Bottlehead Crack

<3 a good 5998 tube does wonder for sure.

 

Yep, for me the 5998 tightened the bass and sparkled the treble a bit. Definitely more detail and clarity, which I would interpret as less syrupy.

But man, the prices! I picked up a matched pair for US$80 back in the day, and soon after they started selling for upwards of US$200 each. A quick search, I see US$300 retail currently. There's NO WAY I'd pay that. So I'd suggest to @Eric Rosenfield that would really be a last-resort tweaking option.

 

Funny enough, while last night when I wrote this post I was all like "Crack is a gimmick", I've now been listening to it all morning and I'm like "Crack is amazing" again. Maybe my brain needs to get used to it, maybe it depends on my mood, I don't know. Yeah, not spending $300 on a tube, but I now have a few different lower cost tubes on their way and I'm really looking forward to seeing what they do with the sound.

 

I would say instead, that the Crack is a one trick pony: it makes sweet magic out of high impedance phones.

Sometimes you want sweet magic. Sometimes you want harsh reality.

 

Clear Top tube arrived about an hour ago.

Oh yeah, this is much better, wow!

 

I just saw you were at times trying to continue to cut through the richness of the crack -- have you tried using a 7236 power tube (tung sol/cetron or sylvania)? This tube has always tilted the sound more for speed and punch - a faster sound signature.

 

I haven't though I have some other power tubes on the way already. I'll definitely add that to the list of tubes to keep in mind though!

 

From memory, the 7236 is basically a computer rated 5998A. Note that the 5998A is very different from the just-5998-with-no-A, and is closer in electrical characteristics to the 6080 and 6AS7 variants. So if you have a decent selection of other power tubes, I personally wouldn't spend a lot of money chasing down the 7236.

 

I would just add that the only 7236 worth chasing (but still wouldn't spend super mega bucks on) is a Tung-Sol or Cetron brand. These are sonically (and internally) different than the run of the mill 5998A (or any other branded 7236 which is usually a 5998A internally anyways) and if I wanted my Crack to lean even faster, the Tung-Sol would be a strong contender for power tubes to do so. I agree with you though, the run of the mill 5998A (usually GE) is much closer to the 6080/6AS7 in sound - though it does elevate the bass a bit more.

Still - nothing wrong with going straight to the top. The superior 5998 does it best, domino plates and done, buy once cry once, but one would be all set.

 

Except tubes wear out and need to be replaced, right? So you’d still have to buy multiple times/cry multiple times?

 

I'm still on my original 5998 from 13 years ago. They are run very conservatively in the Crack, which means a very long lifetime.

Still wouldn't pay US$300 for one.

 

You learn to hoard your favorite tubes with time since once you've bitten the bug... you never really go back to SS and you sometimes find yourself coming back to the same tube several upgrades later.

 

This is just good advice, in audio, and elsewhere in life with purchases.

 

This comment is hurting my brain. One being all set can be great! But how incredibly boring would this hobby be if we were *ever* all set?

 

You could search out new music instead of new gear...

 

Pffft, that's just crazy talk.

 

I seriously don't understand how the 6XX has soundstage now.

The Clear Top tube basically solved all my problems with the Crack. Combined with the Custom Cans mod (with the "m" foam), this now sounds better (to my tastes at least) than cans and rigs I've heard that cost thousands of dollars. Holy shit.

 

Bottlehead Crack journey update:
I ordered a handful of tubes people had recommended in various channels to try out. On top of this, @lcmusiclover very kindly offered to send me a box of tubes he wasn't using in exchange for making a donation to a health based charity (in my case, I made a donation to the Child Tumor Foundation, chosen for personal reasons).

All the tubes he sent me were power tubes. After trying out all of them, the best seemed to be a Haltron (GEC) 6080 and a WE 421.The WE 421 is a particularly expensive tube NOS, as lc pointed out.

In addition to this I purchased and received a NOS RCA 6080, a NOS Svetlana 6N13S, and a new production JJ ECC802s input tube, and just today got the adaptor for the pair of GEC CV4079s power tubes.

I was most exited to try out the WE 421 given its reputation. And indeed it does something incredible with the sound, giving it a kind of depth and realism and a je ne se qua I'm not even sure how to describe. Unfortunately, it's also very dry and harsh. Despite the Crack's reputation for making everything sound warm and lush, the WE 421 paired with the Clear Top sounds like a solid state amplifier. It's better with the JJ tube, adding a bit of warmth, but it's still harsh in a way I can't get around.

The Haltron was almost the opposite of this, a tube that made the music back off and gave it a kind of delicacy none of the other tubes did. It's a beautiful sounding tube, but it doesn't grant the depth and mystery ingredient that makes the 421 special. Still, paired with the JJ tube, this was what I defaulted to for a while. The main problem with it is that with laid back or soulful music it's wonderful, but with aggressive rock or metal it just sounds limp and weak. For that kind of music, I could actually throw on the WE 421 and it would transform the normally sedate 6XX into a muscular beast. (How the 6XX is capable of all these different kinds of sounds on tubes still boggles my mind, it's like transforming it into completely different headphones.)

The RCA 6080 I saw described as average in every way, and I have to agree with that sentiment. While I think it's a relative step-up from the stock GE tube (which is still pretty good with the Clear Top to brighten it up), I'd basically rather listen to the Haltron in most cases.

The Svetlana meanwhile is just harsh and grainy without any of the 421 magic. A real let down IMO.

The JJ meanwhile is a good balance between the super-warmth of the stock input tube and the clean and stark sound of the Clear Top with most power tubes. I really only preferred the Clear Top with the stock GE tube; with the rest of the tubes it was too clean for my tastes compared with the JJ. And of course the JJ has the added benefit of being new production so I hopefully don't have to be worried about the world running out of them one day.

However, today the GEC CV4079 adaptor arrived so I could use the tubes that came a few days ago, and oh yeah. The guy who recommended to me on the Sonic Visions Discord (Uniqusername) said that it "comes pretty close to GEC 6AS7 at fraction of its cost". I don't know what the GEC 6AS7 sounds like, but it has mixes all the things I like about the Haltron and 421 tubes together. If I had to quibble, it'd be that it's still a little too aggressive-sounding for my tastes, and I might still switch back to the Haltron when I want to chill. But it does the aggressiveness without any of the harshness of the 421 at all, everything is clear and sweet. (Once again, I prefer it with the JJ tube to the Clear Top.)

Due to international shipping, I still have three more tubes coming that I'm going to try, but I think I'm done at that point; even if all of them are duds, the CV4079s/JJ combo is so good I don't think I need to look anymore.

Tubes still on the way:
* RCA 6AS7G
* Thompson 6080WA
* Brimar 12AU7WA

So far, none of these tubes has cost me more than $50, but all together obviously it adds up to a bit of money and unlike most audio gear, I'm not sure what the resale value looks like for tubes that are no longer NOS. Still it's worth it to settle the nervosa and, I suppose, not wait until the NOS tubes get even more expensive. Plus having a tube like the Haltron I can throw on when I want to change the mood is like having an entirely different headphone I can transform my 6XX into. Anyway, I can always send them on to another person in exchange for a health-related charity donation.

Some other things about the Crack:
* There's some kind of fault in the wiring or whatever where every hour or so they'll be some kind of static come through for a second and then disappears. It's infrequent enough that it doesn't particularly bother me. Still this is the problem with buying a kit someone else put together when I'm not handy at all. On the Bottlehead forums they talk about this kind of thing being easy to solve, you use a chopstick to find the bad solder point and resolder it. But I've never soldered anything in my life.
* To make matters worse, I idly tried to pull the volume knob off (since it doesn't look like it's screwed on) to see if it'd be easy to replace it with a nicer-looking one. Instead of pulling it off I just pulled the assemblage up, and now basically every time I adjust the volume I get a little bit of static as well, made worse by the fact that the volume pot seems to be a bit wobbly. So that's annoying. And it's another thing that seems like it'd be easy to solve with a soldering iron. Maybe I can find someone in the neighborhood who can come over and touch up the solder joints.
* One problem with the design of the Crack is that the input tube is right next to the volume knob. I have the amp on my left side, and that means if I'm not careful if I reach over to adjust the volume I can hit the input tube. Besides the tube being hot, the tube does not get firmly seated in the socket and will just tilt over to the side at a touch, which sends the most deafening and actually painful static through the headphones. (No wonder this technology went out of style.)

The whole thing does make me see the appeal of a more expensive, prebuilt amplifier that's put together by a professional and designed in a more thoughtful way. (Someone on another forum even offered to loan me a ZMF Pendant for a while, and I have to say that I'm constantly floored by the generosity of the audiophile community.) At the same time, this Crack sounds so goddamn amazing that I'm loathe to part with it, plus I'd have to go through the expense and nervosa again with the tubes of that new amp. (Not to mention figure out how to fit it on my already all-too-crowded desk.)

So for the time being I'm happy with the Ol' Crack. It's utterly transformed my humble 6XX into something in a different league. Honestly, I only wish I'd dived into tubes earlier; maybe I could've even gotten the tubes more cheaply since prices apparently shot up during the pandemic and war in Ukraine.

 

So I lifted up the Crack and pressed on the solder points a little bit, and now I don't seem to be getting static when I adjust the volume anymore. So that's nice.

 

He's here too, as @uniqusrname in both places tho (without the "e"), and is our resident genius amp builder/modifier/lore-master. Anything he says about Crack tubes or modifications, you should listen to.