This is the second part of the Bottlehead Crack build. It’s time to place all the parts on the freshly painted chassis and prepare for the final assembly of the amplifier. This part is just the preparation of the chassis before soldering the part on the terminals,tube sockets and power transformer. From here on, it’s all about the circuits and electronics.
Bottlehead Crack overview:
- Part 1:Â Cabinet and chassis
- Part 2:Â Mounting the parts
- Part 3:Â Soldering the components
- Part 4:Â Speedball Upgrade
- Part 5:Â Hot Rodding with film caps
The male power plug and on/off switch is the snap in type. And they just snap right in. There is a build in fuse box with a 1A 250v fuse.
I was a little disappointing because of the RCA jack quality. They are gold plated, but it’s very cheap stuff and for just a few cent’s more, they could have gotten a much nicer quality. I’m probably going change them later myself. Sound quality wise, I highly doubt it will make much of a difference anyway. But I really like nice things and I know they’ll make you feel better in the long run.
Because I have swapped the default potentiometer for a nice Alps Blue Velvet, I had to file the hole more narrow for the indexing pin to make it closer to the shaft. The chassis is made of laser cut aluminium, so it wasn’t too hard to do.
The Alps blue velvet has a very nice feel and is incredible well balanced even at the lowest volume levels. In my experience, this is not the place to save a few pennies. I also considered a Dale potentiometer, but I’m not sure I like the stepped levels.
A perfect fit.
The 1/4″ female headphone jack. Standard quality, but I like this type. It’s very reliable and gives a good connection. I will consider upgrading to a Neutrik plug with lock later. I’m undecided about that.
The ceramic octal socket. I love ceramic stuff, it’s a nice material.
The back of the chassis. I know it’s stained, but it came that way. Â Notice the terminal socket that has been mounted on the octal socket. Also notice the safety ground next to the power plug.
The nine pin socket. Â Notice that I have intentionally installed the socket from the bottom and not the top as you’re supposed to. Â
This is to hide the socket so the tube is the first thing you’ll notice and not the socket. Â I saw a Bottlehead Crack on Head-fi with this configuration and I think it looks nicer.
The power transformer is installed along with the painted bell cover. It’s very heavy. Â
Terminal strips has been placed on each side of the transformer. Â
These numbered stickers will be unbelievable helpful when doing the wiring and soldering. Trust me.
Now it’s time to start wiring and soldering. Can’t wait.
Go to Part III: Soldering the components