Bottlehead Crack

Hey brother, I see you've been posting about the mainline across several threads. I've been the owner of one since January, and since upgrading to it + bifrost 4490, I've moved into speakerland since I've found myself at a very happy place with my headphones. Organic (more of a laidback yet full sound), spacious (with incredible depth and width, with you seated 5 rows back), extended yet deep bass, very smooth treble... altogether combined for a listening experience that could last for hours.

I could endlessly sing praises for the mainline 4490 combo, but I would advise you to try to listen to a mainline first before buying. The torpedo and mainline are built from the same design philosophy (parafeed topology) and most of us haven't had the pleasure to compare the two of them (I believe @MisterRogers once owned a mainline and now has a T3).

Let me know if you have any questions!

 

Very interesting! Compared to the ultra-refined trebles of the mainline, crack's lively highs can actually come across as slightly coarse and harsh on occasion (although never thin and piercing like low end solid state). This is tube, source and headphone dependent of course, but nonetheless makes me very curious to spend some time with a T3. It remains near the top of my short list of future projects, but amidst all the praise it gets, the occasional references to perceived brightness do make me wonder how it would ultimately match with hd800's to my ears (obviously much less of an issue if hd650's are the intended headphones).

If you do build/pick up a mainline, it would be awesome if you could do a side by side comparison with your T3 and provide some impressions while both are under your roof. I don't think anyone has done this yet, and it deserves doing as between the two top end diy HP kits available. If I happen to build a T3 before you build a mainline, I will make sure to do the same!

 

I heard the stock tubes can be thin sounding so I will try rolling a different tube in the t3. I want that lush tube sound.

It sure is one of the most dynamic amp I heard so far.

 

I am not sure if you guys have seen this before or not but this has to be the most amazing Crack build that I have ever seen!

https://plus.google.com/photos/108890459358226980635/albums/5534811468801667841?banner=pwa

 

Ooh, very pretty. Not sure I'd be comfortable with hot glue holding those big caps in place though; it does get warm under there.

 

What is the recommended usage hours per day for the Crack or tube amps in general ?

Would it be suitable for gaming, and turning the crack on for 8-12 hours per day ?

 

There is no limit on the daily usage. Tubes will burn out after 1000-1250 hours. The tubes give off a decent amount of heat. While I love the crack, it wouldn't be my first choice for a gaming setup. Mainly due to its output characteristics and being specialized for high impedance headphones. I am unknowledgeable on gaming headsets, what are you planning on using?

 

I am using it with HD650. Playing foobar music/FLAC in the background whilst gaming

 

Then everything should work out fine. I was imagining a headphone with mic (like Senn Game line). May get a bit hot under the chassis with that much use, but I've accidently left my Crack on for 24 hr + stretch and no harm.

 

Has anyone else tried the Psvane 12AU7? It's a new production tube and one of my new favorites. It's holographic with the 5998 and also does really really well with my 6080s. It's hard to describe the sound because it's just very linear. Not exactly as natural sounding in terms of timbre as the clear top but very precise and slightly warm, I suppose. I haven't rolled it in in a while though, since I've been rediscovering how amazing the 6080+Gold Lion combo is. A friend is letting me borrow his Chatham 6080 and it's excellent.

On the other hand, I finally went for the Garage1217 12AU7>6SN7 adapter and a Raytheon VT231. All the reviews I've seen with the Raytheon tube rolled into the Crack...all three of them...claim that the heavens opened up and the angels themselves descended with instruments in hand to give the listener a private concert... so we'll see how that goes. Might get a little awkward with a bunch of angels in my apartment, since I do have a roommate.

E: first thing that's going through that Raytheon tube is Hendrix. I wonder if the gaping maw of hell will appear in my driveway to let him out...

 

Listening to the Raytheon VT-231 for the last few days (HD650 defoamed), I have to say that I am impressed. No gaping maws of hell, but the soundstage above all is a big step above the 12AU7 such that it feels everything has been pushed out in front of me and spread out even further. The 12AU7 tubes I described as 'holographic' have been stripped of that title. Sense of space, imaging, and separation are a significant step up. I understand what people mean by 3d soundstage now.

Timbre isn't as realistic as my RCA clear top but isn't far behind, and I'm on the fence as to whether overall clarity is better vs a good 12AU7. But the soundstage really is holographic compared to anything I've ever heard before in my own rig. Definitely need more 6SN7s to test further.

I will note my issues with the adapter, which doesn't quite fit snugly into the socket and has been having some intermittent connectivity issues. I'm emailing the G1217 guy about it before making a judgment.

 

Have you checked the DC voltage at the grid of the output tube to ensure your bias with the VT231 is correct? Proper bidding makes a positive difference with the 12BH7 and E80CC.

 

There's a special sale right now on the 120V versions until July 4th as long as they are available. Buy the Crack for $250 and you can add on the Speedball for $50. After this they will use universal transformers.

http://bottlehead.com/product/crack-otl-headphone-amplifier-kit/

 

As I recall the 6SN7 is a drop-in with an adapter, no change in bias necessary. Someone let me know if I'm wrong.

It's good enough I don't wanna go back to 12AU7. Modding the Crack with an octal socket wouldn't be that difficult would it? Besides having to make a larger hole for the thing, maybe moving the speedball boards over to the side a bit.

 

Hi. I need an new power tube. I'm seriously considering a Tung Sol 6080. I found these on eBay

http://www.ebay.com/itm/252447214718

but they don't look like the ones pictured earlier in the thread, both the lettering and the pins.

Any comments on this deal? I'm also not sure I need two, so if anyone wants to split this buy, let me know.

 

Those look like real Tung Sol 6080s. Don't worry about the lettering being different. From the pics in the listing, these are the things I would look out for:




~$30 each seems to be the going rate for a buy-it-now, NOS tested one. I'm sure you could could pick a single one up for $20 or less if you are patient & someone lets an auction run from zero. Depending on your situation, life might be too short to worry about saving $10.

At $30 or less It's a nice tube and, bearing in mind the cost of the amp, it's price to performance ratio is spot-on for the Crack, I reckon.

 

Many thanks @Jeb

 

Hey guys was looking to get some opinions this and this. Do these pair well together in the crack+speedball or should I be looking at something different?

 

There are other types of 6080's? Could you link me a guide for them? Would there be a better option over the GE 5814 and would it pair better with some type of 6080 or a different type?