Crystal Hammer

⏱️Overview

This will be a somewhat unusual project post. I normally don’t show off stuff that didn’t need much creative work, but in this case it has a very long history (since 1997). It has gone through many modifications and it is still used every day, now in our kitchen for playing music.

📷Pictures

Gallery here.
It has pictures from 2020 and up, showing old look and the newest merge of 2 HiFis. Needless to say, their cases weren’t compatible at all, so there is a lot of black tape around.

📜History

It all started as a Panasonic RX-FT530 Dual Cassette Player. My mom bought it for me in 1997 (its production date inside has 1995), before I started technical high school. It was also around the date when I started learning electronics in practice and later in theory (from 20 years ago) at school.

Since then it has gone many changes and had lots of features, many of them aren’t present now:

• Blue LED for radio stereo indicator. Obviously, the first thing to do.
• A switch for super fast cassette rewinding (Do feel free to spool through). Tape looked after a bit uneven inside, but very useful.
• Green LED lights under both cassette decks (in middle) to see where the tape is at (how much on left and right barrel). Also extremely useful.
• I removed the closing decks, and was just having cassettes clearly visible while using.
• A small LED for the marker on frequency ruler for analog radio. I think it broke at some point leaving me without a ruler. I guess due to putting it apart and together again, fast and too many times, while not caring much where I place its parts.
• Not sure when, I splashed it with (white, silver and gold) oil paint?, from PCB markers I had back then (obviously too many).
• A digital clock, at some point on right side. Wasn’t very accurate so it didn’t last long there. Left a switch and 4 places after its buttons in back though.
• More input sockets, output audio socket to other amplifier, switch for it etc.
  I remember at some point of experimenting with other amplifier I accidentally put like -30V into HiFi, killing its power AMP chip. Which I then replaced, was a good challenge. While still being a teenager I obviously needed this HiFi.
• Since these became not needed later, all holes got covered with black tape (at least 10 already, in total).
• At some point I added a 5V regulator 7805 and USB sockets so I could power other devices from HiFi, e.g. a clock
  (Instead of ridiculous AA batteries. One can use a 3V regulator or a resistor (e.g. 200Ω) with 3V zener diode).
• It has spent a few years, abandoned in cellar. Gathering dust and wishing for a better future.
• Many years later, I ended my history with cassettes (recorded them on PC into FLAC and OGG, and threw out after).
  In 2020 the cassette decks (with all that mechanical nonsense and engine) flew out to electronic garbage bin too. It was just the amp and radio then.
• I wanted to have a digital radio, that stayed at given frequency. And BTW a MP3 / USB player, why not.
  So I ended buying a cheap, local, 2nd HiFi (anyway with Chinese components) which just featured both. It had crappy sound due to small speakers (no bass at all), we used if for short, but naturally I wanted to merge its insides into my old speakers from Panasonic.

🔍Details

The final “HiFi” currently features a digital radio, USB or SD card player (from that 2nd cheap “HiFi” product) and analog input.
Its radio forgets frequency after power off though, so power is always on. It was too in Panasonic, IDK why, using about 0.5 to 1W constantly, power amp is likely always on.

I scrapped that stupid Class D amp (MIX3018) from 2nd HiFi, I prefer that AB, although it has too much power. Then located its audio outputs and connected to old LA4108 power amp (low quality, too much power), but with better quality anyway.
Later I also added a double potentiometer (which I even had available) for volume on front, since the original was making noise when turning.

I will eventually just use op-amps to speakers someday, and will throw out the big old PCB too, from which just 20% is now used. Then it will be just speakers and case from the oldest HiFi.

There are now 3 extra buttons on top (power on/off (hold) / input, next and previous) to control 2nd HiFi. Light press switches, 0.5N force, my favorite. I put rubber cover on top, to protect form any liquids💧, this is kitchen after all🫖💦.

For a while I had a cheap tiny Bluetooth receiver in analog input, powered from USB, but I dropped it, too much noise and once a while it did reconnect etc. Audio cable is more reliable, even cheaper.

I still use its regulated 5V outside but in different connector (PC like), to power an outside thermometer (was from a PC case) and a digital LCD clock.

Lastly I added a small white LED lamp, that’s always on, and helps moving around the kitchen at night, before reaching main light switch.

⌛Conclusions

So: why didn’t I just buy a new HiFi that already has all those features, instead of continuing with this old junk?
Several reasons:

• Firstly, there is no such thing as a product that has all features / properties that I need, with proper control and interface (knobs, convenient buttons, menu, etc). This can only be achieved by continuing to develop it myself according to my current needs.
  I now see all electronics products just as ingredients for further modification. Ideally I would create one from start, but that’d be too much time and effort spent, just for our kitchen.
• Secondly, I am an anti-consumer, I usually hate buying. It needs a lot of time for research, to find a product that is closest to: not a hoax/hype, reliable, functional, fair-priced, still cheap, durable (will work for long), allows repairs, looks okay, black, etc. (all at once; add needed, strike out not needed ?). On top of that I don’t like spending money (I like saving it) to support companies, which constantly produce (soon-to-be) garbage.
• Lastly, it is a fun and easy hobby that grants better more customized products for daily use.