FAO : cecil , errin and Doc and anyone else who can help

shaheen · Post by **shaheen** » Fri Oct 12, 2007 4:08 am

Hi guys , I do not know enough about trannies and stuff to answer this, but how many amps do you know of which use MOSFETS in their output section, not the power supply side,

thanks
Appriciate it

Post by **Francious70** » Fri Oct 12, 2007 7:20 am

Most amps, unless they specify BJT's, are going to be MOSFET's. Unless they're tube amps.

Post by **VW337** » Fri Oct 12, 2007 2:04 pm

^^ what he said

Post by **Wakeup** » Fri Oct 12, 2007 2:23 pm

shaheen · Post by **shaheen** » Sat Oct 13, 2007 4:10 am

Thanks guys , so does that mean all the PG amps, Xenon and RSD, JL amps, DLS amps , Audison and USAmps all use Mosfets in their output stage.

Thanks , having a discussion with a guy who is insisting only RF amps use Mosfets in their output stage which gives them "punch"

twisted · Post by **twisted** » Sat Oct 13, 2007 6:16 am

shaheen wrote:Thanks , having a discussion with a guy who is insisting only RF amps use Mosfets in their output stage which gives them "punch"

WOW

Post by **Francious70** » Sat Oct 13, 2007 8:11 am

shaheen wrote:Thanks guys , so does that mean all the PG amps, Xenon and RSD, JL amps, DLS amps , Audison and USAmps all use Mosfets in their output stage.

Thanks , having a discussion with a guy who is insisting only RF amps use Mosfets in their output stage which gives them "punch"

I know Xenon amps use BJT's in the output stage. And I'm pretty sure they did in all their flagship amps before the Xenon as well, but I'm not 100% on that.

And the MOSFET's arn't what makes an amp have "punch". Some people would even say that there is NO audible difference in amps, but hey, that's just Richard Clark and my opinion.

1moreamp · Post by **1moreamp** » Sat Oct 13, 2007 10:05 am

shaheen wrote:Thanks guys , so does that mean all the PG amps, Xenon and RSD, JL amps, DLS amps , Audison and USAmps all use Mosfets in their output stage.

Thanks , having a discussion with a guy who is insisting only RF amps use Mosfets in their output stage which gives them "punch"

Having Mosfets outputs does not mean a amp has PUNCH. Mosfets are a economical high current output device. they have always represented a high current alternative to Bi-polar transistors.
This along with the ongoing price reductions and output capacity gains in design, make the Mosfet the chief competitor against BJT's in a amp design. Mosfets were generally not used before the late 80's when they finally had viable power devices on the market (i.e. they were the last of the power devices to be manufactured and marketed for use in audio amps)

Neither format has a complete answer to all of the issues of a solid state amp. But I think Mosfet amps may be a more economical to produce. If you will look at PG's lower line products like the XS and Tantrum < all excellent products> but all considered to be lower line Ryval type competitor based products. PG offered a run for the money to Rf and others by marketing products that compared favorably both is price, power, and design.

Rockford Fosgate has always had market share of the car amp business from way back in the 80's on. They have always used Mosfets except in their very first amp they made long long ago. It was clearly a engineering decision to make and market their products this way, and from my understanding of the manufacturing side of the business its all about profitability and profit margin.
That and the much loved and adored Fosgate Bass boost of +18 DB's which has always been a real big winner for them over the years. IMO

I think the 18 DB's bass boost is where RF get their so called PUNCH from, and this can be duplicated by using a Zapco Keyboard type EQ < another much over priced and adored item from the past>

I'm bad mouthing RF products I have made enough money repairing them over the years to put a couple cars in my yard

Thanks mostly to their market share and the huge amount of abuse they get by their proud owners. Who seem to be able to blow them up as easily as any other amp made by anyone else...

On a technical side I would tend to think that any PUNCH difference in any amp would be based internally on its power supply energy storage and possibly its output impedance and damping factors. I say this because these things control the overall power side of this picture.

As I am opening myself up to be debated here I am closing my comments about this in the same post as I made them. I think with adequate web search most of what I have said can be verified rather that disputed by those that know it all. Have a great day