[krikor]

 
My preferred sound is clear and natural and realistic. Being used with HD650 and HD600.

I know there are endless threads about the HD650 vs. HD600, but sifting through those is daunting, and since you brought it up...
 
What is your opinion of the two with the Crack? Noticeable differences? I've got the HD650 but have been thinking about picking up the HD600 to explore its character as well. I wonder if there is as strong a difference as there is between the Beyerdynamic DT990 and DT880.

 

[FunyunBreath]

  I'm curious... do you happen to what's the difference between the 6080WC and 6080WB? Sonically or otherwise. My Crack came with the Sylvania JAN 6080WC. Thanks!

 
I've wondered that myself actually. Not sure what the differences between WA WB and WC are.
 
My first crack kit from 3 years ago came with a GE 6080WA. This new one came with the Sylvania 6080WB. The GE tube may just be old and dying but it sounds muddy and flat in comparison to the Sylvania.

 

[Maxhawk]

Alternate output tubes to try that aren't as expensive as the 5998:
 
Bendix/Chatham 6080WB graphite plate (around $50-$60 if you wait for a good deal on ebay) -- very musical, good imaging, more bass than the 5998 (as are most equivalent tubes). 
 
Sylvania Gold Brand GB6080 ($10-$30 on ebay) -- luscious, more creamy midrange than standard 6080
 
Mullard CV2984 ($40-$80) -- Seems more analytical with tighter bass than my stock GE 6080

 

[JamieMcC]

  Alternate output tubes to try that aren't as expensive as the 5998:
 
Bendix/Chatham 6080WB graphite plate (around $50-$60 if you wait for a good deal on ebay) -- very musical, good imaging, more bass than the 5998 (as are most equivalent tubes). 
 
Sylvania Gold Brand GB6080 ($10-$30 on ebay) -- luscious, more creamy midrange than standard 6080
 
Mullard CV2984 ($40-$80) -- Seems more analytical with tighter bass than my stock GE 6080

 
You might like to add these to the list the GEC 6080 $35ish Svetlana Winged C 6H13C $10ish and Chatham 6as7g $15-20ish

 

[Zashoomin]

To those inquiring about the Khozmo attenuator, it came in last week and I have been playing around with it for a little.  It sounds wonderful, measures correctly, looks beautiful, and everything seems to be working swimmingly.  Mine came in a lovely blue color and I think that with the new mkII design that there will be less problems when compared to the mkI.  

 

[FunyunBreath]

This is an excellent tube combo to try out:
 
-Amperex 12au7 ( Holland made, branded for Hewlett Packard)
-5998
Compared to other combos I've been testing the mids are just absolutely glorious. Very full bodied with a rumbling low end. Highs are crisp and clear without being to sharp. 

 
 
This particular Amperex is usually super cheap since it's branded HP. I think I picked it up on Ebay for like $18.
 

 

[lextek]

Curious which tube do people find have the most affect on sound? Power or input?

 

[nailbunny7]

Curious which tube do people find have the most affect on sound? Power or input?

My instinct would have to say input 'should' have the most effect on sound.

 

[NightFlight]

My instinct would have to say input 'should' have the most effect on sound.

I thought the same.

When I was guided on this question the clear cut answer was the output tube. That is not to say that input tube changes have no effect on tonal signature.

If you are deciding which to start with, then my experience with the crack would be to start with the output section.

 

[sasquatch98]

Right now I'm listening to a Darkvoice 336se with my HD580s and loving it even with the stock tubes (new ones on the way though). How does the crack compare to the 336se sound quality wise? I'm interested in the crack since it would be easier to upgrade or repair in the future it seems to me although I don't have any complaints about the 336 so far. 

 

[FunyunBreath]

I thought the same.

When I was guided on this question the clear cut answer was the output tube. That is not to say that input tube changes have no effect on tonal signature.

If you are deciding which to start with, then my experience with the crack would be to start with the output section.

 
I would agree with you on that. I've noticed power tubes seem to have a much bigger impact on soundstage, dynamics, EQ, and bass impact. The input tubes are a much more minor difference in comparison. Even switching between completely different tube types like 12au7, 12bh7, and 6sn7.

 

[NightFlight]

   
I would agree with you on that. I've noticed power tubes seem to have a much bigger impact on soundstage, dynamics, EQ, and bass impact. The input tubes are a much more minor difference in comparison. Even switching between completely different tube types like 12au7, 12bh7, and 6sn7.

 
It is less so than the output section for sure. But I've seen a lot of people discounting the effect the input tube has on the signature when I've found this to be not true at all.  I've found my favorite so far to be a tung-sol 12BH7, which requires some minor circuit changes to the input C4S boards to get the most out of it. But without those circuit changes dropping in a 12BH7 can result in a bit of a change for the worse. 

 

[FunyunBreath]

What effect do these circuit changes have on on the 12bh7's sound?
 
I've been running 12bh7's in my speedball'd crack for quite some time now and they sound great to me. Similar to a 6sn7 but without the A/C heater noise. Curious what the changes would be to make them sound even better.

 

[NightFlight]

  What effect do these circuit changes have on on the 12bh7's sound?
 
I've been running 12bh7's in my speedball'd crack for quite some time now and they sound great to me. Similar to a 6sn7 but without the A/C heater noise. Curious what the changes would be to make them sound even better.

 
Tightens up the bottom end and just dials in the voltage seen on Terminals 1 and 5. You'll want to see ~75-85v there.  There's a very active input tube mod thread on the BH forums where you'll find the info: http://bottlehead.com/smf/index.php?topic=5989.0
 
Awesome thread there. There's a recommendation to upgrade the transistors on the input C4S boards to which should be done as well. Jumping to the end you'll find Maxhawk designed and had printed a whole new CS4 board to accommodate easier rolling! 

 

[FunyunBreath]

Awesome thanks for the links!
 
Is there any harm in using 12bh7's without doing these mods? I had been under the impression that with the speedball in place it was safe to use them, just want to make sure though.