better amp configuration

[longthrow]

hi guys,
i was wondering which power amp scheme is better:
a power amp with twice a rail voltage or a bridged power amp with supply rails half of the other.
help, suggestions are welcome....

[Gordy]

Consider that for a bridged amp to work correctly the two amps must be exactly matched. Also consider the loop through which the current must flow, including the power supply components (because what flows out must flow back...).

If all other factors are equal, I would choose the higher voltage instead of the bridge configuration.

[AndrewT]

Hi,
the answer "better or worse" depends very much on the SOA capability of the output stage and on the power output level.

I tend towards using +-2vs IF the output stage can meet the SOA demands required of it.

[richie00boy]

Bridging loads the PSU more nicely and keeps nasty currents out of ground, but it's more complicated.

[longthrow]

Originally posted by Gordy
Consider that for a bridged amp to work correctly the two amps must be exactly matched. Also consider the loop through which the current must flow, including the power supply components

hi gordy,

yup, all amps are equal, except for the rail supply voltage & amp scheme..

[longthrow]

same power is to be delivered into the load,same impedance..
also,over all system gain is the same..

[janneman]

Originally posted by Gordy
Consider that for a bridged amp to work correctly the two amps must be exactly matched. [snip]

No, that's no requirement. The system will work flawlessly even if the amps are mismatched several dB's. You may not be able to get the max output level, but quality doesn't sufer.

Jan Didden

[djk]

"two amps must be exactly matched"

The Yamaha B2-X is a bridge amp. One half runs in class A at ±6V, the other in class AB at ±60V.

Audio (formerly Audio Engineering) published a DIY design to bridge a stereo amp with only one external channel. The 'hot' from the external channel became the 'ground' for the stereo amp. This worked fine at lower frequencies where the bass is common to both channels.

[hienrich]

hi longthrow,

musta bai!!!

well, for a better speaker excurtion control, I would not go for a bridge amp since damping factor is cut to half when you go bridging....

if you have seen car amps that are usually driven in bridge config, subwoofers are going in and out excessively to the extremes because damping factors are so little to control excursion, this also means that
a bridged amp has a higher output impedance compared
to a single one....

of course power is multiplied by approximately 4.



karon pako bai.......busy kaayo kinabuhi...heheheheheh

macweb

[longthrow]

ok ra bay...


with the same power level,lets say 500Wrms into 8ohms,
that would be approx 90v per rail while if we use a bridged amp,rail voltage is cut to half (45v per rail)
considering the conditions (post#1 & 6)

well now,which is better in terms of performance, cost, efficiency, safety......etc..

from my point of view, bridged amp costs more since higher current is required; that would be more filter caps & more output devices....

btw,which is more safe for the power supply block; i'm planning use an smps for this amp..