Whats the difference between class A amps and class B etc?? I heard that class A runs at 100 percent input or something but what does this mean for me? How would it affect me and my playing? The vox ac30 isnt class A i dont think where as i think alot of laney's are....
There is a really great artivle on tehis on teh Mesa website, but simply put, Class A amps get an extra harmonic, which is cancelled out in Class A/B push/pull amps, which adds a nice sweetness.
They tend to be point to point wired, rather than circuit board, which has impolications for long term reliability. The resting current is the same as when the amp is being played, so they produce more heat, which ,ay or may not be an issue.
They are not automatically superior, but there are certainly some very nice Class A amps.
Whats the difference between class A amps and class B etc??
While I'm admittedly no amp expert, I was able to ask an expert this very question a few years ago. There are many things that
distinguish Class A operation from Class A/B, and he went through it all with me starting from a rather technical standpoint.
In the end he gave me a fairly easy to understand explanation - so here it is in a nutshell:
-- The power tubes in a Class A amp are operating at “pretty close to full power” whether or not a signal is being amplified. As long as the
tubes are being operated at reasonable voltage and bias range we're okay. The beauty of this type of operation is that there is no
significant difference between the tubes work interval and its rest interval. The distortion products created by this method of operation
are very musical sounding and the overall tone has a pure quality. When combined with the right output transformer, the harmonic blend
created by the tube distortion characteristic and transformer saturation (that is to say, just past the point of maximum linear operation), is
rich, full and fat sounding. It sounds pretty much like an amp turned up loud even when it isn't because it's operating nearly full out in a sense.
-- In class A/B operation the tubes are getting a big break. When no signal is present the tube is essentially at rest. When you begin to play,
there occurs a transition from "off" state to "on" state between the push-pull pairs of tubes. This transition, known as the crossover region,
produces a noticeably different type of behavior typically referred to as crossover distortion. Crossover distortion contributes a harshness
to the sound which can give the amp an aggressive personality. This can be interpreted as a good thing depending on what you are trying to
accomplish musically. The real up side of Class A/B operation is its inherent efficiency. The simple fact that each tube has a rest interval in
its duty cycle allows the tube to operate at higher output during its work interval or "on" state. Thus, a power amp operating in Class A/B
will typically produce about 30% more power than a comparable Class A amp. Since the typical output transformer in a Class A/B amp
will not be required to operate at high continuous current, it will spend less time in saturation mode. This contributes to the clarity and detail
of the power amp sound. An additional advantage of Class A/B is that because they tend to run cooler, tube life can be extended somewhat.
For strictly comparative purposes however, the essence of the debate is sound quality. We are attracted to the Class A sound because of its warmth, sonic complexity and rich harmonic content. The Class A/B sound is more articulate, dynamic and gives us the sensation of immediacy.
I paraphrased a lot there, but I hope this helps your question - feel free to ask if you still don't understand.
Cheers . . .
Well explained mate, awesome job thanks. I learnt quite a few things then. you do good work ian
yeah well i guess then in my situation perhaps the class a/b amp might be better. I mean I want a really nice clean warm sounding amp for when i wanna play clean but realistically i would spend alot more time in overdrive or with pedals.
I started worrying because the amps i have been looking at are not class A (except the orange 30 watt) but I'm not sure whether it will matter much with my limited skill level and my type of playing.
Is class A suited much to rock? i guess thats a big question to ask. perhaps i could use our wonderful friend mike mccready as an example (I have that disease :- iwannabelikemikeitis..) Although obviously more complicated, would his amps be class A?
"I dont question, our existence
I just question, our modern needs"
Well explained mate, awesome job thanks. I learnt quite a few things then. you do good work ian
yeah well i guess then in my situation perhaps the class a/b amp might be better. I mean I want a really nice clean warm sounding amp for when i wanna play clean but realistically i would spend alot more time in overdrive or with pedals.
I started worrying because the amps i have been looking at are not class A (except the orange 30 watt) but I'm not sure whether it will matter much with my limited skill level and my type of playing.
Is class A suited much to rock? i guess thats a big question to ask. perhaps i could use our wonderful friend mike mccready as an example (I have that disease :- iwannabelikemikeitis..) Although obviously more complicated, would his amps be class A?
Mikes uses quite a few different amps (he uses both Class A and A/B).
For example: His Marshalls are Class A/B while his Matchless are Class A
Don't get too caught up in the amp classification as to what genere it will be good for. The tube type can have almost as much to do with the sound as the operating class. You can get great tones out of either the character is just slightly different. There are great class A and class A/B amps that work for pretty much everything. neither is "better" there are just trade offs. It's kind of like the argument about PCB vs. Handwired, turret board construction etc. If you do it right, you can get great examples from any kind of construction. The character is a bit different with the classification.
Use a Marshall JCM800 4211. It's a 2x12 combo with channel switching
I use the overdrive on the amp and a Marshall bluesbreaker II pedal set to boost for extra drive and sustain when needed. Sounds good I think.
Hey guys i thought i would post in this thread. Just had some queries about the vox ac30 i have been looking at. I didnt get much of a play on it at the music shop and i didnt get much time to play around with the overdrive. I noticed that the amp doesnt come with a channel footswitch which wouldnt be a problem, I could just buy an A/B switch box, but as far as I can tell theres no way to switch from clean to crunch/overdrive instantaneously. Is this correct? I have my effects pedals that i would run through it including distortion but i heard that the amp still should be in the overdriven mode to run them? So how if at all possible would you swich from a gorgeous ac30 tone to some serious distortion? thanks for the help as always
Keegan
"I dont question, our existence
I just question, our modern needs"
the AC30s don't have a clean and drive channel. they have normal and brilliant channels. each with their own volume, and a master volume (assuming you're looking at the current AC30CC2).
so, i'm assuming you could set up one channel to be overdriven by cranking it and leave the other one clean, but you're going to get a big volume jump when you switch. it isn't like an amp with a drive channel.
best bet, is to set up the amp slightly overdrive, and go from clean to dirty using your guitar's volume control. and depend on the pedals for more distortion.
and generally, yes, i find distortion pedals sound better when they're run into slightly overdriven amps as opposed to perfectly clean ones.
Thanks mate yeh im looking at the current ac30cc2. So i would just buy an a/b switch box and give that go then.. Are there any amps similar to this vox that have a seperate drive channel? Just seems alot easier to me to have a clean channel and a distorted channel, probably because i am a novice.
"I dont question, our existence
I just question, our modern needs"
off the top of my head, the orange rocker 30. a few bucks more but not much. has clean and dirty channels and will be somewhat similar to the vox soundwise as it has a similar tube array.
off the top of my head, the orange rocker 30. a few bucks more but not much. has clean and dirty channels and will be somewhat similar to the vox soundwise as it has a similar tube array.
yup, the Rocker 50 is a little more of the same look with the 2x12 configuration. THe Rocker 30 is only the single 12, it just depends on the application.
I would say AD30 twin Channel or HTC (about 1399 US for the HTC) as well but they are a little darker woolier than the AC30CC's not that I see this as a bad thing really. I'm sure you could make it a little more chimey with blues or blue dogs but I can't vouch for that yet. I think what they did is give you a cleaner clean channel and then use the regular channel they built on the single channel AD15's and 30's for the overdriven crunchy channel. The AD's are a lot more reserved than the Rockers though too at lower volume levels. Just like AC30's they need to Breath to show off the greatness.
They aren't that much more expensive really and they sound fantastic.
My Girlfriend said to me..."How many guitars do you need?" and I replied...."How many pairs of shoes do you need?" She got really quiet.
I just heard today that the vox custom classics have been manufactured in China for the last two years or so. All this time i thought they were still made in britain.. Would this have any effect on the custom classic line do you think? I just know that the Chinese are good at cutting costs of things.
"I dont question, our existence
I just question, our modern needs"
I just heard today that the vox custom classics have been manufactured in China for the last two years or so. All this time i thought they were still made in britain.. Would this have any effect on the custom classic line do you think? I just know that the Chinese are good at cutting costs of things.
i had one of the chinese built AC15s. it was a rock. no quality issues whatsoever. it sounded great. i sold it because the reverb wasn't very good (but that wasn't a build quality issue, it's a design issue) but i'm planning on buying another soon now that i have a good outboard spring reverb unit anyway.
i haven't heard complaints about the reverb in the AC30s.
Well after a bit of looking around and ALOT of questions I have narrowed it down to my main interests. These are:-
Vox Ac30
Orange rocker 30
Mesa Boogie 5:25
Marshall Jcm 2000 Tsl 60watt
Fender '65 super reverb reissue
Fender Super sonic
Fender Hot Rod deville
A big list i know. I have become a bit worried after i learnt that the vox and the orange (the two that seemed to interest me the most) are now made in china. As well as celestion speakers... I dont know whether this would matter or not, i have heard people saying it doesnt make a difference and heard alot of people saying that the sound and reliability have dropped big time..
Originally i wanted a nice warm clean amp that will also dirty up with a few effects pedal added aswell. But realistically I probably will be using distortion at least 70% of the time so maybe I should just settle with a amp with strong distortion? like the marshall maybe? Anyone have any opinions or ideas? My influences are pretty much Pearl jam, more pearl jam, U2 and mainly 80's - present rock.
I also just want to thank everyone thats been giving me feedback recently about guitars effects amps etc.. Ive found it really helpful and really appreciate everyones help.. Sorry about the long post guys.
"I dont question, our existence
I just question, our modern needs"
Comments
There is a really great artivle on tehis on teh Mesa website, but simply put, Class A amps get an extra harmonic, which is cancelled out in Class A/B push/pull amps, which adds a nice sweetness.
They tend to be point to point wired, rather than circuit board, which has impolications for long term reliability. The resting current is the same as when the amp is being played, so they produce more heat, which ,ay or may not be an issue.
They are not automatically superior, but there are certainly some very nice Class A amps.
distinguish Class A operation from Class A/B, and he went through it all with me starting from a rather technical standpoint.
In the end he gave me a fairly easy to understand explanation - so here it is in a nutshell:
-- The power tubes in a Class A amp are operating at “pretty close to full power” whether or not a signal is being amplified. As long as the
tubes are being operated at reasonable voltage and bias range we're okay. The beauty of this type of operation is that there is no
significant difference between the tubes work interval and its rest interval. The distortion products created by this method of operation
are very musical sounding and the overall tone has a pure quality. When combined with the right output transformer, the harmonic blend
created by the tube distortion characteristic and transformer saturation (that is to say, just past the point of maximum linear operation), is
rich, full and fat sounding. It sounds pretty much like an amp turned up loud even when it isn't because it's operating nearly full out in a sense.
-- In class A/B operation the tubes are getting a big break. When no signal is present the tube is essentially at rest. When you begin to play,
there occurs a transition from "off" state to "on" state between the push-pull pairs of tubes. This transition, known as the crossover region,
produces a noticeably different type of behavior typically referred to as crossover distortion. Crossover distortion contributes a harshness
to the sound which can give the amp an aggressive personality. This can be interpreted as a good thing depending on what you are trying to
accomplish musically. The real up side of Class A/B operation is its inherent efficiency. The simple fact that each tube has a rest interval in
its duty cycle allows the tube to operate at higher output during its work interval or "on" state. Thus, a power amp operating in Class A/B
will typically produce about 30% more power than a comparable Class A amp. Since the typical output transformer in a Class A/B amp
will not be required to operate at high continuous current, it will spend less time in saturation mode. This contributes to the clarity and detail
of the power amp sound. An additional advantage of Class A/B is that because they tend to run cooler, tube life can be extended somewhat.
For strictly comparative purposes however, the essence of the debate is sound quality.
We are attracted to the Class A sound because of its warmth, sonic complexity and rich harmonic content.
The Class A/B sound is more articulate, dynamic and gives us the sensation of immediacy.
I paraphrased a lot there, but I hope this helps your question - feel free to ask if you still don't understand.
Cheers . . .
- Ian C.T. vom Saal
<b><font color="red">CONTACT ME HERE</font>: www.myspace.com/ianvomsaal</b>
♫ ♫ ♫ ♫ ♫ ♫ ♫ ♫ ♫ ♫ ♫ ♫ ♫ ♫ ♫ ♫ ♫ ♫ ♫ ♫ ♫ ♫ ♫ ♫ ♫ ♫ ♫ ♫
yeah well i guess then in my situation perhaps the class a/b amp might be better. I mean I want a really nice clean warm sounding amp for when i wanna play clean but realistically i would spend alot more time in overdrive or with pedals.
I started worrying because the amps i have been looking at are not class A (except the orange 30 watt) but I'm not sure whether it will matter much with my limited skill level and my type of playing.
Is class A suited much to rock? i guess thats a big question to ask. perhaps i could use our wonderful friend mike mccready as an example (I have that disease :- iwannabelikemikeitis..) Although obviously more complicated, would his amps be class A?
I just question, our modern needs"
For example: His Marshalls are Class A/B while his Matchless are Class A
- Ian
<b><font color="red">CONTACT ME HERE</font>: www.myspace.com/ianvomsaal</b>
♫ ♫ ♫ ♫ ♫ ♫ ♫ ♫ ♫ ♫ ♫ ♫ ♫ ♫ ♫ ♫ ♫ ♫ ♫ ♫ ♫ ♫ ♫ ♫ ♫ ♫ ♫ ♫
http://www.sweetwater.com/expert-center/techtips/d--01/12/2005
The Orange Rocker 30 or 50 and 100 are pretty good ones to try out really. Very Wooley. Just don't read thier marketing....
I use the overdrive on the amp and a Marshall bluesbreaker II pedal set to boost for extra drive and sustain when needed. Sounds good I think.
You can hear it here (sort of) on the rhythm parts
http://profile.myspace.com/australianpearljam
I've played through a few of the newer Marshall valvestates, wasn't mad about the sound. more of a distorsion/gain than the overdrive which I like.
Keegan
I just question, our modern needs"
so, i'm assuming you could set up one channel to be overdriven by cranking it and leave the other one clean, but you're going to get a big volume jump when you switch. it isn't like an amp with a drive channel.
best bet, is to set up the amp slightly overdrive, and go from clean to dirty using your guitar's volume control. and depend on the pedals for more distortion.
and generally, yes, i find distortion pedals sound better when they're run into slightly overdriven amps as opposed to perfectly clean ones.
I just question, our modern needs"
yup, the Rocker 50 is a little more of the same look with the 2x12 configuration. THe Rocker 30 is only the single 12, it just depends on the application.
I would say AD30 twin Channel or HTC (about 1399 US for the HTC) as well but they are a little darker woolier than the AC30CC's not that I see this as a bad thing really. I'm sure you could make it a little more chimey with blues or blue dogs but I can't vouch for that yet. I think what they did is give you a cleaner clean channel and then use the regular channel they built on the single channel AD15's and 30's for the overdriven crunchy channel. The AD's are a lot more reserved than the Rockers though too at lower volume levels. Just like AC30's they need to Breath to show off the greatness.
They aren't that much more expensive really and they sound fantastic.
I just question, our modern needs"
i had one of the chinese built AC15s. it was a rock. no quality issues whatsoever. it sounded great. i sold it because the reverb wasn't very good (but that wasn't a build quality issue, it's a design issue) but i'm planning on buying another soon now that i have a good outboard spring reverb unit anyway.
i haven't heard complaints about the reverb in the AC30s.
Vox Ac30
Orange rocker 30
Mesa Boogie 5:25
Marshall Jcm 2000 Tsl 60watt
Fender '65 super reverb reissue
Fender Super sonic
Fender Hot Rod deville
A big list i know. I have become a bit worried after i learnt that the vox and the orange (the two that seemed to interest me the most) are now made in china. As well as celestion speakers... I dont know whether this would matter or not, i have heard people saying it doesnt make a difference and heard alot of people saying that the sound and reliability have dropped big time..
Originally i wanted a nice warm clean amp that will also dirty up with a few effects pedal added aswell. But realistically I probably will be using distortion at least 70% of the time so maybe I should just settle with a amp with strong distortion? like the marshall maybe? Anyone have any opinions or ideas? My influences are pretty much Pearl jam, more pearl jam, U2 and mainly 80's - present rock.
I also just want to thank everyone thats been giving me feedback recently about guitars effects amps etc.. Ive found it really helpful and really appreciate everyones help.. Sorry about the long post guys.
I just question, our modern needs"