What does "class A" mean?

[SpamBot]

This thread should provide further clarity.

That reminds me of the insides of a new Orange amp: Click.

Makes me sick, charging $2G for an amp with all the parts pcb mounted:scowl::scowl:

 

[rbonner]

Very nice and informative explanation Bob.
Could you explain (in simple terms) how we can get out of this awful economic mess?

Well yes Jim I could... Lots of economics in college and have, nobody's listening; especially when I was working for the Senator on my last job. I had a plan for the end of the oil crisis.

I'm going through my own economic mess with wife. That's why all my amps are for sale. Maybe she saw that first episode of hoaders and paniced?

USA could sell Nebraska and fix everything too, hahahahahaha

I've sorta been looking for a job once again... need company to run, country to overthrow or project to oversee...

BOB

 

[mikeyswood]

Engineering geeks...no sense of humor!

(sorry: "humour")

Two atoms walks into a bar. One turns to the other and says "I think I lost an electron."

The other says "Are you sure?"

The first says "I'm positive!"

 

[fdeck]

Which is why everyone uses class D:

much simpler.

Are the arrows on the MOSFETs pointing the wrong way?

 

[Korladis]

Well yes Jim I could... Lots of economics in college and have, nobody's listening; especially when I was working for the Senator on my last job. I had a plan for the end of the oil crisis.

I'm going through my own economic mess with wife. That's why all my amps are for sale. Maybe she saw that first episode of hoaders and paniced?

USA could sell Nebraska and fix everything too, hahahahahaha

I've sorta been looking for a job once again... need company to run, country to overthrow or project to oversee...

BOB

You're selling off you're monster rig?



NOOOOOOOOOOOOOOO!

 

[Jim C]

need company to run, country to overthrow or project to oversee...

It's a damn shame that MD and SD are so far apart.
With your political contacts and economics background and me with my manufacturing and former CIA contacts we could ....

PS - And I think your wife is way cool; live and let live

 

[rbonner]

It's a damn shame that MD and SD are so far apart.
With your political contacts and economics background and me with my manufacturing and former CIA contacts we could ....

PS - And I think your wife is way cool; live and let live

Yeah I will let her live...

 

[Bob Lee (QSC)]

except that picture seems to invert it for some reason which Class A amps don't do!

Class A means that the power amp runs at full current the whole time and amplifies the whole signal. They're rarely more than 10watts so if you see a class A amp that is bigger than that it's pure marketing mumbo jumbo ie. Vox ac30s

The reason that picture inverts the signal is because it's a common-emitter amplifier circuit. And it is class A.

Amplifier classes are not restricted to certain polarities.

 

[Bob Lee (QSC)]

I know we are all joking around and having some fun here, but there is a serious problem with the concept of the numbers on your volume knob. Of course this misconception is far more common among guitarists than bass players, but it does exist especially among bass noobs.

The idea is that there is some relationship between the numbers on the volume knob (1 -10) and the power the amp puts out. This idea is the basis of the joke of a knob that goes to "11" implying 10% more power output.

The confusion here is between power output and GAIN. It's not even possible (or shall we say extremely difficult) to even try to set up an amp so "10" represents the maximum power (loudness) available from it. Why? Because the power OUT of the amp depends on the signal level INTO it! So where you have the volume control set on your bass or how "hot" it is etc. will all change which number corresponds to which amount of power out. In fact how hard you play the bass (It's all in the fingers) is in itself a big factor. The thing that REALLY matters is the amp power meter or clipping light if it has one. That one truly will be saying that, yes, you are at the limits of that amp.

But we've all seen noobs here going on and on about "I was getting tremendous volume out and the knob wasn't set past ten o'clock" (or some knob number). Just meaningless jibber jabber dudes.

+1

That's one of the biggest points of confusion among novices. And the fact that some store salesmen play it up doesn't help: "Listen to how loud this amp is amp is at 12 o'clock. Now listen to this one (the amp he really wants to sell you), it's just as loud at 9 o'clock!"

I once spoke on the phone with a DJ who called to ask why his new amp had to be turned up to 2 o'clock to be as loud as his previous amp was at about 10 o'clock, even though the new amp was a modest step up in power rating. I explained to him about gain, and how it wasn't dependent on power rating, but it didn't seem to sink in; he was still concerned with the knob positions. I asked him how loud the old amp was if he turned the gain up higher. He said he couldn't turn it up past about 12 o'clock, or the red lights would start flashing and he'd get distortion. Bingo! I told him, "Well, there's your reason why the gains are different."