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That's one of the things I really love about this amp. You can really hear what each tube brings to the table. Of course there are some that sound pretty close and you need to find the right combination for the particular headphones you're listening to. I think you'll find that rolling the 12au7 will help just as much as the 6080.

You should contact Bottlehead and they'll shoot a couple off to you if they think it's even necessary. Like I said, post something on their forum and see what other folks think. Believe me, there's plenty of knuckleheads like you and me that have done much worse and since these CCS boards can be used on almost all their kits, you won't be the lone ranger. The Bottlehead forum is there to troubleshoot and discuss upgrades and design. It's a fantastic resource but only if you use it!

I think Nebby's right. It would be a good idea to post something over on the Bottlehead forum (Crack forum) just to be sure. If you didn't cut the leads too short, you and always try and slip the tip of a toothpick under the transistor as you wet the solder one lead at a time. Just be careful not to "cook" the semiconductor. The Speedball does a lot to deepen and tighten the bass. I'm not sure which headphones you're using (impedance?) but there's a dandy table on the Bottlehead Crack forum for finding the right size output cap for a given impedance. Crack

Hey crappy, You should let the components and tubes burn in for a while. Or you might want to wait till the Speedball's installed. Even 24 hours will help in every category. Some tubes will quiet down after some burn in. Regarding the heat on the top plate, be sure and stick those feet that are included in the kit under the case. Without any airflow the plate does get pretty hot around the vents. That's where the plate resistors for the 6080 are and they get hot. I've run my Crack amp (with and without the Speedball) 24/7 for days and days with no problems (although it does get very warm).

Swanky? Man, I haven't heard that term in a looong time! Any of you guys remember the cologne company called Swank? They used to have all kinds of funky nic-nacks and a friend of mines dad had a collection of them. He gave me a tiny TV that was actually a cigarette lighter but if you put a 35mm slide and a couple of batteries in it, you could see the slide image on a 3" sq screen. I took a picture of Walter Cronkite and kept that slide in it. I kinda gave up on it since it ate batteries like mad. That is a killer build !

Hey Nebby, If you're new to the wonderful world of tubes, I highly recommend starting out by buying old tubes from a reputable seller and avoiding the eBay bargains till you get a little experience under your belt (even seasoned tube guys get stuck with junk from auction sites from time to time). TubeDepot is good as well as TubeWorld and Upscale Audio. You pay more but they all stand behind what they sell (and all the test equipment in the world can't predict some premature failures or noises that don't happen for a hundred hours or so). I like TubeWorld since they have well tested used tubes that I can try and not pay an arm and a leg for . Once I find the tubes that really do it for me, then I can look for some new old stock and pay the big bucks for them. Also, you don't have to worry about long burn in times with used tubes (although it is a good idea to warm them up without a signal for a couple of hours and give them a few hours with music before you get super critical).

The guys are in the beginnings of moving into a larger commercial location. This will include a dedicated listening room and Doc has plans to hold some amp building classes there and will have an open house once the dust settles. That's probably going to happen in Oct.. There's even a gin, vodka etc. distillery in the same complex (with a tasting room!). IIRC, it's on Bainbridge Island.

All the bugs should be ironed out in the manual now so, just take your time. If you don't have a nice wire stripper, you should buy one. A great deal of building this kit is cutting wires and stripping the ends. I put a strip of tape on my bench top and marked it with the most numerous measurements so I didn't have to pull out a ruler with every wire I cut (I think I marked it in 1/2 inch increments for 8 inches or so). There's plenty of step by step pictures so double check your work against them. There are several instructions that tell you to solder one end but not the other. Follow those closely since that usually means you need to connect at least one other lead to that junction and it always better if you only have to solder those junctions once. Have fun!

Yes,.. you can use all the 6080 subs as well as the gazillion 12au7 subs in the Crack. I've tried most of the the usual suspect and I'm currently running a Tung-sol 5998 and a CBS/Hytron 5814a in mine and lovin' every minute of it! There's a good bit of info regarding all kinds of tube rolling/mods etc on the Bottlehead/Crack forum. Bottlehead Forum - Index

Hey Torpedo, I see you like St Vincent too. Did you see um on "Austin City Limits" on PBS?

I went on Saturday. It was actually a nice little show with a high percentage of good sounding rooms IMHO. The Magico room driven with VAC electronics was one of the highlights. So was the Evolution speakers/darTZeel room. The Quad/Convergent Audio Tech. and the Audio Note UK rooms also had really good sound. Kind of a sleeper demo that had surprisingly real life sound was a small company called Inex Innovations. They build a cable system that uses optical cables for analog signals (I think?). All I can say is if the sound they were getting from a pretty modest vinyl system was the result of these cables, then these guys are really onto something. They're local here in the Bay Area and I might just have to beg them to borrow a pair ($2k a pair,.. yikes!). I was able to listen to just about everything in one afternoon. It seemed like there was a much more relaxed atmosphere compared to the big shows. Maybe these smaller regional shows are the wave of the future.

Who you callin' old? Yeah, I'm still lovin' the Crack. It's a real enjoyable listen while my ZD is like a magnifying glass for picking the sound apart.

Yeah, I've been neglecting my shilling duties lately but I think I'm on the comeback trail! Ha,.. it took me a bit to find the VW in your avatar this time!

I recently built this Bottlehead kit (actually, I had it at Chicago), and I have to admit, it's crossed my mind a few times to sell my beloved Zana Deux since I started listening to it. The kit is about as easy as they come (more cutting/stripping wires than anything else) and I did it in about 4 hours. Here's the killer part. The cost of the basic kit is just $220 and an upgrade kit with CCS boards for both the 12au7 and 6080 cathode follower is another $100. The stock Crack has a strong tubey character but with killer bass and liquid mids and highs. With the upgrade (called the Speedball), the sound becomes more transparent and fast. The frequency extension sounds better (particularly in the bass) and a quieter background reveals some of the best stage depth I've heard with dynamic headphones. Speaking of which, the Crack is recommended for high impedance cans (120 ohm) but I've been using my 40 ohm AD2000's and it sounds killer with them. It did however, run out of steam with a pair of K701's. In Chicago I borrowed ASR's HD800's for a bit and suffice it to say, I'm looking to buy a pair of them as we speak. So,.. if you've ever picked up a soldering iron or stripped a wire, this would be a great kit to get your feet wet and build an amp that you might just never need to upgrade from. BTW, there's a Bottlehead forum where other guys and gals who've built this amp can help you along if you get stuck or better yet, let you know how to do further mods on this kit. Crack OTL Headphone Amplifier Kit

I'm still lovin' my Crack. Hmm, that didn't sound like I meant it to (or maybe it did!). I'm finding that it does a great job with my ATH AD2000's which are lower impedance but also, high sensitivity. With the Speedball upgrade (CCS on each tube) the bass on the 2000's is the best I've heard it. Super tight, clean and lower than I'm used to hearing it. I listened to ASR's HD800's and I probably shouldn't have. Except for the Silver Ghost and the Pinnacle, I think it's the best I've heard 'em. Now I'm trying to scrap up enough to buy a pair. The price on the kit has skyrocketed to $219 with the Speedball still at $99. I think it's a total giant killer and about the easiest kit you could ever want. So far, the only cans that I've tried on it that makes it run out of steam are the K701's.

More great pic's you guys! Makes me wanta be back there! Graham, which banana is Joanne?

Yeah, weird huh? Maybe the town council is trying to improve on their image as a toxic waste dump. But,.. it's not very far from Oakland's Jack London Sq and Yoshi's Jazz Club. John Pizzarelli is playing that weekend,.. great guitarist!

Yup,.. I'm figuring on going on Saturday. AES is in SF this year too,.. and maybe I'll get over to Denver this year. (man, I love those mattresses at the Tech Center hotel!)

Fantastic pic's Peter (as always)! Since I've gotten home, I've avoided my local purveyors of duck fat fries and foie gras encrusted links. It just wouldn't be the same without a picture of Britney Spears looking over me! Thanks for taking me along!

Somehow, they always know where the "nuts" are buried. It's a gene thing I guess. That CanJam was one for the history books! BTW, Ed, if Rek's tongue is still stuck in your ear, I know a good psychiatrist that can probably get it out.

Hey you guys,.. is there a meet coming up? For anybody that's wondering, you can send stuff to the hotel. There's a small charge for storage ($5 I think) plus a charge if it's heavy. There's also a FedEx Kinko's on site if you need to send something out.If you have an account with UPS or FedEx, you can also leave a package with the concierge for shipping out. I'm really looking forward to seeing all you guys there and being abused mercilessly!

Man, I wish I could've made it there but the money just wasn't there! For you guys that want to hear something pretty special, make sure and visit Bobby Palkovic's Merlin Music Systems room. He really knows how to set up a great system in those shitty hotel rooms and the Joule Electric amps don't hurt either. It's not your knock you socks off demo (which I get pretty sick of after a day or so) but just nice pure music. Not to be missed IMHO. Enjoy!

When we had a Headfi room at VSAC in 2008 (much smaller event but the same type of thing), I realized after a little while of "guarding" our gear, that when there's more than one person in the room, neither one knows if the other one is keeping an eye on things or what. What you end up doing is showing folks how to use the stuff. Almost all the exhibits at a big show like that are conducted by someone who spoon feeds the attendees so folks get nervous about turning on stuff even when they should know how to work it. Since there's going to be a number of listeners who know nothing about high end headphones, keep it simple. For example, if you have several headphones you want to bring, just leave your favorites hooked up and put the others off to the side so folks can look at them. They almost never ask to listen or plug them in themselves no matter how much they want to. In fact, sometimes you'll have a bunch of folks just standing there looking at headphones and as soon as you sit down and start listening yourself, they get the idea that it's OK and they'll have a seat and listen. In hindsight, it would probably be a good idea to to put a sign up telling people to help themselves. So, I guess the point is that this will be a totally different sort of thing than these guys are used to. They'll be hesitant to even touch your gear at first. You'll get a number of guys asking you what you're selling or expecting a sales pitch. I always told them," I'm not here to make money,.. I'm here to figure out how to spend every penny I own!" They always think that's funny,.. One way to free yourself from your set up is to be sure and have explicit instructions available for working it (display these in a way that they can't miss it!) If you have discs, be sure and put a note on your disk wallet (or whatever you have) asking people to help themselves but to replace the discs when they're done. If you're going to be keeping an eye on things, be sure that you know how to operate all the gear. Take a quick scan of what's there and ask the owner how you eject it, load it or shut if off if it doesn't seem obvious at a glance. If there's something that you don't know, it's pretty likely that someone else won't either and they'll ask you for sure! I guess my last piece of advice is, after the rooms close for the day (around 5pm) keep an eye out for large platters of shrimp or other party trays (hand trucks of Absolute is also good). Drop whatever you're doing and follow them. They'll lead you to the rooms that have afterpartys planned. Pay particular attention to the ones that are in European vendors rooms. These rooms will have women and unspeakable activities long into the night. Believe me when I say that "Swedes know how to parrr-taaa!" If anyone asks you what you're doing there, tell em you're meeting Danny from Positive Feedback there. Everybody loves Danny!

Hey you guys. I haven't visited the boards lately so here's the lowdown on the repair. The problem(s) with Al's amp were pretty pedestrian. I kinda figured it would be seeing that it rocked and rolled 400 miles and then suddenly died. The filament transformer is on isolation mounts so it's free to move a tiny bit. The thousands of tiny movements loosened a couple of wires that crossed it which in turn moved some others. A ground from the high voltage board was totally loose and the wire from the regulator selector to the first regulator tube was just hanging on by a thread (it may have even been just the insulation since it broke 1/4" away from the solder joint). A 50 ohm wirewound was fried and during the testing I managed to cook the MosFet and diode twice! (I did try and find the MosFet that Kevin suggested but didn't find any in stock right off hand). There were a few other iffy connections/cold solder joints that I fixed both in the PS and the amp section. I can't really remember which ones I actually "touched" with the soldering iron since that was during the first round 2 weeks ago. Overall, nothing very exciting but man, hooking those sockets back into the lid with just 2 inches of clearance without dropping a single nut back into the chassis was a challenge (just another good reason to find a girlfriend with tiny hands!).

All the talk about food in the San Mateo area reminded me of the Prince of Wales Pub. They had a famous hamburger that put down some pretty stout stomachs. It was called the Habanero Burger . Unfortunately it's closed now but the web site still endures! Be sure and check out the quotes at the bottom. "It's not a meal, it's an ordeal!" Bummer, it was fun to watch big egos writhe on the floor! The Habanero Hamburger "Hall of Flame"