Donald North Audio — Owners Thread

Discussion in 'Headphone Amplifiers and Combo (DAC/Amp) Units' started by Huxleigh, Aug 12, 2016.

  1. m17xr2b

    m17xr2b Friend

    Friend
    Joined:
    Mar 26, 2016
    Likes Received:
    3,298
    Dislikes Received:
    51
    Trophy Points:
    93
    Location:
    United kingdomland of fish and chips
    I wouldn't go so far as to generalise, I'm sure there might be some headphones(MySphere is one of them) or speakers that work like magic with 2A3s, unfortunately Sennheiser isn't one of them or Audeze, or Hifiman, or ZMF etc..
    I branched out from the 2A3 family not because I'm a weirdo when it comes to tubes even if it might be true, there was a need for quality even the top 2A3s couldn't fulfil. The saving grace was the European 2A3 somewhat equivalents outside of heater such as PX4, AD1. There might be other such as E406n, LK4112.

    [​IMG]

    I don't want to take away from the quality of the Stellaris, I still haven't found out if it has a base sound outside of tubes, the wetness DNA amps are known for, Stellaris especially is due to tube selection, not the components themselves.

    Currently running U52, AD1 and C3g, the resolving power with HD690 can easily keep up with a Utopia without the small stage.
     
    Last edited: Dec 26, 2019
  2. m17xr2b

    m17xr2b Friend

    Friend
    Joined:
    Mar 26, 2016
    Likes Received:
    3,298
    Dislikes Received:
    51
    Trophy Points:
    93
    Location:
    United kingdomland of fish and chips
    You need to crack some eggs to make an omelet.

    New super tube(IMO) uncovered for Stratus/Stellaris, Bri mar 13 D3. While browsing old russian tube datasheets I noticed they specified an equivalent to the 6N1P in a Voshod manual, the british 13 D3. While not quite true due to the higher plate resistance it does hold promise and brimar does specify a 20K and up loading resistor. Curves are fairly similar and similar gain. http://www.r-type.org/pdfs/13d1.pdf
    [​IMG]

    The 13D family had an industrial purpose yet delivered some of the best tubes, the 13D 2 is one of the best 6SN7s, glenn users go crazy over 1 3D1 to the point supply has dried up. Thankfully this won't be the case here but it's good to be careful.

    Now, this is a 12V tube and cannot be used as is so don't even try it. An adaptor is necessary, I think an ebay 12AU7 to 6DJ8 one would work as pins 4 and 5 on the tube have to be tied together and flow with 9(CT). Pin 9 will remain unused in the amp socket. Testing showed it pulled 580mA at 6.31V.

    I took a different route, these can be expensive 50£, I hate adaptors, having destroyed 200£ worth of tubes recently with shitty bulgarian ones I explored other options. Flying leads and DIY.
    [​IMG][​IMG]

    C V4069 is the flying leads versions marked as equivalent, quite a bit of confusion over other versions such as CV 4051. NOS are around 20£, I have both, construction is identical and sound pretty much the same and great out of the box, can't say burn in is needed but these two are still under investigation. Until we can confirm both can be used CV406 9 is the best bet.

    The sound?
    These bring out the fun side of the Stellaris which can be too serious at times, like a mafia hitman but now with a rocket launcher.
    Low end is punchier than usual and deeper, not by much but enough to be a pleasant and welcomed improvement, extra focus. Midrange has beautiful tone, similar to what the PX4 is to the 2A3 without greyness, one of my few complaints about the 6N1P.
    Very present top end when called for, even if not the last word in fine detail I'm enjoying the extra sparkle and extension that's somewhat missing on 6N1Ps from memory. Fantastic clarity and instrument separation, holographic imaging, maybe the best out of the normal inputs.
    The AVVTs are neutral with a hint of brightness and slightly coarse in an absolutely 1st world problem way, the british tube synergies exceedingly well, there's no weird frequency dips or bumps and involvement is off the scale.

    Technically a super rare 200£+ EC C40 is a more refined tube yet the 1 3D3 is more musical and rich, dynamics for days, everything is big and bold. I'd rate it over even the most esoteric 6N1P. I even prefer the arguably lower quality U52 over 422A with it. 422A already has a boosted midrange, synergy isn't there.

    In the Project Ember 2.1 my go to for testing input tubes and hearing close to 50 tubes from cheap to 500$ ones, it's in my top 5 for sure, the same hauntingly beautiful tone is there, just far less technicalities.

    This is the tube that should come stock with DNA amps, soldered so it can't be changed, would have saved me a whole lot of rolling.
     
    Last edited: Jan 18, 2020
  3. ogodei

    ogodei Headphone Heaven Gatekeeper

    Friend
    Joined:
    Feb 9, 2016
    Likes Received:
    1,650
    Dislikes Received:
    5
    Trophy Points:
    93
    Location:
    Chicago
    @m17xr2b

    Your enthusiasm is certainly beguiling.

    Bit of a long post, I got lost a little in the flying leads discussion. If i follow:
    • 13D3 is a close equivalent of 6N1P, but is a miniature, and is expensive
    • VC4069 is an equivalent of 13D3, but has flying leads, and is inexpensive
    • The testing you did is with the VC4069 attached to a 9 pin PCB board, not with a 13D3 in an adapter
    So, super tube is actually the VC4069 \ F6158 ?
     
  4. m17xr2b

    m17xr2b Friend

    Friend
    Joined:
    Mar 26, 2016
    Likes Received:
    3,298
    Dislikes Received:
    51
    Trophy Points:
    93
    Location:
    United kingdomland of fish and chips
    Well, yes, and I wanted to not list the full name of the tubes to avoid price hikes, some sellers love to browse forums and mark up as soon as anything gets interest.

    13D3 is the equivalent of 6N1P according to the russians, there's nothing miniature about it, same size. Both were built as 6SN7 substitutes.
    CV4069 should be identical to 13D3 AKA CV4068 but with flying leads that require soldering.
    I have both 13D3 and CV4069, they sound identical in the project ember 2.1, the flying lead is better to solder on PCB with the right heater config from the get go and avoids adaptors.
    There's also CV4051, marked as a subsitute for CV4068 AKA 13D3. That one is in testing, could be the same tube, sounds the same, just a hair lighter, may be tube variance.
    All three have identical plate construction, position, getter, everyting.

    The super tube is any of these. Only Brimar made them.
     
    Last edited: Jan 18, 2020
    penguins likes this.
  5. ogodei

    ogodei Headphone Heaven Gatekeeper

    Friend
    Joined:
    Feb 9, 2016
    Likes Received:
    1,650
    Dislikes Received:
    5
    Trophy Points:
    93
    Location:
    Chicago
    Got it, thanks. The miniature thing was from a too quick read of the PDF you linked.
     
  6. Donald North

    Donald North Friend

    Friend
    Joined:
    Oct 4, 2015
    Likes Received:
    747
    Dislikes Received:
    0
    Trophy Points:
    93
  7. ergopower

    ergopower Friend

    Friend
    Joined:
    Mar 21, 2018
    Likes Received:
    359
    Dislikes Received:
    9
    Trophy Points:
    63
    Location:
    South Central PA
    I thought you were just typing too fast, but actually that's pretty clever
     
  8. Claud

    Claud Living the ORFAS dream

    Friend
    Joined:
    Dec 23, 2018
    Likes Received:
    897
    Dislikes Received:
    48
    Trophy Points:
    93
    Location:
    North Carolina
    Mr. North, you mean a 6SN7 ,right? It just happens that I have a 6SN7 to 9 pin convertor. I also have LOTS of NOS 6SN7 tubes since my Cary preamp uses them. Does my Stratus have to be otherwise modified than the convertor?
    Do you have a favorite 6SN7?
     
  9. Claud

    Claud Living the ORFAS dream

    Friend
    Joined:
    Dec 23, 2018
    Likes Received:
    897
    Dislikes Received:
    48
    Trophy Points:
    93
    Location:
    North Carolina
    By the way, the prices for 6SN7s are extremely jacked up already and the good ones were bought up 10 or so years ago.
     
    Elnrik likes this.
  10. Donald North

    Donald North Friend

    Friend
    Joined:
    Oct 4, 2015
    Likes Received:
    747
    Dislikes Received:
    0
    Trophy Points:
    93
    Unfortunately there is a lot of misinformation on the internet - ECC33 is not equivalent to a 6SN7. The 6SN7 has a mu of 20 whereas the ECC33 has a mu around 35.

    You can try the 6SN7 in your Stratus with adapter or a 6CG7 directly in it. You will notice the gain reduce around 5dB.
     
  11. m17xr2b

    m17xr2b Friend

    Friend
    Joined:
    Mar 26, 2016
    Likes Received:
    3,298
    Dislikes Received:
    51
    Trophy Points:
    93
    Location:
    United kingdomland of fish and chips
    For what it's worth, I did try my best 6SN7s in the Stellaris, for whatever reason everything sounded way to soft, even the treble tilted ones.
    ECC33 has a weird tone, similar to what the metal base GZ34 does, a peak in the lower treble that gets fatiguing over time.
    The 13D3 is close to a ECC32, tone as well but not as soft in the low end and not as lush in the mids.

    I don't think it's necessarily the high plate resistance ones, I dislike many ECC40s, it's just the early ones I'm keen on, same with 6N1Ps. Anyway, apart from the exotic inputs I won't share here I can say I'm done rolling inputs, I always had a feeling I'm missing something, the 13D 3 was it. If anyone had a brimar 6BQ7A, it's that on steroids.
     
    Last edited: Jan 18, 2020
  12. gurubhai

    gurubhai Friend

    Friend
    Joined:
    Sep 25, 2015
    Likes Received:
    249
    Dislikes Received:
    1
    Trophy Points:
    43
    Location:
    India
    Dunno what those russians were smoking but 13d3 has 14k plate resistance compared to about 5.5k of 6n1p. That's nowhere close to being an equivalent.
    The 13d3 may be great tube but I doubt that it would work well in a circuit designed for a 6n1p. At the very least, one would expect to see a plate load twice the plate resistance which I doubt is the case here.
     
  13. m17xr2b

    m17xr2b Friend

    Friend
    Joined:
    Mar 26, 2016
    Likes Received:
    3,298
    Dislikes Received:
    51
    Trophy Points:
    93
    Location:
    United kingdomland of fish and chips
    I don't get why you doubt when you don't have the amp or know the circuit. Loading is fine, more than twice.
     
  14. gurubhai

    gurubhai Friend

    Friend
    Joined:
    Sep 25, 2015
    Likes Received:
    249
    Dislikes Received:
    1
    Trophy Points:
    43
    Location:
    India
    The reason I had a doubt was because it is common practice to use a plate load of 3-4 times, of course I did not know anything about Stellaris circuit so I wasn't sure. Anyways, if the stellaris indeed has a plate load of 6 times or higher as you say then the 13d3 tube would indeed work in this specific case. However, just mentioning that the plate resistance was higher and saying that some people consider it as an equivalent is a bit misleading. While you may know what you are doing but other people reading this may not and may roll it in a amp which might be entirely unsuitable.

    As for not having the amp in question, I don't see that as relevant when discussing tube parameters. I am tempted to be snarky and say that once you have deviated so much from the stock tubes, you yourself no longer own a 'Stellaris' However I shall refrain from that as I do enjoy reading about your experiments and the exotic tube rolling. Carry on!
     
  15. m17xr2b

    m17xr2b Friend

    Friend
    Joined:
    Mar 26, 2016
    Likes Received:
    3,298
    Dislikes Received:
    51
    Trophy Points:
    93
    Location:
    United kingdomland of fish and chips
    It's not some people:
    [​IMG]


    That would be true if I'm modifying the amp, yet I can always revert back to stock by using the stock tubes, I don't want to change components, not in destructive way.

    I don't have a curve tracer but tested the CV4069 with some random values between 150-170V with -2.5,-3.5 grid gave between 3.8 and 5.8mA current, a pass in my uneducated book.
     
  16. Claud

    Claud Living the ORFAS dream

    Friend
    Joined:
    Dec 23, 2018
    Likes Received:
    897
    Dislikes Received:
    48
    Trophy Points:
    93
    Location:
    North Carolina
    Why go through all of this when you can buy a 6N1P that has been selected to meet Mr. North's specifications and then cyro treated? I think I will just stick with my Ruby Tiger Selects. Once again, thank you m17xr2b for exploring the limits of tube rolling the DNA Stellaris and as it also applies to the Stratus.
     
  17. m17xr2b

    m17xr2b Friend

    Friend
    Joined:
    Mar 26, 2016
    Likes Received:
    3,298
    Dislikes Received:
    51
    Trophy Points:
    93
    Location:
    United kingdomland of fish and chips
    To sum up:
    13D3 = CV4068 = CV4069 = very good, new not unobtanium fave for 2A3
    CV4051 = just good-ish,
    Cryo = lipstick on pig

    I gave that tube a base, tubes love bases.
    [​IMG][​IMG]
    Grips the PCB from both sides, can be handled like any other 6SN7.
     
    Last edited: Jan 19, 2020
    Lasollor, Claud and famish99 like this.
  18. Claud

    Claud Living the ORFAS dream

    Friend
    Joined:
    Dec 23, 2018
    Likes Received:
    897
    Dislikes Received:
    48
    Trophy Points:
    93
    Location:
    North Carolina
    I like those bases. Are they converters?
     
  19. m17xr2b

    m17xr2b Friend

    Friend
    Joined:
    Mar 26, 2016
    Likes Received:
    3,298
    Dislikes Received:
    51
    Trophy Points:
    93
    Location:
    United kingdomland of fish and chips
    In a way yes CV4069 to 6N1P for the Stellaris, built them earlier today on a 3D printer. I left an intentional gap between the tube and base as the material isn't too heat resistant and shouldn't touch the glass. Been running it for over 5 hours and it's holding strong.
    It's this with a printed shell for support and ease of use.
     
  20. Claud

    Claud Living the ORFAS dream

    Friend
    Joined:
    Dec 23, 2018
    Likes Received:
    897
    Dislikes Received:
    48
    Trophy Points:
    93
    Location:
    North Carolina
    Does the CV4068/69 have the same pin out as the 6N1P? I just bought 4 of them on Ebay. Two from Jolly Old... and two with orig boxes from South Africa. All Brimar tubes.
     

Share This Page