[i luvmusic 2]

   
Whith my 300 ohms senns hd800 with gain switches off 25 is pretty loud with hi res files and 30 with regular recordings your DT 880 are 600 ohms .Thats weird and you didnt change the gain switches under!

 
no i have not get to that part.i know it's weird.

 

[mordy]

Hi AFB,
 
I am glad that the prescription from Dr. Mordy worked:
 
 
AFB: "I kind of got annoyed at my latest pairs of tubes last night... Basically, none of them sounded right to me at this point."
 
Dr. Mordy: "So what to do to bring back the excitement and enjoyment? Play a really well recorded track with your favorite combination of tubes and just enjoy the music. Listen for new details emerging, estimate how wide the sound stage is (in my case how far outside the speakers the sound seems to emanate, tested with closed eyes and pointing a finger to where the sound seems to come from - I mean, u need a little exercise while listening), listen how realistic the cymbals and bass drum sound. With a good recording and great tubes the magic comes back....
 
My present favorite combination is the IR tubes with DTox. A very sweet mid range, plenty of detail, and all the punch and slam and shimmer I want in the lows and the highs."
 
AFB: "All I can tell you is that these (6DT6) are the most pleasant -i.e. toe-tapping- tubes I've tested since I started rolling again a couple of weeks ago; and a solid part of that pleasantness is because they are balanced imo. EF92'd that is. As Daft Punk would say, these tubes just "bring life back to music"!"
 
Now I have a question: The Dtox tubes are just great and very involving and musical with a TT index of 5+. Having re-discovered the 6AV6 tubes (BTW, I have never come across tubes that changed more after burn in than the 6AV6; it's like all the imperfections burned away) they sound truly great with a huge holographic 3D sound stage and immense detail. But listening to them I feel like I am at the platform overlooking the Rainbow Mountains in China. It's ooh and ah, but a little distant and less involving, manifest by a TT index of 3. Why?

I could listen all day long to the 6AV6 tubes but why do they not engage me emotionally as much as the Dtox tubes. Why? (Still extremely enjoyable.)
 
Could it be that the 6AV6 appeals more to the intellectual faculties and the 6DT6 to the emotional faculties?
 
Just switched from the 6AV6 to my Japanese 6DT6 and I am catching myself toe tapping.
 
Here is a picture of the Heptoad enjoying toe tapping music:
 

 
Man, I can't keep my right foot still!
 
The Dtox make me feel good, the 6AV6 make me marvel. In the words of the end of the Vitaphone clips of the 20's: That's it, there ain't no more!

 

[mink42]

Can anybody give any insight as to whether to go for the MKIII or MKIV? Planning on doing some tube rolling in the future.
 
Setup will be STX>LD MKXX(X)> Sen HD600
 
Have had trouble finding some comparisons so far 

 

[Edgard Varese]

First impressions of GE (Japan) 6DT6 on EF92 setting... quite positive.  At the moment it sounds like the sibilance is tamed a bit, while retaining a nice balance otherwise between bass and mids.  But I'm going to listen more.
 
The thing that bothers me is that I knew I didn't want to fiddle with the amp for a reason... I dropped a screw and lost it, of course (I'm a bit awkward and clumsy with these kinds of things, which is why I was reticent about strapping earlier).  Anybody got a spare screw for a Little Dot I+? 

 

 

[MIKELAP]

  Hi AFB,
 
I am glad that the prescription from Dr. Mordy worked:
 
 
AFB: "I kind of got annoyed at my latest pairs of tubes last night... Basically, none of them sounded right to me at this point."
 
Dr. Mordy: "So what to do to bring back the excitement and enjoyment? Play a really well recorded track with your favorite combination of tubes and just enjoy the music. Listen for new details emerging, estimate how wide the sound stage is (in my case how far outside the speakers the sound seems to emanate, tested with closed eyes and pointing a finger to where the sound seems to come from - I mean, u need a little exercise while listening), listen how realistic the cymbals and bass drum sound. With a good recording and great tubes the magic comes back....
 
My present favorite combination is the IR tubes with DTox. A very sweet mid range, plenty of detail, and all the punch and slam and shimmer I want in the lows and the highs."
 
AFB: "All I can tell you is that these (6DT6) are the most pleasant -i.e. toe-tapping- tubes I've tested since I started rolling again a couple of weeks ago; and a solid part of that pleasantness is because they are balanced imo. EF92'd that is. As Daft Punk would say, these tubes just "bring life back to music"!"
 
Now I have a question: The Dtox tubes are just great and very involving and musical with a TT index of 5+. Having re-discovered the 6AV6 tubes (BTW, I have never come across tubes that changed more after burn in than the 6AV6; it's like all the imperfections burned away) they sound truly great with a huge holographic 3D sound stage and immense detail. But listening to them I feel like I am at the platform overlooking the Rainbow Mountains in China. It's ooh and ah, but a little distant and less involving, manifest by a TT index of 3. Why?

I could listen all day long to the 6AV6 tubes but why do they not engage me emotionally as much as the Dtox tubes. Why? (Still extremely enjoyable.)
 
Could it be that the 6AV6 appeals more to the intellectual faculties and the 6DT6 to the emotional faculties?
 
Just switched from the 6AV6 to my Japanese 6DT6 and I am catching myself toe tapping.
 
Here is a picture of the Heptoad enjoying toe tapping music:
 

 
Man, I can't keep my right foot still!
 
The Dtox make me feel good, the 6AV6 make me marvel. In the words of the end of the Vitaphone clips of the 20's: That's it, there ain't no more!

 

[TrollDragon]

The Neutrik NJ3FP6C-B has arrived and the quality of this jack is literally night and day from the original one.

 
While I was installing this new jack I was going to put a couple of switches in the back of the case for strapping, two single pole double throw's with (On/Center Off/On) would give you 1-7 / EF95 / 2-7 by just flipping the switch. Alas I had no Center off switches just SPDT's, so that is a stop at the electrical suppliers.
 
Here is a very interesting revelation... I understand the the Pre Out has no protection circuitry but in looking at the board it appears the Headphone Jack has NONE either.

 
The larger gauge Red, Black and Blue wires on the bottom of the board attach to the headphone jack. The smaller gauge Brown, Black and Blue wires on top go directly to the Pre Out RCA jacks on the chassis back. I was under the assumption the Pre Out was a different part of the board circuitry, not just a piggy back on the Headphone Jack.
 
So in buying "NOS" tubes from eBay and Rajindar the tester/shipper guy is having a busy day, he forgets to put a few tubes through the tester... He drops a shorted one in your order, you plug the new tubes in and smoke rolls out of one of your HD800's driver... Not good... He says "My tube is guarantee" in his auction and that he'll replace the bad tube for you no problem!
 
So this amp provides no protection for your headphones as well. I don't know if all OTL's are like this or not but it is very disconcerting to know this could happen because of a $3 tube... Some food for thought and I don't know what the chance of this happening would be if at all.
 
Anyhow enough of the Prophecies of Doom...
 
Here is the MK IV with the new jack installed.

 
Cable connected and the DT880's sounding as great as ever.

 

 

[MIKELAP]

  The Neutrik NJ3FP6C-B has arrived and the quality of this jack is literally night and day from the original one.

 
While I was installing this new jack I was going to put a couple of switches in the back of the case for strapping, two single pole double throw's with (On/Center Off/On) would give you 1-7 / EF95 / 2-7 by just flipping the switch. Alas I had no Center off switches just SPDT's, so that is a stop at the electrical suppliers.
 
Here is a very interesting revelation... I understand the the Pre Out has no protection circuitry but in looking at the board it appears the Headphone Jack has NONE either.

 
The larger gauge Red, Black and Blue wires on the bottom of the board attach to the headphone jack. The smaller gauge Brown, Black and Blue wires on top go directly to the Pre Out RCA jacks on the chassis back. I was under the assumption the Pre Out was a different part of the board circuitry, not just a piggy back on the Headphone Jack.
 
So in buying "NOS" tubes from eBay and Rajindar the tester/shipper guy is having a busy day, he forgets to put a few tubes through the tester... He drops a shorted one in your order, you plug the new tubes in and smoke rolls out of one of your HD800's driver... Not good... He says "My tube is guarantee" in his auction and that he'll replace the bad tube for you no problem!
 
So this amp provides no protection for your headphones as well. I don't know if all OTL's are like this or not but it is very disconcerting to know this could happen because of a $3 tube... Some food for thought and I don't know what the chance of this happening would be if at all.
 
Anyhow enough of the Prophecies of Doom...
 
Here is the MK IV with the new jack installed.

 
Cable connected and the DT880's sounding as great as ever.

 

 
i guess its related also to the fact why i cant use the mk3 with my Pioneer amp because of the caps ! And i would not be happy to see my HD800's drivers go up in smoke

 i think after that horror story ill use a cheap pair of  headphones for burnin .Come to think of it when you burnin tubes do you have to have a headphone plugged in if so why exactly never tought of it actually. Any data on this guys .

 

[mink42]

It's generally recommended to have your cans plugged in during burn in

 

[TrollDragon]

As I read more and more about this, a lot of the people out there who roll and "tinker" with different tubes have picked up a used tube tester for checking tubes they buy. I'll dig up more info on this.

Update:
Well unless you are selling tubes then a simple emissions tester will work to check for shorts.

Gleaned from AK...

If you are just wanting to determine good from bad and shorted tubes a simple emissions tester will be more than enough to work. If this is your first tester I would recommend buying a small, decent emissions tester like a Sencore Mighty Mite or other respected emissions tester, make sure that works and then you can move up to a transconductance tester if you still feel you need one after using the emissions tester for a while.

The best test as they say is to make sure it is not shorted and works and then plug it into the circuit it will be used in.

http://www.audiokarma.org/forums/showpost.php?p=5486527&postcount=13

Maybe I am just getting too wound up in the possibility of failures and should just not worry.

I would use cheap headphones for initial power up and burn in, just to be safe.

 

[MIKELAP]

Do these  6n30p DR tubes look original first pair to be from 1979 for $161.00 and second set around same price from 1990. Whats the verdict thanks.
 

 

[TrollDragon]

Well the USAF 6AH6WA's have arrived, I used the rubber nubby that MIKELAP suggested as there was one in my 500 piece CTC Rotary Bit Kit. 400 of the 500 pieces are sanding disks but that's another story... And it works like a charm! Thanks MIKELAP for the excellent tip!

Two strands of 30 AWG bare wire wrap wire are now soldered between pins 2 & 7, let me tell you that was a fun job in itself.

My fingers are absolute poision to the markings on tubes. I am going to have to devise a way to hang into the tube while cleaning pins without removing all the letters...

Maybe cotton gloves or something similar.

Now to put them in and see if I destroyed them with the soldering job.

The things we do in the quest of audio greatness, I'll need to find a sound picture like Mr. mordy has to describe these tubes.

 

[TrollDragon]

WOW these USAF 6AH6WA's are the absolute best tubes I have heard to date...
Just like David Crosby said "Separate the Whe-eat, from the Chaff".
 
The Sound picture of these tubes.

After running the 6BY6's for a while which I was really enjoying the sound of, it has a good bass presence that I tend to crave. I found the 6BY6's a nice step up over the stock GE 5654's which have very little bass to speak of.
 
Then I popped in the 6AH6WA's... Incredible, it's like I am listening to a totally different amplifier. The clarity and dynamic range has increased 10 fold in my opinion. The bass is punchy, goes deep and is very, very enjoyable. After listening to these new tubes for a few hours I am finding the 6BY6's bass which I enjoyed, starting to be a little muddy now...  
 
Tracks Tested with the USAF 6AH6WA's
 
Dire Straits
Walk of Life, Lady Writer and Money for Nothing.
 
The Doors
L.A. Woman, The WASP and Riders on the Storm.
 
Santana
Black Magic Woman.
 
Crosby, Stills and Nash
Wooden Ships, Déjà Vu and Almost Cut My Hair.
 
Some amazing tracks through the DT880's IMHO.
 

 
Permanent strapping of 2 & 7

 
The lit up version, these tubes are not really a nice tube for the LED glow.

 
Thanks to gibosi for recommending that I might like this tube!

 

 

[MIKELAP]

  WOW these USAF 6AH6WA's are the absolute best tubes I have heard to date...
Just like David Crosby said "Separate the Whe-eat, from the Chaff".
 
The Sound picture of these tubes.

After running the 6BY6's for a while which I was really enjoying the sound of, it has a good bass presence that I tend to crave. I found the 6BY6's a nice step up over the stock GE 5654's which have very little bass to speak of.
 
Then I popped in the 6AH6WA's... Incredible, it's like I am listening to a totally different amplifier. The clarity and dynamic range has increased 10 fold in my opinion. The bass is punchy, goes deep and is very, very enjoyable. After listening to these new tubes for a few hours I am finding the 6BY6's bass which I enjoyed, starting to be a little muddy now...  
 
Tracks Tested with the USAF 6AH6WA's
 
Dire Straits
Walk of Life, Lady Writer and Money for Nothing.
 
The Doors
L.A. Woman, The WASP and Riders on the Storm.
 
Santana
Black Magic Woman.
 
Crosby, Stills and Nash
Wooden Ships, Déjà Vu and Almost Cut My Hair.
 
Some amazing tracks through the DT880's IMHO.
 

 
Permanent strapping of 2 & 7

 
The lit up version, these tubes are not really a nice tube for the LED glow.

 
Thanks to gibosi for recommending that I might like this tube!

 

 
Your not alone to like these tubes they are among my favorite tubes also. I have 10 sylvania JAN 6AU6WA on the way will be good for a while with these .Burnin in G.E. JAN 6136 at the moment you probably know that you can buy socket adaptors for those EF95 TUBES right you leave jumpers on EF92 setting and you plug in your EF95 tubes in socket adaptor . Heres a picture and a link where you can buy these adaptors in China i bought them there a while ago and also adaptors for 6AH6 and 6AU6 TUBES got infos in next post  they are $38.00 shipped if your interested .
   http://www.ebay.com/itm/1x-EF95-EF91-EF92-Vacuum-tube-adapter-socket-converter-/300961753333?pt=Vintage_Electronics_R2&hash=item4612b7e8f5                                                                                                                                                                                                                               

 

[MIKELAP]

  WOW these USAF 6AH6WA's are the absolute best tubes I have heard to date...
Just like David Crosby said "Separate the Whe-eat, from the Chaff".
 
The Sound picture of these tubes.

After running the 6BY6's for a while which I was really enjoying the sound of, it has a good bass presence that I tend to crave. I found the 6BY6's a nice step up over the stock GE 5654's which have very little bass to speak of.
 
Then I popped in the 6AH6WA's... Incredible, it's like I am listening to a totally different amplifier. The clarity and dynamic range has increased 10 fold in my opinion. The bass is punchy, goes deep and is very, very enjoyable. After listening to these new tubes for a few hours I am finding the 6BY6's bass which I enjoyed, starting to be a little muddy now...  
 
Tracks Tested with the USAF 6AH6WA's
 
Dire Straits
Walk of Life, Lady Writer and Money for Nothing.
 
The Doors
L.A. Woman, The WASP and Riders on the Storm.
 
Santana
Black Magic Woman.
 
Crosby, Stills and Nash
Wooden Ships, Déjà Vu and Almost Cut My Hair.
 
Some amazing tracks through the DT880's IMHO.
 

 
Permanent strapping of 2 & 7

 
The lit up version, these tubes are not really a nice tube for the LED glow.

 
Thanks to gibosi for recommending that I might like this tube!

 

 
Your not alone to like these tubes they are among my favorite tubes also. I have 10 sylvania JAN 6AU6WA on the way will be good for a while with these .Burnin in G.E. JAN 6136 at the moment you probably know that you can buy socket adaptors for those 6AH6and 6AU6 TUBES right. heres a picture and a link where you can buy these adaptors in China they are $38.00 shipped if your interested the way they are made your amp is on the EF95 setting you put the adaptors in the amp and your 6AH6 OR 6AU6 tubes in adaptors and your good to go .                                                 http://www.ebay.com/itm/2x-6AU6-6AK5-tube-adapter-socket-converter-free-shipping-/300960155101?pt=Vintage_Electronics_R2&hash=item46129f85dd                                                                                                                                                                                                                                                                                 
 

 

[mab1376]

   
Your not alone to like these tubes they are among my favorite tubes also. I have 10 sylvania JAN 6AU6WA on the way will be good for a while with these .Burnin in G.E. JAN 6136 at the moment you probably know that you can buy socket adaptors for those EF95 TUBES right you leave jumpers on EF92 setting and you plug in your EF95 tubes in socket adaptor . Heres a picture and a link where you can buy these adaptors in China i bought them there a while ago and also adaptors for 6AH6 and 6AU6 TUBES got infos in next post  they are $38.00 shipped if your interested .
   http://www.ebay.com/itm/1x-EF95-EF91-EF92-Vacuum-tube-adapter-socket-converter-/300961753333?pt=Vintage_Electronics_R2&hash=item4612b7e8f5                                                                                                                                                                                                                               

 
I bought those adapters and they didn't work