Discussion in 'Amps and Cabs' started by EADGBE, Aug 2, 2006.
cranked and then it becomes class A/B?
Operating classes are determined at the "cranked" point, so no, it's AB.
To confuse things, if they determined the class at 'low volume', then technically it might be considered AB2, since half the wave form is produced by each of the tubes.
Note that all your favorite "class A" amps are not class A, but in fact AB2. (AC30, Dr Zs, Mesa, etc.)
Of course, there's always the question of why it matters!
or why you would play a 100 watt marshall real low?????
That's not what AB2 means.
The "2" portion means that the output tubes are drawing grid current during a portion of the cycle. Hardly any MI amps (the big SVT might be an exception) run AB2.
AB1 is commonly abbreviated to AB.
Actually, there are more than a few class AB2 guitar amplifiers.
OK, now I'm curious...
My understanding is that it takes a pair of cathode-follower stages after the PI (or something else that can source tens off milliamps) to source the grid current that it would take to run the outputs AB2. The typical 100K (or even 47K) plate resistors on a PI won't hack it...
So... besides the SVT bass amp, what are a few of these guitar amps that run AB2?
Classes explained. http://www.aikenamps.com/ClassA.htm
Because they have one of the best clean sounds of any amp.
I'm sure that's the sweet spot, right?
Heck a Twin Reverb set to 2 or 3 is beyond playing a small room and a big amp like that will never open up unless you're in a stadium! I just like to turn amps up some...
SO.... if my Dr. Z is not Class A, and not Class AB2, is it regular A/B? Class Z? Class A/B/Y? Confused & Stupid!
I can play my 1/2 stack 2555 Jubilee at room volume. I can actually practice at home with it with out disturbing anyone. But then again, when I put it on the front porch and crank it...well that's a different story. The valleys echo with it.
There are also single-ended class A amps with more than one tube in series. Some of the small Gibson combos of the late 50s are classic examples of that design.
100 watt Super Lead + Variac + Hot Plate + knobs on 10 = Heaven.
variac AND a hot plate? I thought they served the same basic purpose?
Like a brake pedal and a clutch serve the same purpose?
No, the clutch brings an engine in or out of gear while the brake stops the car. Can you explain?
they'll both slow the car down, but they do it completely differently, no?