[JamieMcC]

  My issue is definitely not coming from the tube. If someone is in the central florida area please let me know as I am willing to pay a fee to have mine checked.

 
Did you know Bottlehead offer a fixed fee repair service.
 
http://bottlehead.com/?product=repair-service

 

[Doc B.]

It's probably just a bad solder joint. Try reflowing the joints and yeah, you can get help on the Bottlehead Forum.

 

[adydula]

There are a lot of 5963 NOS tubes that work very very well with the crack...for about $15 or so a matched pair!
 
Alex

 

[music max]

  There are a lot of 5963 NOS tubes that work very very well with the crack...for about $15 or so a matched pair!
 
Alex

Wow that seems like a pretty good deal presuming that they sound decent with the Crack.

 

[adydula]

5963's are a good 12AU7 substitute....I have several and they all sound great..the price is not too crazy but that will probably change with time.
 
Alex

 

[krikor]

Went to the estate sale of a former electronics repair man and audio engineer over the weekend, and picked up a bunch of 12AU7 tubes and a couple of "Winged C" 6AS7 tubes. May have overpaid, but it went to a good cause. Not sure if what I've got is any good, and I don't have any way of testing other than giving them a listen, though it will be fun trying these out. Gave one of the 6AS7 a listen with an older looking Mullard 12AU7 (says Made in Great Britain), but there was some background noise/hiss/rushing. Swapped it out for an RCA clear top which on a brief listen sounded OK, albeit a bit subdued and lacking detail, however the noise was gone so it must have been the Mullard and not the 6AS7 with the problem. Then swapped in another Mullard that looks a bit more recent (says Made in England) and that was quite nice sounding. Can't wait to have some time to explore all these further.
 

 
Sylvania, Tung-Sol, Telefunken and Mullard... 

 
Misc. unmarked long plates

 
Four unmarked short plates

 
Some strange ones:

 
Clear top RCA looks like it might have some damage on the top (not sure if this could affect sound)

 

[DDDamian]

Dude, nice score happy rolling....

 

[JustinBieber]

Is it okay to use 12au7a tubes in the Crack instead of 12AU7?

 

[adydula]

Yes..check the tube rolling thread over at Bottlehead...
Alex

 

[JustinBieber]

Has anyone added carbon fiber wrap to the top base? Any problems with heat from the tubes?

I'm thinking of getting 3M wrap, black stain for the wood, and some smoked tubes. It will look great.

 

[JamieMcC]

Has anyone added carbon fiber wrap to the top base? Any problems with heat from the tubes?

I'm thinking of getting 3M wrap, black stain for the wood, and some smoked tubes. It will look great.

 
I would expect a good quality automotive vinyl such as 3M would easily cope with the moderate temperatures the Cracks top plate reaches.
 
A while back I was looking at doing something like the link below for a Crack build as you can get the thermal chromate liquid crystal in vinyl wrap sheet form now and can cut it to suit.
I tried out a sample strip and it worked well the only reason it didn't proceed was the vinyl came in two temperature ranges and all the 30-60 degree C product was out of stock and only the lower 20-35 degree C was available which meant when at working temperature the vinyl had fully changed to a solid colour all over which was not what I was looking for. 
 
https://www.youtube.com/watch?v=peewxRlNVqg

 

[JustinBieber]

Thanks. I just ordered a sheet. Will update when I install it. 

 

[DDDamian]

  Thanks. I just ordered a sheet. Will update when I install it. 

If it's a real carbon-fiber sheet you have no worries - there's some beautiful work done with that in the gallery over at the BH forum.

 

[moriez]

Hey guys. Need a little help.
 
When I first received my pre-build Crack the bell end was slightly corrosive. Don't ask me why or how. I took it off to sandpaper it with non too good result so I recently bought a nice black replacement. What I remember from taking the bell end off and especially trying to screw it back on, is that it was SUPER tedious task that I'd never repeat in my life! Well, it must be done. The solution may seem obvious to some of you but what is the easiest way to replace the bell end for an unexperienced DIY-er? Special attention anywhere?

 

[Ritchiepurple]

Hi guys,
 
I recently tried installing the speedball upgrade to my bottlehead crack but now the damn thing wont work at all. I have asked on the bottlehead forum and they provided tons of help but I just can't seem to fix it. Is there anyone UK based on the forum that would be willing to repair it for me and getting it into full working order? I would of course be willing to pay.