WOPL update for PL400

[Geegz]

Definitely non-ferrous (Bueller, Bueller, Bueller) metal so it’s aluminum or unobtanium.

You can see the small bend where it attaches, I believe between the base of the heat sink and the chassis.

 

[Gepetto]

Trying to understand the small numbers below dB numbers - which show 100 at 0dB, 80 at -1.5dB, 60 at -4.5dB. Doesn’t seem to match wattage unless +3dB is 200 watts, but then 50 should be at -3dB.

Hint:
20 x log(70.7%) = -3dB
20 x log(80%) = -1.93dB

and so on...

 

[BlueCrab]

Ahh... So it's voltage, not power. Appreciate the hint.

 

[WOPL Sniffer]

Meters are eye candy to hypnotize the owner and they are not to be believed.....

 

[stetter]

yes, defiantly eye candy only

 

[oldphaser]

Thanks.

Yet another question. What does 0dB on the VU meters represent - reference power out? 200 watts into 8 ohms for the PL400?

There was a "meter service bulletin" issued on this very subject.

For a Phase Linear 400 series 1 amp, 0 VU corresponded to 50 watts or -6dB.
NOTE: This was different for the 700B.

I also started a thread on the very subject of analog style VU meter calibration a while ago.

Ed

 

[laatsch55]

Thanks for that Ed, I was hoping you'd set us straight..

 

[BlueCrab]

Amazing. It's actually what I measured. For some reason I'm always a bit surprised when science works.

Sorry for covering old ground. I'm going to go find the thread, so I can ask more questions.