It depends on how you define a preamp and what load should be capable of.
Just as you have LM3886 chipamps and 200W Class A monoblocks.
You also have opamp based preamps with a few MA bias driving 10k load.
As well as preamps with 200mA bias capable of driving 600 ohm or even lower.
It is an individual choice.
No absolute right or wrong in either case.
Patrick
Just as you have LM3886 chipamps and 200W Class A monoblocks.
You also have opamp based preamps with a few MA bias driving 10k load.
As well as preamps with 200mA bias capable of driving 600 ohm or even lower.
It is an individual choice.
No absolute right or wrong in either case.
Patrick
Two examples from my own.
The F5XPre is what I use, and will drive any load down to 100ohm.
The ZGF lineamp is what I built for a friend.
Will drive 10k with reasonably low distortion.
And it doesn't use any global negative feedback.
Both have their own appeal.
Patrick
The F5XPre is what I use, and will drive any load down to 100ohm.
The ZGF lineamp is what I built for a friend.
Will drive 10k with reasonably low distortion.
And it doesn't use any global negative feedback.
Both have their own appeal.
Patrick
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I'm saying its an outlier design... If I put a truck engine in a lawnmower, that's as logical as putting power MOSFETs in a small signal chain. You can do it, but why? What if the output cable is accidentally shorted - you'd better have a fuse to stop the cable burning!
How much loudspeaker power do you need for your normal listening ? 4W ? 10W ?
How much max. power does your power amp have ?
Why would anyone ever need 60W (as in chipamps), or even 600W (as in some Class AB monoblocks) ?
It is DIY.
Anyone can freely choose what he wants to do, without having to justify to the rest of the world.
My 2 cents,
Patrick
How much max. power does your power amp have ?
Why would anyone ever need 60W (as in chipamps), or even 600W (as in some Class AB monoblocks) ?
It is DIY.
Anyone can freely choose what he wants to do, without having to justify to the rest of the world.
My 2 cents,
Patrick
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Crest factor & transients is why - a decent recording of Tchaikovsky's 4th Symphony would be an example where the cannon blasts come in. A factor of 10 in power is 10dB, only a factor of 3.1 in voltage terms...
I have used 2SA1145 / 2SC2705 as outputs in my preamps and also as prepredriver in power amps. I am now redesigning all of them to use 2SJ77 / 2SK214 devices. Hitachi really knew how to make transistors.
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