[amcananey]

My experiences trying 12AU7s (and ECC82s), 12BH7s, E80CCs and 6SN7s -- and taking Bottlehead guidance into account -- has firmly convinced me that the best thing to do is to stick with 12AU7s and their ECC82 equivalents. There are plenty of these out there, so you are hardly limiting your ability to roll tubes forever. And you will be using the tubes that the Crack circuit is optimized for.

If your goal is the best possible sound quality, and you don't want to use 12AU7s / ECC82s, then I think you should modify your Crack for the tube type you want to use. For 12BH7s, this means replacing some of the LEDs on the 9-pin socket with resistors. For the 6SN7s, it means replacing the nine-pine socket with an octal socket so you don't need to use an adapter.

This isn't just a matter of convenience, but rather one of performance. I have FOUR 6SN7 --> 12AU7 adapters at home with three different designs from three different manufacturers. They ALL result in unacceptable noise, even when used with 6SN7s that are dead quiet in other amps. And my Crack is dead quiet when used with my various 12AU7s.

Regards,
Adam

 

[brunk]

My experiences trying 12AU7s (and ECC82s), 12BH7s, E80CCs and 6SN7s -- and taking Bottlehead guidance into account -- has firmly convinced me that the best thing to do is to stick with 12AU7s and their ECC82 equivalents. There are plenty of these out there, so you are hardly limiting your ability to roll tubes forever. And you will be using the tubes that the Crack circuit is optimized for.

If your goal is the best possible sound quality, and you don't want to use 12AU7s / ECC82s, then I think you should modify your Crack for the tube type you want to use. For 12BH7s, this means replacing some of the LEDs on the 9-pin socket with resistors. For the 6SN7s, it means replacing the nine-pine socket with an octal socket so you don't need to use an adapter.

This isn't just a matter of convenience, but rather one of performance. I have FOUR 6SN7 --> 12AU7 adapters at home with three different designs from three different manufacturers. They ALL result in unacceptable noise, even when used with 6SN7s that are dead quiet in other amps. And my Crack is dead quiet when used with my various 12AU7s.

Regards,
Adam

 
I have an EH 12BH7, do you find better performance after the proper modification than the 12AU7?

 

[amcananey]

Can't say. I didn't find my 12BH7s to be better than my 12AU7s in an un-modified Crack. The Bottlehead guys recommend modding the Crack if you plan on using 12BH7s. I didn't want to get locked into 12BH7s, so I never made the recommended mod to my Crack.

 

[brunk]

Can't say. I didn't find my 12BH7s to be better than my 12AU7s in an un-modified Crack. The Bottlehead guys recommend modding the Crack if you plan on using 12BH7s. I didn't want to get locked into 12BH7s, so I never made the recommended mod to my Crack.

 
Yeah, I am debating if i should put the resistors in first thing and save the LEDs for later, but i just dont know. Perhaps if there is a Mouser/Digi-Key part number for those LEDs i would roll a couple times and see what seems best. Do you know the part number by chance?
 
EDIT: A quick search turned up the LED as HLMP-6000

 

[amcananey]

Those LEDs are not fun to install. In fact, they might even be the worst part of the build. They are relatively delicate and you're working in a small, crowded area of the amp. My desire to muck around with that socket multiple times is exactly zero.

You may be more skilled and/or patient, but I just don't have the temperament for it...

Best,
Adam

 

[Nowhere]

here's my reaction to listening to the bottlehead crack + speedball on the hd600 for the first time. (from the hd600 thread). just got mine and listened to a few songs on it. very satisfied.
 
first reaction follows:
 
-------------------------
 
OMG!!! just received the bottlehead crack + speedball i ordered, i've never thought music could sound this good.. i started to tear up as a unstoppable reaction to the experience, i almost can't listen to it as i feel i'm unworthy to hear these sounds that are floating around me so ethereal. BY THE STARS! literally taking my breath away.
 
listened to around 5 songs on it so far and just wow, wow, wow! mindblowing.
 
don't even know how to describe it except heavenly or ethereal.
 
listening to Sugar Ray - Spinning Away from the beach soundtrack atm and it's transcendent. :O
 
just had to vent somehow to my reaction from just now hearing this for the first time.
 
humbled.

 

[amcananey]

LOL! HD600 + Crack is indeed sublime, and amazingly cheap for what you get. That specific combo easily outperforms most other amp + headphone combos costing many times more.

Congratulations and enjoy it!

Best regards,
Adam

 

[Nowhere]

indeed, sometimes things actually live up to the hype.
couldn't be happier with the sound i'm hearing from that combo.

 

[whatthedac]

Nowhere, that's the experience I'm hoping for.  I ordered the HD 650's about a month ago with the C5 (to hold me over until the Crack ships).  My friend asked me how the combo was and I said, "I definitely notice a difference when I listen to my 650's for a while and then put on my other (inexpensive) headphones -- they now sound muffled.  But, I was expecting something more mind blowing."
 
I think the crack will be what I'm looking for, but I ordered it without the speedball.  A few weeks later I then saw it go on sale with the speedball (for only $25 more than what I paid) and was tempted to cancel my existing order and get the deal, but I thought I'd support the small biz.  I can always get it later and will now have something else to look forward to.

 

[Nowhere]

  Nowhere, that's the experience I'm hoping for.  I ordered the HD 650's about a month ago with the C5 (to hold me over until the Crack ships).  My friend asked me how the combo was and I said, "I definitely notice a difference when I listen to my 650's for a while and then put on my other (inexpensive) headphones -- they now sound muffled.  But, I was expecting something more mind blowing."
 
I think the crack will be what I'm looking for, but I ordered it without the speedball.  A few weeks later I then saw it go on sale with the speedball (for only $25 more than what I paid) and was tempted to cancel my existing order and get the deal, but I thought I'd support the small biz.  I can always get it later and will now have something else to look forward to.

 
hopefully you obtain a similar experience as i have... try not to expect to be blown away or that it will be the most amazing thing ever because oftentimes if you do that even if something is great it becomes a letdown. i knew it would be great but kept to a realistic expectation and just kind of let it be what it was going to be.
 
mine has the speedball, some minor upgrades here and there from the previous owner and i'm using a great rca cable so i can't say if it will be the exact same experience without being the exact set up as i have. and since i never heard the basic crack unit i can't compare if mine is that different.
 
well, anyway i hope it works out for you.. if it's even close to what i'm hearing from my set up i can't imagine anyone being disappointed.

 

[FlySweep]

One the really great things about the Crack + SB is that not only does it sound fantastic with the 600/650, if you're ever inclined to move from the HD6x0 to the HD800.. there's no need to fret about finding a suitable amp for the Senn flagship: the Crack sounds TERRIFIC w/ the HD800.  I've heard the HD800 on a number of well regarded amps.. and, IME, the Crack + SB remains one of the best pairings, regardless of price.

 

[amcananey]

One the really great things about the Crack + SB is that not only does it sound fantastic with the 600/650, if you're ever inclined to move from the HD6x0 to the HD800.. there's no need to fret about finding a suitable amp for the Senn flagship: the Crack sounds TERRIFIC w/ the HD800.  I've heard the HD800 on a number of well regarded amps.. and, IME, the Crack + SB remains one of the best pairings, regardless of price.

 


+1

 

[W0lfd0g]

I got over the GEC 6AS7G phase. Good sounding tube but definitely not worth the asking price on ebay nowadays.

To each their own. For some it's cables. For me it's tubes. I hope my GEC brown base phase continues.

 

[skeptic]

  One the really great things about the Crack + SB is that not only does it sound fantastic with the 600/650, if you're ever inclined to move from the HD6x0 to the HD800.. there's no need to fret about finding a suitable amp for the Senn flagship: the Crack sounds TERRIFIC w/ the HD800.  I've heard the HD800 on a number of well regarded amps.. and, IME, the Crack + SB remains one of the best pairings, regardless of price.

 
+2 

 

[trentrosa]

I notice lotsof folks upgrade the capacitors in their crack w/ sb, and was just wondering what the main advantages are and where I could possibly buy some in the future?