![Bottlehead crack schematic](https://kumkoniak.com/21.jpg)
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. I can't find any schematic for the bottlehead crack. I stumbled onto a build log of an Bottlehead OTL crack headphone. It did however, run out of steam with a pair of K701's.ĭIY Audio Projects Forum: FAQ. 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. 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. With the upgrade (called the Speedball), the sound becomes more transparent and fast. The stock Crack has a strong tubey character but with killer bass and liquid mids and highs. The cost of the basic kit is just $220 and an upgrade kit with CCS boards for both the 12au cathode follower is another $100. The kit is about as easy as they come (more cutting/stripping wires than anything else) and I did it in about 4 hours. I may move this post to the DIY sub-forum but figure this would be a good place to start.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. OK with metal or plastic housing instead of wood, but I don't have easy access to machine shop equipment if I need to machine a custom case or even just drill holes, etc. OK with a slightly more complex or technically complicated build, possible troubleshooting required, etc. Readily available components - I don't want to hunt for holy grail tubes, transistors, test batches of 100+ to find a good unit, etc. Similar footprint and heat signature - I don't want a space heater Total expenditure under ~$500 - rough cost of previous modded crack build Compatible with same tube families (12au) if possible - I want to use existing tube inventory
![bottlehead crack schematic bottlehead crack schematic](https://cdn.head-fi.org/a/11536574.jpeg)
![bottlehead crack schematic bottlehead crack schematic](https://i.imgur.com/6nRqm3m.jpg)
Similar relax-fi, easy listening / non-fatiguing sound without dissolving into warmpoo, punchy-poo, etc. OTL - specifically want an OTL sound signature for use with 300ohm HD6xx and ZMF Auteur drivers Can anyone recommend a DIY amp similar to the Crack sound-wise with the following:
![Bottlehead crack schematic](https://kumkoniak.com/21.jpg)