[DemonicLemming]

I actually picked up a set of Brimar tubes a little over a week ago, and they're one of my two favorite sets for the Lyr.  However, Skylab did mention pages back that they might not actually be Brimar tubes, but simply rebranded from another manufacturer.  Either way, I think they sound great.
 
It would be interesting to see a Schiit amp using some EL84 or 12AX7 tubes - they seem very popular.  As long as they stay away from the $400/per 300B tubes...
 
Quote:

Thanks for adding another tube option to the list Jamato.  This thread is fun but is rapidly building up my tube inventory.  I have two versions of Russian 6N1P's on their way as well as 6N23's.  I thought about a set of Brimars as they looked cheap...until,likely someone here, also thought they looked cheap. 
 
I wonder if any of the new Schiit products on the drawing board will use any of these tubes? 
 
The good thing is that my Lyr will not run out of tubes for a long time.  At 5000 hours per tube pair....  I can survive 17.25 years....assuming that I never turn the amp off.  

 

 

[Jason Stoddard]

 
Quote:

\It would be interesting to see a Schiit amp using some ... 12AX7 tubes - they seem very popular.  


 

Google "mike moffat 6dj8" to see why that ain't gonna happen.
 

 

[TruBrew]

Do 6EJ7's work. I am having a hard time determining what tubes I can buy. It is 9 pin, but I don't know if there is more to it than that.

 

[jamato8]

There are many 9 pin tubes but only a few of those designs will work. I am not familiar with the tube you mention. I would use the 6DJ8 and tubes of that family, and the 6N23P, 6N1P and the 6BZ7 and 6BQ7. You can't just plug in a 9 pin tube as the electrical properties can be and most likely are, totally different. Also some tubes have a totally different pin out for the sections of the tubes. 

 

[DemonicLemming]

Would it be related to his introducing the tube years back in a Theta pre-amp?
 
Hm...along those lines, any thoughts of a tube-based DAC?
 
Quote:

 

Google "mike moffat 6dj8" to see why that ain't gonna happen.
 

 

 

[olor1n]

Quote:

There are many 9 pin tubes but only a few of those designs will work. I am not familiar with the tube you mention. I would use the 6DJ8 and tubes of that family, and the 6N23P, 6N1P and the 6BZ7 and 6BQ7. You can't just plug in a 9 pin tube as the electrical properties can be and most likely are, totally different. Also some tubes have a totally different pin out for the sections of the tubes. 

I've seen matched RCA's listed on ebay but on the box one is labelled 6BQ7 and the other 6BQ7A. I'm assuming these are the same thing, but perhaps made at different times. Ideally, how closely do these tubes have to match (manufacture date, labeling etc)?
 

 

[MrScary]

I went back and put the Amperex white label Holland tubes back in the Lyr and instead of my typical quick judgement I have been listening to them for a day and they have some nice qualities to them they are much warmer than the 6N23P's and have as much bass the mids are the same but the one thing that shines is a slightly holographic sound that the Amperex give on most music. 192-24 Orchestra music is just beautiful with the Amperex, Jazz is nice as well as the blues... Rock is about the same as the 23's

 

[ZorgDK]

I bet the Amperex would be good for binaural recordings then. 

 

[MrScary]

I bet the Amperex would be good for binaural recordings then. 

Maybe when I get my semiens and Valvo's in that will be the real test they are suppose to really be holographic. The Amperex just sound good all around have a nice airy sound I sold my orange label Amperex PQ's on ebay they were not too good in the LyR IMHO.

 

[Jason Stoddard]

Quote:

Would it be related to his introducing the tube years back in a Theta pre-amp?
 
Hm...along those lines, any thoughts of a tube-based DAC?

Yep. While I'm more tube-agnostic, Mike has a loathing of the 12AX7. "Only fit for table radios," I believe was his quote. He introduced the hi-fi world to the 6DJ8 in the Theta preamp (not Theta Digital, we're talking paleolithic history here.) I mean, the earth cooled, and there was Mike, making hifi gear. Or so it seems.
 
Now, a 6SN7--Mike gets *very* excited about that tube. Not that it's going to drop into a Lyr. 
 
And yes, fair warnings above: not all 9-pin tubes have the same pinout, and dropping one of those in Lyr will not be a good day. If you're not familiar with tube-rolling, or, better, a DIYer who understands pinouts, tube types, and transconductance, I'd stick to the ones that people are using successfully.
 
And nope, no plans for a tube DAC. For current-output DACs, tubes don't have a proper low-impedance input to drive (or, well, to be fair, their transconductance is low when compared to solid state, so the cathode is still relatively high impedance.) For voltage-output DACs, we still prefer to stay on the solid state side for summing, etc.
 
You can expect that all our DACs will have discrete analog stages--Mike was using opamps in the Theta Gen III when I came around, and I turned him around to discrete in the Gen V with a discrete stage that measured (and listened) much better than the uber-super-duper opamps he was using at the time. That's a whole 'nother story--200 parts on a 4 x 6" teflon board with no soldermask . . .
 

 

[ZorgDK]

Interesting info Jason, thanks for that.
 
 

 

[Bobcow]

Quote:

Quote:


Yep. While I'm more tube-agnostic, Mike has a loathing of the 12AX7. "Only fit for table radios," I believe was his quote. He introduced the hi-fi world to the 6DJ8 in the Theta preamp (not Theta Digital, we're talking paleolithic history here.) I mean, the earth cooled, and there was Mike, making hifi gear. Or so it seems.
 
Now, a 6SN7--Mike gets *very* excited about that tube. Not that it's going to drop into a Lyr. 
 
And yes, fair warnings above: not all 9-pin tubes have the same pinout, and dropping one of those in Lyr will not be a good day. If you're not familiar with tube-rolling, or, better, a DIYer who understands pinouts, tube types, and transconductance, I'd stick to the ones that people are using successfully.
 
And nope, no plans for a tube DAC. For current-output DACs, tubes don't have a proper low-impedance input to drive (or, well, to be fair, their transconductance is low when compared to solid state, so the cathode is still relatively high impedance.) For voltage-output DACs, we still prefer to stay on the solid state side for summing, etc.
 
You can expect that all our DACs will have discrete analog stages--Mike was using opamps in the Theta Gen III when I came around, and I turned him around to discrete in the Gen V with a discrete stage that measured (and listened) much better than the uber-super-duper opamps he was using at the time. That's a whole 'nother story--200 parts on a 4 x 6" teflon board with no soldermask . . .
 

Good to hear some more info

 

[jamato8]

I am glad the Lyr went with the 6DJ8. I have built equipment to use both and one piece I built I have adjustable operating points. I has both 9 pin and octal sockets. After extensive, as in a couple of years use, listening with the best there is 6SN7's and some of the best 6DJ8 types I prefer the 6DJ8 type for what I would term as more "life" to the music. In all areas of frequency response, transparency and realistic depth and width with imaging, I find that for me, the 6DJ8 edges out the 6SN7 but I love the looks of the Tung sol round plate black glass. 

 

[sphinxvc]

What about 6SN7 / 7N7 with an appropriate adapter?  I can understand if it's not officially condoned but for you DIYers or tube gurus out there, how does that sound?

 

[Jason Stoddard]

6SN7s need a ton more voltage to perform at their best--hell, they'll take a plate voltage nearly 4x that of the 6922--one of the reasons we didn't go with them. The last thing we need is *more* heat, ha!