For 6AS7G tube rollers here .....
Aug 19, 2016 at 3:28 PM Post #3,752 of 9,502
Thanks mate, I know which tube it is for sure and it does settle down. I'll wait and see, but as long as it doesn't get worse the impact is very minimal to zero so I won't worry a great deal. The tubes themselves are supposed to be decent according to a few people in the 339 thread. Here is a picture, I would be curious what tube people here these are.


I have a number of these in NOS I bought from a big tube seller in Europe years ago. For some reason he totally disappeared but he had huge stocks of about everything from a case of 500 metal base GZ34 Mullards, etc. Anyway the tube is nice and has a warm character with a decent soundstage and solid bass though not the deepest. A good tube. Most of mine have a bit of getter appearance (looks like getter) right over the heater that can happen with some tubes when you burn them in and I have even had them do this when testing. Some come from the factory this way and people think they are used tubes but they aren't. 
 
Often gassy tubes will take 30 minute to an hour to absorb the gas, if they are going to. I have some 1929 27 mesh plates that do this and then they are fine. Some will put older tubes in an oven at 300 for an hour or so and let them cool back down. This activates the getter and absorbs any gas that has gotten into the tube. 
 
Aug 20, 2016 at 1:52 AM Post #3,753 of 9,502
 
I have a number of these in NOS I bought from a big tube seller in Europe years ago. For some reason he totally disappeared but he had huge stocks of about everything from a case of 500 metal base GZ34 Mullards, etc. Anyway the tube is nice and has a warm character with a decent soundstage and solid bass though not the deepest. A good tube. Most of mine have a bit of getter appearance (looks like getter) right over the heater that can happen with some tubes when you burn them in and I have even had them do this when testing. Some come from the factory this way and people think they are used tubes but they aren't. 
 
Often gassy tubes will take 30 minute to an hour to absorb the gas, if they are going to. I have some 1929 27 mesh plates that do this and then they are fine. Some will put older tubes in an oven at 300 for an hour or so and let them cool back down. This activates the getter and absorbs any gas that has gotten into the tube. 

If you put them in the oven at that temp won't the plastic simply melt? Am I misunderstanding what you meant, or are the tubes heat resistant to such temperatures?
 
Aug 23, 2016 at 12:33 AM Post #3,754 of 9,502
A couple of general tubes but around my wa2.

1) is using gec 6as7g tubes, one with rounded base and with straight base ok?

2) in using a pair ot tubes (both the same) if it sounds ok would it matter if the tubes's measurements were not matched (or unknown)

3) what would putting 6922 (6dj8) tubes where the rectifiers go do to the amp or tubes. I accidentally did it a while ago and the sound was fine in the minute or two they were in there before i realised what i had done.

Thanks
 
Aug 23, 2016 at 12:37 AM Post #3,755 of 9,502
NightHawks sounded like crap at first. Really awful.

20 hours + they really started to come into their own. Now I adore how they sound. Especially the treble. No elevation, sibilant or harshness. Just sweet and detailed.

They are dull and boomy from new. Boom goes away and treble sweetens. I wonder if many hear these when they are new and then get put of them. I would. I now thing they are very under rated.

ZMF + HD800 + RS1 should have you set.


That might explain why they sounded so sh.....t when i demoed them the other week and regardless of "YMMV" i could not see how these were enjoyed by persons here
 
Aug 23, 2016 at 4:59 AM Post #3,756 of 9,502
That might explain why they sounded so sh.....t when i demoed them the other week and regardless of "YMMV" i could not see how these were enjoyed by persons here


Before purchasing I had read that they needed 100+ hours burn it time. From new they sounded broken. Just rubbish. I ended up rigging a iPod to them and played musc into them continuous for 4 days. After that I couldn't believe how they sounded. Sold my LCD-X the next week and I really can't see myself using the LCD-3 again. I far prefer the Hawks.
 
Aug 24, 2016 at 11:21 AM Post #3,757 of 9,502
How can a headphone sound crap from new and then sound good after 100 hours? They would never sell. It would be suicide for the manufacturer. 
 
Aug 24, 2016 at 4:21 PM Post #3,758 of 9,502
  How can a headphone sound crap from new and then sound good after 100 hours? They would never sell. It would be suicide for the manufacturer. 


I know. I don't know why they did that. Probably why they have been very polarizing. They are so good to my ear I went back and bought a second pair as a spare. I then decided to do a side by side test. New and over 100 hours. They are completely different.
 
Aug 24, 2016 at 7:04 PM Post #3,759 of 9,502
^ ..have noticed this with AKG K7XX recently.
 
Aug 25, 2016 at 4:16 AM Post #3,760 of 9,502
^ ..have noticed this with AKG K7XX recently.


Some new HP's are using drivers with rubber mounts. Like a speaker. NightHawks do. The theory is the rubber takes a while to loosen up. Kinda explains a lot.
 
Aug 25, 2016 at 3:14 PM Post #3,761 of 9,502
A couple of general tubes but around my wa2.

1) is using gec 6as7g tubes, one with rounded base and with straight base ok?

2) in using a pair ot tubes (both the same) if it sounds ok would it matter if the tubes's measurements were not matched (or unknown)

3) what would putting 6922 (6dj8) tubes where the rectifiers go do to the amp or tubes. I accidentally did it a while ago and the sound was fine in the minute or two they were in there before i realised what i had done.

Thanks

In case you didn't get your questions answered:
  • Yes.
  • No, it will not matter in a single tube/ channel arrangement, in a parallel (two tubes/ channel) arrangement one tube may work harder than the other if not matched.
  • I looked at this (pin-outs between the 6922 and EZ80) and I don't see any likely harm to the amp.  It appears that 6922 (6DJ8) tubes would perform as half wave rectifiers in the power supply instead of the intended full wave rectification with the EZ80.  Not something I would ever think (or want) to try though; so your saying the amp actually worked fine?  How was the sound?
 
Better send those GECs to me for safe keeping, just in case!
beerchug.gif
 
 
Aug 25, 2016 at 5:24 PM Post #3,762 of 9,502
In case you didn't get your questions answered:
  1. Yes.
  2. No, it will not matter in a single tube/ channel arrangement, in a parallel (two tubes/ channel) arrangement one tube may work harder than the other if not matched.
  3. I looked at this (pin-outs between the 6922 and EZ80) and I don't see any likely harm to the amp.  It appears that 6922 (6DJ8) tubes would perform as half wave rectifiers in the power supply instead of the intended full wave rectification with the EZ80.  Not something I would ever think (or want) to try though; so your saying the amp actually worked fine?  How was the sound?

Better send those GECs to me for safe keeping, just in case! :beerchug:  
Thanks for that. Luckily i have enough room in my house to keep my gec's but thanks for the offer

When i put the 6922 tubes in the rectifier spots it was fine. But they weren't in there for too long. And it sounded fine. It was that somehow i remembered what i did as opposed to the drawing my attentuon to it
 
Aug 25, 2016 at 7:24 PM Post #3,763 of 9,502
  1. Thanks for that. Luckily i have enough room in my house to keep my gec's but thanks for the offer
  2. When i put the 6922 tubes in the rectifier spots it was fine. But they weren't in there for too long. And it sounded fine. It was that somehow i remembered what i did as opposed to the drawing my attentuon to it

 
  1. ​​Your so welcome, the offer is indefinite!
  2. In effect, your predetermined calculated experiment (
    wink_face.gif
    ​) very likely didn't damage your 6922s; it just (in theory) cut the max. power delivery of the wa2's power supply in half.  But, in all seriousness, that swag is what helps define rectifier characteristics sometimes for the better.
 
Happy listening, Cheers!
 
BTW - a triode/ pentode (e.g. 6922) is just a rectifier (e.g. EZ80) with more electrodes (more grids/ screens etc.) applied in slightly different configurations.
 
Aug 25, 2016 at 7:30 PM Post #3,764 of 9,502
ru4music thanks for your indefinite offer.

I've offered something quite similar. People sometimes "complain" about burn in time so for them i'm happy to burn in their amps FOR FREE, eg wa5, and send it back to them when i think it's ready. Strangely enough i haven't had anyone take up this generous offer. The same offer goes for top end headphones too

That's just tbe generous type of guy that i am, just like yourself
 
Aug 25, 2016 at 7:35 PM Post #3,765 of 9,502
@ru4music thanks for your indefinite offer.

I've offered something quite similar. People sometimes "complain" about burn in time so for them i'm happy to burn in their amps FOR FREE, eg wa5, and send it back to them when i think it's ready. Strangely enough i haven't had anyone take up this generous offer. The same offer goes for top end headphones too

That's just tbe generous type of guy that i am, just like yourself

beerchug.gif

 

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