I’m assembling the MK2 filter, got to step 5 power test and got the following:
All 12 measured voltages are 7.64 to 7.65 V (red) and -7.64 to -7.65 V (green). I’ve measured input voltage as 9.19V. So on the plus side they’re all the correct sign and symmetrical. The downside is they’re not 5V!
I did read old threads which suggested changing batteries in multimeter which I did, but results are identical.
I’m using a switchable PS with next voltage below 9V is 6V (measures 6.14V with multimeter), so that’s not much use to compare.
I’ve checked that I put the 7805 and 7905 voltage regulators in the correct place.
Voltage readings off the voltage regulator pins are:
7805: +7.66V, +7.73V, +8.53V
7905: -7.64V, -8.4V, -7.74V
One point to note: I put the resistors on the board first (sorry force of habit; I am aware of the general principle of RTFI about reading instructions, but I presume that has no bearing on this issue).
Any ideas? Have I fried the voltage regulators?