Bottlehead Forum
General Category => Technical topics => Topic started by: JamieMcC on August 31, 2015, 08:36:57 PM
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Would the Russian 6S15P be suitable for the Mainline? From what I can find out it looks a possible candidate there doesn't seem to be much info out about it other than its said to be equivalent to WE437 / 3A-167M / 6C45? Can anybody help shed a bit of light on these.
Cheers
Jamie
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I believe the 6C15P is like an older version of the 6C45P. I suspect it would work, but wonder about the reasons for its discontinuation.
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If you want to fool around with something else you can triode wire a 7788. I don't think it will sound as good, but you can make it work.
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That's interesting thanks, the 6C15P I found where a bit pricy but I will keep a eye out now for some more reasonably priced ones.
The only other thing the I am really curious about and would like to try out perhaps with Mainline sometime in the future is some Nickel or pinstripe output transformers. The TL404 auto formers are sadly out of my price range. Do you think it would be possible to find a off the shelf mu transformer that would be suitable for trying out in the Mainline could you give some guidance on what sort specifications I would need to look out for?
Thanks
Jamie
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How much functionality are you willing to give up in the Mailine?
The TL404 will remove the possibility of balanced outputs and the impedance switching function.
There are other non-parallel feed transformers in the $400-600 price range that will make even more sacrifices.
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Hi Paul I only really run high Z phones on the Mainline, HD800 and T1 so not to worried about being able to switch for lower impedances.
What sparked my interest was that I noticed some CineMag full Nickle OT, and *think* (topology details are sketchy at the moment) these are custom made for a parallel feed headphone amp. This was what initially caught my attention the only specs I have seen so far has been 10K:300 with a centre tap on the primary and a 32 Ohm tap on the secondary. They are not available at the moment but price wise are anticipated to be $225 a pair when they are made available for diy use later in the year. I couldn't help but wonder if they just might be suitable for use with the Mainline?
Cheers
Jamie
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You would need a lot more data to know for sure.
Initially, the impedance ratios are not at all ideal for use in the Mainline, and the center tap on the primary of the transformer is generally not a strong suggestion that the transformer was made for a single ended circuit.
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You would need a lot more data to know for sure.
Initially, the impedance ratios are not at all ideal for use in the Mainline, and the center tap on the primary of the transformer is generally not a strong suggestion that the transformer was made for a single ended circuit.
Oh well another idea bites the dust and I had just about convinced myself that the price was justifiable if suitable ::)
Hopefully there will be some more specs available later one way or another that might prove handy.
Thanks for the taking a look anyhow.
FYI The Nickel CineMag are a upgrade option for the new Torpedo III amp from EPC details of which are a little scarce at the moment.
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Oh well another idea bites the dust and I had just about convinced myself that the price was justifiable if suitable ::)
Hopefully there will be some more specs available later one way or another that might prove handy.
Thanks for the taking a look anyhow.
FYI The Nickel CineMag are a upgrade option for the new Torpedo III amp from EPC details of which are a little scarce at the moment.
Maybe it's time for you to make a from-scratch build! Do you frequent diyaudio.com at all?
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Maybe it's time for you to make a from-scratch build! Do you frequent diyaudio.com at all?
I do have a look around diyaudio.com from time to time. At the moment my basic understanding is pretty limited but slowly improving. Perhaps with a bit more perusing of my copy of Morgan Jones amp book and one day in the future I might try my hand at a scratch build.
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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.
I am curious for somebody to try them in a Mainline and see what they think... http://www.diyaudio.com/forums/vendors-bazaar/240937-various-tubes-sale-3.html#post4608106 (http://www.diyaudio.com/forums/vendors-bazaar/240937-various-tubes-sale-3.html#post4608106)
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Those things look like they were built for soviet tanks. Very heavy duty construction.
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Actually I think they were built for Soviet aircraft radar, but not sure.
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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.
The 6C45PI is an update to the 6S15P, and uses a platinum grid to further suppress secondary emissions, and it would seem to be a hair more expensive to manufacture.
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I couldn't resist trying the 6S15P in the Mainline and the results have been interesting there is certainly some noticeable differences to the 6S45P-E Gold Pins I have been running for the last 9 months.
(https://www.head-fi.org/content/type/61/id/1576004/width/200/height/400/flags/LL)
So a few observations here
http://bottlehead.com/smf/index.php?topic=7660.msg84169#msg84169 (http://bottlehead.com/smf/index.php?topic=7660.msg84169#msg84169)
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The linestage Paul Birkeland built for me is a version of the Soul Sister/Kugelis project that appeared in VALVE some years ago. Up front are IAG TVC volume controls, and it uses the 6C45Pi tubes your post was inquiring about, driving MQ cobalt B7's powered by dual shunt-regulated power supplies and EL84 current sources. There is plenty of power for driving just about any headphone loads and my Senn 600's sing sweetly. The coupling caps were upgraded to TF V-caps. Paul designed some pretty casework for the piece as well. Cheers, Hank in Eugene
Here are two pics, the linestage sitting on a separate phonostage both PB's work, and under the hood of the linestage.