[Artsi]

  Rollers here strap 1-7 with a socket wire on the MK II without noise, possibly try setting your switches to EF-95 & NS and then put a strap wire in 1-7 with the tubes to see if the hum returns.
Also a 1-7 strap while in EF-92 mode might cause you some serious hum as well.
 
I'd double check your wiring with a meter.

 
 

I'm going mad with this 7-1 strap hum problem. 

 7-1 strap works with wire in the socket, but i can't get it work without humming through switches. I resoldered everything what i added. Changed switches to new ones. Checked and measured everything ten times.
 
Problem must be something with grounding, it sounds like it. Could switches get some interference from little dot housing. I live in old house with only phase and zero wirings.

 

[gibosi]

  You were right gibosi about solder had a loose connection  sounds good now . Thanks .

 
Good news!
 
So first impressions... How do your 6BQ7A sound?

 

[TrollDragon]

  I'm going mad with this 7-1 strap hum problem. 

 7-1 strap works with wire in the socket, but i can't get it work without humming through switches. I resoldered everything what i added. Changed switches to new ones. Checked and measured everything ten times.
 
Problem must be something with grounding, it sounds like it. Could switches get some interference from little dot housing. I live in old house with only phase and zero wirings.

I have shielded wire on my switches with the shields not connected to anything just trimmed flush with the wire jacket, shrink tube on the ends where the switch wires leave the shield and jacket. It was suggested to me that I might ground one end of the shield to the chassis if I encountered a hum but leave the other end of the shield unconnected. It never happened so I never did.
 
I can't really see a hum in only one position due to the wire or switches...
 
The ground pin on the 110V mains socket in back connects directly to my board... So if you have only a two wire mains going to the amp it might be the problem.
 
I am assuming that this is the way your switches are connected up?

 

 

[Artsi]

  I am assuming that this is the way your switches are connected up?

 

Everything is connected just like that. I thought that on-off-on switch has some leakage and changed it to made in Japan switch and after that changed on-on switch to new one too. Measured that all modes connects correctly. Moved wires from jumper pins straight to socket solderings etc... 

 Next i'll need to change wall power outlet to better one with "safety" ground.

 

[MIKELAP]

   
Good news!
 
So first impressions... How do your 6BQ7A sound?

First thing i noticed with these tubes is the black backround, its very detailed but warmer sounding than the 6av6 tubes this could be my next best tube but will compare more with the 6av6 will get back to you on this .And thanks to Troll Dragon's extended jumpers this dreaded operation is a breeze to do now.

 

[MIKELAP]

Can the ECC83 tubes go with this mod also they are double triodes 

 

[gibosi]

 
First thing i noticed with these tubes is the black backround, its very detailed but warmer sounding than the 6av6 tubes this could be my next best tube but will compare more with the 6av6 will get back to you on this .And thanks to Troll Dragon's extended jumpers this dreaded operation is a breeze to do now.

 
I am not surprised that you like these tubes. The 6BQ7A is often shipped from the Schitt factory with their Lyr. In researching the 6BQ7A and the 6DJ8, I spent some time reading the two Schiit tube rolling threads to help me decide which tubes to search for. While many people preferred the more expensive 6DJ8, others really liked the 6BQ7A. For sure, they are an inexpensive way to get a taste of the 6 volt dual triodes.
 
http://www.head-fi.org/t/549508/schiit-lyr-the-tube-rolling-thread
 
http://www.head-fi.org/t/673709/schiit-lyr-tube-rollers
 
I have spent a little time listening to the Siemens and Mullard 6DJ8 I recently received, and very predictably, their sound follows the "British - Holland - German sound continuum" (copyright AFB lol), with the Mullards being the warmest and the Siemens being the most neutral. Further, the Mullards have a very smooth top end, while the Siemens have the most "air". And of course, the Amperex are in the middle. I need to spend more time listening to these three tubes, but so far, first impressions, I think I prefer the Amperex.

 

[gibosi]

  Can the ECC83 tubes go with this mod also they are double triodes 

 
The ECC83 / 12AX7 are 12 volt tubes. And therefore, a different mod, similar to AFB's "Flying 12AT7 tube", is necessary. I am assuming that AFB is currently working on just such a mode that is a little more elegant and practical.

 

[MIKELAP]

 
First thing i noticed with these tubes is the black backround, its very detailed but warmer sounding than the 6av6 tubes this could be my next best tube but will compare more with the 6av6 will get back to you on this .And thanks to Troll Dragon's extended jumpers this dreaded operation is a breeze to do now.

gibosi you mention the sound being holographic if it is what i think it means i do ear stuff in a Zubin Mehta cd and man id  swear something is in the room i ear sounds that seems to come from outside hard to explain but i like it alot .

 

[gibosi]

  gibosi you mention the sound being holographic if it is what i think it means i do ear stuff in a Zubin Mehta cd and man id  swear something is in the room i ear sounds that seems to come from outside hard to explain but i like it alot .

 
"Holographic" is just a fancy way of saying "3D."
 
The clarity and transparency of these tubes against a very black background can often convey the sense of being able to precisely locate the position of the various vocalists and instruments in space. Sometimes it seems that I hear things behind me... which can be pretty uncanny.... but for me, this added dimensionality really enhances the listening experience.

 

[MIKELAP]

   
"Holographic" is just a fancy way of saying "3D."
 
The clarity and transparency of these tubes against a very black background can often convey the sense of being able to precisely locate the position of the various vocalists and instruments in space. Sometimes it seems that I hear things behind me... which can be pretty uncanny.... but for me, this added dimensionality really enhances the listening experience.

Think you guys brought us to the next level its great .Thanks 

 

[Sony Slave]

   
Yes indeed, 30 awg wrapping wire works great.
 

Do you strip the ends wire and wrap them around the pins?
 
That's what am I am seeing correct>

 

[gibosi]

  Do you strip the ends wire and wrap them around the pins?
 
That's what am I am seeing correct>

 
Yes, this is exactly what I did. I left the insulation on because I was concerned that if the entire wire was stripped bare, it might come into contact with the metal in the center of the socket, and this might possibly create an electrical short circuit. This might be a bad thing.....

 

[Audiofanboy]

   
The ECC83 / 12AX7 are 12 volt tubes. And therefore, a different mod, similar to AFB's "Flying 12AT7 tube", is necessary. I am assuming that AFB is currently working on just such a mode that is a little more elegant and practical.

 
Well, actually, I have had a DIY adapter for almost two weeks for those 12V tubes lol; I just haven't taken pictures of it to show my Schiity -some would even say Matsushiity- work. Truth is, since I thought that either the tube I had or something in my soldering was bad (intermittent dropouts in either channel every couple of minutes), I didn't dare show what I did until I knew it worked.
 
Fortunately, the problem came from somewhere else in my sound chain (it happened regardless of tubes I used) which I have fixed since, so I'll post pics of the "adapter" soon! Don't get your hopes up too high though, it's basically a compact & clean version of the "flying 12AT7" mod with shorter wires (actually so short, I had trouble getting the wires to go to each socket...). But, I'm sure someone could just add some shrink wrap and make the same adapter look at least decent. Also, I used stranded wires because the wires are only soldered on one end and "stuck" in the socket adapters on the other end, but come to think of it, solid core would definitely be the way to not get a wobbly adapter.
 

   
I am not surprised that you like these tubes. The 6BQ7A is often shipped from the Schitt factory with their Lyr. In researching the 6BQ7A and the 6DJ8, I spent some time reading the two Schiit tube rolling threads to help me decide which tubes to search for. While many people preferred the more expensive 6DJ8, others really liked the 6BQ7A. For sure, they are an inexpensive way to get a taste of the 6 volt dual triodes.
 
http://www.head-fi.org/t/549508/schiit-lyr-the-tube-rolling-thread
 
http://www.head-fi.org/t/673709/schiit-lyr-tube-rollers
 
I have spent a little time listening to the Siemens and Mullard 6DJ8 I recently received, and very predictably, their sound follows the "British - Holland - German sound continuum" (copyright AFB lol), with the Mullards being the warmest and the Siemens being the most neutral. Further, the Mullards have a very smooth top end, while the Siemens have the most "air". And of course, the Amperex are in the middle. I need to spend more time listening to these three tubes, but so far, first impressions, I think I prefer the Amperex.

 
I haven't even dared to go delve in the Schiit thread yet, as it seems like an other pool of varying opinions that would just drain my wallet quicker than buying DR tubes lol... But I gather that there aren't that many 6DJ8 tubes considered top tier, so the choice isn't that hard considering how much feedback there is on the internet. Philips, Siemens, Mullard, some German manufacturers and an occasional US tube, but you quickly go into second tier. I'm not buying a pair of Siemens CCa for $300 shipped from some crazy country quite yet!
 
For 12Ax7 types -different pin layout than 6DJ8 tubes indeed- it is the same thing with perhaps more variety, if only because it's a large family; there are maybe 3-5 top recognized European tubes, and then all their iterations in time, sprinkle a RCA or so, and you don't have that much to pick out of essentially.

 

[foreign]

I tried the mullards 8100 they are yet to burn in but the treble is terrible has anyone found this changed after burn in ??