Originally Posted by goneten
Okay, so when exactly is a pot used and when do you not need to use a pot?\
You only use a pot when you need to.
But if you need to add pots to one device's setup, you add them to both for the sake of symmetry.
You need to use a pot when the UUTs lack appropriate level setting facilities of their own. One common example of inappropriate level setting facilities iinclude most modern AVRs that adjust levels in relatively large steps. You need to match levels in steps no larger than about 0.05 dB or no steps at all.
I mean none of this was discussed earlier, it's just an added variable now.
It seems like common sense to me.
As far as level-matching goes, do you just measure the voltage at the speaker terminals at a particular master volume setting and then write those values down, and then rinse and repeat for the second amp?
Yes. Actually I have never written the voltage down. I pick a voltage that is easy enough for a bonehead like me to remember. As you point out you can adjust the master volume setting to facilitate this.
Originally Posted by FMW
I did these tests a dozen years ago.
Of course, it seems all tests were done dozens of years ago. I never see anything recent.
DBTs of good equipment are about as exciting as watching paint dry. We started testing in the late 1970s and by the mid-late 1980s when the Stereo Review tests were done, people had to be paid to play. Not a lot, but they had to be paid.