Hi all!
I've been enjoying my Crack with Sennheiser HD650s and recently purchased the Speedball upgrade. Before I install it, I thought I would do a quick sanity check on resistances and voltages again before proceeding. A couple voltage readings bothered me. (One a little, one a lot)
1st: Terminal Voltage Actual
1 75-90 77.9
2 170 164.1
4 170 163.9
5 75-90 72.7
So in the above readings, it looked like they should be the same for 1 and 5, I was surprised that 5 was that much lower than 1. Anything to be concerned about?
Also, when measuring A1, A6, B1, B4, each of those should be 90 VDC. However, I got the following:
A1 72.4
A6 77.7
B1 77.6
B4 72.4
Each lower than should be and consistently low. These are the readings that bother me most. Should I be concerned with any of these? Does it signal some tube issue? I am currently running the two tubes that came with the amp.
Thanks in advance for all your help!