#1
i know mosfet is a semi conductor, but what does it do, how does it affect the sound tone wise.
The laney nexus head offers tube output or Mosfet out put stage, Warwick heads have mosfet stages in them.
How do they work? How do they compare to Tube output or Solid State output?
thanks alot
#2
I am not an electrical engineer but basically a MOFSET is the board that makes an amp a digital/ss amp.

It is often used for fast switching and also can handle high amounts of power without heating up.

The most important thing with them is that they are made/designed well. Poor quality = poor sound reproduction.

Overall, and this is very simplified, most people complain that they impart a thin, dead, flat tone effect.

However, in good amp circuits they can mimic tube sound quite well, as in tube/ss combinations.

The MOFSET's dont typically handle clipping as well as tubes, that is where people discuss the warmth or fullness they hear in a tube amp when overdriven versus the harsh, hollow or trebly type of distortion from an ss/digital when overdriven to clip.

Regardless, when considering an amp I wouldn't worry too much about it other than trying the amp yourself and ultimately what is important to you in purchasing one.

Hope this helped somewhat...you can always google "mofset amp circuit" and catch alot of this.
#3
Dazz pretty much has it.

its another way of saying "this solid state amp is pretending to be a tube"

thats not necessarily a bad thing tho, my solid state is a mosfet circuit and it does just fine at both quiet and loud settings.
Grammar and spelling omitted as an exercise for the reader.
#4
A MOSFET is an acronym. The T stands for transistor. Which is a solid state chip used in lieu of a tube. A "SS head" and "MOSFET head" are one in the same, but it's a different, more modern transistor that's more flexible. And it's also kinder when clipping.
Quote by Cody_Grey102
I was looking at a used Warwick Vampyre LTD 5'er for about $200. I went home to grab my wallet and came back and some jerk with an epic beard got it already..
#5
Another comparison is weight and cost, open up a 500 watt SS amp and you will see just one transformer, open up a 200 watt Hiwatt (all valve/tube) and you will see two mini substations or massive transformers which are very expensive.
Most Hybrid amps use a single or pair of valves (usualy ECC83s/12ax7s) in the preamp which is where the tone is produced, this goes some way to emulating a tube amp but much of it is just a gimmick.
G&L L2500
Squier Affinity Jazz Bass 5
Ashdown RPM pre-amp
Ashdown Little Giant 1000
300 watt 15" powered cab
450 watt 15" powered sub bass cab
2x10 + horn
1x15x10 + horn
#6
Originally, 'solid state' just meant 'transistorised' rather than 'valved'. The original transistors were the germanium type, so beloved of overdrive purists. A MOSFET is a Metal Oxide Silicate Field Effect Transistor, an evolved version of the original transistor.
As mentioned, it doesn't heat up as much, because it does the job more efficiently, consuming less power, and reacting more quickly and consistently.
And that's where I'm going to (respectfully) disagree with John. I reckon the valve pre-amp/MOSFET hybrid solution is pretty damn good. It is a compromise tho', but one that cuts the bottle count from 8-12, down to one or two; and does away with an artificially restrictive output transformer. Surely it can't be a bad thing.
Think of it as running a mic into a quality valve pre, then into a PA system: a quality sound with good audibility.
#7
don't decide between one of those. Just get both in amp. I suggest a Genz-benz GBE 1200. Nuff said.
Duck

Bass tones are hard to find.
My Band
Mesa Boogie M-Pulse 360
Madison MAB 4x10
Warwick Thumb BO 5
#8
Personally, specs of an amp shouldn't matter, if it sounds good then buy it. Don't buy an amp just because it's a valve amp if it sounds like crap.