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Questions and Answers 7
®
Questions And Answers
©2004 PS Audio International Inc. All rights reserved.
Owner’s Reference
Humbuster III
it is very difficult to measure the DC offset on the power line. Most meters will not do it accurately.
On a typical Fluke meter, the input circuits would have to be set to accomodate the full waveform,
so there is no clipping on the input stage. So for 120VAC, the meter would have to be on the 200V
scale. (169V peak on the sine wave) Most 3-1/2 digit meters are limited to 0.1V resolution on this
scale. Also the meter specs usually say the last digit can always be off by one. So, unless there is
more than 200mV of DC, the result you measure is pretty meaningless. If you allow the meter to go
to the 200mV DC scale, then the input stages are being driven into clipping most of the time, and
again the reading is meaningless. (it doesn’t tell you that... it will give you a number) A 4-1/2 digit
meter will start to give meaningful data, but it wouldn’t be accurate.
You can operate the HB-III on any AC line voltage or frequency your country has to offer. The HB-III
is rated for a maximum of 2200 watts at any voltage from 90 VAC to 240 VAC.
The HB-III is non-current limiting and may be used with any sized power amplifier, projector or
source equipment in you system. It is recommended the HB-III be used separately if the load is a
big one, such as a large power amplifier or projector. Multiple source equipment may be connected
to a single HB-III if desired.
How can I
measure the DC
voltage on the AC
line accurately?
What voltages
can I run the HB-
III on and how
much power will it
handle?
Is the HB-III
current limiting?
Humbuster Manual.indd 7
10/7/08 8:42:11 AM
