[silverhead]

I wish I knew how to take it apart.. But I think it's glued together.  Otherwise I'd fix the connection mix up.

 

[mink70]

I've owned a Crack that I bought from a fellow Head-Fier for several weeks, and I have to say that my initial impression with the HD800 and HD650 was not great. Compared to my JDS Labs  portable C421 op-amp powered unit (about $170), the Crack sounded bassy, rolled off on top, slow and lacking in detail—poky and boring. This was with a Sylvania 12BH7 driving a Tung Sol 6080. What I've discovered since is that the Crack is more responsive to tube rolling than any piece of equipment I've ever heard. Which is to say, unbelievably so.
 
Since then: I tried plenty of 12AU7s—Telefunken (my fave), Amperex bugle boy and globe, Mullard, RCA cleartop, EH Russians—then tried 12BH7s. Among those, RCA long black plate was best, with a clear, analytical, extended sound. So I got the Chinese adapter and tried a Sylvania brown-base 6SN7GT. The sound came alive for the first time. Dynamic, involving. Then the Tung Sol 5998 (actually a Chatham 2399) arrived, which I liked a lot. More air, bigger soundstage, easier, more fun. But it didn't love the Sylvania. So I tried all the input tubes again. The 12AU7s were okay (the cleartop sounded nice, but very midrangey and rolled), the RCA 12BH7, again, offered an incredibly detailed and wide-band sound, but a little cold and uninvolving. So today I tried a Raytheon VT-321. Some of the best sound I've ever heard, anywhere, anytime. Burnished, dynamic, intense detail, cavernous acoustic, and so engaging. A sound so compelling it's almost mysterious. All kinds of reverberant cues are audible—singers breathing, people moving—and there's a palpable sensation of air compressing in the microphone. Details like the spittiness of a trumpet or the wood of a drum rim are now completely audible. All of this makes listening fun rather than just impressive in an audiophile kind of way. Was going to try a Tung Sol round-plate 6SN7 but no desire to mess around with the amp anymore. The improvement from stock is simply amazing. 
 
Now if I could only figure out how to decrease the gain a little. Turning down the digital volume control in Audirvana is probably not a great idea. Oy.

 

[EraserXIV]

Nice, thanks for the impressions. I've been looking to roll my input tube for a while but can't seem to decide which direction I want to go. Was going to go for the Telefunken but the 6SN7's seem pretty interesting. How did the Tele pair with the 5998?

 

[liamstrain]

Quote:

I wish I knew how to take it apart.. But I think it's glued together.  Otherwise I'd fix the connection mix up.

 
Try warming it up a bit - depending on the type of glue used, you might get enough flexibility to crack it open. 

 

[Cryok95]

Finally managed to get my speedball and other upgrades soldered in today.

It sounds amazing. Really can't believe the details. Gonna roll a RCA 12bh7 black plate tomorrow

Pics to come

 

[skeptic]

I've owned a Crack that I bought from a fellow Head-Fier for several weeks, and I have to say that my initial impression with the HD800 and HD650 was not great. Compared to my JDS Labs  portable C421 op-amp powered unit (about $170), the Crack sounded bassy, rolled off on top, slow and lacking in detail—poky and boring. This was with a Sylvania 12BH7 driving a Tung Sol 6080. What I've discovered since is that the Crack is more responsive to tube rolling than any piece of equipment I've ever heard. Which is to say, unbelievably so.

Since then: I tried plenty of 12AU7s—Telefunken (my fave), Amperex bugle boy and globe, Mullard, RCA cleartop, EH Russians—then tried 12BH7s. Among those, RCA long black plate was best, with a clear, analytical, extended sound. So I got the Chinese adapter and tried a Sylvania brown-base 6SN7GT. The sound came alive for the first time. Dynamic, involving. Then the Tung Sol 5998 (actually a Chatham 2399) arrived, which I liked a lot. More air, bigger soundstage, easier, more fun. But it didn't love the Sylvania. So I tried all the input tubes again. The 12AU7s were okay (the cleartop sounded nice, but very midrangey and rolled), the RCA 12BH7, again, offered an incredibly detailed and wide-band sound, but a little cold and uninvolving. So today I tried a Raytheon VT-321. Some of the best sound I've ever heard, anywhere, anytime. Burnished, dynamic, intense detail, cavernous acoustic, and so engaging. A sound so compelling it's almost mysterious. All kinds of reverberant cues are audible—singers breathing, people moving—and there's a palpable sensation of air compressing in the microphone. Details like the spittiness of a trumpet or the wood of a drum rim are now completely audible. All of this makes listening fun rather than just impressive in an audiophile kind of way. Was going to try a Tung Sol round-plate 6SN7 but no desire to mess around with the amp anymore. The improvement from stock is simply amazing. 

Now if I could only figure out how to decrease the gain a little. Turning down the digital volume control in Audirvana is probably not a great idea. Oy.

Thanks for the impressions on the raytheon tube. That's one I've always wanted to try and just may have to pick one up now.

As far as reducing the volume (aka padding the pot), take a look at www.goldpt.com/mods.html

 

[dsound]

+1.  The Crack definitely responds well to tube upgrades.  My tube-rolling path went from stock (Sylvania 6080) >RCA 6AS7G>Chatham 5998.  
 
The RCA 6AS7G produces such a wonderful musical experience.  Very laid-back and relaxing.
 
In my limited experience with the 5998's, they retain the musicality of the RCA's and add a sparkle to the highs that are really engaging.  Also, the bottom end seems to gain additional tightness and detail.
 
My only regret is that I didn't get into this hobby 2 years ago.. when 5998's were much cheaper.. my wallet hurts.
 

Spoiler: Spoiler

 
Quote:

I've owned a Crack that I bought from a fellow Head-Fier for several weeks, and I have to say that my initial impression with the HD800 and HD650 was not great. Compared to my JDS Labs  portable C421 op-amp powered unit (about $170), the Crack sounded bassy, rolled off on top, slow and lacking in detail—poky and boring. This was with a Sylvania 12BH7 driving a Tung Sol 6080. What I've discovered since is that the Crack is more responsive to tube rolling than any piece of equipment I've ever heard. Which is to say, unbelievably so.
 
Since then: I tried plenty of 12AU7s—Telefunken (my fave), Amperex bugle boy and globe, Mullard, RCA cleartop, EH Russians—then tried 12BH7s. Among those, RCA long black plate was best, with a clear, analytical, extended sound. So I got the Chinese adapter and tried a Sylvania brown-base 6SN7GT. The sound came alive for the first time. Dynamic, involving. Then the Tung Sol 5998 (actually a Chatham 2399) arrived, which I liked a lot. More air, bigger soundstage, easier, more fun. But it didn't love the Sylvania. So I tried all the input tubes again. The 12AU7s were okay (the cleartop sounded nice, but very midrangey and rolled), the RCA 12BH7, again, offered an incredibly detailed and wide-band sound, but a little cold and uninvolving. So today I tried a Raytheon VT-321. Some of the best sound I've ever heard, anywhere, anytime. Burnished, dynamic, intense detail, cavernous acoustic, and so engaging. A sound so compelling it's almost mysterious. All kinds of reverberant cues are audible—singers breathing, people moving—and there's a palpable sensation of air compressing in the microphone. Details like the spittiness of a trumpet or the wood of a drum rim are now completely audible. All of this makes listening fun rather than just impressive in an audiophile kind of way. Was going to try a Tung Sol round-plate 6SN7 but no desire to mess around with the amp anymore. The improvement from stock is simply amazing. 
 
Now if I could only figure out how to decrease the gain a little. Turning down the digital volume control in Audirvana is probably not a great idea. Oy.

 
 

 

 
 

 

[mikek200]

Quote:

 
 
My 6SN7 to 12AU7 adapter(s) showed up from China finally.   The first one (nice, gold looking one) doesn't work.   The second one that showed up does work, however.
 
Do you run the risk of toasting the transformer by using this setup with no other modifications?
 
My unprofessional opinion is that compared to my RCA clear top 12AU7, the  GE and HP 6SN7 tubes I bought cheaply, both sound nice.   I'm getting more output out of them (louder in the headphones at the same volume setting) than 12AU7 tubes.
 
This is my opinion about how the sound has changed:  Less sibilance out of 'S' words, as if maybe the high end is more compressed.  Boomier bass at the 80ish-150hz range which is somewhat annoying.   But otherwise, stereo separation seems to be slightly wider and the sound is a bit more tight and punchy.  Sort of like taking a little hit of nitrous oxide where the whole world feels a bit more refreshing, rubbery, and springy.  Like being thrown into a padded cell after winning the lottery..   I'm not sure I'm good at describing what I'm hearing, but I think the 6SN7 tube can make the hairs on the back of your neck stand up better with some songs than the 12AU7.  
 
It looks weird having one jammed into the front of the amplifier though.   I haven't yet researched what brands or models of the 6SN7 are desirable.  I paid 5 bucks for this pair.  Both are made by GE (one was made by GE for HP.)  So they look identical and sound identical to my ears.  
 
Does anyone have the pinout so I can figure out why the nicer looking one is broken?
 
By the way, this is the one that doesn't work:
 

 
 
It's got a nice ceramic top with gold plated pins and sockets.
 
Meanwhile, this one works fine
 

 
 
It looks to be of lesser quality, but it works... It also costs less on ebay.     I'm trying to figure out how to take the white one apart, but I think it's expoxied together. 
 
And since I'm bored, I figured out the pinout combos of both adapters.  The 'nicer' looking one has two mixed up connections:
 

 
Do you happen to have the link,to the second adapter,or,maybe the exact name.
Unfortunately,I ordered the first one...might need a backup
 
Great post-thank you,excellent info.
 
Mike

 

[silverhead]

Here's the link to the auction.  Multiple are available.  This is also the best price I found:
 
http://www.ebay.com/itm/320659633166

 

[Utopia]

I'm getting interested in trying to build one of these for my Beyerdynamic T1s, but I'm wondering it the Crack is perhaps a little bit too bright for those? As I've understood it, it's not quite as warm-sounding as the Woo amps or Darkvoice/La Figaro, and the T1 can definitely use some added warmth. Has anyone tried that combination? 

 

[TheKillerPiglet]

Quote:

I'm getting interested in trying to build one of these for my Beyerdynamic T1s, but I'm wondering it the Crack is perhaps a little bit too bright for those? As I've understood it, it's not quite as warm-sounding as the Woo amps or Darkvoice/La Figaro, and the T1 can definitely use some added warmth. Has anyone tried that combination? 

Yes, it is a top notch combo. Not bright at ll, gives the T1 some much needed body without sacrificing precision. I really enjoy it with the humble RCA 6AS7G and 12bh7 tubes. This is a very warm combination. The Crack can easily sound warmer than the 339 (which I also own) while the 339 can easily sound sharper than the Crack. Much depends on the tubes.
 
I have tried countless tube combinations in both amps, including 6sn7's in the Crack and EF80 types in the 339. They are both highly enjoyable amps. I do not think you can go wrong.
 
A couple of things to keep in mind:
 
- if you are planning on picking up HE500's then the 339 is your choice. It drives them nicely, listening to this combo right now (RCA Red 6sj7's, Sylvania 6080WC's in amp, Bugle Boy 6992's pinched waist in DAC).
 
- the 339 needs twice as many tubes, so twice as much money to roll. If you are going to stick to 600 ohm T1's, or 300 ohm Senns (the 650's are just plain seductive on these amps) then I'd go the Crack route.
 
Another thing to keep in mind: they both share the same power tubes....
 
 
KP

 

[dsound]

Listening to my just-completed (5minutes ago) Speedballed Crack.. Very impressed with the improvements in all frequencies.  Great job Doc!
 

 

[elwappo99]

Quote:

Listening to my just-completed (5minutes ago) Speedballed Crack.. Very impressed with the improvements in all frequencies.  Great job Doc!
 

 
Congrats on the build! How about some pics?

 

[Doc B.]

Quote:

 Great job Doc!
 

Thank you. We continue to receive many Crack kit orders every day. The crew just got another good sized batch of 6080 tubes in and I believe another week or two worth of orders will begin packing today and shipping very soon.

 

[dsound]

Quote:

 
Congrats on the build! How about some pics?

 
Sure 

 (go Bruins).  Please excuse the rats-nest of wires.
 
Does anyone know if there's is there a burn-in period for the Speedball?