This is a continuation of my previous kitchen HiFi modding. Now with replaced electronics for power supply, amplifier and input selectors. Only radio and case stayed the same. So roughly half is made by me.
✍️Motivation
Previously there was here an ancient old power amp chip LA4108, from around 1995 or so when this HiFi was build, with 2 cassette decks. This amp was way too powerful and not quality enough for our times. Since I didn’t need much power, I just remade it with a very simple op amp amplifier, feeding speakers. I also wanted a holder to put my old audio player in place instead of just lying flat and hardly seeing its LCD. Lastly my mother found it hard to see what to press for radio and lost the volume knob behind our kitchen stuff since I moved it on side.
Op-amp amplifier feeding 2.7 Ω speakers through 47 Ω resistors. I still had OP275 lying around since like 2002 so I used it. Well it could be NE5532 or anything really. I didn’t bother with any transistors (class AB or A) at all to boost current or more power op-amps, because it was enough and we don’t need to hear it too loud 🔉🤫.
Selecting 1 of 3 audio inputs from: FM radio, player (Sansa Fuze+ with Rockbox firmware), and external audio cable (going from my room to kitchen, analog but through Ethernet cable). This is done using a MCU (worst for today Teensy 2.0, only because I have bought it long ago when I started and wanted to use it for any purpose finally, it’s ancient 8bit and 5V too, while I moved to 3.3V in my keyboards and all). Code was like just 50 lines, 3 buttons, 2 outputs for old 12V stereo relays, and 3 outputs for LEDs to show which input is selected to play.
Power supply for player 4.1V not from battery anymore, slightly with noise due to this. Op amp uses +-16 V from 2 regulators LM317 and LM337 from a 15W transformer (could be less, but it’s what I got since years waiting, not used). Another with 12V for relays, and 5V for MCU. So yeah kind of nuts 5 voltage regulators here. It’s likely the reason it takes 3.5W from 220V wall, already doing nothing and about 5W doing something.
⌛Conclusions
Well half of my conclusions are already in my previous project for this HiFi back there. I.e. no reason at all to buy new stuff, better to modify this over 20 year old classic, especially after I painted it so funny. It was also working so best to extend it further and make it better for me.
So far I can say it is a joy to use and really good audio quality for me. I didn’t hear any noise, especially not like before. I hope it will last for few years at least, until I come up with something new I’d like to add. Or possibly get my stuff from inside and use new speakers, who knows.
One definite down side is that it took me about 5 days of holiday to do this, so it was way more than I’d like and lots of work still. Another bad thing is that it uses 4 W power constantly, likely just because of so many voltage regulators here. But I won’t complain about this. I got more power lost in stuff that’s constantly on in the house all the time.
I described here my PC and its water cooling (WC). It also features my own fan controller, which motivated me to finally create this page. Obviously, I’m using my own firmware in heavily modded keyboard with my PC.
I got my first PC in 1992, as seen in my very first post here. I had many more since then. I’ve put my full PC history in last chapter, at bottom.
Until 2004 I had no big issues with PCs and their noise. Those had 2 medium fans (about 9cm), one on CPU other in PSU. Surely those weren’t quiet (just cheap) and were mounted firmly so their vibrations were even amplified.
Before WC
In 2004 I bought a new Pentium 4 and decided that I had enough of that noise, “a PC should not be heard” I said. So I first started buying “quiet” fans:
Well the small 9cm: Zalman CNPS7000A-Cu wasn’t that great, was full copper (whatever, too heavy), and with so little space between fins it was great at gathering a lot of dust, but it had a nice knob regulator.
Years later I found a good one: Scythe Grand Kama Cross 2 for next CPU. It’s big but not very heavy, and has a 14cm fan which actually makes it way quieter. It’s still used in my mother’s PC.
Well that was rather a waste of money. Not very expensive, but not very quiet either. Yes until now, I’ve spent much more for WC in total, but it was used in 3 PCs already. I’d even say it was more universal than those “quiet” PC fans dedicated to some socket or one GPU type only.
WC Kit
I bought a WC (not to confuse with ?) kit from a local company Cpc/Hydrox. Needless to say they changed company name like 3 times, didn’t last long etc. But sometimes their parts still appear on auctions. I even sold my surplus once this way. To put it short, their cooler was crap, their WC PSU plain garbage (cheapest and also had a loud fan), water pump is just a cheapo for aquarium. So a kit was really a bad way. But water blocks were cheap and really good.
My PC evolved the most since 2004, when I bought that Pentium 4 and started water cooling it. My current PC still has most of the WC parts from that time (water blocks, 6mm (~1/4″) tubes, water reservoir and pump).
My choice for that kit and 6mm was its low price. Seriously, whenever I tried looking at other water blocks after (thinking I could maybe improve mine), all were 10 or 12mm (~1/2″) diameter and literally 3x more expensive.
PC WC Modding Rant
Back then, once a while, I was looking at pics of modded water cooled PCs, with “style” and plenty of lights too. How do I put it, just IMO OFC, let’s just say that’s the most illogical (retarded) thing to do with a PC. It’s the same approach as in modding cars. It’s a huge profiting business, a hype and really nothing more IMHO. Apart from water cooling, which is the most logical way of cooling, but for PCs it is way overpriced. Modded PCs are the culmination of commercial stupidity, visible from a distance and eye catching (i.e. self promotion).
For me it was a matter of how loud my PC still is, best measured in acoustic dB. Just like I said: “a PC should not be heard”, I also add: “and should not emit any light” or otherwise be visible even. Of course, since my PC is on floor under own desk, I do have some white lights to make it visible when needed.
And it also mattered a lot more for me to have other modifications. as described in next chapter.
Radiator
I changed the radiator from kit, to a decent (got it used) copper for one 12cm fan. It was too small as it turned out. Water was heating up, fan didn’t manage to cool it when CPU was at maximum. At some point I had two such one fan coolers. I think it still wasn’t enough, definitely not for CPU and GPU, and too much tubing trouble. So at that point I bought a 3 fan radiator Black ICE GT Stealth 360 and I’m still using it today. It isn’t very deep and it’s easy to vacuum clean the dust from it. I do this like once in 6 months.
After moving my PC to WC (water cooling, right), I surely hated every CPU stock fan, especially those loud, stupid, cheapest Intel vibrating fans. I once even just cut off that fan of radiator and mounted a quiet Noctua 9cm fan above it, this worked well and was way quieter.
Fans
At some point I searched for quietest fans. After I think 4 tries I settled for Noctua. It actually varies from model to model. And the downside is their ugly, distinct color, which I didn’t spray black, I don’t want to risk damage.
For the radiator I bought 3 Noiseblocker fans (to be cheaper than Noctua and black already). They also have those rubbers good for mounting on radiator. I’d say they’re okay at low RPM, but not when higher, I can hear some motor noise.
HDD
Naturally after having CPU and GPU water cooled and quiet, the next thing is PSU and HDD.
HDD is easier. I used to wrap it in cloth, but this makes them too hot. So now I have one in some foam, covered by some old noise reduction foam, with the back being open to air.
PSU
I did try 2 noiseless fanless PSUs in 2004 or 5:
Yesico FL-550ATX, a heavy tank (big parts) that was always hot, but quiet
and Seasonic X-460FL, a light empty, too expensive, low power PSU, that wasn’t 0dB quiet, it had some high frequency hiss noise.
After Pentium 4 for better GPUs, I needed more power but there were no such fanless PSUs. I made a very stupid thing and tried using both fanless PSUs in 1 PC. Just connected their grounds and I killed Yesico this way?☠️.
Finally, some time later I found an awesome PSU: Antec CP-850. I even bought a 2nd one for my other PC, a year after. It is bigger then most though. Inside, it wasn’t freaking all cramped to still fit the old retarded dimensions from very first PC ATX PSUs. It is just stupid: airflow is chaotic, no space left, all big hot inductors are nearby big capacitors (which don’t like heat) etc.
Bigger PSU is spacious inside and its design with components in lines is good for airflow, thus the 12cm fan is rotating very slow. BTW I eventually replaced it to a quieter one. There is a big surplus of power 850W, I’m probably using 130W to 300W. So it won’t heat up and suffer from it and/or make noise.
Case
Yes the Antec PSU is bigger and won’t fit most PC cases, at the time there were only 3 available for it, but that was just a stupid commercial for their products. PC cases are likely my last concern and I buy them as rarely as possible. I used this PSU outside of my PC case from 2008 for 15 years now. My other PC has it on top. Eventually I moved to even smaller PC case and I placed it inside, thus making it look like it does now, sticking out.
🛠️Modifications
Apart from water cooling things, I have many utility mods for (or in) my PC:
external relay 220V to power water pump, and DAC (earlier audio amplifier) when PC is on
for years I had just a simple analog knobs for PC fans, now I have my own fan controller
2 USB switch I use it to switch my keyboard and mouse between my PC and a laptop. Works like a charm, I can’t imagine not having this now. I did it on a universal PCB with relays, since I had them available, but they do use 2,5W when on. There are 2 USB input ports and 4 output USB cables: one pair to PC and other to laptop. There are 6 relays, for 5V, D+, D-, and GND is common.
external switch for monitor input, near keyboard This was a bit tricky. I had to disassemble my decent LCD monitor, get to the switch, solder some wires, and add a long 2m cable with external switch. It is extremely useful, I don’t have to lean to press and wait like that too.
📜My full PC history
Well this chapter is very optional, since it has quite nostalgic value for me, but otherwise it’s just mostly (ancient) history. Yeah, it’s almost 30 years since my first PC.
Legend for the below table:
? – I’m not sure about exact amount or date 💀 – Dead, it broke by itself. Obviously very undesired. 🔨 – I killed it, so my fault. By bad overclocking @, or by accident otherwise. ♻️ – Sold it, eventually. 🗑️ – It became electronic garbage. ☑️ – Still using it.
As a kid I didn’t have new PCs too often, they were also getting faster and obsolete quite often. Then after a brief period of having newer hardware (mostly GPUs) somewhat often, while most of them died too early I think I realized it’s not good to buy (they’re soon to be garbage anyway).
Later I realized that since years CPUs don’t really get much better, yet they do cost same or more. Thus my CPU and MB is still from 2012 (happy 10 years man). I did have them overclocked for few years, but now I even don’t. It gets 30% faster, but uses 30% more power. So I’d rather have 100W (not 130W) at idle, when I just listen to music or watch something. I don’t need that extra 30% like I did when I was building C++ often, for Stunt Rally.
After all PCs are just tools (and not just gaming like consoles) but for learning, creating and entertainment too. So naturally buying a PC is an investment, that has to be done rationally.
Some time later I decided it will be better to buy (instead of new PC) a new ergonomic chair (for PC) and a bed. Those are similar priced but much better for health.
➡️End
Well in Sep 2023 I bought a new PC, even with case, only PSU still same. Added it to history table. It feels way faster than my previous, like 3 to 5 times. It seems I’ve skipped a new PC (CPU+MB) somewhere along the last 11 years. I always aimed for new PC to be at least 2 times faster to not waste money and time for updating. It needs some time to update, like a week to choose right components, move OS setup, etc. I cleaned dust in this now old PC and moved to air cooling again, then set it up and gave to my mother. Replacing previous one, which was way too slow, nowadays even movies were not smooth. Yet still almost all PCs of mine drain above 100W at idle. Well it’s good to update and do stuff faster, but of course still a high cost for new technologies.
At end of 2021 I bought a WLtoys K969 RC drift car. I will describe here all the modifications I made to it. Also with few review remarks about it, less important comments and rants are italic.
Video here. Drifting in empty office on carpet and kitchen floor (best of montage). Camera was just from old phone: LG K10 2017 Car camera: Ion Snapcam LE, like mentioned below Software used to for video eiditing: Kdenlive on Debian GNU/Linux with KDE
📜History
I guess I should write this chapter here, since being almost 40 requires (an attempt for) an explanation ?. Well, as a child I only had a few (probably Russian) cars from 80s, Two did have a cable from controller, and the one that was radio controlled had only 1 button to go backward, which also made it turn. Yeah I also can’t even. As a teenager, at some point I got an RC car. It had rear wheel drive and used 27MHz. I think I drove it only 2 times. It was fast and meant to drive outside. It had rubber tires so it stuck to asphalt and would rather flip over instead of sliding. It seemed kind of hopeless (compared to today RC toys) and felt like something is missing.
✍️Motivation
In the mean time I got interested in WRC and 4WD on gravel, played a couple of such games too. And finally made my own Stunt Rally. There was a time when I was a lot interested in tires and car simulation.
Recently, once a while I was watching various videos about RC toys. Technology moved forwards a lot in them too. This way, I found out about RC drift cars of 1:28 scale, and after days of watching videos and researching what would be cheap, but still good for drifting at home (or office) I found this WLtoys K969 and saw how it drifts at home. I think I watched later other 1:28 cars (like Mini-Z, Mini-Q etc.), and realized that even thought they are much more expensive they aren’t much better. At least for me as a first car, I don’t intend to drive RC professionally or on tracks. There are also cars and people who prefer RWD only drifting (front wheels move freely), but I was never a fan of that.
So I think this RC is a nice, real life example, even if in smaller scale. It surely reacts and changes direction much faster than real cars. But is certainly less complicated, has no: LSDiffs, torque curve, gearbox, central differential, etc. In this RC all wheels rotate the same, electric motors don’t even need gearbox, suspension has only stiff springs, and there is no flexibility in tires, since those are from hard plastic here.
🛠️Modifications
So the things that I changed and added first to last are as follows:
Moved the pin from servo‘s steering arm higher for more steering angle range. There is a video here where it was easy.. But, a huge but here, as it turned out (for me) the upper hole for this screw is wider and I couldn’t just simply use the same screw from lower hole. Thus I had to go creative to achieve this. Since I soldered a lot, I came out with a solution of putting few wires together for right diameter, then soldering one end to a tiny PCB part (with 1 hole), and just bending 2 wires out of the other end. It still holds well. Visible on my last picture. I guess this isn’t that important but is very good to have. Without this, steering angle is lower, making wider turns, but you still can make tight turns by drifting with quickly spinning wheels to oversteer (lose grip on car rear).
Made throttle range adjustable. How to video here. BTW I recommend that channel, it has many good videos including for this RC car. This is actually the most important one. Without this it will be difficult to not spin out wheels all the time. For small rooms, throttle range needs to be even lower. Of course they made the car to be cheapest, and even didn’t add the most important adjustment to it, I didn’t need those side buttons, so why not having this instead. Meh, always have to make things usable myself.
Added more weight on front. I cut out a universal PCB (my favorite kind) and made a place to solder down wires holding extra weights, they fit well. I used 4 in total, 2 on each side. One weights 4.5g, so this is 18g added on front wheels. This made center of gravity to shift (like 6mm or so) towards front and made the car oversteer even more, it drives better. There were some videos on doing that, just gluing 10g weight. Isn’t crucial though, still can drift without this. My front PCB is also used for lights and wires.
Added front and rear car lights. They are good for better orientation of how the car is rotating and what’s its direction. I mean it is actually easier (for me) to tell this by seeing those lights on floor, especially if car is far. The only way of doing this is making holes in chassis and hot gluing LEDs to it. I’ve spent too much time with lights, first making them in car. This way anytime I hit something harder they would change angle, go loose or break off. I also made a second mistake and made holes bigger to have LEDs with cases. It turned out the cases were too big and so long that made wheels hit them, if chassis is low. I will cut them to minimum and glue again. Good thing about that hot glue is that I can actually melt it with soldering iron again when I change my mind.
Made the RF sender battery use a 18650 LiPo. I don’t get why they didn’t already (was probably cheaper). When full, 4 AAs give 6V, LiPo is 4.2V, but RF sender still works. I thought it would be more difficult, but it was really easy. Just throw out 4AAs compartment and place the 18650 or any other LiPo here. Doesn’t seem to use much power, I didn’t charge it for a month or more. I only don’t know if it maybe decreases range? But with all being digital it may not be affected.
Added bottom lights. I had some old LEDs lying around, now 2 are on rear before wheels and 2 on front before wheels. Their location with chassis holes makes this cool blue X on floor now. I had only two 3mm LEDs so I also used 2 SMD LEDs, which I soldered out from those LiPo chargers (who needs them, red when charging is enough, and were so bright that I couldn’t even?). Then I added two 5mm LEDs (too big, SMD are better) green on left side, yellow-orange on right, located right after and above wheels. This turned out to be useful to know even better how the car is rotated from distance. So later I added same (close) colors to front, behind wheels. I soldered all on small cuts of universal PCBs.
Changed to a bigger car battery. The included 400mAh battery allowing 30 min runtime is laughable. Yeah I can’t imagine drones with 15 or less minutes at all. It was cheap and light, which is why they made it, right. After all, the freaking top speed has to be highest, like it was important at all. It drifts at much lower speed already. My new battery is 1200mAh and allows 1h 30 min drive time (so 3x more). It was made from two LiPo 603450 batteries, each size: 50x34x6mm. Glued with tape, fits nicely in same place, is just much higher and it weighs 45g. Secured it with some cardboard and mouse pad fragments on sides and wire (with thick insulation). I just had to remove their protection, because with it, it would stop for few seconds when pressing throttle too rapidly (very annoying).
With new battery I’ve also done new electrics in car. namely:
4 pin socket for battery, normally plugged in.
ON-OFF switch. I used a 6 pin Tactile Power Micro Switch (self lock on) 7*7mm to switch + from both LiPo batteries.
4 pin socket for charger, plugged in when charging.
4 micro switches for lights (on-off, one small package). I added 47Ω resistors at end of each. I call this a fuse box, their purpose is prevent battery short circuit if by accident some wires connect.
5 pin socket (3 used now) to connect chassis lights.
2 trimmer potentiometers 1kΩ, for dimming car lights and bottom lights.
All this required access, so I made a “door” in half of car’s front windshield.
In total, the boards with bottom LEDs and all electrics weight 27g. Seems too much, but whatever?♂️. Each LED has a 330Ω resistor before. LED calc can be used if needed.
Charger Made using 2 popular modules: TP4056 / TC4056A Lithium Battery Charger and Protection Module. Just added 4 goldpin connector for car socket and that standard 4 pin PC connector for 5V. It does charge the battery in about 1h 30min. I’m not sure if it’s too fast or okay. The 4056 chips are heating a bit too much (at start), so I’m using a small copper radiator on them. Besides of removing blue LEDs from chargers (mentioned earlier) I also reduced the red LEDs brightness, resistors are now 20kΩ (way more). I hate this approach of adding LEDs, even for “turned on” indication and making all LEDs as bright as it can be. I guess if they could they’d made them visible from space or neighboring countries, that would be the best commercial?.
Radiator for main motor. Having more time to drive showed that it heats a lot, especially in smaller rooms. So I used thermal glue and glued some small aluminum radiators (1 cut to match motor length) bottom to motor and side to car bottom, which is aluminum, so good for cooling too. I’m guessing an even better way could be using copper tape around motor and gluing that to car bottom? Not sure. Either way some cooling is needed and would be better to have it done already.
Added some rubbers (cuts from mouse pad) below chassis mounting points (I saw something similar in a video). And later some foam around the car, better late than never. This is to soften hard hits, those happen a lot at start when first learning to drive, especially without reduced throttle. Additionally, at home I do jumps sometimes, banked and U turns (up to like 80 degrees, on a bent sheet of metal I had in cellar) and flip overs can happen this way etc.
At some point while reversing I almost broke one differential end (those, like all parts are plastic). I only noticed when one wheel wasn’t driven. But I managed to put it together with a wire soldered around it, so it doesn’t fall apart completely and works, a bit uneven though. Parts are freaking expensive, probably few times more than their worth. I hate this approach. If someone bought all parts separately it would cost like 2 or 3 times more than the car itself. Plus the waiting for shipment takes time.
After some bigger hit, I broke the thing that holds chassis on front. It is filled with holes and plastic, so no wonder. I made something stronger (and heavier like all I did) from a metal part, M2 and M3 screws. Is more difficult to use but should last longer, if I don’t break the plastic part that it’s mounted to.
Added a mount for camera on roof. Camera is Ion Snapcam LE, it weights 28g, with its own battery. It even lasted longer than car drive. I didn’t yet make it lighter by using car’s battery. Not sure if I will. Unfortunately, videos are horribly shaking when driving, because of uneven wheels.
In total the car with camera weights now 288g. So it is a lot more (was 160g at start) and the front suspension won’t allow more. Without camera and extra weights it is about 240g. I think it still drives well despite the extra weight. But surely when lighter it was quicker and more responsive (less mass and inertia).
Now I’m waiting for new wheels, with aluminum rims. The default wheels on this cars are cheap, all-plastic and uneven. Even like 1mm difference in height when rotating. This makes the car shake a bit. Surprisingly it doesn’t affect driving somehow, and it wasn’t easy to spot. Only slow time videos showed it and those from car camera, which are rather unusable.
Maybe for future (not sure if I’ll try/do any of these): I was thinking of making the controller use IR distance detection for throttle (instead of potentiometer which I already once cleaned since dust made it go chaotic). Using a MCU (Teensy 3.2 which I have lying around doing nothing) with LCD, buttons and rotary encoder for a GUI that allows adjusting all ranges and offsets without potentiometers. I also had an idea about having a light MCU in car to use RF (e.g. NRF24L01 2.4GHz modules) to send some measurements to controller MCU, like: battery voltage (for remaining drive time), motor temperature, car acceleration, rotation and direction (from those popular new accelerometer chips), and making all car lights toggleable and dimmable (with PWM) from controller. Lastly very doubtful, but maybe if I used PC mouse optics and chip I could get real velocity and position on some surface.
⌛Conclusions / Review
I personally can’t imagine having fun with an outdoor, fast / touring car, with rubber tires. Neither with a smaller car that doesn’t have 4WD and drift. And those big RC cars that can slide on gravel (and jump up few meters) are quite big, very expensive (I seriously would buy a new PC instead) and require a big area or a track. And outdoor and indoor tracks aren’t close, are likely paid per hour and have other people. Plus parts for more expensive cars are of course more expensive.
To summarize, I would recommend the WLtoys K969 car, especially as first RC car for indoor use, with more fun because of drifting. But with a few remarks.
I don’t really recommend driving this car without modification 2 (throttle range adjust). I did it at start and it was chaotic. Some say modification 1 (more steering) is also crucial.
Another thing that many say, is that the 2 smallest gears wear out rather fast. Those that drive each differential, both from plastic again. Why on earth aren’t all gears from metal.
Well as I mentioned few times already, nearly all parts are from plastic, which can be a problem. Surely is for small gears. Later if you drive on uneven surfaces or jump, etc. then mountings for suspension will wear out or break (since closest to floor and from plastic). Still (and maybe that’s why) there are many metal upgrade parts and kits, but I don’t recommend any, at all. I have seen too many negative comments from people who say that those don’t even fit together, are bigger, leave less clearance etc. So they just look cool, and that’s it.
The rest of my modifications were optional and just an easy hobby, that lets me spend some fun time, but not with my PC as usual.
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.
The newer two of my heavily modified keyboards. This time having Teensy 3.1 (or 3.2) as microcontroller with a tiny 1″ monochrome OLED display. Firmware was based on Kiibohd, it was a fork with my extensions. I added display support (with a library), menu for editing e.g. macros/sequences, few demos and a game. I did improve them further in my newer firmware, with bigger display.
🛠️Modifications
The first operation I did, was cutting off most of all rubber domes. This makes the keys much softer to press, so needs less effort or fatigue. The result is minimized pressing (actuation) force and distance. Simply more pleasant and comfortable. Also healthier, since the risk of keyboard injuries decreases. I already did that earlier on my two oldest keyboards in 2005 and 2006.
✍️Motivation
Originally most keyboards need about 50 gram force needed to press keys, and probably 4 mm distance. After cutting, the distance is about 1-2mm, the force is at 23 gram for CK3 (top), 33g for CK4 (bottom) and 9-18g for CK5. This can also be varied per key (more detail can be seen on pictures (galleries below), but ultimately the lowest value depends on keyboard’s foil thickness.
⌨️Additional keys
For CK4 there are also few small extra keys. Which were present already in my earliest keyboards CK1 and CK2. Those are glued on top and are made from lightest 0,5N switches available. The row above numpad is used for my audio player control. Rest is custom. This part is optional and I didn’t do it for CK3. The disadvantage is the difference in pressing those switches and much lighter normal keyboard keys. They are smaller so you can fit more, but are less convenient to press. Lastly, regular keys can be used to switch layers instead.
⚙️Microcontroller (MCU)
The second step was replacing the keyboard controller board, with my own. The hardware is composed of Teensy 3.1 (or 3.2) with a tiny 1 inch OLED display (SSD1306, monochrome, 128×64) and a bunch of wires to connect to the original keyboard’s matrix.
The reason for this was to take advantage of already made open source Kiibohd controller allowing any imaginable keys assigned and layers. Also possible are macros, key combinations and even mouse buttons and movement simulation. But changing any of this required rebuilding controller software and uploading to controller, through already present USB.
It was a bit simpler to start at the time, instead of writing my own later.
📊Features
After getting it to work, I implemented my own menu where you can edit sequences, stored in memory (remembered after power off). The sequences are very useful for not typing passwords or simply binding some useful macro combinations or commands dynamically. Which needed a display and menu for entering.
Once I’ve done the useful stuff, I got carried away and implemented several demos on display and even a falling blocks game. I also wrote about it in this forum post.
📂Sources
The code is in my fork here with some more detail.
📷Galleries
There are picture galleries below, also from assembly and videos.▶
All galleries up to now, from my keyboards are as follows (newest first):
Most pictures have some description text (explaining what I did there).
This is an older topic with less information, just for history purpose. If you’re interested see my newer keyboards or the newest ones, with more explanation, own controller and display.
These were my first modifications for keyboards.
They were both done on a Logitech Ultra X Flat, a well done, solid keyboard. Surprisingly different for same model made after 1 year.
✍️Motivation
Originally most keyboards have about 50 gram force needed to press keys, and probably 4 mm distance. After first step of cutting rubber domes the distance is about 1-2mm, the force was about 22 gram for CK1 (bottom) and 33g for CK2 (top). This can also be varied per key.
📊Features
The second step was removing the middle part with arrows. Which I find unnecessary and worse (less keys) than the same from numpad. In CK1 I’ve bent the foil and hid it under. It was risky, but the foil survived. The CK2 was different, it was made from two identical keyboards, thus no need to bend, only cut the metal and foil. That too was risky since the foil could have connections around the cut off part. It was only for numpad, the bigger part had whole foil under.
Years later I modified CK2 further and bent the foil to create CK4 keyboard. And that’s 11 years already, so this would answer any doubts for longevity of such modifications. The number of times I disassembled it, changed something, and put it together is also quite high.
The third step was adding extra keys. Using my oldest program for showing pressed keys and their codes, I figured out that there are more possible keys in keyboard matrix, that are just not connected. So I added them with wires and glued on keyboards. First as regular switches with metal domes, small and hard to press. Later using rubber switches, lighter to press. But turned out to be an even bigger fail since they wear out and stop connecting. They have some resistance too (like maybe 300 ohm) in addition to the resistance of foil traces (maybe 150 ohm). So finally I ended with the smallest metal dome switch I found, with force 0.5 N (50gf). It feels different than other keys but otherwise is good.