[rbc3]

In general, it seems to be common practice to raise the volume on the source quite high (often to max), but make sure you don't introduce any clipping and distortion into the signal. If you hear distortion, pull the source volume back until the distortion is gone and then a few more just to be safe.

 
Yes, I just read that somewhere else the goal of turning the volume up as high as possible on the source device is to get the best signal to noise ratio as possible on the output.

 

[NightFlight]

  Mine came from here
 

 
Well, after months of leaving and returning to Russia (I imagine dancing/vodka/gypsies/cigars/vodka and the deep high seas) the beat up package covered in Cyrillic writing has finally showed! Initial impression is good. Gotta reel in the hype, only a few minutes in and will re-bias after break in. But I will reveal the 6S15P has ....
nah. I'll keep this one quiet.

 

[Loquah]

   
Well, after months of leaving and returning to Russia (I imagine dancing/vodka/gypsies/cigars/vodka and the deep high seas) the beat up package covered in Cyrillic writing has finally showed! Initial impression is good. Gotta reel in the hype, only a few minutes in and will re-bias after break in. But I will reveal the 6S15P has ....
nah. I'll keep this one quiet.

 
What the? Did I miss something? Is there an alternate tube for the Mainline?

 

[NightFlight]

Page 97

 

[JamieMcC]

   
Well, after months of leaving and returning to Russia (I imagine dancing/vodka/gypsies/cigars/vodka and the deep high seas) the beat up package covered in Cyrillic writing has finally showed! Initial impression is good. Gotta reel in the hype, only a few minutes in and will re-bias after break in. But I will reveal the 6S15P has ....
nah. I'll keep this one quiet.

 
 

 

[Loquah]

Page 97

LOL. Turns out I even commented on it at the time...

 

[mcandmar]

Here is some info i posted on the Bottlehead forum which may be of interest to you Mainliners..
 

I found a bit more information on the 6S15P tubes.  They were manufactured in Friazino from 1959-1969 which is an interesting little town as it was home to a couple of different Institutes of technology and did a lot of development work for the military.  The tubes were later discontinued and replaced with the 6S45P which was supposed to be cheaper to manufacture.  Interesting feature of the 6S15P is the use of gold grids, and fact the mica spacers, getters, and glass are all subtly different is what made me curious as to who manufactured them.
 
For comparison i have included a couple of pictures along side a Sovtek, Reflector, and ElectroHarmonix 6S45P.   The EH and Sovtek are obviously the same tube, however the EH versions test better and are also perfectly matched so its safe to conclude they are just cherry picked examples.  The pair i have came in Woo Audio box's so its possible Woo did the matching.  Its also worth noting of the two sets of 6S15P's i have all four measure almost identically, vs the 45's which tend to be all over the place.

 

 

 

[Loquah]

You pushed me over the line! I officially bought a pair of 6S15P on eBay last night. Looking forward to trying some tweaks with my Mainline again. Hopefully it won't turn into an addiction!

 

[NightFlight]

I saw those. They were the same price as from Russia (and the post from the Ukraine is likely more reliable) the only dependency being the DOM differences. But I think they should still be quite close in spec.  I think that's it for rolling. I don't think there are any more drop-ins.
 
When I biased the 6S15P to 145V (they were off by about -20V) then the differences between them and the EH tubes got smaller and it cleaned up a great deal.  But the properties that Jaime lays out are pretty much still there. I find it slightly less mid centric and more holophonic. I'm a sucker for the holophonics. Improved guitars/strings/space and slightly more punch in the bass are all welcome. Male vocals are a bit less emphasised but pretty much everything else is kicked up a notch.
 
This is just comes from a quick listen before they've fully settled in. The impression of the difference was somewhat obvious after a swap, and then has lessened after biasing and continued listening as audio memory of the EH fades. Huge difference in audiophile terms. Reality? We're not so sure.

 

[Loquah]

6S15Ps turned up today. Looking forward to getting them out...

 

[Textfeud]

I saw that the Bottlehead S.E.X is discontinued. Will there be a successor? Wanted to buy one for planars and my Zu speakers

 

[Solarium]

My mainline is ugly, is there anyone who offer paint/sanding services? I want it to have a makeover or else I have to stash it somewhere out of sight!

 

[NightFlight]

Really? They say beauty is in the eye of the beholder. Just spray it gloss black and be done! Your listening to it, not looking at it.  Then again, I think mine turned out okay.

 

[Loquah]

My mainline is ugly, is there anyone who offer paint/sanding services? I want it to have a makeover or else I have to stash it somewhere out of sight!

Show us a picture and we might be able to suggest some solutions

 

[punit]

The Oppo PM 2 is a great match with Mainline. My bedside rig :