power tubes? Or if you couldn’t see anything internally, did you check the headphone jack itself and connections there?

Yes of course I swapped both tubes, multiple sets of both tubes in fact, to be absolutely sure.
The lost channel was for headphone out as well as pre-out to my speakers.
I guess I won't be doing 10 hours anymore... more like 3-4 hours max per day I guess! But still I am very disappointed it should go out like that I mean many people routinely break in their tubes like 72 hours straight.

 

[sam6550a]

Yes of course I swapped both tubes, multiple sets of both tubes in fact, to be absolutely sure.
The lost channel was for headphone out as well as pre-out to my speakers.
I guess I won't be doing 10 hours anymore... more like 3-4 hours max per day I guess! But still I am very disappointed it should go out like that I mean many people routinely break in their tubes like 72 hours straight.

The best clue that you provided is that the problem also exists at the PREAMP output, therefore the problem is in the low power driver stage. This narrows it down considerably, and since the thermal load of the driver is a fraction of the output stage, tends to negate the argument of power on too many hours per day. Running any all tube amp 10 hrs a day is not excessive, tube gear, including my power amps, can and do run 18 or 24 hours with out detriment, assuming that they have been properly designed.
Knowing that the problem is in the driver stage, I would check the tube voltages, component values, and do not forget the volume potentiometer. Good luck!

 

[elgato4711]

Check for a "blown" resistor on the output path using a DVM.