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

Comments

  • pitdogg2pitdogg2 Posts: 9,848
    Nice Aaron.
  • mhardy6647mhardy6647 Posts: 17,653
    :)
    "It's like watching a roomful of people who couldn't get through college algebra discussing the flaws of quantum physics theory. I guess it could be fun, but it's ultimately a waste of time." -- seen on audiokarma

    "Some amps run on self bias, some amps run on fixed bias. But his amps run on confirmation bias." -- seen on audioasylum

    "Writing about hifi is like dancing about architecture" -- paraphrasing some wag (possibly Frank Zappa)
  • agfrostagfrost Posts: 2,127
    Nice, Aaron.

    About how often does BH run sales?
    Jay
    SDA 2BTL * Musical Fidelity A5cr amp * Marantz DV-9500 * Modded Adcom GDA-600 DAC * Rythmik F8
    Micro Seiki DQ-50 * A hodgepodge of cabling * Belkin PF60
    Preamp rotation: Krell KSL (SCompRacer recapped) * Manley Shrimp * PS Audio 5.0
  • Tony MTony M Posts: 5,366
    Nice! <3
    Most people just listen to music and watch movies. I EXPERIENCE them.
  • ALL212ALL212 Posts: 753
    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
  • mrbironmrbiron Posts: 4,717
    Is there a BH product you haven't built...
    Zu Audio Omen MK-1B's, Peachtree Decco65, Bryston BDA-2, Cheap TT, PS Audio UPC200, PS Audio AC3's, Zu Mission SC's, HTPC, One, Bottlehead Reduction & Crack w/Speedball
  • ALL212ALL212 Posts: 753
    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
  • SCompRacerSCompRacer Posts: 6,737
    agfrost wrote: »
    Nice, Aaron.

    About how often does BH run sales?

    Aaron is encouraging Bottlehead to start a frequent flyers discount program.
    Make yourself necessary to someone. Ralph Waldo Emerson

    Salk SoundScape 8's * Audio Research Reference 3 * Bottlehead Eros Phono * Park's Audio Budgie SUT * Krell KSA-250 * Harmonic Technology Pro 9+ & Pro 11+ * Signature Series Sonore Music Server w/Deux PS* Twisted Pear Buffalo III Dual Mono ESS Sabre32 DAC * 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 *

  • ALL212ALL212 Posts: 753
    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
  • ALL212ALL212 Posts: 753
    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
  • nbrowsernbrowser Posts: 7,914
    Oh Myyyyyy!
    Living room: Samsung UN55KU7000 4K UHD HDR 55 inch TV, Marantz CD6004, Pro-Ject Debut Carbon, Parasound zPhono, Mac Mini, Oppo BDP-93, XBox One S 2Tb, Kenwood DPX792BH car deck for radio purposes, Marantz SR5010 AVR, Parasound HCA-1200II, Front SDA 2 modded with Larrys Rings and RD0-194-1 tweeters, Rear Onkyo SKF-4800 Towers, Center CSiA6, BOOM Tannoy TS2.12 Sub, Audioquest Evergreen interconnects just about everywhere except from AVR to amp, MIT Terminator 4, MIT AVT3 speaker cables with extra terminals covered up Monitor 5 Jr+ in the wings for a center channel.
  • mrbironmrbiron Posts: 4,717
    If there was a fire and you could only grab one bottlehead kit, which one would it be?
    Zu Audio Omen MK-1B's, Peachtree Decco65, Bryston BDA-2, Cheap TT, PS Audio UPC200, PS Audio AC3's, Zu Mission SC's, HTPC, One, Bottlehead Reduction & Crack w/Speedball
  • pitdogg2pitdogg2 Posts: 9,848
    Aaron would go down with the ship
  • ALL212ALL212 Posts: 753
    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
  • pitdogg2pitdogg2 Posts: 9,848
    I knew it lol
  • mrbironmrbiron Posts: 4,717
    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...
    Zu Audio Omen MK-1B's, Peachtree Decco65, Bryston BDA-2, Cheap TT, PS Audio UPC200, PS Audio AC3's, Zu Mission SC's, HTPC, One, Bottlehead Reduction & Crack w/Speedball
  • ALL212ALL212 Posts: 753
    "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
  • EndersShadowEndersShadow Posts: 15,611
    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)
Sign In or Register to comment.

Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!