Bottlehead: Crack-a-two-a build

'Tis the season for building stuff. BH ran a sale, I'm addicted - it all worked out.

So far so good. Heater tests all pasted. Just waiting on a couple of nylon standoffs that were missing.

Guts:
2ew84fwmxeaa.jpg

Top sans tubes:
8hz6aku4hq13.jpg

Aaron
Enabler Extraordinaire

Comments

  • agfrost
    agfrost Posts: 2,430
    Nice, Aaron.

    About how often does BH run sales?
    Jay
    SDA 2BTL * Musical Fidelity A5cr amp * Oppo BDP-93 * Modded Adcom GDA-600 DAC * Rythmik F8 (x2)
    Micro Seiki DQ-50 * Hagerman Cornet 2 Phono * A hodgepodge of cabling * Belkin PF60
    Preamp rotation: Krell KSL (SCompRacer recapped) * Manley Shrimp * PS Audio 5.0
  • Tony M
    Tony M Posts: 11,159
    Nice! <3
    Most people just listen to music and watch movies. I EXPERIENCE them.
  • ALL212
    ALL212 Posts: 1,577
    agfrost wrote: »
    Nice, Aaron.

    About how often does BH run sales?

    Usually around holidays. Next one might be Easter. It's kind of randomized. I go this one on the Thanksgiving sale.

    Aaron
    Enabler Extraordinaire
  • mrbiron
    mrbiron Posts: 5,711
    Is there a BH product you haven't built...
    Where’s the KABOOM?!?! There’s supposed to be an Earth shattering KABOOM!!!
  • ALL212
    ALL212 Posts: 1,577
    Not many.. I’ve not tackled (nor intend to) the large pre and power amps. The also have a mid range pre and power that don’t interest me.

    This is #12 or 13... I admitted to being addicted.
    Aaron
    Enabler Extraordinaire
  • SCompRacer
    SCompRacer Posts: 8,504
    agfrost wrote: »
    Nice, Aaron.

    About how often does BH run sales?

    Aaron is encouraging Bottlehead to start a frequent flyers discount program.
    Salk SoundScape 8's * Audio Research Reference 3 * Bottlehead Eros Phono * Park's Audio Budgie SUT * Krell KSA-250 * Harmonic Technology Pro 9+ * Signature Series Sonore Music Server w/Deux PS * Roon * Gustard R26 DAC / Singxer SU-6 DDC * Heavy Plinth Lenco L75 Idler Drive * AA MG-1 Linear Air Bearing Arm * AT33PTG/II & Denon 103R * Richard Gray 600S * NHT B-12d subs * GIK Acoustic Treatments * Sennheiser HD650 *
  • ALL212
    ALL212 Posts: 1,577
    Almost done. Ran into a snag with the last couple of wires being buried behind the output caps. I think I can get 'em in there.
    t1fsubsd5t05.jpg



    Aaron
    Enabler Extraordinaire
  • ALL212
    ALL212 Posts: 1,577
    DONE! Darn thing works too!!

    gy1k2gp4cakt.jpg

    ojlsk03x08iv.jpg

    And in defense of my addiction - there is another, the Mainline, hiding off to the right out of picture.

    re9ls5b6np2j.jpg
    Aaron
    Enabler Extraordinaire
  • mrbiron
    mrbiron Posts: 5,711
    If there was a fire and you could only grab one bottlehead kit, which one would it be?
    Where’s the KABOOM?!?! There’s supposed to be an Earth shattering KABOOM!!!
  • pitdogg2
    pitdogg2 Posts: 25,555
    Aaron would go down with the ship
  • ALL212
    ALL212 Posts: 1,577
    Honey... the house is burning down...ya...the kids?....what kids? Grab the damn amps and then come back until we have all of them out. Love you!!
    Aaron
    Enabler Extraordinaire
  • pitdogg2
    pitdogg2 Posts: 25,555
  • mrbiron
    mrbiron Posts: 5,711
    ALL212 wrote: »
    Honey... the house is burning down...ya...the kids?....what kids? Grab the damn amps and then come back until we have all of them out. Love you!!

    That's terrible..................you would actually save your "Honey" as well...
    Where’s the KABOOM?!?! There’s supposed to be an Earth shattering KABOOM!!!
  • ALL212
    ALL212 Posts: 1,577
    "Honey" understands... gear first!

    Eval:

    This amp is really a Crack on power supply steroids. The basic AC filtering is almost exactly the same and the steroids come from the circuit boards that are voltage filters. The two outboard cards are high current with 6AQ5 tubes to assist and the center board is a dual channel low current board. So none of the fancy stuff is directly in the signal path. Each channel gets it's own filtration. The main tubes are exactly the same as the Crack.

    You can get somewhat close to this with the Crack mods but the plate size doesn't allow for much in the way of modifications. This plate is big and has extra room. The big ClarityCaps fit without having to add risers or even just drop them free (as I did in my Crack build).

    Crack with the Speedball is a tad over $400.
    Crack-a-Two-a without the TwoQuiet is $700

    The Crack-a-two-a includes a balance pot, mainly there as the default volume pot has issues with low volume balance. You can leave this out if you put in a $20 Alps blue or any good volume (I used the goldpoint stepped attenuator because I had one left over).
    The TwoQuiet is a stepped attenuator add-in and is very good but also very expensive. I suspect anyone building this could just put in the Alps Blue or similar and be happy. The TwoQuiet is also a lot of extra soldering.

    Comparing the sound to my very broken in Crack on Steroids (not the BAC) and using HD650's...

    The Cracka2a has a better "extension - freq response" but damn they are close. Soundstage a tad better... I guess overall a tad better.

    Worth $300? If you plan on putting in big film caps and making mods - yes, you have the room to do so (and the parts to do so, BH includes screwed down wire tie bases for the big caps). If you have higher ended headphones - nothing major needed - also yes. If you just want a nice tubed headphone amp to run your basic headphones on...it would be a reach to justify the $300.

    Aaron
    Enabler Extraordinaire
  • EndersShadow
    EndersShadow Posts: 17,593
    Thanks for the review! Someday I'd love to own a fancy headphone amp like the Crack.
    "....not everything that can be counted counts, and not everything that counts can be counted." William Bruce Cameron, Informal Sociology: A Casual Introduction to Sociological Thinking (1963)