Recently I posted a review of the construction stage of my Bottlehead Crack amplifier. The amp’s been in action for a few weeks now and I’m ready to share a review of my impressions. I’m not going to start with the normal list of specifications for the Crack because it’s so variable due to the massive range of modifications you can make to it. What does matter are the following details:. Tube driven amplifier for headphones. Designed for high impedance headphones (ideal with Sennheiser and Beyerdynamic cans).

1. Bottlehead Crack Speedball Review
2. Bottlehead Crack Vs

Buckets of power Overview The Bottlehead Crack is a DIY kit sold by Bottlehead in America. It costs around $350 fully shipped to Australia and takes a couple of days to put together if you take your time, but could be completed in a day of assembly, committed soldering and testing. If you want to know how easy it is to build one of these for yourself, you can check out the build post here: For $350, this amp is simply incredible. To put it into perspective, the Crack performs on par or better than products like the Woo Audio WA3 ($580) and Schiit Lyr ($550).

Bottlehead’s basic headphone amplifier kit, the “Crack”, is probably the most well known, and best regarded, kit-based/DIY headphone amplifier there is. I’ll probably do the speedball soon and start tube rolling soon alsoso much fun to be had, so little time. Bottlehead Crack OTL AMP (Kit/DIY) - Official Thread. As in I only have one pairing, but each tube has 2 spares! The Pairing I enjoy the most is the Cleartop 12AU7 with Winged C Svetlana 4A57G. You won't have to buy another tube for a long time unless you want to tube roll. Compared to other BH Cracks: In my opinion it sounds noticeably better than stock Bottlehead Crack in A-B comparison.

Because of its DIY nature, you can get brilliant performance for a very low price. On top of that, building it yourself means you know what’s going on inside and can easily add to it and improve it either on your own or using the add-n “Speedball” kit from Bottlehead. Tubes, Glorious Tubes The Crack uses 2 tubes in its design – a small 12AU7 model at the input and a larger 6080 model to provide the output power. Don’t worry if you don’t know what that means, I didn’t either when I started. Actually, I still didn’t know even after I had finished building the amp – it’s only been in recent days of research and reading up on the great Bottlehead Forum that I’ve learned more about it.

Using tubes means two things. 1 – the sound from the amplifier is smooth, liquid and magical.

2 – it’s very easy to adjust and upgrade the sound by simply swapping tubes. The 12AU7 and 6080 combo that’s supplied with the Crack do a great job. The sound from the Crack was an instant and significant upgrade over the output from my Audio-gd NFB-5.2 and it’s not a slouch. After building and listening to the Crack for a while I became curious about upgrading the tubes (or valves as we call them in Australia). This was compounded by some minor issues with the supplied tubes which likely resulted from the trip from America to Australia. I found a local supplier called Evatco who were able to offer a selection of replacement options.

I ordered a Mullard 6080WA, a Cleartop RCA 12AU7, and a Mullard ECC82 which is an alternative to the 12AU7. After a bit of playing around, I found that the combination of the Mullard 6080WA and RCA Cleartop 12AU7 tubes provide the sweetest sound and the upgrade only cost around $50!! Sound Quality This is why you’d bother buying an amp in the first place. This is what matters and it’s where the Crack really delivers. I’m running my Crack (yes, plenty of humour available with this amp) from the line outs of my NFB-5.2 which is connected to my laptop via USB and is running 96kHz / 24-bit sound. My headphones of choice with this setup are the s. Admittedly, the choice of headphones is simple given the need for high impedance headphones with the Crack, but more on that later.

The most immediate characteristics of the Crack’s sound are openness and smoothness. The sound is liquid and creamy, but never slow or veiled. It’s just real.

The music flows out of the Crack like it would flow straight from the instruments. There’s space and depth and separation between the instruments, but again it’s delivered naturally – nothing artificial.

I had heard talk about analogue sound being smoother and more natural, but had never really paid much notice. Moving from the solid state sound of the NFB-5.2 over to the Crack immediately showed me why analogue sound has such avid fans. I’m not suggesting that tube amplifiers will always outperform solid state because there are some truly amazing solid state amplifiers out there, but they cost a whole lot more than this $350 gem. I feel pretty safe suggesting that you will not find a better amplifier for the same dollars as the Crack.

In fact, I think until you’re spending in excess of $700-800 on solid state, you will have trouble finding better sound. Clarity Without realising it, I somehow didn’t expect high levels of clarity and detail from the Crack because of its simple and analogue design. It certainly surprised me. It’s not analytical in its sound like a solid state amp might be, but there’s no lack of detail and the beautiful separation of different sounds and layers means you can really enjoy the music and the details, not just pick the music apart to hear separate details. Sound Signature The Crack’s sound is basically neutral, but perhaps slightly warm. It doesn’t add significant colouration to the sound that I can hear, but it does bring out the extended bass more than my NFB-5.2. The Crack makes the bass from the HD650s sound fuller and meatier, but it doesn’t make the sound significantly warmer overall, just fuller at the bottom end.

Top end sparkle and air is still great, mids are well-balanced, liquid and smooth, and the bass is full and solid, but not forward of other frequencies. Overall, I think it seems a little warmer because everything is so smooth. Of course, the signature can change with a simple swap of tubes (valves).

The Cleartop RCA 12AU7 I bought makes the sound a bit leaner and brighter, but does so at the expense of ambience and space within the music so it’s all a matter of personal preference. I guess the key here is don’t decide on the Crack because of a sound signature because that’s adjustable with simple tube swaps. Overall Presentation This is the smile-inducing part of the Crack’s sound. I don’t feel like the Crack dramatically enlarges the soundstage of the HD650s, but it’s placement and layering of sound is flat-out holographic. Individual instruments and sounds are perfectly separated and spaced around the soundstage to a degree that’s surprising at times and almost enough to make you look over your shoulder or second-guess if you’re alone in the room! All of this adds up to a sound that’s fun, addictive and realistic. It’s probably not an amp for people who like to dissect music and analyse recordings, but it is definitely an amp for anyone wants to really enjoy their music in a way they might not have previously.

The Crack brings music to life in all it’s amalgamated glory. The music is presented as a whole, magical soundscape, not a series of analytically correct, but unrelated parts. It’s been quite a revelation to me and has me subscribed to the benefits of high quality amplification. A Note About Headphone Impedance The design of the Crack results in a high output impedance. In layman’s terms, this means that it doesn’t work particularly well with low impedance headphones.

Most headphones on the market are low impedance (. An amplifier relies on impedance to control and limit the movement of the headphone drivers.

If the headphone impedance is less than or close to the amplifier output impedance, it’s ability to stop (or dampen) the movement of the driver is reduced and can result in lower sound quality. Where the Crack really excels is with 250 ohm and and with 300 ohm Sennheisers (among other options). It consistently receives rave reviews when paired with HD650s, HD800s, T1s, DT880s, etc. Closing Statements If you own or are thinking about owning some high impedance headphones and want to get the most out of them without spending $1000+ on an amplifier, have a serious think about the Bottlehead Crack. It’s easy to build (and fun), and will easily give you the best headphone experience that $350 can buy!

Add to that the ability to tinker, upgrade, swap tubes and generally customise your amplifier and it’s an amazing bit of kit – get you one! Thanks for reading! I didn’t get the Speedball.

There is a really slight background hum that’s really only audible when you’re listening for it and I think adding the Speedball might rectify this – I plan to get it in the future, but was interested in getting the stock kit and getting to know it before upgrading. The 240V transformer is a different version of the normal unit they put into the kit – i.e. It’s built into the kit (and looks exactly the same as the 110V one from what I can tell) – it’s the dark grey cube at the back of the amp with the curved metal top. Thanks for the compliment on the wood finish.

Bottlehead Crack Speedball Review

I used Black Japan stain and put it on lightly and irregularly. I also sanded it a little irregularly in between staining and varnishing (and in between coats of varnish). I used a satin varnish. Good idea on a group buy.

Fantastic write up Lachlan. The only reason i ended up here was that bottleneck have a offer on this weekend buy it & get the speed ball free and if you ask me that is a real bargain.& now just needed some more feedback on it and your writeup made my mind up so thanks to you and there offer i have got one but the wife is going to be a little pissed with me mind you. I was looking at the crack a while back last year & after spending weeks researching valve amps i was going to buy it but due to work never go t round to it until i received an email from bottlehead regarding there offer and guess what i could not say no who wouldn’t.there going to power my 650’s with high end rme converter 32 bit 192 khz.kind regards sy. Nice write up. My kit arrived today.

(QLD) Just a Q on tubes. I’m not very knowledgable on tubes You state “I found that the combination of the Mullard 6080WA and RCA Cleartop 12AU7 tubes provide the sweetest sound” (aren’t these both the output?) But later “The Cleartop RCA 12AU7 I bought makes the sound a bit leaner and brighter, but does so at the expense of ambience and space within the music so it’s all a matter of personal preference.” Is it that you accept (prefer) the loss of ambiance and space. Thanks for any clarification Simon.

Well I've hooked this beast up and it is a beast! It's almost as big as my PS4 and it's twice as tall. The power tube is massive! It's like a light bulb. The guy who built it was sound, kept me up-to-date with the whole process and his work is stunning(Pictures to come when I review it fully. I've heard so much about this amp, people say they are made for each other and it's an end game set up.

Bottlehead Crack Vs

I already think highly of the HD650. It's a world class headphone in a midfi price bracket. It's warm, smooth with a refined upper end but a little rolled off. The bass is typical of open dynamics and rolls off. I was excited when I first paid for the Crack, but I've heard the HD650 on a lot of gear so how much better can they get.

I plugged it in and press play.WTF! When I first heard the LCD-2 I was hot with this depth and precision. Same thing here, am I listening to the LCD-2? Sounds like it but further inspection it's the HD650 but with punch and kick. The upper end is energetic when the music asks for it and the bass is slamming.

A lot of songs have a slight bloom but it's not a technically deficient bloom like a bad bleed, it's an emotion music needs. Vocals sound real, the space expands and sounds deep, vocals sound deep and curvy, surrounded in a beautiful haze.

Details are there but the music takes your attention. Switching to more lively tracks the combo is snappy and keeps up.

Sometimes I feel like I'm listening to the ever slightly snappier HE-500 but the wetness of the HD650. I've been comparing them to both planars with the Schiit Lyr 2 which is a worthy endgame amp for them. What shocked me the most was the HD650's ability to image and sound spacious.

It's not AKG spacious but it goes beyond the Philips X2 with this amp. It sounds full and lively so so it doesn't come across as lean. The mids are faultless but another shock was the bass punch. It digs a bit deeper and slams nicely.

I'm not going to tell you this is the best thing I've heard technically but music wise; I've never heard anything so glorious, beautiful and just damn musical like this. I love the LCD-2 but all it has over this combo is bass extension. It's not even an upgrade it's a side grade for those who want a sub bass focus. Hear this combo and try call the HD650 slow, boring, lacking soundstage. I love the Vali but in comparison, the Crack is way above anything the Vali can put out.

This amp makes the HD650 reach it's final form. I knew the HD650 truly scaled but I thought it was exaggerated, now I'm a believer.

If you have the HD650 and want an upgrade, just buy the Crack + SB. It sounds better than any Schiit I've heard and better than the Little Dots hands down.

When the HD650 and Crack come together they become something you spend over 1K+ to try get, even then.the musical feeling is unmatched. Listening to the Final Fantasy 9 soundtrack brings that emotion I felt with the game. Every tube amp I've tried that isn't a hybrid has been the same with the Q. The Bottle Head has a 120ohm output impedance. I don't really want to roll any tubes, the stock sound perfect.

I won't really venture into any upgrades I also cant't see how you can inprove the crack. I was listening to my Sounds Of Nature album and played the thunderstorm.my God! It's by far the most realistic representation I've heard. Seriously if you have the HD650 and you don't have the Crack, you are missing out big time. Don't worry about any other headphone just pair these two together and be happy.