Bare Knuckle Pickups Forum
Forum Ringside => Guitars, Amps and Effects => Topic started by: Gary on November 26, 2005, 06:03:15 PM
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I hear a lot of people talking about the benefits of class A amps. Are there any that are reasonably available e.g. that I could try out at a local music shop?
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yu mean available for a reasonable price, or reasonably easy to find in a music shop? Theres plenty of class A amps out there! usually in combo form mind you. obviously check out the Vox AC30CC - which is made in China or somewhere, but still awesome sound and great value for money. Also i can't reccommend enough the cornford Harlequin, which sounds amazing, but is only 6W, so obviously can't really be used for gigs etc.
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I meant reasonably easy to find - so I can try some out and see what all the fuss is about.
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There is an Epiphone 5w amp. Any amp with just one power valve/tube will be class A, I think.
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Its called a Valve Junior - 5w and just one control - you can pick one up under Ģ100
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Right...Vox AC30s are not class A...end of lesson
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Right...Vox AC30s are not class A...end of lesson
On the vox site it says they are. Now I'm confused.
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Vox have been miss-selling for years. I should have said true class A to be clearer.
It is really a hot biased class AB amp. It is class A when clean but as it distorts it becomes class AB as the output valves don't pass current through 360 degrees of the input wave cycle. So the typical singing vox AC30 overdrive is class AB, when it's clean it's in class A.
Hope that clears it up - you need a bit of valve theory to get your head around operation class!
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i'd heard this aswell, to be honest. Weird how they can get away with it actually! the VOX AC30 is probably the most famously "*classA*" amp the world has to offer :?
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Laney's LC30/VC30 are class A btw.
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Laney's LC30/VC30 are class A btw.
theres a good point - they're pretty damn cheap, and if yu want lower price/wattage, then theres 15 watt versions aswell! Most music shops have 'em round here!
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yeah, i have the lc30; pretty versatile and decent sounding IMHO
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Yep i got an LC30 as well, and also tried LC15R, VC30 , LC50, all very good amps.
BTW Steve do you know if the LC30 needs biasing or if its self biased?
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whats the main differences between LC30 and VC30?
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I want to find out..the LC15and VC 15 are class A/B, I'm suspicious of the LC30 and VC30, I'm guessing they follow the Vox poweramp design...never trust what an amp manufacturer says!!
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i played the LC15 t'other day and it didn't sound very VOXish at all. Only on low volume on music shop tho, i didnt really get a chance to have a propper go. It didnt sound bad. needed pedals! :P
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Ok,
LC15/30/50 are more modern than the VC15/30 series.
LC have 1 more preamp valve and 1 more gain stage.
VC series is the one that supposedly sounds like an AC30.
I got no clue if the LC30 is 100% ClassA or ClassA/B, it says ClassA though. I just wonder if i can change power valves without rebiasing (i think i can).
Thats about it.
BTW there is a BIG difference between the LC15R and LC30/50 in build quality. LC30/50 have chassis mounted valves, pots and jacks wired OFF the pcb, whereas the LC15R has them pcb mounted.
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The THD Univalve looks interesting - 15w for under a grand. Anyone tried it?
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The THD Univalve looks interesting - 15w for under a grand. Anyone tried it?
Great sounding amp, a touch noisy but it does sound juicy. I prefer it to the Bivalve and the Flexi 50. The BiValve sounded plain odd when pushed, the Flexi is a bit soft and the bass is a bit tubby for my tastes. Good lead amp though, not for rhythm, at least for me.
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It's probably cathode biased so a swap should be fine.
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Vox have been miss-selling for years
The Ashdown Peacemaker say "Class A" on the front but I've read they're really A/B.
i can't reccommend enough the cornford Harlequin
Me neither. Only 6W but everyone of them is the best I've heard. Got my Cornford for Ģ350 second hand too. :) If you want a recording or play at home amp then check out a second hand Harlequin.
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Had a VC 30 for 3 months couln't get rid of it fast enough. The clean channel is good but the dirty side is a horrible muddy mess of a sound. I ended up putting a pedal infront of the clean channel. It then started buzzing and humming for England and the valves kept falling out because of the cr@p holder. Oh yes and the valves are mounted direct onto the PCB board which is not good for the PCB because of the heat generated in class A. The FX loop is unusable because it ruins the tone. My pedals are Keeley so I know they are fine.
For me class A is good for clean but I prefer AB for distorted
Sean
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As Hjm said, the Vox ac30 isnīt a true class A amp. But neither are their clones, like the laney lc30 or the vc 30. Matchless amps arenīt true class a, either. Mostly every amp in the market marketed as class a, isnīt.
This is a good definition that i took from the aiken amps webpage:
A push-pull amplifier is defined as operating in class A if, at the full UNDISTORTED output (just prior to clipping), the plate current flows in each tube for a full 360 degrees of the input conduction cycle.. If each side is in cutoff for exactly half the input cycle, it is a class B amplifier. If the amplifier is designed such that the plate current flows for more than half, but appreciably less than a full cycle, it is then a class AB amplifier.
Aiken amps webpage provides a lot of useful info on its page, I believe that we should try to make amp makers start speaking the truth. Still, Itīs my opinion, just that.
cheers!
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So what are some good Class A options :?:
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I just wanted to pop in. If you want a big meaty sounding distortion. You know the huge sound i mean, more modern with a fuller tone and beefed up lows but still beautifully tube, then go for Class A/B, eg DSL's (head, not combo).
I tested a Matamp 1224 Mk V and that has a class switch. This switches from class A with 1 or 2 valves, to Class A/B with 2 or 4 valves. The distortion sounded best (to me) on the class A/B 4 setting.
It all depends on your style and whether you want tube clean and distortion or tube clean and pedal distortion etc.
The best advice is always test everything and find whats right for YOU. Hopefully you should find tube amps warmer, more harmonically rich and fuller at louder volumes. As well as finding hand wired tube amps even more harmonically rich in comparison with their printed circuitboard tube counterparts.
Hope that helped and confused you. Im good at doin that :)
Best Regards
joe n