Crack;Bottlehead OTL
Apr 11, 2014 at 4:01 PM Post #4,622 of 12,335
  Looks great. How does it sound?


Based only on couple of hours so far to me its almost like a cross between a 5998 and the Mullard 6080wa. It has a big, bold & fast sound which is punchy and dynamic that's for sure.
 
Its darker weightier and more tubey sounding than a 5998 while keeping some of its refinement but not quiet with the same levels of resolution and finesse as the 5998. There is more slam and punch to the bass!
 
Sound stage reminds me of the Mullard its got that detached holographic surreal-ness to it with lots of air and separation. Its certainly stands out as being different to the tubes I have tried so far.
 
Apr 11, 2014 at 5:06 PM Post #4,624 of 12,335
I love how Bendix 6080 tubes w/ graphite plates look: very rugged and tough... they've got a nice weight to them, too (in hand and in sound).. they're a nice compliment to the more elegant-looking, ST-shaped 5998.  Terrific dynamics.. wonderful bass.. and a great sense of smoothness.  Not quite as transparent and spacious as the 5998.. but the Bendix 6080 I have (with slotted graphite plates) has a deeper stage that's quite addictive to listen to.
 
Apr 11, 2014 at 5:15 PM Post #4,626 of 12,335
Funny hearing about these, as my first kit build in the 90's was a long defunct amp kit from World HiFi that used a 6080. I happened across several of those graphite plate tubes at some estate sale or other, and tried them out in that very first kit amp. I think I still have a stash of them somewhere.
 
Apr 11, 2014 at 6:53 PM Post #4,627 of 12,335
Few weeks ago I was about  to paint the transformer and when trying to unscrew it (I had my headphones on and didn't here it cracking )
I used my kung-fu grip and totally snapped the six lug terminal strip that's holding the transformer  ..I was getting  worry since it looked like I was going to wait weeks or longer to get the replacement ..I was blown away with the BH support ! ,the parts ("and then some")  came in yesterday and I'm really getting close to finishing my sweet El Crack ,Thank you Bottlehead ,especially Doc B. !
P.S. love the badge
 

 
 
 
Quote:
 
Based only on couple of hours so far to me its almost like a cross between a 5998 and the Mullard 6080wa. It has a big, bold & fast sound which is punchy and dynamic that's for sure.
 
Its darker weightier and more tubey sounding than a 5998 while keeping some of its refinement but not quiet with the same levels of resolution and finesse as the 5998. There is more slam and punch to the bass!
 
Sound stage reminds me of the Mullard its got that detached holographic surreal-ness to it with lots of air and separation. Its certainly stands out as being different to the tubes I have tried so far.

I have been playing with my "red bank" for few weeks and found the answer ..,at first i couldn't figure out why this candle didn't sound right on Crack when I got it ,tried my DV336SE and loved it ,why ?...try to pair it with  6SN7 
wink.gif

 

 
P.S. try Savant with this tube ...your might like it to much ,lol
 
Apr 12, 2014 at 12:30 AM Post #4,629 of 12,335
I finally got around to changing the volume control in my Crack; something which I had only meant to do for the last several years.. sigh. I went with a Valab 23-position 50k-ohm ladder stepper. Two thoughts:

1) This is easily the most craptastic switch I've ever touched.

2) I really should have done this a LONG time ago. I wasn't expecting much and at first it seemed like I was right. Then I realized how much it had changed the ability to separate things from each other (hear choral voices as individuals, etc). I can only assume it reduced either noise or distortion to achieve this as the tonal balance and range didn't change at all.
 
Apr 12, 2014 at 1:40 AM Post #4,630 of 12,335
A few pages ago I wrote about my crack which makes a background hum/noise. I re-braided the signal inputs with furutech copper cable really tight and the noise is still present. Is it possible that some of the tubes introduce a breezing sound? I have been using the same tubes for almost three years.
 
By the way, installing a new volume attenuatior seems like a really nice thing to do. If I can manage to fix my noise that will be next on my list! 
 
Apr 12, 2014 at 4:54 AM Post #4,631 of 12,335
  what do you guys think of crack vs project ember ? which is better? I can't find very much reviews on it.. 

 
All of those garage amps are hybrids, not all tube designs. They use a tube for the preamp but solid state for the output sections. They are all rip-off's of either the Bravo amps or a design posted on a DIY audio form some 4-5 years ago, with supposedly better parts. I've never heard them nor will I ever buy one, because they're way too expensive for what they are, in my opinion. For the money, a Bottlehead Crack is a clearly superior choice.
 
Apr 12, 2014 at 3:59 PM Post #4,632 of 12,335
Do you have to make any internal modifications to the crack to use 6SN7 as the driver tube or does it only require a socket adaptor?

 
6SN7's are nominally drop in equivalents, and some users have reported great success simply by using ebay adapters.  Others of us have had real trouble with plainly audible noise when using these adapters.  I've tried 2 different adapters (one user reported trying 4 different adapters without success), and both had pretty significant noise issues.  As discussed here and on the bh forums, the theory is that these issues could be resolved by using a wallwart to run dc to the 6sn7's heaters.  They are apparently more prone to noise than 12au7's when supplied with ac.  But I don't know anyone who has actually taken the time to try this mod and report back.  Hope that helps!
 
Apr 12, 2014 at 4:21 PM Post #4,633 of 12,335
   
6SN7's are nominally drop in equivalents, and some users have reported great success simply by using ebay adapters.  Others of us have had real trouble with plainly audible noise when using these adapters.  I've tried 2 different adapters (one user reported trying 4 different adapters without success), and both had pretty significant noise issues.  As discussed here and on the bh forums, the theory is that these issues could be resolved by using a wallwart to run dc to the 6sn7's heaters.  They are apparently more prone to noise than 12au7's when supplied with ac.  But I don't know anyone who has actually taken the time to try this mod and report back.  Hope that helps!

I don't think the adapter is the source of noise (I have 2 and both work very well ) ,6SN7s are known for microphonics ,hum,etc ,out of the bunch of 6SN7s I have, some have slight hum and some don't and they are dead silent ,if I would have to recommend one tube that would most likely work well it would be   VT231 - NOS TUNG SOL 6SN7 - 1940's - 6SN7GT TUNG SOL (black bottle),this were reported for the last few years to be very quite on a lot of different tube amps 
EDIT; I have few that have very bad hum on DV336SE but not on Crack 
 
Apr 12, 2014 at 5:38 PM Post #4,634 of 12,335
I do hear good things about VT231's but my comment above was simply repeating what bottlehead's engineers have noted several times on the bh forums.  Your red text misses the critical final clause - that 6sn7's are more sensitive with respect to the type of power delivered to their heaters.  The crack supplies AC when DC is the ideal for 6sn7's in particular.  
 
Certain tubes may well be less prone to this, but Adam and I both tried many different tubes and the noise ranged from annoying to terrible.    
 
Apr 12, 2014 at 5:44 PM Post #4,635 of 12,335
   
All of those garage amps are hybrids, not all tube designs. They use a tube for the preamp but solid state for the output sections. They are all rip-off's of either the Bravo amps or a design posted on a DIY audio form some 4-5 years ago, with supposedly better parts. I've never heard them nor will I ever buy one, because they're way too expensive for what they are, in my opinion. For the money, a Bottlehead Crack is a clearly superior choice.

Thank you for this information, I guess that leaves me with the choice between Valhalla and the BH, the Valhalla just seem like the safer way to go DYI wise :\ 
I am looking for something that will really brings out the bass capabilities of the HD650.. I heard them with Naim DAC-V1 it was freaking amazing, only if I was richer :frowning2:
 
Since the Naim is a SS do you think it will be hard to find a Tube amp with same sound signature bass wise? 
 

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