Color Classic analog board re-design, needs community feedback.

jonschultz

New Tinkerer
May 16, 2026
5
10
3
USA
github.com
Progress report:

I have started to move parts from one of the original boards, since not all parts are in yet, and it seems a safer bet as to start with fresh parts (except for all electrolytic capacitors)

not done yet, but work is in progress!

once it's populated i will run a test to see if the power supplies work, before trying it out inside the color classic. ill keep you all posted!
The board looks great, awesome work!
 
  • Like
Reactions: JDW

ArjenCNX

Tinkerer
Oct 20, 2025
88
115
33
IMG_0800.JPG
 

Attachments

  • IMG_0802.JPG
    IMG_0802.JPG
    1.6 MB · Views: 26

techknight

Moderator
Staff member
Dec 2, 2021
122
125
43
North Carolina
Well, got it all together, and on first power up the 5/12/-5 PSU side doesnt work, ill have to de-bug it to see what is holding it up. ill keep you posted on the progress

The amount of times I can count where I had issues with that PSU id be rich. I can say that I am not surprised, hopefully you iron it out.

Make sure standby voltage is making it to the TDA4605 via the opto circuit from the switchon stage.
 
  • Like
Reactions: ArjenCNX

ArjenCNX

Tinkerer
Oct 20, 2025
88
115
33
The amount of times I can count where I had issues with that PSU id be rich. I can say that I am not surprised, hopefully you iron it out.

Make sure standby voltage is making it to the TDA4605 via the opto circuit from the switchon stage.
Yeah, you got that right! so the HV supply switchmode is working, the +5 +12V one isnt starting through the power on command from the keyboard, im going to find out why that is, i do have the +5V from that HV switchmode side, and that is supposed to power up and activate the main PSU.