My Bad ............Yammie 663!

[speakerman39]

Not according to Bob Carver, on page 11 of his Sunfire amplifier whitepaper he cited that high power high performance amps in the $8,000, $10,000, $15,000 price range use Bipolars.

http://www.sunfire.com/pdf/Sunfire_Amplifier_Whitepaper.pdf

Man do I find this most interesting. If this is true, then why do most audiophiles prefer the MOSFETS? Also, why are they more expensive than bi-polar transistors? Surely, the MOSFETS offer more than just better efficiency/transfer rates....right? Funny thing is, I used to own a Bob Carver car amp.....what a coincidence. I am just trying to learn more about this as I find it fascinating.

 

[speakerman39]

Mosfets are more efficient yes, sound better, not likely.

Seth, mind to explain more on why you believe that? I want to learn more. As I mentioned, my conclusions were drawn on my own research and therefore not necessarily correct. Perhaps, I got some more researching to do.....LOL!!! However, most audiophiles prefer the MOSFETS for one reason or another.

 

[PENG]

Man do I find this most interesting. If this is true, then why do most audiophiles prefer the MOSFETS? Also, why are they more expensive than bi-polar transistors? Surely, the MOSFETS offer more than just better efficiency/transfer rates....right? Funny thing is, I used to own a Bob Carver car amp.....what a coincidence. I am just trying to learn more about this as I find it fascinating.

Good questions, but I am not sure if most audiophiles in fact prefer MOSFETs. MOSFETs may be more expensive because of a number of reasons, including higher manufacturing cost due to lower volume/demands relative to Bipolars. Being more expensive does not always make it a better choice for a certain application. There are other important factors in power amplifer designs, the choice of the types of transistor is just one of the many factors. My guess is that depending on a particular design, either type could end up being better.

 

[mtrycrafts]

Just read your last post. 750 cubic feet is a small room. How far are you going to be sitting from your speakers?

To give you some idea of how much power you are going to need, Here is a link to a power calculator:
http://www.crownaudio.com/apps_htm/designtools/elect-pwr-req.htm

Here is a link to a page explaining power requirements and what effect them.
http://www.crownaudio.com/amp_htm/amp_info/how_much_power.htm

Enjoy the reading.

Fred

I have seen this now several time and decided to read the link.
It is not designed for home audio power needs as their examples and calculations are for very large auditoriums. For that, 6dB spl drop with doubling the listening distance is correct. For small rooms, like at home, the loss is somewhat less, 4dBspl to maybe 5dBspl, so less power is needed than what it calculates.

 

[mtrycrafts]

... If this is true, then why do most audiophiles prefer the MOSFETS? .

Because they are more gullible for urban legends and rumors? Facts usually don't get in their way

 

[Seth=L]

Bi-polar and Mosfet amplifiers can both be transparent into respective loads. From my limited understanding a mosfet amplifier that is stable with lower impedance loads is very expensive to build. It would be more efficient, but not necessarily sound better. There is plenty of good reasons to use mosfets to build more expensive amplifiers, and the biggest reason is the efficiency. Try not to think of one as better than the other, just different characteristics that make either a good choice for a certain crowd. If you wanted a low cost receiver or amplifier with mosfet output devices they would likely use integrated output devices (at least from what I have seen) so these type of amplifiers and receivers are available at lower prices.

 

[speakerman39]

Good questions, but I am not sure if most audiophiles in fact prefer MOSFETs. MOSFETs may be more expensive because of a number of reasons, including higher manufacturing cost due to lower volume/demands relative to Bipolars. Being more expensive does not always make it a better choice for a certain application. There are other important factors in power amplifer designs, the choice of the types of transistor is just one of the many factors. My guess is that depending on a particular design, either type could end up being better.

Thanks Peng for the info. Beginning to understand a bit better.

 

[speakerman39]

Because they are more gullible for urban legends and rumors? Facts usually don't get in their way

Sometimes the truth is what we construct it to be...........that is, what fits our needs is nothing more than a big part of our wants.

 

[speakerman39]

Bi-polar and Mosfet amplifiers can both be transparent into respective loads. From my limited understanding a mosfet amplifier that is stable with lower impedance loads is very expensive to build. It would be more efficient, but not necessarily sound better. There is plenty of good reasons to use mosfets to build more expensive amplifiers, and the biggest reason is the efficiency. Try not to think of one as better than the other, just different characteristics that make either a good choice for a certain crowd. If you wanted a low cost receiver or amplifier with mosfet output devices they would likely use integrated output devices (at least from what I have seen) so these type of amplifiers and receivers are available at lower prices.

Kinda makes sense Seth. Amps powering a low ohm load usually do cost more. Many of which employ MOSFETS in the design. So, perhaps many assume that the MOSFETS are better because of the manufacturing costs associated with making them albeit higher costs translates to better performance. We all know, that this is NOT always the case.