CRT Micro - A Modernized Piece of Tube History
5/20/2025:
This is the worklog for the CRT Micro, a successor of the esteemed CRT Mini that I made, featured at MGC 2025!
The CRT Mini for reference:
5/22/2025:
My general idea is to make a DAC with all of the features (plus more) that was in my CRT Mini.
The feature-set is as follows:
I want the CRT Micro's board to be able to be used with a wide variety of viewfinders that run off of 5V; however, you could supply different voltages if required, but the final assembly wouldn't be as small. The CRT that will be in the CRT Micro is from a Sony Camcorder, CRT:M01KQM07WB; though, the CRT also has this model number on it: 451-310-21.
6/4/2025:
I started working on a PCB referencing schematic for the PAM8403 Audio Amplifier and the MS1836S HDMI to AV DAC.
The footprint is 80mm x 26mm.
6/13/2025:
After lots of work I completed V1 of the CRT Micro Board! Here's what it looks like:
6/14/2025:
I just put in the order to JLCPCB, I decided not to include some components in the SMT Process and opted to solder the HDMI Port, C44602, Analog Dial, and the Interface connector, which saved me a good amount of money!
6/20/2025:
The PCBs arrived! I tested the boards and they didn't work. I know the schematic I referenced had to have been good, so I must've made an error. I still need to wait for the parts that I need to solder on by hand to arrive so I can fully test the board(s).
6/27/2025:
The other parts that I planned to solder on arrived! (I have a lot more than just these obviously)
7/8/2025:
I assembled the boards but they didn't work! After testing some issues it just involved removing 2 resistors and bridging one of those connections. It required some small soldering, but when I order revised boards in the future, the issues will be fixed. In fact, I've already corrected and revised the PCB file.
7/9/2025:
I tested all of my connections, another thing that I forgot to mention before, is that I used THT HDMI Ports, which were very pleasant to solder! A lot better than some SMT ones that I've soldered in the past.
Later that night I was able to do a very basic test with the board hooked up to my Bench Power Supply, and it went great! Here's how it looked! (note: It looked even better and sharper in person, but my camera didn't do it justice)
Things in front of screen for size reference and resolution: (on the left is 34 AWG Magnet Wire & on the right is a Ball-Point Pen):
8/24/2025:
Earlier I said that I wanted to have an Expandable Docking System as one of the main features of my project, well here is my solution. The CRT-Micro Breakout Board! This board has many pads for expansion; such as, Left and Right speakers, Composite video output to go to the CRT, and Voltage pads for 1.2, 3.3, and 5V. On later revisions of this project, I'd like to swap the speaker pads for L and R audio data, or just make it a 12-pin connector. (note: the model in this photo has the connector on the wrong side of the board, an oversight I had while making the render. No difference to the physical PCB though)
8/28/2024:
The boards arrived and they look great!
9/12/2025:
I did this earlier for one of the boards but never noted it; I added small 7x7mm aluminum heat sinks to the main chip on the CRT-Micro Main-board. This helped the chip to dissipate/get rid of a lot of heat, and it runs amazing now!
9/13/2025:
My last Summer Project, the PiPal, had pretty thick walls, and I want to stray from that because the goal of this project is to be expandable and compact, so I've aimed for walls with a thickness of 1.25mm. I spent all day doing the CAD and printed over 10 bottom shells to make sure everything fit just right. I also bought some speakers to go with the board in the shell of the CRT Micro.
9/14/2025:
Here is the finished top piece for the base of the CRT Micro!
9/15/2025:
Here is the finished base for the CRT Micro! It has rubber feet that are recessed in the bottom for a clean look, a neat top-piece that brings the build together into a sleek form-factor. There are 5 screw holes, 4 of which go through the top piece, creating an even and sturdy look. The pieces were 3D printed on my Bambu Lab P1P at 0.16mm layer height, with zero supports except for the screw holes for the top piece.
10/3/2025:
I updated the PCB design and breakout boards to include S-Video as well! I also fixed all of the errors from the first version of the board!
10/30/2025:
I've completed everything for this project! Here is a photo dump of the progress that I've made, I'll make sure to include the showcase video further down this post! Thanks so much for all your support thus far! I also updated everything in my design to include threaded brass inserts, so there isn't a possibility of cross-threading any of the screw-posts.
Showcase Photo:
Showcase Video:
CLICK HERE if embed doesn't work
5/20/2025:
This is the worklog for the CRT Micro, a successor of the esteemed CRT Mini that I made, featured at MGC 2025!
The CRT Mini for reference:
5/22/2025:
My general idea is to make a DAC with all of the features (plus more) that was in my CRT Mini.
The feature-set is as follows:
- HDMI Input
- Stereo Audio
- Dual Speakers
- Analog Volume Control
- Expandable Docking System
- Small & Narrow Form-Factor
I want the CRT Micro's board to be able to be used with a wide variety of viewfinders that run off of 5V; however, you could supply different voltages if required, but the final assembly wouldn't be as small. The CRT that will be in the CRT Micro is from a Sony Camcorder, CRT:M01KQM07WB; though, the CRT also has this model number on it: 451-310-21.
6/4/2025:
I started working on a PCB referencing schematic for the PAM8403 Audio Amplifier and the MS1836S HDMI to AV DAC.
The footprint is 80mm x 26mm.
6/13/2025:
After lots of work I completed V1 of the CRT Micro Board! Here's what it looks like:
6/14/2025:
I just put in the order to JLCPCB, I decided not to include some components in the SMT Process and opted to solder the HDMI Port, C44602, Analog Dial, and the Interface connector, which saved me a good amount of money!
6/20/2025:
The PCBs arrived! I tested the boards and they didn't work. I know the schematic I referenced had to have been good, so I must've made an error. I still need to wait for the parts that I need to solder on by hand to arrive so I can fully test the board(s).
6/27/2025:
The other parts that I planned to solder on arrived! (I have a lot more than just these obviously)
7/8/2025:
I assembled the boards but they didn't work! After testing some issues it just involved removing 2 resistors and bridging one of those connections. It required some small soldering, but when I order revised boards in the future, the issues will be fixed. In fact, I've already corrected and revised the PCB file.
7/9/2025:
I tested all of my connections, another thing that I forgot to mention before, is that I used THT HDMI Ports, which were very pleasant to solder! A lot better than some SMT ones that I've soldered in the past.
Later that night I was able to do a very basic test with the board hooked up to my Bench Power Supply, and it went great! Here's how it looked! (note: It looked even better and sharper in person, but my camera didn't do it justice)
Things in front of screen for size reference and resolution: (on the left is 34 AWG Magnet Wire & on the right is a Ball-Point Pen):
8/24/2025:
Earlier I said that I wanted to have an Expandable Docking System as one of the main features of my project, well here is my solution. The CRT-Micro Breakout Board! This board has many pads for expansion; such as, Left and Right speakers, Composite video output to go to the CRT, and Voltage pads for 1.2, 3.3, and 5V. On later revisions of this project, I'd like to swap the speaker pads for L and R audio data, or just make it a 12-pin connector. (note: the model in this photo has the connector on the wrong side of the board, an oversight I had while making the render. No difference to the physical PCB though)
8/28/2024:
The boards arrived and they look great!
9/12/2025:
I did this earlier for one of the boards but never noted it; I added small 7x7mm aluminum heat sinks to the main chip on the CRT-Micro Main-board. This helped the chip to dissipate/get rid of a lot of heat, and it runs amazing now!
9/13/2025:
My last Summer Project, the PiPal, had pretty thick walls, and I want to stray from that because the goal of this project is to be expandable and compact, so I've aimed for walls with a thickness of 1.25mm. I spent all day doing the CAD and printed over 10 bottom shells to make sure everything fit just right. I also bought some speakers to go with the board in the shell of the CRT Micro.
9/14/2025:
Here is the finished top piece for the base of the CRT Micro!
9/15/2025:
Here is the finished base for the CRT Micro! It has rubber feet that are recessed in the bottom for a clean look, a neat top-piece that brings the build together into a sleek form-factor. There are 5 screw holes, 4 of which go through the top piece, creating an even and sturdy look. The pieces were 3D printed on my Bambu Lab P1P at 0.16mm layer height, with zero supports except for the screw holes for the top piece.
10/3/2025:
I updated the PCB design and breakout boards to include S-Video as well! I also fixed all of the errors from the first version of the board!
10/30/2025:
I've completed everything for this project! Here is a photo dump of the progress that I've made, I'll make sure to include the showcase video further down this post! Thanks so much for all your support thus far! I also updated everything in my design to include threaded brass inserts, so there isn't a possibility of cross-threading any of the screw-posts.
Showcase Photo:
Showcase Video:
CLICK HERE if embed doesn't work
Last edited:
