Mark’s Repair Blog


Welcome to my tech blog page! A brief summary what you can read/see here:

All about my audio repair
I’m not a professional, although I’ve been busy fixing audio equipment for quite some time now. I don’t nearly know all about repairs, but since a lot of defects are related to its age, years of use, wear and tear a lot of fixes are in essence the same.
As an amateur photographer I usually make a lot of pictures with my DSLR or smartphone to keep track of repairs and document the constructions during disassembly. These come in very handy to reassemble the device, but also to illustrate repairs in a blog.
A lot of interesting work has been done a long time ago but I hadden had the time to put all together in a blog post. I will add those as well and change the date back to the time I was working on these repairs.
A nice timeline will then eventually start to show in the index on the right hand side of this site.

DAC and transport list CD players
My interest in the Philips TDA1541A and TDA1547 D/A converter and the search for affordable and good second hand CD players asked for a good source of CD players and what type of DAC and transport/laser unit is used.
I combined several sources and created my own list and uploaded it into a WordPress table. Now I can easily search for brand, model, DAC or transport type as I ran into an interesting sale.

As mentioned before, this list is a combination of several lists everywhere on the internet and deduplicated. Any fault I found base on my own knowledge/experience and information elsewhere on the internet have been update up until the date below.
There will still be errors in the list, I’m trying to keep the list as frequently updated as possible but using this list is your own risk. I cannot be held responsible for the content of the list.
The total list now holds a total of over 4000 CD players of all kinds of brands/models. If you have your own list or if know new brands/models, corrections in the current list, please let me know, then I’ll add those to the list.

Moving Message / LED displays development
Since a few years my interest have started to shift towards development of digital circuits, printed circuit boards, 3D designed and 3D printed items. So a move towards to the more creative side of me.

I own a Snapmaker 2.0 3D printer that is also capable of laser engraving/cutting work (only 1.4W) and CNC milling. Haven’t tried out the milling feature yet, will do soon!

That has come to a new section on this site, that leans more towards the development of something new in order to get something working again or give/add new features to a device. These devices are LED message boards in all shapes and sizes.

Those old 80’s and 90’s style displays can be found on the second hand market, in many cases incomplete and/or non-functional. RS232 interfaces are common on the business line of those displays before infra red remotes came and option. Nowadays RS232 is nowhere to be found on a modern computer. RS232 to USB converters often aren’t completely compatible. That creates the opportunity to design and build something new and “upgrade” these displays to simplify the use.

One of the projects I’m currently working on are wifi enabled displays (based on Arduino board) that host their own wifi network and web site to configure/setup that device. No more RS232 or USB cables, just your smartphone.

These are the subjects of new projects that, from time to time. I will write about on this site.

Last updated at: January 12th 2023