[Solarium]

Got my BH Crack w/ speedball today! Finally seeing what all the fuss about (after all these years, and returning the massdrop BH crack kit back in 2014). Haven't even gotten to the tube rolling yet, and even when using the stock tubes I'm impressed. I'm surprised that the synergy with my iDSD as the DAC is greater than with my bifrost multibit, due to iDSD's warmer signature. Listening to norah jones actually gave me goosebumps and made my neck hair stand up! What are all your experiences in what kind of DAC's to pair with the Crack?
 
Someone in another thread mentioned some upgrades for the crack, including film caps, Valab 23 stepped attenuator volume pot, and a Triad c-7x choke. Where do I get these components? Do they make more of a difference than tube rolling?
 
If anyone's selling output tubes from the 5998 (TS/Chamtam) and 6080 (TS/Bendix) series and also input tube like CBS Hytron-JHY 5814a with flat grey/black plates, please let me know Let the tube rolling begin!

 

[grausch]

  Someone in another thread mentioned some upgrades for the crack, including film caps, Valab 23 stepped attenuator volume pot, and a Triad c-7x choke. Where do I get these components? Do they make more of a difference than tube rolling?

 
I have not tried any other tubes, but I believe common consensus is that once Speedball is installed, the difference between tubes is much smaller than before. Although that being said, there is a tube-rolling thread on the Bottlehead website so you could read through that (http://bottlehead.com/smf/index.php?topic=663.0).

 
Stepped attentuator and choke can be bought off ebay. For film caps, ebay may be a good option. Other options are http://www.partsconnexion.com/, www.hificollective.co.uk/ or https://www.parts-express.com/. Depending on where you are geographically located, you may need to shop around to get the best prices.
 
Regarding how much of a difference they make, I can honestly say that I don't know. My hearing is not bad, but with my DT770s I notice almost no difference and I am not sure whether or not I am imaging these differences. At any rate, modding the Crack is fun, but I ran into diminishing returns from the beginning - a stock Crack that is properly built is still an excellent amp.

 

[Tom-s]

Schottky diodes rectifiers are another worthy upgrade (+-10$).
E80cc/12bh7/5687 switches are another cheap one but not as easy.
With these the FAQ #3 could best be implemented on the VALAB attenuator from the start (more easy when installed from the start).

 

[Solarium]

   
I have not tried any other tubes, but I believe common consensus is that once Speedball is installed, the difference between tubes is much smaller than before. Although that being said, there is a tube-rolling thread on the Bottlehead website so you could read through that (http://bottlehead.com/smf/index.php?topic=663.0).
 
Stepped attentuator and choke can be bought off ebay. For film caps, ebay may be a good option. Other options are http://www.partsconnexion.com/, www.hificollective.co.uk/ or https://www.parts-express.com/. Depending on where you are geographically located, you may need to shop around to get the best prices.
 
Regarding how much of a difference they make, I can honestly say that I don't know. My hearing is not bad, but with my DT770s I notice almost no difference and I am not sure whether or not I am imaging these differences. At any rate, modding the Crack is fun, but I ran into diminishing returns from the beginning - a stock Crack that is properly built is still an excellent amp.

The diminishing returns is exactly what I was thinking about too, especially since I bought it prebuilt with the speedball in a practically new condition for $300. I have no experience in modding the crack at all. Getting both the TS5998 and the 5814a input tube would add about $100 to the amp, which is about 25%. I didn't know about tubes making a smaller difference with the speedball installed, but that's good to know. I'm going to listen to the crack some more and figure out whether I want to continue using it before committing myself to more upgrades. I like the tube sound, but it typically does not go well with EDM, which is 90% of what I listen to. I'm also considering getting the iFi iCAN SE to go along with my iDSD, although I'm completely satisfied with the iDSD amp portion too after EQ'ing.

 

[ChrisR1]

Have any of you fine gentlemen or women compared Sylvania's "vintage" 6AS7G with RCA's 6AS7G in their BH Crack? I love RCA's version, I was thinking about picking up an old Sylvania for rolling or at least backup...

 

[nykobing]

i have one of those Sylvania's someplace and I remember it sounding exactly like an RCA one. I am pretty positive RCA made it.

 

[grausch]

  The diminishing returns is exactly what I was thinking about too, especially since I bought it prebuilt with the speedball in a practically new condition for $300. I have no experience in modding the crack at all. Getting both the TS5998 and the 5814a input tube would add about $100 to the amp, which is about 25%. I didn't know about tubes making a smaller difference with the speedball installed, but that's good to know. I'm going to listen to the crack some more and figure out whether I want to continue using it before committing myself to more upgrades. I like the tube sound, but it typically does not go well with EDM, which is 90% of what I listen to. I'm also considering getting the iFi iCAN SE to go along with my iDSD, although I'm completely satisfied with the iDSD amp portion too after EQ'ing.

My first mod was the VA Labs attentuator. When I received it, the PCB was installed upside down. Luckily by looking at pictures of other builds I realised what the problem was and PB on the Bottlehead forums was very helpful in explaining how to check for in, out and ground. I was a bit nervous installing it, but it worked first time and set me on the path for further upgrades. I then rebuilt the Crack using higher gauge cloth-covered wire.
 
Next upgrades were replacing my input jack and RCAs, then the Schottky diodes, replacing the last resistor in the PSU with a choke, replacing the first two PSU caps with 470uF caps, replacing the final PSU cap with a 270uf a film cap, bypassing the final PSU cap with four Russian cruise missiles.
 
I still have the Speedball waiting (more than a year now) and film caps for the audio path, as well as some bigger Russian cruise missiles for bypassing duty.
 
With the current mods, the biggest changes are a) the effectiveness of the gravity mounted plate has increase tremendously and b) it now takes seven seconds for the audio to fade once I switch off power (was definitely shorter before mods). There may be an increase in bass, but it was impossible to test that by ear. It could also very well be my imagination. Perhaps a set of HD 650s would make the changes more noticeable, but at this point I just enjoy listening to the music.
 
Modding the Crack is a great confidence-builder since it is so easy to work on, but once you add on the cost of components, shipping and import duty you can easily get to the cost of the Mainline. No matter how much you mod the Crack, the Mainline is still the superior amp. Just something to bear in mind. 

 

[q2klepto]

So i received my used Bottlehead Crack w/ Speedball a couple weeks ago, it has a 220v step down transformer as i am in Canada (120v).  Plugged everything in, fired up - tube glow was sexy - but had an extremely loud humming noise.
 
I guess ill be looking at the build and troubleshoot the problem - but wondering if anything i can focus on first, and which pages in the manual i should be looking at?

Thanks!

 

[nykobing]

  So i received my used Bottlehead Crack w/ Speedball a couple weeks ago, it has a 220v step down transformer as i am in Canada (120v).  Plugged everything in, fired up - tube glow was sexy - but had an extremely loud humming noise.
 
I guess ill be looking at the build and troubleshoot the problem - but wondering if anything i can focus on first, and which pages in the manual i should be looking at?

Thanks!

It might be something so simple as a bad tube, do you have other to try. I have tubes that hum in the crack, but are silent in other amps.

 

[JamieMcC]

  So i received my used Bottlehead Crack w/ Speedball a couple weeks ago, it has a 220v step down transformer as i am in Canada (120v).  Plugged everything in, fired up - tube glow was sexy - but had an extremely loud humming noise.
 
I guess ill be looking at the build and troubleshoot the problem - but wondering if anything i can focus on first, and which pages in the manual i should be looking at?

Thanks!

 
I suggest you subscribe to the Bottlehead forum and post in the Crack section you will be able to converse directly with the Bottlehead team and the Cracks designer to help with trouble shooting
 
Edit looks like you already have

 

[ChrisR1]

So I've been enjoying my Crack w/ Speedball that I completed a few weeks ago immensely using Fiio X5->Crack/Sball->Senn 600.  All genres of music are far more engaging and lifelike, and I can listen with relish for hours.  
I've been told that switching to a dedicated DAC such as Schiit bifrost would be another big improvement in my listening experience.  I'm hesitant to do this for the simple reason that I like how easy it is to fire up the system and listen for a little while here and there using the X5 as source.  The improvement in my listening experience is already immensely improved from using the Schiit Vali (accurate, but not very engaging) making me wonder if another big bump in quality awaits me if I pick up a Bifrost.  
Can any of you guys who have a Fiio X5 comment on the difference relative to a dedicated DAC through their Crack/speedball?  It does have Texas Instrument's top-of-the-line DAC chip, but I know that a DAC is more than just the actual chip...
Any guidance would be greatly appreciated! 

 

[adydula]

Stay where you are and enjoy...
A.

 

[audiojun]

So I've been enjoying my Crack w/ Speedball that I completed a few weeks ago immensely using Fiio X5->Crack/Sball->Senn 600.  All genres of music are far more engaging and lifelike, and I can listen with relish for hours.  
I've been told that switching to a dedicated DAC such as Schiit bifrost would be another big improvement in my listening experience.  I'm hesitant to do this for the simple reason that I like how easy it is to fire up the system and listen for a little while here and there using the X5 as source.  The improvement in my listening experience is already immensely improved from using the Schiit Vali (accurate, but not very engaging) making me wonder if another big bump in quality awaits me if I pick up a Bifrost.  
Can any of you guys who have a Fiio X5 comment on the difference relative to a dedicated DAC through their Crack/speedball?  It does have Texas Instrument's top-of-the-line DAC chip, but I know that a DAC is more than just the actual chip...
Any guidance would be greatly appreciated! 

Both The Bifrost 4490 and Multibit is an excellent dac for the crack & HD600. I only compared it with a few dacs such as xonar essence stx, an ebay multibit nos dac, fiio e10. The Bifrost just better, it's a league or 2 above the dacs I tried.

Also running from computer as a source has the advantage of using programs such as JRiver. I highly recommend trying it they have a free 1 month trial. I personally found surround effects on medium with no environment effects awesome for soundstage also the EQ is perfectly done and lossless.

 

[Tom-s]

On the bottlehead forum i found the suggestion of the Gustard X20 DAC.
Here in EU it's about the same price as the Bifrost (the normal one, that is) 
Reading material: http://www.head-fi.org/t/780385/gustard-x20-dac
Might be worth it. Can't tell. 
I'm happy using a M2U.

 

[deserat]

I own the X5 and the Bifrost ( currently multibit but was just Uber ), unfortunately while I own the Crack it's probably still being put in a box so that it can be shipped.  I have however run both the X5 and the Bifrost through the Lyr2 and the hdva 600 ( yes using line out). I do it every so often still just because I like to hear the difference.  In both cases the sound is night and day while driving HD800 and HE 560's.  The first thing you'd notice is the the Bifrost is louder so you can turn the volume down about 1/4 turn on the amplifier.  After that with the multibit anyway, there is a  noticeable difference in soundstage size and mind boggling difference in instrument separation and positioning. It is most apparent in songs that have alot going on, the first song that dropped my jaw in amazement was Tools 10,000 days pt 2, the thunder just became more real and the raindrops because distinctly audible - but orchestral music and even glitch take on a whole new life.  I like the x5 I  use it on the go  with my Momentums ( which I hate ) but  for me anyway it's not even in the same sonic league as the Bifrost. The modi 2 would be better comparison. 

How apparent this will be with the Crack.... I don't know yet. Depends on how resolving the Crack is and on your headphones.   Will loop back once it's assembled and been running for a bit... that'll be a month or so though.