#1
just wanna know cus i have tri mode but i dono witch i shuld use
#2
Class A cleans are more even, while A/B are more like a Fender Strat neck pickup. Distortion-wise, Class A is more modern, and A/B is more break-up sounding. Hard for me to explain tbh.
#4
Quote by qotsa1998
Class A cleans are more even, while A/B are more like a Fender Strat neck pickup. Distortion-wise, Class A is more modern, and A/B is more break-up sounding. Hard for me to explain tbh.


haha..... take this and flip it around.
Quote by HxCori<3
you sir, are the ultimate UG stereotype, praise a not so good metal player, zakk, put down other peoples playing, seriously say I WAS GONAA PLAYZ SOME UBER LEEDS LOZLOERLS~1!!!11!, and then critique epiphones as if there worth a second glance
#5
Quote by qotsa1998
Class A cleans are more even, while A/B are more like a Fender Strat neck pickup. Distortion-wise, Class A is more modern, and A/B is more break-up sounding. Hard for me to explain tbh.


Please, if you don't know what you're talking about, don't post.


The operating classes just describe what method an amp uses to amplify. It's nothing a guitarist needs to worry about. If you're really interested in finding out about it; run a search (which you should done anyway).
#9
Quote by mr_hankey
Please, if you don't know what you're talking about, don't post.


The operating classes just describe what method an amp uses to amplify. It's nothing a guitarist needs to worry about. If you're really interested in finding out about it; run a search (which you should done anyway).


What do you mean a guitarist shouldn't be concerned about it? Last time I checked, a Class A VOX AC30 sounded a helluva lot different than, say, a Class A/B Peavey Classic 30. Although those are relatively different amps anyway, they're both popular among classic rock/blues players, and they're somewhat similarly voiced (VOX= British, Peavey= Not quite British, but not quite American either).
Quote by Diet_coke_head
I love taking a nice dip of some horse shit, so good.
#10
Vox AC30s aren't actually class A iirc.

Edit: I should clarify, they are sold as class A but are technically not, same with a lot of other amps. Amps with a single power tube generally are class A though.
Schecter C1 Classic Left Handed
Line 6 POD HD500
Peavey Valveking 112
#11
Quote by selkies
so for my amp distortion i shuld use a


It's a matter of taste.. If you can't tell the difference by ear and playing dynamics, just run with A/B. It's the most efficient of the two.

Also,(and I'm not a EXPERT), but I've read plenty of articles that say that amps with a Class A mode of operation still operate as A/B (maybe to a degree? not sure)...
Washburn D-12
Ibanez RG
Ibanez RG 7321
Epiphone Les Paul / EMG 81 85
Fender MIM Ash Stratocaster
Digitech Whammy
Small Stone Phaser
Boss SD-1-Modded
Boss MT-2-Modded
Boss CE-5
Boss DD-3-Modded
ISP Decimator
B-52 AT-212
#12
Class A - When an amplifier's stage devices are passing current at all times, including when the amplifier is at idle (no music playing), whether the amplifier is single ended or push-pull, the amplifier is said to be biased in Class A. Because the current is flowing at all times, an input signal causes the current to be immediately diverted to the speakers, and therefore, the sound is very "fast". In the case of a push-pull amplifier, there is also less crossover distortion when the signal passes from the positive to the negative or negative to positive, since each side of the push-pull section is already "on". If all stages of the amplifier are biased in Class A, and the amplifier operates in Class A to full output (enough current flowing at idle that could be required for full output), it is said to be a "Pure Class A" amplifier. Pure Class A designs are understandably expensive to build and are usually only found in high-end boutique amps.

Class AB - As its name implies, this is sort of a combination of Class A and Class B operation. If an amplifier operates in Class A mode for only a portion of its output, and has to turn on additional current in the devices for the remainder of its output, it is said to operate in Class AB. Most amplifiers are in this category since they operate in two classes. In class AB and B, the amplifier is slower than in Class A because there is a finite time between the application of the input signal and when the devices are turned on to produce a flow of current to the speakers. However, Class AB and Class B are more efficient than Class A and do not require such large power supplies.
#14
Quote by thankyougermany
What do you mean a guitarist shouldn't be concerned about it? Last time I checked, a Class A VOX AC30 sounded a helluva lot different than, say, a Class A/B Peavey Classic 30. Although those are relatively different amps anyway, they're both popular among classic rock/blues players, and they're somewhat similarly voiced (VOX= British, Peavey= Not quite British, but not quite American either).


Those amps are both class A/B. That is, if they're both 30w (or more). I think it's a good idea to not worry about classes because 1: most 'class A' amps are actually class AB, and 2: there are other factors which affect tone and feel so much more. Choosing your amp based on operating class makes about as much sense as choosing it based on whether the input jack is on the left or the right side.

Quote by Axeman99
Amps with a single power tube generally are class A though.


Single-ended amps (which can have more than one output tube) are always class A.
Last edited by mr_hankey at Apr 29, 2008,
#15
Quote by mr_hankey
Those amps are both class A/B. That is, if they're both 30w (or more). I think it's a good idea to not worry about classes because 1: most 'class A' amps are actually class AB, and 2: there are other factors which affect tone and feel so much more.


Single-ended amps (which can have more than one output tube) are always class A.


Huh. Interesting. Do you know of a couple amps that ARE class A?

I'd guess some of the old Marshalls but I'm not sure.
Quote by Diet_coke_head
I love taking a nice dip of some horse shit, so good.
#16
Quote by thankyougermany
Huh. Interesting. Do you know of a couple amps that ARE class A?

I'd guess some of the old Marshalls but I'm not sure.


Single-ended amps: (Epiphone Valve Junior, Laney Lionheart, Fender Champ). Bigger class A amps are uncommon since they require heavier and more expensive output transformers. The Orange Rocker 30 is the only amp which comes to mind right now (note the wattage: 30w from a pair of EL34s. Biased in class AB, they can easily put out 50-60w).
#17
If I remember correctly, all the matchless amps are class A.
Not taking any online orders.
#18
From Mike Soldano:

Class A and Class A/B
Class A and Class A/B describe how the power tubes work within the power section. To properly explain the technical differences between these classes of operation would be an entire article in itself. However, the characteristic differences can be summarized as follows:

Class A/B amps tend to have greater dynamics, sounding punchier, tighter, and cleaner, and have cooler running tubes. The Class A amp sounds more vintage and squishy, because it's compressing and distorting more. Tubes in a Class A amp tend to run hotter as well. For the same given tube compliment, Class A/B will produce two to three times as much power as Class A. An example would be an amplifier with two 6L6s in the power section. Operating in Class A, the maximum power we could expect would be around 20 watts, while operating in Class A/B would easily yield 50 watts.

Just for tube life alone, I believe Class A/B is the way to design any amp. The amp will run more efficiently with more power, and you'll enjoy not having to replace power tubes as often. If the tonal characteristics of a Class A are desired, an A/B amp can be carefully designed to do that (the Soldano Atomic and Astroverb are good examples of such a design).


So class A/B is the way to go, and they can be designed to sound like a class A.
Jackson KV 2, Jackson COW 7 (both in B), Jackson Demmelition V
Bogner Überschall (blue rev)
Marshall 1960B Vintage (2x V30 & 2x G12T75)
TC Electronic G Major
BBE Sonic Maximizer 422A
Weber Mass 150w
ISP ProRackG
T.Racks Dinopower
#19
Engineering 101 stuff: Amplifier classes were meant to describe a single amplifier stage. In the case of a push-pull amplifier stage, it describes each half of the stage. The class letter(s) indicate whether the amplifier stage is conducting for the entire cycle of the input signal, or only a portion of it.

If the amplifier stage conducts for the entire input cycle, then it's class A.

If the amplifier stage conducts for exactly half of the input cycle then it's class B.

If the amplifier stage conducts for less than half of the input cycle then it's class C.

If the amplifier stage conductrs for more than half, but less than the entire input cycle, then it's class AB.

Classes B, C, and AB assume that the amplifier stage will not conduct during a portion of the positive or negative half cycle, but NOT both. In other words, a class B amplifier stage (or half of a push-pull amplifier) may crop off either the positive half cycle or the negative half cycle, but NOT a portion of each half cycle - that sort of clipping would be considered distortion rather than a class of operation (though it's a great way to get fuzz!).

Real world stuff: A single-ended amplifier is, by definition, class A. There isn't any other transistor or tube to take over if it conducts for less than a full cycle.

A push-pull amplifier is class A if both of it's tubes or transistors are conducting for the full cycle. One is pushing current while the other is pulling. They change roles twice during each cycle.

If one of the tubes or transistors conducts for exactly half a cycle, and the other conducts for the other half cycle, then the push-pull amplifier is class B. Crossover distortion is common when the signal crosses the zero centerline, and the two devices swap roles, so this class of operation is NOT popular with audio amplifiers.

Operating a push-pull amp in class AB mode, with each device conducting slightly more than half of the cycle, dramatically reduces the crossover distortion associated with class B operation, and is more efficient at providing higher power levels than class A. Each tube or transistors is responsible for providing only a little over half of the total voltage swing of the output signal.

Class AB push-pull amps get more power from the same tubes as a class A configuration, but they can't completely eliminate the crossover noise when one side or the other shuts down for the remainder of the half cycle. This is why some purists insist that class A is better. The bottom line, really, is whether you like what you hear. If you have a class AB amp that shakes the foundation of your house, and you love the tone, then crank it up and enjoy the power!
#20
Quote by thankyougermany
What do you mean a guitarist shouldn't be concerned about it? Last time I checked, a Class A VOX AC30 sounded a helluva lot different than, say, a Class A/B Peavey Classic 30. Although those are relatively different amps anyway, they're both popular among classic rock/blues players, and they're somewhat similarly voiced (VOX= British, Peavey= Not quite British, but not quite American either).

LOL, Vox AC30's aren't class A you dolt
#21
Yes in the end having a Push-pull amp operating in class A wont make much of a difference from an AB one since the power tubes will still cancel out the even harmonics which is inherit to the push-pull design. so if you want that sound you gotta hand out your 100 bucks and buy a valve junior, boo hoo