are class A Mic pres the best?

[gsilbers]

on every expensive mic pre its says its class A, but what does that mean. someone told me that class A is not nesesary the best. but what makes a good mic pre from a bad one, or an expensive from a cheap mic pre?
any elec engineers around here who can provide some tech info?

[wwittman]

The electrical engineering viewpoint is almost irrelevant in audio.
We're not recording satellite data.. it's MUSIC.

Whatever preamp sound the best to YOU is the best. For you.

[DavidJ]

Good question. Here's what Rupert Neve has to say about it. The Class A info is towards the end of the page.

******//www.rupertneve.com/portico5012.html

[HandCrafted Lab]

Full tube A class,without any feedbacks and electrolitic capasitors in signal chain...


Affinity a2

******//www.gearslutz.com/board/showthread.php3?p=518202

[Fletcher]

Originally Posted by gsilbers

on every expensive mic pre its says its class A

Not on every one... but on a lot of them

but what does that mean

It means that the wave form is amplified as a whole; it means that the wave is not amplified as separate parts.

someone told me that class A is not nesesary the best.

...and they were right. That doesn't mean that they're bad, it means that each and every different pre needs to be judged on it's own merit for each and every application in which you use that pre.

The difference between "good" and "bad" is how the pre sounds to you in a given application. What makes one pre more expensive than another pre is the cost of design and the cost of parts. Very often pre-amps that are built with more expensive parts will sound better than mic pre's that are built with cheaper parts... but not always. The quality of the design is integral to the sound of the mic-pre... and some pre's [like the FMR Audio "RNP" for example] is designed to sound excellent but not cost a lot.

"Good" and "bad" like "beautiful" and "ugly" are defined differently by each and every one of us. If all any man wanted to look at were 'super models' there wouldn't be pornsites full of 3-400lb women now would there?

[MarkRogers]

Hey Fletcher, that was extemely well put. Cool...

That Wikapedia link was great too, Robert.

After reading the original question I was expecting a bunch of opinions, not such useful info...

[HandCrafted Lab]

It`s difficult for me to agree, that at A class there can be competitors in work with pre amplification for microphones or instruments - anyway there where unpainted sounding is required. And to paint it`s possible and with the help of stranger EQ - and how it`s necessary, with variations,unlimit. Seldom meet 1 cascade working not in A class(even in EQ).

[Ziggy!!]

Originally Posted by DavidJ

Good question. Here's what Rupert Neve has to say about it. The Class A info is towards the end of the page.

******//www.rupertneve.com/portico5012.html

right... and digidesign say there summing math is flawless and macdonalds say there food is healthy.

I guess they must be right



If it sounds good it is good... Of course there are always those people that will listen and say "that sounds great"... then turn their nose up when they find out it is using monolythic components, or is class A/B. I'm guessing its the same type of person that won't by a nice pair of jeans because of the brand it carries...

Some people buy into blatent stereotyping like "class A is the smoothest and warmest"...

[joaquin]

I tought that class "A" refered to a filter when measuring frequency response to conpensate for the non-linearity of the Human Ear!?

[dtucker]

Originally Posted by wwittman

The electrical engineering viewpoint is almost irrelevant in audio.
We're not recording satellite data.. it's MUSIC.

Whatever preamp sound the best to YOU is the best. For you.

In the immortal words of Marv Albert:

"YEESSSSS!"

[lucey]

Originally Posted by gsilbers

on every expensive mic pre its says its class A, but what does that mean. someone told me that class A is not nesesary the best. but what makes a good mic pre from a bad one, or an expensive from a cheap mic pre?

"Class A" tells you nothing about the sound, only the broadest terms of the design. In general terms expensive mic pres have expensive components and cheaper pres have cheaper components like IC's. Design Time, Labor/Overhead, Marketing and market Placement are all part of the price too.

Class A is inefficient and hot, but it's very open sounding when well done. Some Class A pres aim for a cleaner direction (GML, Millenia) and some are more colorful, although in their day they too aimed to be clean in many cases.

Class AB has it's own signatures. Have you ever played guitar amps that were Class A, AB, Op Amp based? Similar qualities there in many cases to mic amps. A Marshall Amp (AB) can sound right for it's application, as can a Vox (A) or a Music Man (ICs).

[Mental Audio]

Originally Posted by joaquin

I tought that class "A" refered to a filter when measuring frequency response to conpensate for the non-linearity of the Human Ear!?

You're reffering to A-weighed I think.

[Ziggy!!]

Originally Posted by lucey

Class AB has it's own signatures. Have you ever played guitar amps that were Class A, AB, Op Amp based? Similar qualities there in many cases to mic amps. A Marshall Amp (AB) can sound right for it's application, as can a Vox (A) or a Music Man (ICs).

But there are exceptions to these rules, particularly guitar amps. Most people consider class a guitar amps to be the smoother and more dynamic. After playing a Fuchs ODS i've decided thats a very broad generalisation. It is class A/B and possibly the smoothest and most responsive amp i've ever played. It also has minimal power amp overdrive... contrary to another generalisation.

I don't think there is a class A Vox. Perhaps maybe the AC-4 but the others certianly aren't. Some people claim that they are class A up to a certian volume but thats a load of tripe... Thats like saying its an all discrete preamp using IC servos.

Its a prime example of "Class A" marketing tricks...

[joeq]

All the manufacturers put the words "Class A" prominently into their advertising these days actually hoping that people will interpret that as being some kind of "rating" instead of description of how the circuit works.

It's a copywriter's dream. The preamps happen to be Class A, and that has that ring of "the best" You wouldn't drink anything other than grade A milk would you? You'd rather get an A than a B on your term paper, right? So buy our Class A preamp.

[Ziggy!!]

Originally Posted by joeq

All the manufacturers put the words "Class A" prominently into their advertising these days actually hoping that people will interpret that as being some kind of "rating" instead of description of how the circuit works.

It's a copywriter's dream. The preamps happen to be Class A, and that has that ring of "the best" You wouldn't drink anything other than grade A milk would you? You'd rather get an A than a B on your term paper, right? So buy our Class A preamp.

In the guitar amp world, manufacturers have gone to the point of calling cathode bias amps "class a"... regardless of whether they are actually class A or not... Whoever started saying an AC-30 was class A should be shot. It is misinformation like this that makes manufacturers think they can mis-use terms to market their products.

[natpub]

pretty sure the 1081 is A/B and it kicks ass

[nosebleedaudio]

Originally Posted by natpub

pretty sure the 1081 is A/B and it kicks ass

The first section is Class A, the 2nd is more like A/B1.
Depending on which version of the 1081 your referring too.
I would take Class A discrete any day. You can take claas A and depending on what its feeding can change the sound, such as transformer ect.
There is also a HUGE difference between Full Class A and a section of the circuit that operates at Class A.
Thats why it will be stated "Full Class A" .
There is also AB1, and AB2 which is closer to Class A.
One obvious test would be low level audio, such as a violin several feet away,this is where Class A outshines AB.
My .02cents