Crack;Bottlehead OTL
Oct 3, 2013 at 10:51 AM Post #2,806 of 12,335
Last night I decided to spend some time tube swapping to see what influence the 12AU7 tube has on the sound. I went back and forth between my CBS 5814a and the 12AU7 that came with my kit (no markings so I don't know what it is). Left the GEC 6AS7G in for the session.
 
I've come to the conclusion that I am just not able to discern subtle differences between various tubes. Maybe my hearing simply isn't good enough to detect the differences. Whatever the reason, I am satisfied that tube rolling isn't for me.
 
So... if anyone would like to sample a NOS GEC 6AS7G Brown Base with about 5 hours on it, I would be happy to pass it on for what I paid ($140 USD plus shipping). I'll put a listing up in the FS forum later today, but if you want a crack at it early (pun intended
wink.gif
) drop me a PM.
 
Oct 3, 2013 at 6:18 PM Post #2,807 of 12,335
I received my Crack and Speedball parts yersterday.  In the process of building it now.  I remember a post from a member that had suggestions for new builds that would get the speedball installed.  A few things to make the speedball upgrade easier to install.  For the life of me I cannot find that post anymore.  Does anyone know where I can find that post or if someone doesn`t mind posting again?
 
Thanks,
Stephane
 
Oct 3, 2013 at 6:28 PM Post #2,808 of 12,335
  I received my Crack and Speedball parts yersterday.  In the process of building it now.  I remember a post from a member that had suggestions for new builds that would get the speedball installed.  A few things to make the speedball upgrade easier to install.  For the life of me I cannot find that post anymore.  Does anyone know where I can find that post or if someone doesn`t mind posting again?
 
Thanks,
Stephane

 
I'm not sure exactly what you're referring to, but I would guess that if you're installing Speedball straight away and not using the amp stock first, you will want to leave out 4 components.
 
The 4 components replaced by the Speedball are:
  1. The 2 long, white ceramic resistors that sit underneath the vents in the chassis plate (sorry, I don't remember the ratings of the components)
  2. The smaller, more "traditional" looking resistors (sausage shape) that sit to the left and right of the big white ones, on the terminal strip nearest the front of the chassis (see bottom edge of the image below)
 
 
Oct 3, 2013 at 6:49 PM Post #2,810 of 12,335
  Loquah.. how does your FA-011 LE sound off the speedballed Crack?

 
A bit sloppy I'm afraid. Even though the LE version has higher impedance than the standard version, it's still only 120 ohms which is about the same as the Crack's output impedance. You can hear the impact. I still find the LEs to be a solid state-loving headphone. They sound good on my Bottlehead S.E.X., but better from the NFB-5.2 (which is a lower quality amp, but better suited for the LEs)
 
Oct 3, 2013 at 8:10 PM Post #2,811 of 12,335
   
I'm not sure exactly what you're referring to, but I would guess that if you're installing Speedball straight away and not using the amp stock first, you will want to leave out 4 components.
 
The 4 components replaced by the Speedball are:
  1. The 2 long, white ceramic resistors that sit underneath the vents in the chassis plate (sorry, I don't remember the ratings of the components)
  2. The smaller, more "traditional" looking resistors (sausage shape) that sit to the left and right of the big white ones, on the terminal strip nearest the front of the chassis (see bottom edge of the image below)
 

 
Thanks Loqah, actually I want to build stock first to get more OMG moments :) and to make sure I built everything correctly before going with Speedball.  I actually found the post I was referring to.  Sorry it was over at the BH here: forums, http://www.bottlehead.com/smf/index.php?topic=1870.0
 
Oct 3, 2013 at 8:14 PM Post #2,812 of 12,335
   
I'm not sure exactly what you're referring to, but I would guess that if you're installing Speedball straight away and not using the amp stock first, you will want to leave out 4 components.
 
The 4 components replaced by the Speedball are:
  1. The 2 long, white ceramic resistors that sit underneath the vents in the chassis plate (sorry, I don't remember the ratings of the components)
  2. The smaller, more "traditional" looking resistors (sausage shape) that sit to the left and right of the big white ones, on the terminal strip nearest the front of the chassis (see bottom edge of the image below)
 
 ​

 
Also angle those those two lower caps so you don't have to bend them when the boards go in. Oh and install the spacers before you start putting components in. It's a real bugger finagling some of those little nuts when there's junk in the way.
 
edit: wow that's possibly the dirtiest unintended sentence I've written on here
 
Oct 3, 2013 at 8:45 PM Post #2,813 of 12,335
  Well, my (second) pair of HD600's arrived today and I *finally* got to hear it with the Crack.  Not surprisingly, the combo is every bit as impressive as I envisioned it being.  Doing some swapping between the 600 & 800 on the Crack tonight.. where the HD800 separates itself from the HD600 is the (spectacularly open) soundstage, more effortless dynamics, an even blacker background, wider frequency bandwidth, and better resolving ability.  Also, I found the HD800's can texture with more finesse.  There are more subtle differences between the two phones.. but those are the areas the differences were most obvious to me.  As far as comfort and fit, I actually prefer the HD600 to the HD800.  Versus the HD800, the HD600 is lighter & I prefer the 600's (comparatively) tighter clamp (since the HD800 tends to shift around somewhat easily when I swing or turn my head).
 
Setting all that aside and coming back to the sound..  I discovered that the HD600 (when driven by the SB'ed Crack) sounds just as engaging and enjoyable (to my ears) as the HD800 does.  Sure the HD800 is more adept and does sound (technically) superior, but what I love most about the Senn/Crack pairing is the organic tonality.  I've also come to realize that with full sized, open headphones, I tend to value tonal quality more than absolute technical ability or ultra-high resolution.  So, I'm going to miss my (already sold) HD800's immense technical ability and mesmerizing soundstage.. but I can't say I'm going to be devastated to see it go... thanks to just how impressive the HD600 sounds w/ the Crack.  This is the second time I've owned the HD600.. now that I've found what appears to be its 'kindred' amp, I don't anticipate this rig leaving my possession for the foreseeable future.

 
Does that mean your millenia's impedance box is for sale by chance? :D 
 
Oct 3, 2013 at 9:47 PM Post #2,815 of 12,335
   
Also angle those those two lower caps so you don't have to bend them when the boards go in. Oh and install the spacers before you start putting components in. It's a real bugger finagling some of those little nuts when there's junk in the way.
 
edit: wow that's possibly the dirtiest unintended sentence I've written on here

 
ROFL!!
 
Great advice too
 
Oct 4, 2013 at 1:35 AM Post #2,817 of 12,335
Sjeffrey - a couple of additional recommendations with the speedball addon in mind: (i) screw on the nylon standoffs for the speedball boards before wiring/soldering the A socket, and (ii) to hook up your output caps using fly leads in the event that you ever want to put in film caps.  Happy building! 
 

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