roger.unc

AMI T8 issue
« on: August 07, 2019, 02:54:04 PM »
Howdy all, Sorry for the cross post. I'm building four KM84s. The gain on the first two turned out fine with AMI T8's that came in one box. I built the next two mics with a T8 pair from a second box and they are super, super quiet . The quiet mics are wired identically to the first two mics. The wiring on all transformers looks the same. I pulled the T8's from the quiet mics and took these measurements:

Blue pair: 215 ohms (same as first pair of T8s)
Grey pair: 22 ohms (same as first pair of T8s)
1V sine wave @1kHz on blue = .046V on grey
5V sine wave @1kHz on blue = .238V on grey
1V sine wave @1kHz on grey = 2.3V on blue

Unless I'm wrong (which is quite often the case) that gives an almost 22:1 ratio on the pair of quiet T8s? They are supposed to be 7:1. Am I wrong on my math or technique? Just trying to rule these out before I troubleshoot elsewhere - or before I reach out to AMI.

Thanks,
Roger

Edit: measured at 1kHz not Hz
« Last Edit: August 08, 2019, 12:01:21 PM by roger.unc »


gyraf

Re: AMI T8 issue
« Reply #1 on: August 08, 2019, 03:00:09 AM »
1Hz is waaaay too low a frequency to judge anything from...

Jakob E.
..note to self: don't let Harman run your company..

roger.unc

Re: AMI T8 issue
« Reply #2 on: August 08, 2019, 11:58:05 AM »
Sorry! Missed a "k" in there. Measurements were at 1kHz.


 

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