How many VA?

MIDIbox FM
1

Hi all,

I will be collecting together the final parts for my 1st MBFM and I’m being a bit cautious about the PSU because I already killed an amp project not understanding fully what I needed!

I’m going to build a PSU as shown in TK’s diagram here:

http://www.ucapps.de/mbhp/mbhp_opl3_psu.pdf

But I’m unsure how many VA I can use on the output, the diagram only mentions 200mA. Most of my suppliers transformers go up from 1.8VA. My logic is that having some VA in reserve shouldn’t cause a problem. What do you think?

I’m going to use a second transformer to power the Core and eventually I will run an LCD as well as some LED’s as shown in Tk’s design for the control surface. How many VA do you think I should aim for on this transformer?

I look forward to some guidance, TIA and a happy festive soldering season :slight_smile:

Dave mK

2

hi;

it’s always safe to use a transformer wich is rated for a higher current (in amperes) then needed.

so the 200mA  the diagram is showing is the minimum your transformer must deliver.

keep in mind that VA is not the current (like 200mA) but i guess it’s the “current x voltage” it can deliver.

something like 1,8VA means it can deliver for instance 18Volts with 100mA.

for the core setup+lcd 500mA is recommended

good luck , marcel