1) rms power 50 W or more
2) class A
3) balanced input
4) ability to drive speakers that go down to 2 ohms
Easiest and cheapest to build would be the Pass/Thagard A75.
(2-part building article for download at FirstWatt)
Thank you all for advices.
The A75 is quite interesting but I think it is expensive and challenging.
Do you think a Pass A40 could drive well a pair of Magneplanar MMG? It could be an easier to build and more affordable alternative to A75. Sadly, its input is not balanced...
@sreten
I'm not a native english speaking person, I'm afraid I've not understood the sense of your contribute. May I ask to clarify a bit? Thanks a lot.
The A75 is quite interesting but I think it is expensive and challenging.
Do you think a Pass A40 could drive well a pair of Magneplanar MMG? It could be an easier to build and more affordable alternative to A75. Sadly, its input is not balanced...
@sreten
I'm not a native english speaking person, I'm afraid I've not understood the sense of your contribute. May I ask to clarify a bit? Thanks a lot.
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With loudspeakers that go well under 4 ohm, it's safer and easier to pick a power amplifier with a MOSFET output stage.
2-ohm capable amplifiers with bipolar output transistors would need a relatively big output stage, or protection add-ons, which makes it more complex.
A 50W class A power amp will require a big case, large heatsinks, and big power supplies anyway.
Full 50W class A in 8 ohm means a minimum idle dissipation of 110W per channel.
220W dissipation for 2 channels is a heat figure that is hard to get rid of with a stereo amp case. Without fans, it would have to be huge.
(the A75 is easy to downsize, btw, and suitable output devices are really affordable)
Easiest for you to do would be to order boards from the diyA store, the BA stuff.
Making PCB's and amp cases are the difficult parts of building an amplifier for most.
2-ohm capable amplifiers with bipolar output transistors would need a relatively big output stage, or protection add-ons, which makes it more complex.
A 50W class A power amp will require a big case, large heatsinks, and big power supplies anyway.
Full 50W class A in 8 ohm means a minimum idle dissipation of 110W per channel.
220W dissipation for 2 channels is a heat figure that is hard to get rid of with a stereo amp case. Without fans, it would have to be huge.
(the A75 is easy to downsize, btw, and suitable output devices are really affordable)
Easiest for you to do would be to order boards from the diyA store, the BA stuff.
Making PCB's and amp cases are the difficult parts of building an amplifier for most.
Well here is my DIY project. I've been using these amps for about 10 years now, and never had a problem (but I admit when its 45 deg in Melbourne like it was 2 weeks ago, I don't turn them on).I'd like to build a pair of monoblock amplifiers that meet the following requirements:
1) rms power 50 W or more
2) class A
3) balanced input
4) ability to drive speakers that go down to 2 ohms
Any suggestion for a good diy project would be much appreciated.
Thank you.
40 Watts class A, balanced in. I drive a 4 ohm ribbon tweeter with these. Never gone down to 2 ohm, but it wouldn't hurt (though you'd get less power out).
http://www.diyaudio.com/forums/solid-state/212424-balanced-class-fet-amplifier.html
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Sandor, go with the Pass proposal - order the PCB's from the DIYaudio store. Lots have been built and you can get help/advice. You are also lucky - Modushop are based in Italy and you can get a very BIG 5U case with heatsinks for about 200 Euros. This should get you to 50W class A per channel with heatsink temps at 60C max.
modushop.biz
Hazard500 amp looks good also - fun project!
modushop.biz
Hazard500 amp looks good also - fun project!
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