Bottlehead Crack

Discussion in 'Headphone Amplifiers and Combo (DAC/Amp) Units' started by OJneg, Oct 3, 2015.

  1. Tom-s

    Tom-s New

    Joined:
    Dec 4, 2016
    Likes Received:
    0
    Trophy Points:
    1
    Location:
    Europe
    Thinking of buying a new headphone for Crack.
    Use it with AKG K340's mostly. Bought the HD 650's once, used it for 1 month (>200 hours), didn't like it for the lack of depth/instrument separation and ease of treble compared to the K340 so i eventually sold it.
    Now it keeps nagging to upgrade my headphones and since this is the HD800 mod forum. How do those with the modded HD800 (not S) feel about it with (modded) Crack?
     
  2. Koth Ganesh

    Koth Ganesh Friend

    Pyrate
    Joined:
    Sep 26, 2015
    Likes Received:
    1,637
    Trophy Points:
    93
    Location:
    Chennai, India
    The BH Crack with Speedball (I had replaced the caps as well) is awesome with the HD 6x0s. You could do better with the HD800 (with mods). To me, it was useful to have prior to the purchase of the Zana Deux Super.
     
  3. sunnygsm

    sunnygsm New

    Joined:
    Jan 19, 2017
    Likes Received:
    13
    Trophy Points:
    8
    Location:
    Canada
    This is on sale right now. I'm really tempted to give it a shot with my HD600s. I'm running a Vali 2 at the minute.
     
  4. Ryu

    Ryu Friend

    Pyrate
    Joined:
    Oct 5, 2015
    Likes Received:
    480
    Trophy Points:
    93
    You won't regret it at all. It will be a huge upgrade over the Vali 2. You can even tube roll to get more out of it. So far the RCA clear top and the TungSol 5998 have been incredible for me.
     
  5. silvrr

    silvrr New

    Joined:
    Dec 16, 2016
    Likes Received:
    16
    Trophy Points:
    3
    Location:
    Chicago
    Has anyone seen any good instructions of the FAQ #3 mod for the resistors on the input or for the choke on the power supply circuit? Pretty sure I understand them, however, wouldn't mind having a go-by or something to reference off of.
     
  6. Steakface

    Steakface Acquaintance

    Contributor
    Joined:
    Nov 5, 2016
    Likes Received:
    53
    Trophy Points:
    18
    Location:
    Michigan
    I completed the Speedball upgrade for my newly built Crack on Friday and have been listening to it through my HD6XX's quite a bit ever since. There's definitely more detail and perhaps some additional ease of presentation. I'm currently using a RCA JAN 6AS7G and a new EH 12AU7 for tubes. For a short time I was using a 6080 Bendix that I got for cheap, but it ended up going bad... so I went back to the RCA. I'm still experimenting with driver tubes that I have on hand and I've found the EH to mesh well with the RCA's tendency for warmth - at least for now. My stock 12AU7 is a Hewlett Packard re-branded Sylvania.

    Listening between the Crack+SB and my Vali 2/EH6CG7 combo and the difference is obvious. The Vali 2 leans towards neutral and seems to have better detail retrieval while the Crack is smooth with a sense of engagement. I feel the Crack could benefit from some more detail retrieval in my case but this could also be a result of the gear and tubes still breaking in. Unfortunately the 5998 is currently out of my price range, but I do have some Erse film caps on the way to replace the electrolytic output caps - hopefully they should help.

    The only thing I really don't like about the Crack is the close up stage, and from what I read about it is it will always be relatively close up. I find the Vali 2 to have a wider stage... although not by much, but enough to notice. Thankfully the Crack's sound is mellow enough for it to not bother my tinnitus. With all that said, I really enjoyed the process of building the Crack and can see why so many people get into modding this thing - it can be addicting.

    I'm unsure how much effort/$$$ I want to put into modding the Crack, instead I'm looking at the Crackatwoa (already!) for a potential upgrade someday in the future. Does anyone have any experience with the Crackatwoa vs the Crack+SB? I've also considered comparing the Crack with the Valhalla 2, just to sate my curiosity.

    Pictures to follow...

    Edit: Here are the pics!

    [​IMG]
    [​IMG]
     
    Last edited: Jun 5, 2017
  7. Jun

    Jun Friend

    Pyrate
    Joined:
    Feb 28, 2016
    Likes Received:
    169
    Trophy Points:
    43
    I had the crack and now the crackatwoa. The crackatwoa will have a wider sound stage. The shunt regulator will offer more channel separation as well as lower noise floor and better dynamics.

    I also have the crackatwoa on sell at a very good price check out the for sale section.
     
  8. powermatic

    powermatic Friend

    Pyrate
    Joined:
    Sep 16, 2016
    Likes Received:
    690
    Trophy Points:
    93
    Looks great, nice job!
     
  9. JeffYoung

    JeffYoung Friend

    Pyrate
    Joined:
    Apr 11, 2017
    Likes Received:
    714
    Trophy Points:
    93
    Location:
    Ireland
    Indeed, nicely finished, Steakface!
     
  10. Steakface

    Steakface Acquaintance

    Contributor
    Joined:
    Nov 5, 2016
    Likes Received:
    53
    Trophy Points:
    18
    Location:
    Michigan
    This is good to know, thank you! Seems Crackatwoa reviews are quite sparse across the internet, I've only found a few of them and even then they aren't as complete as they could be. I found a few hits on the Bottlehead Amp Comparison thread on Head-Fi, as well as the few posts on Bottleheads' forum.
     
  11. Thaitao

    Thaitao New

    Joined:
    Dec 28, 2016
    Likes Received:
    5
    Trophy Points:
    3
    Location:
    Viet Nam
    This is my impression too, i feel the Vali 1 has better detail and wider soundstage compare to the bottlehead with speedball (i have heard Vali 2 and prefer Vali 1 to it). I don't know why people said that Bottlehead Crack with Speedball is superior to Vali.
     
  12. Steakface

    Steakface Acquaintance

    Contributor
    Joined:
    Nov 5, 2016
    Likes Received:
    53
    Trophy Points:
    18
    Location:
    Michigan
    I've made some changes to my Crack since my previous post and they've paid off pretty well.

    First, I replaced the RCA 6AS7G with a Russian Winged C. I initially didn't like this tube as it was a little grainy with the EH, but it relaxed when I paired it with my warmer RCA 5814A. The new combination has slightly better detail retrieval and a noticeably wider soundstage than the previous setup while still retaining a smooth sound signature. Turns out the EH driver tube had a mid-range etch that seemed to drown out some detail and make everything sound closed in.

    I also installed the Erse film caps. The effect this had on the amplifier was bigger than I thought it would be. I noticed the changes mostly in terms of improved microdynamics, macrodynamics, plankton, and a slightly blacker background. At this point, I still think the Vali 2 might have a slight edge in overall detail retrieval, but the gap has certainly tightened to the point where sometimes I'm not too sure.

    The only other mod I've put any thought into is fitting a choke to improve the power supply. I'm not sure how I feel about drilling through the board with all the components still attached, but I do know a guy with a nice drill press. Maybe one day, I hear the improvements a choke makes are worth it.

    Anyway, here's a pic of the board with the new caps installed. I installed the Alps pot during the initial build.

    [​IMG]
     
    Last edited: Jun 9, 2017
  13. AllanMarcus

    AllanMarcus Friend

    Pyrate
    Joined:
    Oct 23, 2015
    Likes Received:
    2,969
    Trophy Points:
    113
    Location:
    Los Alamos, NM
    Home Page:
    I recently installed two RCA jacks for pre-out on the crack, and I drilled the holes with no issues. Pilot holes first, then larger holes, then the full sized holes.
     
  14. JeffYoung

    JeffYoung Friend

    Pyrate
    Joined:
    Apr 11, 2017
    Likes Received:
    714
    Trophy Points:
    93
    Location:
    Ireland
    Definitely this. Otherwise you'll end up with slightly triangular-shaped holes. (While a drill-press or mill will minimise this, it won't completely eliminate it. Stepping up in size will.)

    PS: is the quote facility dead? I tried on both Safari and Firefox, but finally had to copy/paste by hand....
     
  15. AllanMarcus

    AllanMarcus Friend

    Pyrate
    Joined:
    Oct 23, 2015
    Likes Received:
    2,969
    Trophy Points:
    113
    Location:
    Los Alamos, NM
    Home Page:
    works fine for me. (Safari 10.1.1 here).
     
  16. Ice-man

    Ice-man Friend

    Pyrate Banned
    Joined:
    Oct 12, 2015
    Likes Received:
    3,455
    Trophy Points:
    113
    I picked up a Crack recently. The guy put it in a box, taped the box and mailed. No packing of any sort. Base was busted up in several placed, but the amp only needed some gentle solder reflow and works great now. The base was easy to repair. I decided to strip off the nasty black stain that came on it and make it my own.

    [​IMG]
     
  17. Ice-man

    Ice-man Friend

    Pyrate Banned
    Joined:
    Oct 12, 2015
    Likes Received:
    3,455
    Trophy Points:
    113
    I'm looking for decent tubes (ts5998, mullard 12au7 or similar) if anyone wants to let go of some extras.

    [​IMG]
     
  18. AllanMarcus

    AllanMarcus Friend

    Pyrate
    Joined:
    Oct 23, 2015
    Likes Received:
    2,969
    Trophy Points:
    113
    Location:
    Los Alamos, NM
    Home Page:
    VERY nice! IIRC, you got an excellent price on that Crack. Beautiful work on the wood. Table router?
     
  19. Ice-man

    Ice-man Friend

    Pyrate Banned
    Joined:
    Oct 12, 2015
    Likes Received:
    3,455
    Trophy Points:
    113
    Thank you sir! Yes, I cut the ridges with a table saw and then used a router to round the corners to give it some visual appeal and make it look a little different than all the others.
     
  20. JeffYoung

    JeffYoung Friend

    Pyrate
    Joined:
    Apr 11, 2017
    Likes Received:
    714
    Trophy Points:
    93
    Location:
    Ireland
    Between the damage, the grooves, and the stripped finish, it ended up with a lovely vintage feel. Perfect for a tube amp!
     

Share This Page