Noob's Guide for using VFD display on Ambika (experts are welcome)

So now when I’m finally home I’m preparing for building my second Ambika, this time I’m sourcing everything myself, including custom case, LEDs etc. but step by step.

First thing I wanna do is installing the VFD display, ordered from here (kudos to kvitekp for sending mine from US), and possibly there will be many builders with the same intention, so let’s make it clear and try to answer all questions regarding this stuff

1) Mounting this particular display on Ambika requires nothing special as all the holes positioned correctly, taking into consideration that those marked K and A on Ambika MB stay unused (the are used for LED backlight, and this isn’t the case for VFD)

2) R0 doesn’t need any resistor, again this used for LED backlight current limiting, so we just solder a bridge

3) Contrast trimpot R36 is still 5k, right?

4) As the VFD consumes much more current, and if You are going to use all 6 voice cards (ladder from tubeohm in my case) I guess You better use more powerful wall transformer. I’m going to use 2 A.

EDIT: Yeah, You definitely need powerful PSU. With 1A I got loud noise on the output, with 1.9A - not.

5) What about capacitors? Are 4700u, 2200u and 100u (C9, C4 and C14, C16, C23 respectively) still enough?

6) Same goes to voltage regulators. Are there possible problems with 7908, 2940T and 7805 (IC5, IC6 and IC7 respectively) exist when using VFD?

If I missed something important please enlighten me and the others to avoid possible desperation and grief :-<
Also hints with proper mounting under Adrian’s case are very welcome.


I would also appreciate information about this as I have a VFD and an Ambika waiting to be built.

Search the forum for the older thread; I’ve posted pictures and some info there. I left out the LCD resistor, trimpot is not needed, and I made no other changes. Never had any power or heat issues so far.

R0 can be omitted, since the display backlight pins (15, 16?) shouldn’t be connected, the connector should only have 14 pins.

The trimpot isn’t needed either, since you can’t adjust contrast on a VFD, it is always close so 180 degrees viewing angle.

thanks guys!

@t2k: Yeah, I’ve seen those photos, but I was unsure about the caps and stuff. Now it all looks much simpler to me.

I’m still only at 2 voice cards. No issues. No trimpot either.