"Shortest Way" SW51 Amp Impressions (Simple SET Amp)

Discussion in 'Headphone Amplifiers and Combo (DAC/Amp) Units' started by Hands, Jul 12, 2019.

  1. Zampotech

    Zampotech Friend

    Pyrate
    Joined:
    Oct 15, 2018
    Likes Received:
    4,195
    Trophy Points:
    93
    Location:
    Moskou
    Home Page:
    That's for sure. All new projects will be forced to stand until I start sending out batches of 4 and 4+.

    The wishes of the new amplifiers will be taken into account as "wishes" and will be used for planning. When the new amps move from the "black cat in a black bag" stage to the "live device" stage, I will be ready to accept real orders. Right now, my priority is to produce the SW51 and fulfill my obligations.

    PS To be honest, I was surprised by the relatively large number of people who wanted to get the SW9 for planar headphones. I didn't know planar headphones were so common.
     
    Last edited: Apr 23, 2021
  2. Baten

    Baten Friend

    Pyrate
    Joined:
    Mar 18, 2018
    Likes Received:
    1,130
    Trophy Points:
    93
    Location:
    EU
    Much more common to own an ortho/planar alongside your usual dynamic headphone than it is to own electrostatics :D I think they've only gained popularity what with Audeze/Hifiman/... refreshes, drop launches, etc,
     
  3. Zampotech

    Zampotech Friend

    Pyrate
    Joined:
    Oct 15, 2018
    Likes Received:
    4,195
    Trophy Points:
    93
    Location:
    Moskou
    Home Page:
    So I guessed right when I bought 500 6P9 tubes for SW9. However, at the time of purchase, I did not think about the SW9, I just could not resist buying these wonderful tubes.
     
  4. MisterRogers

    MisterRogers Ethernet Nervosa

    Pyrate
    Joined:
    Sep 27, 2015
    Likes Received:
    2,063
    Trophy Points:
    93
    Location:
    Aurora, CO
    Home Page:
    You chose well mate; there's a growing number with '+ planar' (dynamic and planar), and planar only peeps. If you bring the magic you did with SW51+, you'll clear out your stock of 6P9 tubes.
     
    • Like Like x 5
    • Epic Epic x 3
    • List
  5. Brian D

    Brian D Facebook Friend

    Contributor
    Joined:
    Jul 20, 2017
    Likes Received:
    175
    Trophy Points:
    33
    Location:
    Arizona
    I'm in for a SW4, thanks.
     
  6. bilboda

    bilboda Florida boomer

    Pyrate Banned
    Joined:
    Nov 20, 2016
    Likes Received:
    834
    Trophy Points:
    93
    Location:
    Miama
    Not sure I'll want another amp, lol. This SW51+ and LTA HP2 synergize very well. I have a prominent bass and piano going on right now, Goodbye For My Father from Wood, Brian Bromberg. The individual decays and trails are in full glory, plenty of space to breathe which is a signature of the HP and the amp. Together, it is strength on strength. Patricia Barber believes in love, Alfie. I believe in the SW51+ and LTA HP2....I also believe in initials.
     
    • Like Like x 1
    • Epic Epic x 1
    • List
  7. atomicbob

    atomicbob dScope Yoda

    Pyrate BWC MZR
    Joined:
    Sep 27, 2015
    Likes Received:
    18,652
    Trophy Points:
    113
    Location:
    On planet
    I will gladly measure any new amplifier created by @Zampotech
     
    • Like Like x 8
    • Epic Epic x 1
    • List
  8. elwappo99

    elwappo99 Friend

    Pyrate Contributor
    Joined:
    Oct 8, 2015
    Likes Received:
    797
    Trophy Points:
    93
    Location:
    SoCal
    I'd also argue in my experience there's a lot more high end amplifiers that work well with dynamic headphones. Whereas there aren't as many amps that are designed for planar headphones (high output and low impedance), and only a small number can really do a great job.

    Even though I own quite a few planar and dynamic headphones I'd be interested in the SW9. Love seeing the progress on this!
     
  9. Mordy

    Mordy Acquaintance

    Joined:
    Nov 18, 2015
    Likes Received:
    63
    Trophy Points:
    18
    What would the effect be on the sound of a 300 ohm headphone driven by the low impedance planar amplifier?
     
  10. Syzygy

    Syzygy Friend

    Pyrate
    Joined:
    Jun 13, 2018
    Likes Received:
    2,144
    Trophy Points:
    93
    Location:
    DFW, Texas
    Other than range of volume (how loud you can get), other sound characteristics depend upon the particular amplifier and its design, and the particular headphone along with its design.
     
  11. Khronos

    Khronos New

    Joined:
    Aug 17, 2020
    Likes Received:
    8
    Trophy Points:
    3
    Location:
    USA
    I've heard the Audio Note stuff is also overrated. I'm honestly intrigued about the OPTs made by Dave Slagle from Intact Audio and Christoff Kraus from Silvercore. Hell, the Silvercore stuff, while expensive on it's own right, is actually somewhat rightly priced for what it is (20 Watt 833c SET Amplifier with Silver transformers for €10K, the next cheapest option being the $45,000 Ming Da, and best of all, it looks badass). If I was more proficient with not shocking myself to death and far less broke I'd put the money to end the intrigue because again, $$$ (the Slagles are probably in the $1800/pair and the silvercores likely not too far behind).
     
  12. ColdsnapBry

    ColdsnapBry Almost "Made"

    Joined:
    Feb 4, 2021
    Likes Received:
    640
    Trophy Points:
    93
    Location:
    Earth
    If someone could help me out and let me know the length of interconnects required for a SW51+ sitting next to a Bifrost II that would be awesome. I was wondering if a foot is enough or if I'll need longer. Thank you kindly.
     
  13. Phantaminum

    Phantaminum Friend

    Pyrate
    Joined:
    Mar 13, 2018
    Likes Received:
    1,976
    Trophy Points:
    93
    Location:
    Dallas, TX
    A foot is all you need.
     
  14. ColdsnapBry

    ColdsnapBry Almost "Made"

    Joined:
    Feb 4, 2021
    Likes Received:
    640
    Trophy Points:
    93
    Location:
    Earth
    Great, thank you.
     
  15. Elnrik

    Elnrik Super Friendly

    Pyrate
    Joined:
    Jan 10, 2017
    Likes Received:
    8,973
    Trophy Points:
    113
    Location:
    Denver CO
    Home Page:
    That's what she said.
     
    • Like Like x 7
    • Epic Epic x 6
    • List
  16. Zampotech

    Zampotech Friend

    Pyrate
    Joined:
    Oct 15, 2018
    Likes Received:
    4,195
    Trophy Points:
    93
    Location:
    Moskou
    Home Page:
    Dear friends.
    While I am in forced idleness because of the quarantine, I will share with you photos of the process of making cases, which are on my home computer.

    First, I will show you the used machines that I recently purchased.

    Don't mind the scary look in my workshop.

    The first bending machine.

    [​IMG]

    The second bending machine. For complex bending profiles.

    [​IMG]

    A set of different dies for bending machines. The most valuable thing in my workshop.

    [​IMG]

    Guillotine for metal

    [​IMG]

    Contact welding machine. Old, but very good Bulgarian machine.

    [​IMG]

    A set of blanks for amplifiers. I don't remember now if it's 4th or 4th + .

    [​IMG]

    The first and second stages of manufacturing the amplifier chassis.

    [​IMG]

    [​IMG]

    The shell of the caps for the transformer. In the cardboard boxes, all the shells of the hoods.

    [​IMG]


    Cap caps.

    [​IMG]

    Manufacture of the front and rear parts of the amplifier chassis.

    [​IMG]

    Blanks for transformer mounting brackets.

    [​IMG]


    I'll show you the rest of the photos as I get to my work computer after the quarantine ends.
     
    • Like Like x 41
    • Epic Epic x 15
    • List
  17. E_Schaaf

    E_Schaaf MOT: E.T.A Headphones

    Pyrate BWC
    Joined:
    Mar 28, 2017
    Likes Received:
    9,589
    Trophy Points:
    113
    Location:
    Staten Island, NY
    Home Page:
    I figured it's time for a little review as I've been living with the SW51+ and Bachelor for several weeks now. Valhalla 2 was my first dedicated headamp, I got one shortly after launch. I've used all of these amps from several DACs including Burl B2 Bomber, Monarchy M22B, and Modi 2U (edit: also Bifrost 2) - the chart below has been my general experience across the board. All of these amps do have their own character which I feel remained clear regardless of source pairings. I never found myself thinking I could confuse one for another. I used the GE tubes atomicbob recommended for Bachelor and whatever tubes @tommytakis put into the SW51. Valhalla 2 stock rear tubes, Amperex green label 7308 in the front.

    upload_2021-5-22_19-21-32.png

    The chart says a lot, but I've got some additional ramblings:

    SW51+:

    love: clarity, colorful midrange, prickly details, crisp image, most revealing of source differences.
    meh: bass quality (feels like it hits a wall and is audibly distorted compared to the others with deep clean tones), lacks grip and follow-through on transients. Slightly 'snippy' and a tiny bit brittle in the high treble. Mildly up-tipped sounding tone.

    I like this amp with Senns (not enough resolve in the bass to hear the amp's weakness here). They play to each others strengths. My enjoyment of this amp with my own headphones is recording-dependent -. For electronic and HipHop/R&B, I found this amp left a lot on the table in terms of tactility. Probably a non-issue for those who listen mostly to acoustics and vocals.

    Bachelor:

    love: slammin bass (for the size/price and vs others here), fatigue free, physically cute, cheap, low-OI is more flexible, 'good enough' technicalities, decent tone/timbre
    meh: harmonically dull, doesn't help with veiled transducers, sounds kinda stuffy, not as much snap in the mids as I'd like, doesn't reveal changes of source as clearly. Just a bit loose overall.

    This amp does a good job with Drop HD58X and ESX900 with a livelier source like the Burl. I found it generally genre-flexible and headphone-flexible, though I always felt like a bit of engagement and clarity was missing compared to the other amps here.

    Valhalla 2:

    love: midrange body without bloat, vibrant without feeling deep fried, good grip in the midbass, good mid-treble clarity that's not fatiguing
    meh: opaqueness / 'simplicity' in the low treble, doesn't rumble much even though it's fairly clean, attacks could be a bit sharper, center image isn't as clearly defined

    Valhalla 2 is a well documented amp so not much more to say about pairings. Solid with Senns, but doesn't lift the veil quite as much as SW51. However, I like this amp very much with Peerless driver headphones specifically. Excellent synergy there. This amp has about as much OI as those drivers can take on the high gain setting. I wish it responded a bit more to tube rolling.

    Nice job @Zampotech ! Looking forward to your future projects.
     
    • Like Like x 24
    • Epic Epic x 14
    • List
    Last edited: May 22, 2021
  18. Elnrik

    Elnrik Super Friendly

    Pyrate
    Joined:
    Jan 10, 2017
    Likes Received:
    8,973
    Trophy Points:
    113
    Location:
    Denver CO
    Home Page:
    Hi @Zampotech and everyone,

    I'm trying to work with Brent Jesse to get a pair of tubes for the 51+. He has EF805S tubes, and near as I can tell they are premium versions of the EF85, but I'm not entirely sure. Can anyone more knowledgeable sanity check that for me? Attached data sheet PDFs if that helps.
     

    Attached Files:

  19. Azimuth

    Azimuth FKA rtaylor76, Friend

    Pyrate
    Joined:
    Nov 9, 2015
    Likes Received:
    6,837
    Trophy Points:
    113
    Location:
    Nashville, TN
    Home Page:
    Pinout is the same. A few variances in specs (EF85 listed first):

    Typical -
    Anode Supply - 250V vs 200V EF805S (max on both is 550V, so safe here)
    Grid Resistor - 60k ohm vs 45k ohm (min. on EF805S was 45k ohm, so higher might be safe)
    Transconductance - 6.0 mA/V vs. 6.5 mA/V (just tube characteristic stuff)

    Max -
    Heater to Cathode voltage - 150V vs. 100V (this is the only thing I would worry about. You'd have to measure what the heater to cathode voltage is now with stock tube, but it should be certainly less that 100V.
    Heater Current - 15ma vs 12.5 ma (lower heater current draw, so totally safe here)

    It seems the EF805S has slightly higher transconductance with slightly lower heater current draw. Basically a slightly more efficient tube.

    And doing some quick research, it seems the the EF805S is the long life version of the EF85. So performance may vary from stock.
     
    • Like Like x 3
    • Epic Epic x 3
    • List
  20. MisterRogers

    MisterRogers Ethernet Nervosa

    Pyrate
    Joined:
    Sep 27, 2015
    Likes Received:
    2,063
    Trophy Points:
    93
    Location:
    Aurora, CO
    Home Page:
    Haven't used those specific tubes, but long life versions (more efficient, lower V & ma specs) of other tubes have generally performed well.
     
    • Like Like x 1
    • Epic Epic x 1
    • List

Share This Page