"Arfa Daily" wrote in message
...

"N_Cook" wrote in message
...
Before wrapping up a Mackie SRM450 powered speaker I took some
representative DC voltages on the complementary pair power devices of the
bass driver amp, for me and all else, future reference.
-42, -88, -42.8
41.2, 88, 42
What would the circuit type/ class name be, for this sort of biasing?

in comparison for horn side amp, same devices
0, -43, -.55
.55 , 43, 0

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
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Class "G" maybe, where the supply on the output devices doubles 'on the
fly' depending on current demand (as in amperes)? Lots of amplifiers are
now. The supplies are often designated "VH" and "VL". First units I ever
came across which used it, were an Aiwa series of hifis, which did the
supply switching with a pair of FETs. I think this covers the principles

http://www.wipo.int/pctdb/en/wo.jsp?...6&DISPLAY=DESC

Arfa



Indeed, the SRM450 Bass amp has 2 supplies : +-45v and +-80v. The higher
voltages are switched in with IRFP150 and 160 Fets.

The HF amp is conventional, using just the +-45v supply.



Gareth.