[hypnos1]

   
Hi punit.
 
Lorspeaker has kindly posted a link to the thread relating to the Feliks-Audio project, which I shall keep updated the minute I get news from these guys.
 
My initial understanding was that the unit would be using 2 6SN7s and 2 6AS7G/6080s, which I feel would be far more preferable to just one of each, or even 2 drivers and just 1 power ( I have been experimenting with a modest unit that uses just 1 6AS7G equiv. (mine being a GEC version) and I suspect that, because of the low amplification factor of this tube family, it really does need TWO in order to provide the necessary power and dynamics.
I have not yet been informed of any change (or consideration of...) in this configuration, but I shall request confirmation anyway...
 
And so therefore, assuming things are still on course for 2 of each, we should be looking at an amp much more up to the mark! Let's sincerely hope so, lol...
 
 
Edit. Have literally just received a message from Lukasz at Feliks-Audio, and he has confirmed that there WILL be 2 6AS7G equivalents (ie 6N13s...which of course we will all replace with our own favourites - even the Russians aren't too bad, if necessary!). So this is good news...and he feels this should also help feed low impedance 'phones.
They are still testing to see if 1 or 2 6SN7s are needed, but I think the most important factor is the 2 powers...
 
A bit more info on the relevant thread...

 
Hi again, punit.
 
Just to update here as well as the Feliks-Audio thread mentioned, they have informed me that they will in fact be using TWO 6SN7s...mainly to help with driving low-impedance 'phones. So that should be a very useful attribute...and as far as I'm concerned, make the appearance MUCH more attractive over the single one perched at the front lol!

 

[punit]

   
Hi again, punit.
 
Just to update here as well as the Feliks-Audio thread mentioned, they have informed me that they will in fact be using TWO 6SN7s...mainly to help with driving low-impedance 'phones. So that should be a very useful attribute...and as far as I'm concerned, make the appearance MUCH more attractive over the single one perched at the front lol!

single 6SN7 does not look that bad sometimes

 
 

 

[hypnos1]

 
single 6SN7 does not look that bad sometimes

 
 

 
Ooh, that's nice, punit...but look what else is accompanying it, lol!  

.
 
Wish my wallet was a bit deeper

...

 

[2359glenn]

 

 

 
Just to update here as well as the Feliks-Audio thread mentioned, they have informed me that they will in fact be using TWO 6SN7s...mainly to help with driving low-impedance 'phones. So that should be a very useful attribute...and as far as I'm concerned, make the appearance MUCH more attractive over the single one perched at the front lol!

I don't see what the 6SN7 has to do with driving low impedance phones. The 6AS7s will be driving the phones.
Having a extra stage will just invert the signal. Each amplification stage inverts the signal so with one 6SN7
1/2 is used for right and 1/2 is used for left and the 6AS7 inverts it back to being the same as recorded.
In a amp with a output transformer the transformer can be used ti invert it back to being right.
Like a 300B amp driven by a 6SN7 1/2 inverts it the other 1/2 inverts it back the 300B inverts it and the transformer
makes it right.
 An inverted signal you might not notice it immediately but it just don't sound right. when the speaker is
supposed to being pushed out it will be going in .

 

[hypnos1]

  I don't see what the 6SN7 has to do with driving low impedance phones. The 6AS7s will be driving the phones.
Having a extra stage will just invert the signal. Each amplification stage inverts the signal so with one 6SN7
1/2 is used for right and 1/2 is used for left and the 6AS7 inverts it back to being the same as recorded.
In a amp with a output transformer the transformer can be used ti invert it back to being right.
Like a 300B amp driven by a 6SN7 1/2 inverts it the other 1/2 inverts it back the 300B inverts it and the transformer
makes it right.
 An inverted signal you might not notice it immediately but it just don't sound right. when the speaker is
supposed to being pushed out it will be going in .

 
Hi 2359glenn.
 
Please correct me if I'm wrong, but surely if 1 is used for each channel (as opposed to being a sequential stage), there shouldn't be a final "inverted" signal?...
Would welcome your comments...

 

[2359glenn]

 

  I don't see what the 6SN7 has to do with driving low impedance phones. The 6AS7s will be driving the phones.
Having a extra stage will just invert the signal. Each amplification stage inverts the signal so with one 6SN7
1/2 is used for right and 1/2 is used for left and the 6AS7 inverts it back to being the same as recorded.
In a amp with a output transformer the transformer can be used ti invert it back to being right.
Like a 300B amp driven by a 6SN7 1/2 inverts it the other 1/2 inverts it back the 300B inverts it and the transformer
makes it right.
 An inverted signal you might not notice it immediately but it just don't sound right. when the speaker is
supposed to being pushed out it will be going in .

 
Hi 2359glenn.
 
Please correct me if I'm wrong, but surely if 1 is used for each channel (as opposed to being a sequential stage), there shouldn't be a final "inverted" signal?...
Would welcome your comments...

There are two amplifiers in a 6SN7.
Unless it was paralleled or only using 1/2 that I seen done.
One in sequence will have the right output then the 6AS7 is going to invert it.
 
Ask this company if the output is in phase. They should know I hope.

 

[hypnos1]

 
There are two amplifiers in a 6SN7.
Unless it was paralleled or only using 1/2 that I seen done.
One in sequence will have the right output then the 6AS7 is going to invert it.
 
Ask this company if the output is in phase. They should know I hope.

 
Many thanks for your reply, 2359glenn - much appreciated. These guys do seem to really know what they're going...looks like they make some really serious bespoke kit. I can't imagine they would ever come up with something outputting out of phase!... But yes, I shall get clarification from them...thanks again

 

[rosgr63]

Some amps use two 6SN7's but only 1/2 side of each 6SN7 is used to drive the power tubes.

 

[hypnos1]

  Some amps use two 6SN7's but only 1/2 side of each 6SN7 is used to drive the power tubes.

 
"Curiouser and curiouser"....I wonder what benefit there is then from using the two tubes as opposed to both triodes of just one?
 
Mind you, if the Feliks guys also use just one triode, that will make it easier if I dare (at some time!) to adapt my C3GSs as replacements, lol!...(Shan't then need TWO per driver, of course!)

.

 

[punit]

I have a pair of Brimar CV 1988 which look like this :
 
http://www.ebay.com/itm/2Pcs-NOS-CV1988-6SN7GTY-CV181-5692-6SN7GT-ECC32-Matched-Pair-/291234795068?pt=Vintage_Electronics_R2&hash=item43cef24e3c
 
I saw a Brimar CV 1988 on Upscale audio which looks like this:
 
http://www.upscaleaudio.com/brimar-cv1988-6sn7gt/
 
Are these the same ?

 

[Skylab]

Well they are obviously not exactly the same

I have only every owned the black glass ones. I have seen the clear glass ones online, but that's it.

 

[gibosi]

I suggest you check out the 6SN7 ID page:
 
http://www.head-fi.org/t/209782/the-6sn7-identification-guide
 
Take a look at the top of the top mica on the smoked glass tubes. I suspect that you will see some sheetmetal structures extending above the mica. Not sure what these are, but I think they are heat radiators. The others you linked to are "version 2" on the 6SN7 ID page. I do not know if these sound different, but obviously the construction is slightly different.

 

[Oskari]

  I have a pair of Brimar CV 1988 which look like this :
 
http://www.ebay.com/itm/2Pcs-NOS-CV1988-6SN7GTY-CV181-5692-6SN7GT-ECC32-Matched-Pair-/291234795068?pt=Vintage_Electronics_R2&hash=item43cef24e3c
 
I saw a Brimar CV 1988 on Upscale audio which looks like this:
 
http://www.upscaleaudio.com/brimar-cv1988-6sn7gt/
 
Are these the same ?

 
I like to think of these as the STC type and the Brimar type. The first pair was made by the STC Oldway factory in Paignton and the second one by the Brimar Footscray factory in what is now the London Borough of Bexley.

 

[rosgr63]

The second pair come in different flavours.
The O getter like those of Upscale Audio are they older ones.
 
Here are some of the clear glass Brimars with and without the tensioners/coolers on top.
 

 

 

[gibosi]

And this appears to be essentially the same tube (without the tensioners/coolers) mounted in a different base.