Class A vs. Class A/B

[ctc1960]

As many tube amplifiers as I have owned in my life, I never paid any attention to class A vs. A/B until I became interested in purchasing an Orange Amp. I am looking at the Thunderverb and the Rockerverb. The Thunderverb is a class A/B whereas the Rockerverb is class A. Could you please explain the difference? I have played both amps, but I am curious about the different classes. Thank you for your time.

[Orphin]

I never paid any attention to class A vs. A/B

Don't.

The Thunderverb is a class A/B whereas the Rockerverb is class A.

Honestly, who told you that?
It's common knowledge that people beleive that the AD30 is Class A even though it's not, mostly because of a marketing scam, but who in their right mind would try to fool you that the Rockerverb series are Class A?

Anyway. The only Orange amp that is Class A is the AD5. Class A doesn't mean that it's better, it's just a different way of operation.
They do sound different, but it's quite marginal. Add a bass and drums to your guitar and no one can no longer hear the difference between the two.
Class A sounds spot on, like 100% in phase, while Class A/B is actually fatter and more full. Again, very small differences IMO..

[aeiouy]

Not really Class A.
But Cathode biased yes!

Cheers

[ctc1960]

Thank you for your replies...Chris

[misterMagoo]

Maybe the Rocker is "class A" (see above) but the rockerverb is A/B all the way. I think the only situation where you would notice the difference (most others wouldn't) would be on a studio recording.

Have you ever heard an amp and thought OH MY GOD that sounded insanely good, and then researched it to find out that it was class A?

Have you ever heard an amp, thought the same thing and found out it was class A/B?

Chances are not many people have, however, great sounds come from both. Buy with your ears not with your brain.

[Orphin]

Maybe the Rocker is "class A" (see above) but the rockerverb is A/B all the way.

No it's not Class A.

The only Orange amp that is Class A is the AD5.

I think the only situation where you would notice the difference (most others wouldn't) would be on a studio recording.

Yeah, either that, or even better, having a feature on the amp that can force the tubes into Class A operation. This way you can switch between the two while playing and listen for that difference. I can do this with my Matamp, and as I said in my previous post, the differences are so suddle that the feature is actually uncalled for. It's quite meaningless except that it has given me the knowledge of knowing the exact tonal difference between to two.

To put it this way. Hypothetically, if Class A was Class A/B and vice versa, amps would still be marketed as Class A as for being "something better" because it's the phrase that sounds better, not the actual tone.

Cigarettes for example are all Class A, what's up with that? Have anyone seen a pack of Class B smokes? Of course not, who would buy those?

[misterMagoo]

I did read that all I was just trying to say the Rocker may be close (hence the quotations) but the rockerverb is nowhere near it.

[gabrielstigmatic]

I've read that technically nothing over 28 watts can be class A.

[Gladmarr]

I've read that technically nothing over 28 watts can be class A.

That's not true. You can make a class A amp much bigger than 28 Watts. The problem is a Class A amp is bigger and less efficient than a class A/B amp. It's cheaper to build a Class A/B amp bigger than 28 Watts (or whatever the tipping point is), because you get more power out of fewer parts.

[gabrielstigmatic]

So if the AD30 is technically not Class A, couldn't Orange be nailed with false advertising?

[Randy Bass]

So if the AD30 is technically not Class A, couldn't Orange be nailed with false advertising?

That sounds like a perfectly pointless endeavour. Nearly all of the large amp manufacturers have marketed their cathode-biased 15, 18, and 30-watters as Class A for a long time. While the fellas on this forum are very confident in their understanding of the precise definition of Class A operation, it may not be black-and-white enough for the legal system in any country where Orange does business. Most importantly, it's not important.

[Orphin]

I think it has to do with that you have the right to call any product "Class A" as for being high quality, e.g. Class A cigarettes..