Bottlehead Crack: OTL Addiction
I think I’m far more excited about the Crack than Lieven is. While the initial frustration regarding the ordering almost made us gave up, by the moment I received the package I really couldn’t wait to start the build and to finally hear what the Crack is all about.
A little DIY Story
If you’ve done DIY before, then you know that doing a clean case work is always more time consuming than doing the electronics part itself. If you’re lucky, the amp that you want to build can be ordered as a package, meaning all the correct parts needed are sold as a package, and you don’t need to order them one-by-one, sometimes from two or three different vendors. So, if I can break down the DIY amp building process, it’s probably something like:
- 20% getting all the right parts ordered and shipped to your door.
- 30% installation and soldering.
- 50% case work: measuring, designing the case for best layout, cutting boards, measuring, drilling, sanding, tapping, all the way to the smallest finishing details.
The last amp I build was a moderately complex electrostatic amp, but I was lucky to have my friend calico agreeing to do the casework for it. So the moment I finished the amp and got it running, I sent the boards assembled and mounted on a plain aluminum plate, so he could start on the casework. I think it took him roughly 6 months to finish the casework, even with his advanced CNC know how. In comparison, it took me 1 month to finish the assembly from the time I got all the parts together.
I still had other DIY projects that I had prepared to build, but I decided to postpone doing any DIY work for an indefinite amount of time, simply because I don’t feel like having to deal with the messy case work.
Building the Crack
In the case of the Crack, I agreed to build the two amps (one for me and one for Lieven) because I knew that the assembly should not be that complicated, and that since we’re buying the package complete with the case and everything being pre-drilled, all I have to do is solder everything together and make sure not to flip the polarity of the diodes and the capacitors.
The Crack arrived, and to my surprise they had included a user building guide that includes step-by-step with pictures! Awesome! I don’t think any other DIY project comes with step-by-step pictures, and it makes such a big difference especially for less experienced DIYer.
The way Bottlehead designed the layout of the amp and the use of mounting posts (for soldering your components into) makes the build easier than a typical point-to-point build. The last point-to-point amp I built was Pete Millet’s SSMH, and though it’s simpler by parts count, the build process was harder than the Crack as it was pure floating point-to-point wiring. Anyway with the Crack, I think they went the extra length to design a layout that’s easy to build. There are some spots that are quite tight for the soldering iron, so it helps to look several pages ahead to see what other components will need to be soldered into that area, and if it would be easier to do the other component first.
On the soldering junction that involves several different components together, the manual clearly state when to solder everything together, again making for a very smooth building process. I also appreciate the fact that Bottlehead included a solid-core hookup wire that makes the wiring work so much easier (solid core wires tend to hold their shape very well, so they don’t move around when you try to solder them). The hookup wire also comes with a heat resistant insulation sleeve, so they don’t melt easily when you’re doing the soldering part.
It’s always wise to take the build slowly, double checking the parts orientation, checking for shorts and ensuring every solder joint is strong and solid. Rushing through the build may lead to mistakes that would take much longer to pinpoint and troubleshoot. Not to mention if you blow a capacitor and need to order a new one to replace it.
I didn’t have any problem with both builds, other than the fact that on my first build, the power switch I received was faulty so the amp is always on (I have to unplug the power cables to turn it off). Out of the three kits we ordered, two amps had the same faulty power switch, so it’ll be good to double check with Bottlehead on this one. On the second amp, I took my time to make for a very clean wiring path, so I can have a nice looking amp for the photos for this article.
I think it took me roughly 6 hours for the first build with the simplistic wiring, and 8-9 hours for the second build with the clean wiring. It took me longer on the second build as I was not in a rush to listen to the amp anymore, and because I needed to measure the length of the hookup wires and to bend them at precise lengths to create a clean look.
If you feel like trying to do a build, I think the Crack is a good project to take on. Not only because the amp sounds very good, but also because it’s relatively simple and it comes with a kickass building manual. All of the parts used are relatively big in size (except for some diodes and LEDs), so it’s not like you have to mess with a lot of tiny transistors, SMD parts, or tiny little op-amps.
I’m so enthusiastic about the Crack mainly because of the sound. Of course the fact that I didn’t run into any problems during the process does make the overall experience easier to enjoy, but ultimately it’s the sound that excites me.
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