Moth 2a3 with external power supply (not si2a3)

Discussion in 'Headphone Amplifiers and Combo (DAC/Amp) Units' started by CEE TEE, Oct 25, 2019.

  1. CEE TEE

    CEE TEE Free Agent

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    Finally had time to get my big Moth up and running well. And it is a treat.

    Teaser Pics:
    image1.jpeg image2.jpeg image3.jpeg image4.jpeg image5.jpeg image6.jpeg
     
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  2. CEE TEE

    CEE TEE Free Agent

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    Initial Impressions: With new KR 2a3 + new production 6SL7 Tung Sol (have not rolled yet)

    My ZD is really sorted right now and very good with my HD800. Reminding me how good it is. Not a ZD Super, but has had some work by Craig/Marv a few years ago to update it some.

    The Moth is better with modded 650. I tried lots of headphones with Moth the other night. I suspect I could roll NOS in place of the new production 6SL7GT driver tubes but it it is already very good! The leading edge transients on Moth are ridiculous, lots of good/quick detail with mids to treble. But with 800 needs some smoothing on top and a bit more bottom end. Elex would be good but bass is missing some control, probably due to needing to adjust internal jumpers for lower impedance. I need to see where the jumpers are at for the speaker impedance inside.

    Still some lower level hum with Moth at higher volume levels that might be a ground thing. Using an Isomax though for everything on the table...not as bad as when resistors were bad on regulators.

    Pulled out the HD600 today. Craig did recommend that exact headphone in the Moth manual...prefer Marv-modded HD650 for cleaner bass.

    Lots of slam and macrodynamics on Moth with 600/650. Surprising amount of weight/tone/slam to bass. The mids and treble have great leading edge attack and good speed with more resolution and detail than the bass but the bass is really fun and enjoyable and everything works well together.. The slower decay of bass warms and thickens the sound so the whole thing is fat/impactful with layers of detail to concentrate on, but mostly I am just engaged and want to enjoy listening for hours.

    HD800 is too lean-sounding on Moth at moment, with bass and low bass just too light and unsatisfying...this is why I may source roll and also 6SL7 roll. My one of two Moth Tubed HyperDACs has some crackling noise that I need to figure out, will try Airist R2R DAC later and see if that helps.

    The Moth just shows what HD600/650 is capable of at the max. So good. Mids to treble on Moth are so clean/wet/glassy/controlled, bass is punchy/tuneful/warm/weighty.


    From memory, the Balancing Act didn't have as much slam/weight but was so sweet and more delicate, had bigger more open stage and only missed out on some lower-end slam/weight. Master of the mids, low-level detail, open space that just kept going. (Hmmm, would be interesting to make a more bassy Balancing Act and have these go toe to toe.)

    Zana Deux right now is balanced well tonally with HD800. HD650 is also great on ZD, much wider L to R on ZD but not much extra depth front to back. This results in Moth being more spherical in presentation from center due to less width. A bit more intimate but a nice natural round presentation. The ZD width aids some separation for listening to layers and individual instruments. (Both are very nice but the overall richness, tone, control, presentation is going to Moth today.)

    There is some warm butter tone in the Moth for sure...


    I'll post more later as I spend time playing with combos and just listening for fun again.

    Might be time for a meet soon. Haul some big rigs out???
     
    Last edited: Oct 25, 2019
  3. CEE TEE

    CEE TEE Free Agent

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    More Impressions LOG: (will add/edit with dates as I go for a week or two.)

    7/13/2020:
    Bought some old US-made 2a3 from a friend for the Moth and they are fantastic. Much more like what I was hoping for in the amp presentation and qualities. More delicate detail, greater sense of openness and space...I don't want to turn the amp off or go back to the new KR 2a3 (bought for the Moth since I liked KR PX4 in the Balancing Act so much). Really needed to roll tubes to get the most out of this amp. Getting closer to the sound that sucked me in and got me hooked on the Balancing Act.

    Now I am also waiting for a pair of old Sylvania 6SL7 to roll in the driver tube position...if the amp keeps improving I'll be very happy.
     
    Last edited: Jul 13, 2020
  4. zerodeefex

    zerodeefex SBAF's Imelda Marcos

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    Premium fucking content. I've heard Marv mention this is Craig's best.
     
  5. CEE TEE

    CEE TEE Free Agent

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    This is taking longer than expected. (Also because I am just enjoying things. :p)

    Rolling tubes? No...

    Rolling Amps and...

    Rolling Sennheisers:
    • BillP-modded HD580 Precision
    • HD600
    • Marv-modded HD650
    • HD6XX
    • SDR/SBAF-modded HD800
    Comparo.jpg
    Thank goodness Summer is over.
     
  6. CEE TEE

    CEE TEE Free Agent

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    I’m waaaaay overdue sharing some impressions and the progress of my personal rigs.

    Much of my journey has to do with amplifiers because my main headphone has been the modded HD800 for years.

    I've come full-circle back to re-purchasing the Super 7 (very modded) and the Balancing Act (fixed and plan to mod).

    I picked up a beautiful Moth 2a3 along the way as well and have 2 endgame solid state amps (Black Widow v1 and DSHA-3F).

    DACS: PS Audio PerfectWave Mk II & Burl B2 Bomber, with Pi2AES. (Moth Tubed HyperDAC has some switching anomalies which make it really fussy starting/stopping and locking back on.)

    Open Back Headphones on big rigs: Mostly HD800, Focal Elex, HD6X0.

    OG Zana Deux Update: Sold and re-purchased the Zana Deux 2 or 3 times. Sold again to Bill-P. :)


    Eddie Current Super 7 v2 Modded

    I had an original first-run unit which was an attempt to go cheaper than the Balancing Act.

    I modded the caps to Jensen Silvers and Superiors which was nice, but still a little dry, less resolving/holographic than the Balancing Act.

    Sold to fund Balancing Act, which is my favorite amp ever owned.

    Recently re-purchased a later unit that has been totally modified (caps and output transformers).

    Here were my notes to the person I borrowed <and then bought> the new S7 amp from:

    The one I had was "drier" and "more dilute". Mine was like...add a touch of harmonic distortion that is not exactly tone. And remove the wet decay. This has older Craig lush-style modded into it. And the transformers must be more bassy/slammin than the Transcendar or Electraprints that were only in the first run. Capacitor mods could slightly sweeten the shape of the decay.

    I am using the S7 tubes that are yours and were in the amp box. Who picked this group of tubes? Damn. This is good for my tastes.

    I could see where some might think a tiny bit warm? But this is a luxurious listen with fantastic balance to me.

    Really tight/snappy bass. Initial rise time and hit. Not like there is boomy quantity or long decay. It's macrodynamics. Must be the modded transformers.

    The sub-bass decay rumble is somewhat restrained.

    But this has that engaging PRAT thing. And some very <slight> wet sheen to mids, upper mids, and treble. This is probably from the capacitors.

    This one plays with the big boys and does so with everything crazily stuffed inside this small chassis.

    S7 is also great because I have a bunch of NOS 6SN7 and can roll them to tweak the tonality and other aspects of sound. Can it keep it going for the long term with the stash of tubes. I feel less concerned firing it up for shorter listens while in the office. (Not eating bigger expensive output tubes.) Love this little beast.
    OPTs changed to Mable Audio Advanced 300B OPTs (V1)
    Interstage caps: .1uF +/-5% 600VDC CuTF VQSX-10J6 VCap Elite Reference
    Feedback caps: 10uF +/-2% 800VDC Jantzen Audio Silver Z-Cap
    Belleson driver tube regulator with Nichicon 25V 4700uF cap
    Alps rk27 20kohm pot


    Eddie Current Black Widow first run (2-chassis version)


    This is the solid state amp with some tube qualities. Rich decay with macrodynamics, bit of ease at the top.

    I now have BW1 and BW2 power supplies for my unit and prefer the BW1 PS. (BW2 PS can be a touch strident.)


    Eddie Current Balancing Act


    My favorite amp was my first Balancing Act. I bought it because I had heard Marv’s rig and it haunted me.

    I bought my first BA from Tari/Radiohead and with KR PX-4 it had the best mids I have ever heard. Something ethereal and spacious, delicate about that sound.

    Emanated from within the space and seemed to just go on…past the headstage.

    Sold it to be “responsible” at one point and ALWAYS regretted that move.

    While I was working at Massdrop and did not have a Balancing Act, Tari/Radiohead sold his last/best Moth 2a3 headphone amp and I bought it.

    But the Balancing Act has high-frequency A/C tube heaters and sounds a bit different. Due to tubes, output transformers, and the tube heaters.

    So I finally bought another one that popped up in Russia. Lots of internals were fried. Probably stuck the wrong tubes in at some point.

    Took me a while to get it repaired. Now it is working well, I have been enjoying it with some cheaper Shuguang 1998 300B (surprising for ~$200) and some EML PX-4 (less bloomy than the 300B).

    PLAN: I will get some more KR PX-4. I also have some Mable Advanced 300B that I want to try in the BA to add some low end impact/extension (to be mounted outboard with a switch on the chassis so I can A/B).


    Moth 2a3

    Man was I busy at Massdrop. Not working on my own system but on all the projects.

    Grabbed the Moth 2a3 plus Moth Tubed HyperDAC (Old UltraAnalog) when Tari decided to sell. The amp got LOST and took a couple months to get to me.

    HUGE wooden crate shows up at Massdrop. And another box with the power supply that had been externalized to lower the heat in the amp.

    Annnnnnd it wasn’t working. I didn’t get it working until after I left Massdrop and had purchased the 2nd BA (which ended up not working either).

    Just getting things up and working, you also gotta find your tube selection…

    I tried JJ 2a3 and KR 2a3. Wasn’t exactly what I was looking for tonally, though presentation was good (not huge but a globular shape).

    Marv helped me find my tubes- NOS Sylvania 6SL7 + some old Hytron 2a3. Bingo- just the right amount of upper end and sparkle/bite. A more open sound. A bit warmer than the S7 overall.


    ECP Audio DSHA-3F


    After leaving Massdrop, I wanted to work on saving/resurrecting some amps in our niche.

    Then the pandemic happened and I got called by a past medical device colleague to work on PPE.

    While doing that for a year, I learned that Doug was going to stop production of the DSHA-3F and I bought one of the OG with both sets of transformers.

    Full disclosure: I am working on this project with Doug now so I will only say that it is one of my TOTL SS amps and makes my Focal Elex sing. I sold my 2nd Black Widow after spending time with this amp.

    This amp is worth continuing. Hope to have new version to show soon.


    BOTTOM LINE: I have my sonic bliss at home and at the office. With tubes and with solid state.

    I can choose tighter/faster/more resolving or warmer/slightly lusher as my taste and mood dictate, along a pretty close continuum and to my preferences. Tonality is also tweakable with tubes.

    I will try some other DACs and headphones for slight tweaking but there’s not much pressure at the moment.

    I’m catching up on pure music listening. Working on audio again will have me listening to test tracks aplenty (if all goes well I can concentrate on making stuff for others).
    I don’t want to wait until I retire to enjoy this stuff. It’s too good and life is too short. |\/|
     
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  7. yotacowboy

    yotacowboy McRibs Kind of Guy

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    Holy shit this is awesome. Thank you so much for this endeavor.
     
  8. zonto

    zonto Friend

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    Interesting point re: the different sounds of the Black Widow power supplies. I felt the BW2 could be a bit shouty with the Utopia, but am curious if that would have been alleviated on BW1.
     
  9. Erroneous

    Erroneous Friend

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    Sounds like that Super 7 found the best home it possibly could have. Thanks for the juicy details on all these great amps. I know it's impossible for you to drag them all to the upcoming meet but damn I sure would love to hear em.
     
  10. CEE TEE

    CEE TEE Free Agent

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    ^Thanks @Erroneous . You did good with this S7. Hope you have found your amp. Looking forward to meeting you in Austin. Thanks for being hospitable. :D

    I wish I could fly these over there but it is going to be a major deal to bring them to a Bay Area Meet sometime (I will).
     
  11. CEE TEE

    CEE TEE Free Agent

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    Forgot to share pics of just what is STUFFED into the Super 7:
    Mable_v1_Trafos.jpg S7_Mable.jpg
    Edit: there are two of these big output transformers stuffed inside plus the power transformer!
     
    Last edited: Apr 17, 2022
  12. Souldriver

    Souldriver Rando

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    As someone who always seems to get to the scene after production stops, this perked my ears up for sure.
     
  13. CEE TEE

    CEE TEE Free Agent

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    Guess I should post this in the thread. Comparing the 3 tube amps after selling OG Zana Deux and Moth Prototype:
    TubesInOrderS.png
    Super 7 is the most desk friendly. :cool:
     
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  14. Bourne Perfect

    Bourne Perfect Friend

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    Let us know when you plan to list that Moth. ;)
     
  15. CEE TEE

    CEE TEE Free Agent

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    ^Ha! Ok.
     

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