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In Reply to: RE: It's not a win/lose situation... posted by Mr_Steady on November 28, 2014 at 10:23:54
If you have a circuit with an output transformer with a 2.5K Primary and an 8 ohm secondary and another identical circuit with a 2.5K transformer with a 16 ohm secondary with each connected to an appropriate speaker load, the power output will be the same. You can stack the speakers in a number of ways and you can rephrase the question in any number of ways but your initial question on the HiEff board remains the same. You don't get 3dB magically.
There's no free lunch.
Follow Ups:
"There's no free lunch."
Yes, that's always seems to be the case.
"you can rephrase the question in any number of ways"
Once more into the breach;
Then why does a solid state amp put out more wattage the lower the speaker impedence? It's almost like a free lunch.
Big speakers and little amps blew my mind!
Watts is a measure of energy used and is a derivative/result of Ohm's Law. Current, voltage and resistance determine watts. This is ONE reason why great amplifiers are designed to produce "more than adequate" current - to deal with low resistance speakers.Just because an amp/speaker circuit can consume 8 billion watts driving a 2 ohm load doesn't mean that it's louder than an amp/speaker circuit which only consumes 1 billion watts into an 8 ohm load.
And let's not forget the speaker's reactive component.
:)
Edits: 12/01/14
...at a high level, the reason a solid state amp might appear to put out more power into lower impedances is that it tends to approximate an ideal voltage source. i.e. zero output impedance/infinite current delivery capability. So...if our voltage source amp can deliver say, 16W into 16ohms, that's 16V across the 16 ohm load. Drop the load to 8 ohms and the 16V remains constant so now we have 16^2/8=32W. Drop the load to 4 ohms and we get 64W and so on. Few amps have the output stage or PS beef to actually accomplish doubling of power when impedance is halved but the trend is present. As always, there are exceptions, notably the Mac SS amps with autoformer outputs. These tend to deliver the same power into any load that matches the tap impedance...just like a transformer coupled tube output stage.
Since this is a high level discussion, we'll avoid the issue of non-optimum primary to secondary coupling that occurs with most OPTs incorporating tapped secondarys when used with the lower impedance taps. I believe this is what gives rise to the impression that transformer coupled tube amps do better delivering power to high impedance loads.
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