Bottlehead Crack build log: On/off PCB assembled

I got the PCBs made.  They sent me 10 instead of 1.  If anyone wants to buy one or more, contact me.


Bottlehead Crack build log: Laser-cut top plate

I got the top plate from the laser cutter today.  This is it after some wet sanding.




I got the plate cut at Smucker Laser Cutting & Metal Fabrication, located in Lancaster, PA.

Bottlehead Crack build log: On/off circuit progress

Finally, some real progress:




The transistor idea didn't work, neither.  I ended up just adding another output to the program.



Parts List

Bottlehead Crack build log: Breadboarding and circuit ideas

I got this on/off circuit set up on a breadboard today.  The stupid voltage divider didn't work for the LEDs, so I have to try to use two transistors to control the LEDs.  They are inside of the switch, by the way.  I need to really start posting some pictures up here.  Here is the new schematic.  I haven't bought the transistors yet, but I am going to get some at RadioShack tomorrow.  It should work, in theory.

Bottlehead Crack build log: PIC programmer

Well, I got this PIC programmer, and with the help of this guy from the microchip forums named Dario Greggio I got the PIC to act as an on/off toggle with the off action requiring a button to be held down for a few seconds.  I've since designed the PCB for the circuit.  If anyone is interested in the circuit, PM me for more details.  Getting a quantity of PCBs ordered would bring down the cost, greatly.  I will draw and post up the schematic here later.

Bottlehead Crack build log: 9-pin socket LED soldering

I was bored and felt like soldering the LEDs and ground wire to the center post I made.


Bottlehead Crack build log: Teardown, top plate design, and capacitor brackets

I got it all torn down days ago.  I haven't decided if I am going to get another top plate laser cut or just modify this one.  I want to go with a Bulgin switch, and not in the stock location.  It's in a bad location where I have the amp sit I burn myself on the tube reaching for the switch to turn it off.  I have a top plate designed in AutoCAD.  I'm just waiting to hear from a place about laser cutting and if I need to add any considerations for beam width (maybe someone here could help me?).  I drew everything literally the size I want it to wind up.  The new tube sockets are smaller in diameter, so I ended up shrinking those holes in the drawing.  I will still need a few more holes to mount a board that does the on/off latching and delays the signal to the headphones because I don't feel like putting the massive effort into pressing the latch to remove the headphones every time I turn it off, and I don't feel comfortable leaving them plugged in when I power it on.


The transformer end bell ended up ugly and rusty with all of the skin oils from handling.  Oh well.  That's getting powder coated and it was the plan from the get-go.




I got the capacitor brackets from Shapeways today.


Bottlehead Crack deconstruction and build log

I bought a Crack off ebay some time ago, pre-built.  It came with AΞON output capacitors.  I've since replaced the RCAs with Neutrik ones and the headphone jack with a Neutrik latching jawn.  The octal tube socket just plain sucks and the signal started becoming intermittent, so I took the amp out of commission and I am going to do a whole slew of things to it.

  • I ordered new tube sockets.  They are the teflon composite type from Parts Connexion.  They have a silver-plated crown springs inside the contacts made of beryllium copper.
  • The capacitors came dangling.  I just used packing tape to keep them held up.  It works and can't easily be seen because it's clear.  It's not ideal so I designed some brackets in SketchUp and are having them made at shapeways for $3.96 apiece.  They made specifically for my capacitors, and you can see the slots for the zip tie.  Click this sentence to visit the site and maybe purchase them. I don't get anything for it.  I designed them and put them up for everybody.
  • The headphone jack is crooked and could use some mounting work.  I am going to look for a machinist to just nip into the top plate a tiny bit to the shape of the jack's flange so it absolutely will not move.
  • I am replacing all hardware with torx hardware.  I haven't found a place where I can get all the same alloy for all of the sizes I need and inexpensive.  McMaster-Carr has them all for cheap, but in different alloys.  Aaron's has any size you can imagine and in whatever alloy you want, but small quantities are expensive.  I would maybe go for larger quantities if people would go in on a buy (hint hint).  Fastenal doesn't really have anything, anymore.
  • I am going to have the top plate and transformer end bell powder coated.
  • I am looking to add in an audio spectrum analyzer circuit I bought some time ago.  I would like it to be after the volume control.  Will there be any impedance problems?
  • I am looking to add a timed relay circuit that won't connect the headphone output at power on until a set amount of time.
  • The Speedball upgrade will be done.  What hardware does that kit use?  If I have excess quantities from the bulk I order for the Crack itself it would be nice to have these used for mounting the Speedball.
  • I am thinking about solid silver wire with cloth insulation, and not with PVC or teflon innards.  Does anyone know of a place that sells a decent selection of sizes and colors (red, white, and black)?  I found a place in the UK, but I would prefer somewhere in North America.

So far I'm impressed with the amp.  I didn't think the sound would change that much from the on-board amp on my STX card.  Naysayers obviously don't understand that impedance is only measured at one frequency point and high-impedance headphones like my HD-650s are quite demanding of power for bass.  You need a healthy reserve of power to drive low frequencies. More Updates to come.

Macroscope?

Why in the world are lenses for cameras to shoot small object up close called macro lenses?  You don't look at small stuff through a macroscope!  Macro- is the opposite of micro-.

Neon colors

Neon is a chemical element.  A gas, not a color.  If people still want to [incorrectly] apply it to a color, it could at least be neon orange.

The formula of crotches

This is the formula of crotches.  The formula solves how many crotches something has, where x equals the number of legs something has.


x(x-1)
2

Top front teeth gap

People with a gap between their two top front teeth are alcoholics.

Sandals and flip flops

There should be a law that legally changes your gender to female if you wear sandals or flip flops.

Unicycles

Unicycles are for idiots.  So are pogo sticks and stilts.

Gangrene

The other night I had this crazy crazy dream and it's affecting my brain more than others in the past.


I was in my room and it was dark.  I was trying to change settings on a surround sound receiver because it was staying on even though it was off.  I look down at my arm and it looks all anorexic.  I get into some light and from my shoulder to my elbow my arm is all gangrenous.  The triceps and all that skin are gone, and the skin on the biceps side is already black and peeling away.  A muscle and blood vein must have been still alive because everything on my forearm was OK and I could use my fingers, and I could move my forearm with my biceps.  So I go outside to the garage and ask my friends brother if he can take me to the hospital and he is refusing because he is too busy.  Then I wonder where my car is to find out his mom took it.  She comes pulling up returning home, and hits a curb, going like 2 mph and flips my car.  I flip out, and she gets all pissed at me for being pissed, despite my arm being almost gone.  Then I get my keys back and I drop them on the side of the street where water is flowing from rain and my keys float away.  She gets them and throws them at me.  So I venture back towards my car and I keep seeing random 5, 10, 20, 50, and 100 dollar bills floating in the gutter and in people's yards, so I figure I gotta get my arm amputated, I might as well consider this money mine, I'm gonna need it.  Then I head back towards my car and a bunch of hood rats are arguing with guns, but they leave me alone.  I go to start my car and that's when I wake up for real.


I have dreams a lot about nuclear war and they're disturbing, but this is weird and I'm paranoid about my arm contracting some kind of infection and rotting off.  I went and looked for pictures of gangrenous limbs and my dream pretty much seemed really realistic and graphic, and I never saw any imagery of that before in any form.