Crack;Bottlehead OTL
Mar 14, 2013 at 1:28 AM Post #1,606 of 12,335
When a tube is approaching its threshold for its mmhos rating, what changes are to be expected? Does the tube sound the same until it fails, or are there noticeable changes that occur as it runs its course?
 
Mar 14, 2013 at 1:32 AM Post #1,607 of 12,335
Tonight when I got home from work, both of my eBay tubes had shown up.  I bought an RCA 6AS7G tube that tested 95/95 and an RCA 12AU7A (clear top) tube that tested 101/102.    It looks awesome with the shouldered tube in there.  The musical aspect of the amp is better.  Stereo separation is wider and the sibilant sounds are handled better.   The only downside is that I hear a 60hz hum out of the power tube and if you pick the amp up and move it around, you get all sort of harmonics out of that tube.   If you tap your finger on the table you hear it through the headphones.  Much like a turntable that is not isolated.
 
Is the 60hz hum a function of the tube or the filtering capacitors?  (could have something to do with my transformer mounted low?)
 
The 6080 tube doesn't behave this way and is quiet.   But, the 6AS7G sounds better while music is playing.   The push and shove of analog parts swapping I guess.   Some photos of my rig tonight:
 

 
 
 

 
 
 

 
 
 

 
 
 
I'm sure everyone has seen photos like this a million times by now, but I'm loving it as a noob.  Laying on the livingroom floor staring into space while listening to music.
 
Mar 14, 2013 at 2:44 AM Post #1,608 of 12,335
For me the input tube was the hum culprit - not the power tube. The microphonics are a different issue - it shouldn't be that sensitive. Did you only get one 6AS7G - it could just be a bad tube... 
 
Mar 14, 2013 at 4:56 AM Post #1,609 of 12,335
Originally Posted by silverhead /img/forum/go_quote.gif
 
Tonight when I got home from work, both of my eBay tubes had shown up.  I bought an RCA 6AS7G tube that tested 95/95 and an RCA 12AU7A (clear top) tube that tested 101/102.    It looks awesome with the shouldered tube in there.  The musical aspect of the amp is better.  Stereo separation is wider and the sibilant sounds are handled better.   The only downside is that I hear a 60hz hum out of the power tube and if you pick the amp up and move it around, you get all sort of harmonics out of that tube.   If you tap your finger on the table you hear it through the headphones.  Much like a turntable that is not isolated.
 
Is the 60hz hum a function of the tube or the filtering capacitors?  (could have something to do with my transformer mounted low?)
 
The 6080 tube doesn't behave this way and is quiet.   But, the 6AS7G sounds better while music is playing.   The push and shove of analog parts swapping I guess.   Some photos of my rig tonight:
 

 
Bigger: http://farm9.staticflickr.com/8247/8555716845_3ea8360570_h.jpg 
 

 
Bigger: http://farm9.staticflickr.com/8246/8556827344_50c9f83ab5_h.jpg 
 

 
Bigger: http://farm9.staticflickr.com/8512/8556828330_1a5fd3d384_h.jpg 
 

 
Bigger: http://farm9.staticflickr.com/8377/8556829356_1e593308f0_h.jpg 
 
I'm sure everyone has seen photos like this a million times by now, but I'm loving it as a noob.  Laying on the livingroom floor staring into space while listening to music.

 
Those pics were excellent.. love the tube closeups..
 
Mar 14, 2013 at 8:33 AM Post #1,610 of 12,335
I only purchased one tube.  Being new to it all, I am keeping an eye on ebay and trying to purchase the reasonably priced stuff that have decent test numbers.  I realize that doesn't really mean anything if they don't sound OK.   I'm waiting to find someone locally that has a cache of tubes I can try out.    I swapped the Electro Harmonix tube in with the 6AS7G and you still have the same result of the hum and rapping on the case picking up the microphonic noise.    With the original RCA 6080 tube in there, you don't have any hum and tapping on the tube doesn't result in any sort of noise.
 
The 6080 tube and the clear top RCA combo also sounds really nice.  It'll be fun to build a small collection of both style tubes to try out.  I'm the sort of person that'll watch ebay for mis-listed Telefunken tubes and attempt to snipe them. 
 
Mar 14, 2013 at 10:56 AM Post #1,612 of 12,335
Mar 14, 2013 at 11:43 AM Post #1,613 of 12,335
Quote:
Does anyone listen via a line out from an ipod compared to a DAC? How much am I wasting the potential of the Bottlehead if I'm just using my ipod' line out? (lossless files) 

Depends on the Ipod, I think.  I have a 3G Ipod Touch which sounds very warm and relaxed using a LOD listening to 24/96 files.  More clear than the headphone out, but not nearly as detailed or crisp as when using something as simple as the ODAC.  I don't mind because I specifically bought a 3G instead of a newer one because it was supposed to have a nice warm presentation, which is what I want when traveling.  I haven't heard anything other than my 6G Nano which isn't as musical or dynamic as the Touch, but is a bit more neutral.
 
This is obviously not with a Crack, but I think in general it holds enough general truth for the question at hand.
 
Mar 14, 2013 at 12:53 PM Post #1,615 of 12,335
Quote:
Does anyone listen via a line out from an ipod compared to a DAC? How much am I wasting the potential of the Bottlehead if I'm just using my ipod' line out? (lossless files) 

 
I ran mine off a Fuze and the headphone output of a laptop many times. I didn't feel like I was missing anything too significant other than all my toys weren't being used
rolleyes.gif

 
Mar 14, 2013 at 4:21 PM Post #1,616 of 12,335
Other than buying and building the Crack, which has transformed my HD800s, the greatest improvement in my music listening experience has been getting away from my computer!!!
 
Getting to this point has been nothing short of a revelation. I'm not sitting upright, staring at a computer screen, distracted by the Internet, surrounded by papers and various bits and pieces of office crap. Instead, I'm relaxed, in an armchair (with a footstool), in my study, with nothing but low light, either reading a physical book or just enjoying the music with my eyes closed.
 
The ipod Touch coupled with Spotify has made it possible. Here is my setup:
 
ipod Touch --> Cable Jive Dock Extender --> Pure i-20 dock --> Blue Jeans Cable coaxial cable --> Audio-Gd Reference 5.32 --> [From here it splits as described below]
 
RCA outputs on Ref. 5.32 --> Mapletree Audio Design LR1 line router --> [See switch positions below]
1. Bottlehead Crack
2. Bottlehead Smack
3. Mapletree Audio Ear+
4. Brocksieper Earmax
5. Emotiva mini-X a-100
 
XLR outputs on Ref. 5.32 --> Mapletree Audio Design LR1 Pro line router --> [See switch positions below]
1. Violectric V181
2. Little Dot Mk VI+
3. Audio-Gd Roc SA
4. Balanced AMB M^3
 
This system is great, because the storage capacity of the ipod Touch isn't a limiting factor. With Spotify, the world is my oyster. The Pure i-20 dock extracts the digital (not analog) audio stream, and passes it to my external DAC, which in turn feeds all of my amps. No computer and no NAS needed. Just WiFi, and ipod Touch and a Spotify account.
 
This is obviously complete overkill, but at it's most basic, here is what I recommend:
 
ipod Touch --> Cable Jive Dock Extender --> Pure i-20 dock --> Bottlehead Crack.
 
The Pure i-20 also has a built-in DAC that is surprisingly good (or, for anyone who has heard my private views on DACs, perhaps not-so-surprising). You just use the RCA outs instead of the coaxial out. And it will charge your ipod while you're listening. For less than $100, it is very hard to go wrong. I have 3 Pure i-20s, and I consider them the Swiss army knife of audio gear - incredibly versatile and shockingly cheap for what they do.
 
FWIW, the Cable Jive cables are ridiculously overpriced. Unfortunately, they are also the best cables of their kind that I have seen, and therefore recommended. Note that when I say "best", I'm not implying that they have any effect on sound quality, it is just that they are very robustly built and I find most ipod cables start to crack shockingly fast. The Cable Jive cable lets me hold my ipod Touch in my hand when selecting music, rather than trying to awkwardly manipulate it while it is plugged into the dock itself.
 
Best regards,
Adam
 
Mar 15, 2013 at 5:23 PM Post #1,617 of 12,335
Quote:
Does anyone listen via a line out from an ipod compared to a DAC? How much am I wasting the potential of the Bottlehead if I'm just using my ipod' line out? (lossless files) 


In my case it did not make a difference with various sources until I went for a hi end dac(Ad Labs RD26 850$). The detail now from the HD700 is really breathtaking. I don't regret the purchase one bit as I hear that the soundstage is larger, instrument separation is perfect.
 
Mar 16, 2013 at 2:56 PM Post #1,618 of 12,335
I came to within one click of getting one of these! I want a tube amp badly and the increase of quality over similarly priced imported product had me convinced. Then I remembered my clumsy attempts at building things as a kid. I'm truly all thumbs and the projects I undertook (including a disasterous attempt at a Hethkit radio I got as a gift) made me realize that I was fooling myself in thinking that this time I'd do better. Although the Bottlehead site suggests that assembly is available, Doc B's recent posting says this has been discontinued. Too bad! Doc if this situation changes I'll be first in line. 
 
Mar 16, 2013 at 3:20 PM Post #1,619 of 12,335
Quote:
I came to within one click of getting one of these! I want a tube amp badly and the increase of quality over similarly priced imported product had me convinced. Then I remembered my clumsy attempts at building things as a kid. I'm truly all thumbs and the projects I undertook (including a disasterous attempt at a Hethkit radio I got as a gift) made me realize that I was fooling myself in thinking that this time I'd do better. Although the Bottlehead site suggests that assembly is available, Doc B's recent posting says this has been discontinued. Too bad! Doc if this situation changes I'll be first in line. 

I had such a great time building mine.  I'd build one for you.
 
Mar 17, 2013 at 3:57 PM Post #1,620 of 12,335
Quote:
Other than buying and building the Crack, which has transformed my HD800s, the greatest improvement in my music listening experience has been getting away from my computer!!!
 
Getting to this point has been nothing short of a revelation. I'm not sitting upright, staring at a computer screen, distracted by the Internet, surrounded by papers and various bits and pieces of office crap. Instead, I'm relaxed, in an armchair (with a footstool), in my study, with nothing but low light, either reading a physical book or just enjoying the music with my eyes closed.
 
Best regards,
Adam


Adam - While I can't say my Crack isn't "laced" with a PC, I 100% agree with your opinion.  Having a long headphone cable (stock) with the HD-600s is also a benefit, because while I'm running all my music from my PC (USB out to a KECES DAC) I am able to get away from the monitor, computer, and the area in general to truly listen without any distraction.
 
Back to your point - It's the distraction that makes a huge difference in what my brain is able to process from a musical standpoint.  Now maybe other fellows on here can still point out every detail while surfing the Head-Fi forums, but I can't!  I enjoy music best with my eyes closed and zero distractions.
 

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