Record Player

Pro-Ject RPM 1.3 GenieI bought a record player in the UK that I’d had my eye on for a while and brought it back to the USA with me, since I saved about 50% on buying the exact same thing over here. I got the Pro-Ject RPM 1.3 Genie in white with an Ortofon Red cartridge and also took back with me some great vinyl that I found at a shop called Stamford Audio in my parent’s tiny village.

One problem – when I plugged it in at my house in the USA, it ran too fast. 🙁

The problem is that it uses a synchronous AC motor, whose rotational speed is determined by the frequency of the AC, which in the UK is 50HZ and in the USA is 60Hz. Fail.

My options were:

  1. Buy a smaller spindle. I ordered one but it was way too small, so I sent it back. I couldn’t find the right one.
  2. 3D-print the right spindle. This requires some skill and access to a 3D printer.
  3. Order a 60Hz motor. I looked into this, and the cost was $100. No way, that’s how much I saved by getting this from the UK.
  4. I’m an engineer – build a 50Hz power supply.

Of course, I picked 4.

Deck

For the last few weeks I’ve been building a deck. My “bible” is the Home Depot Decks 1-2-3 book, which does a fairly good job of explaining how to build a deck to someone with reasonable carpentry skills.

This is actually only my second carpentry project – the first being some shelves in the garage.

If there’s anything I have learned, it’s the following:

  1. Don’t be afraid to buy the right tools.
  2. You will need at least two drills (corded and cordless). You will need a cordless one for difficult areas, and a corded one for the screw that won’t go in or the hole that won’t appear.
  3. You always need more screws/nails.
  4. Measure twice, cut once.
  5. Your posts will try to sink to the centre of the earth. There is nothing you can do to stop it, so you may as well make the posts stick further out of the ground in anticipation.
  6. If you are British, get some SPF-50 and a hat.

Headphone Amplifier

I have a third generation iPod. It still works, so when its battery died, I replaced the battery myself. It still works well. However, this generation has a problem with sound quality due to low quality components used in the internal amplifier. So, I decided to make myself a decent amplifier to connect to the line level output of the iPod. I just had to build it into an Altoids case.

Amplifier

I based it on the popular CMoy amplifier circuit design, and it uses a stereo Burr Brown operational amplifier with high quality support components.

Headphone amplifier

It sounds amazing, and I can’t wait till my new Sennheiser HD-595 headphones arrive. In fact, these headphones require an external amplifier. The iPod just won’t drive them.