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Alternatives to class A?


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I am looking to replace some class A amps, not because I don’t like them but for practical considerations. But, having been spoilt by them, am struggling with where to go next.

 

The issue – we have one living space that is used for listening to music, watching TV/movies but also provides background/ambient music during the evening. It is the later that causes the issue.

Being class A (well first 50 watts) they produce a bit of heat, and while they don’t get overly warm to the touch they do heat up the room over time. As summer approaches again (in Perth) we have found that we are turning the stereo off, and only using it for more critical listening, and this somewhat defeats the purpose – particularly as off means no music!

 

So I am seeking some thoughts on alternatives, I am looking (hoping) for that liquidness in the highs one gets with class A, but without so much heat. Have tried a class A/B amp but it is not quite as good – although I would probably be happy with it I had not owned the others :unsure:.

 

Are there class A/B amps that people would recommend in this regard and what about class D - or is that a step to far?

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I brought an amp off a local guy who is a bit of a wiz and it is a fantastic sweet sounding amp.

Does not draw much power at normal listening levels but I think it is 190w/ch into 8 ohms.

I will chase up the details later if you like.

 

He builds many types of amps and does repairs and upgrades.

Edited by rocky500
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Do you have a budget? Are you able to do or know someone who can diy? I use Hypex nc400 mono blocks and am very happy with them but you could also use the cheaper yet almost as good Hypex UCD amps. A dac that has pre amp ability connected directly into these makes a very listenable simple system if you don't want to use a pre amp.

 

There are other brands of class d ready made but you would have to look online for these. Red Dragon is one that comes to mind.

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Personally I'd suggest not having preconceptions about amp topology.  It's all in the execution at the end of the day.  Go out and have a listen, or better yet try and arrange some home demos.

 

Arcam class G amps definitely worth having a look at in your situation. 

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IMHO there is no substitute for class A, and once you've been used to it you will miss it.

 

A good compromise would be to seek out an amp that offers high and low biasing,  That way you can use low biasing during hot weather and high biasing the rest of the time,

Edited by bronal
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Another well regarded amp is the Gato which @ was selling. Perhaps still available. http://www.stereo.net.au/forums/index.php/topic/92316-fs-gato-dia-400/#entry1485863

 

Thanks mate but its gone to its new home. Great amplifier.

 

Yes, I think Davidro & Bronal are correct  - if you like Class A, then stay with it, and install/pay for the air con. I find all designs have their pro's and cons. 

 

My domestic constrains mandate smaller amps that run cool. I am running AHB2's at the moment - the so called "Class G". They are a very detailed and a super clean amplifier. Not overly clinical like Devialet but certainly not like tubes at all. No meat on the bones, that tubes give you. 

 

BTW Devialet is out - you can fry and egg on them once they have been running for 5 minutes. I couldn't live with the heat they made. The PassLabs Int 60.5 I demo'ed ran alot cooler than the Devialet, but like all PassLabs, was a monster. 

 

What about a pair of X30.5/8's ? they don't run especially hot for class A. Luxman also run very cool for class A, but, and it is a but, they are VERY thick sounding. 

Edited by Tom.Stopforth
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Just tried turning my Amp off and it looks like it uses 12 to 13W idle.

Goes up to 25 watts at a ambient listening level.

This amp runs very cool and sounds wonderful. Seems to sway more towards a Class A type of sound. Very sweet.

 

Local guy puts them together LINK

 

 

post-107190-0-26426800-1449133229_thumb.

 

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Hi @@oinksta,

 

I had the same problem as you as I have no air conditioning. I can recommend Modwright KWA 100SE amps. I bought one of these based on reviews and use it in the summer months instead of my 805 valve amps which produce heaps of heat.

 

The Modwright is a great amp, I can easily swap it with my valve amps as the sound quality is very similar. The Modwright runs very cool and has been a pleasant surprise, I think Modwright is underrated.

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Thanks mate but its gone to its new home. Great amplifier.

 

Yes, I think Davidro & Bronal are correct  - if you like Class A, then stay with it, and install/pay for the air con. I find all designs have their pro's and cons. 

 

My domestic constrains mandate smaller amps that run cool. I am running AHB2's at the moment - the so called "Class G". They are a very detailed and a super clean amplifier. Not overly clinical like Devialet but certainly not like tubes at all. No meat on the bones, that tubes give you. 

 

BTW Devialet is out - you can fry and egg on them once they have been running for 5 minutes. I couldn't live with the heat they made. The PassLabs Int 60.5 I demo'ed ran alot cooler than the Devialet, but like all PassLabs, was a monster. 

 

What about a pair of X30.5/8's ? they don't run especially hot for class A. Luxman also run very cool for class A, but, and it is a but, they are VERY thick sounding.

I have lots of hot glowing glass........ I'm with Andrew.... Crank the air cond up.....sounds like you love your amp :-)

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Get some JC1's, you can switch between high and low level bias-

Bias Level Switch
The Bias Level switch offer s two bias setting for the output transistor s. In its Low (left) position, extremely
generous bias idle current and class A operation mak e crossover and higher-order odd harmonic
distortion inaudible. In its High (right) switch position, bias idle current is increased to perfectly match
the characteristics of the JC 1s output devices. This all but banishes these distortions. With its Bias Level
switch set to High, the JC 1 will run quite warm and consume more AC power when it is idling or playing
at low listening levels. If your JC 1 is VERY well ventilated, you may find the high bias offer s a sonic
improvement. If your JC 1 is mounted in a cabinet, or ventilation is restricted in any way, we recommend
you leave the Bias Level Switch in its Low position.

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And I was worried I wouldn’t get much of a response!

 

Quite a bit to check out there.

 

Budget is probably around the 5K mark.

 

Current amps are a couple of Emotiva XPR-2, speakers are Pioneer S-1EX. The speakers are definitely staying.

 

Thanks for all the help, from what has been said so far, will probably check out Arcam (Perth dealer?), “the local guy†and may look at Hypex. 

 

Wrt Hypex how similar in sound are the UcD vs nc400, may give the UcD’s a go and if I don’t love them they would be sufficient for driving surround speakers.

 

Again, thanks for all the help.
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And I was worried I wouldn’t get much of a response!
 
Quite a bit to check out there.
 
Budget is probably around the 5K mark.
 
Current amps are a couple of Emotiva XPR-2, speakers are Pioneer S-1EX. The speakers are definitely staying.
 
Hypex how similar in sound are the UcD vs nc400, may give the UcD’s a go and if I don’t love them they would be sufficient for driving surround speakers.
 
Again, thanks for all the help.

 

Sorry but those Emotiva amps aren't class A design and there is absolutely no way they are running 50 watts per channel class A. Don't care what the marketing mumbo jumbo says from Emotiva either.  To run 50 watts per channel true class A you'd need enormous heat sinks and completely different chassis design.  Check out below design for a 50 watt per channel class A amp from Shanling (and even this is not a true class a design)

 

379941-shanling_slm_a40_mk_ii__class_a__

 

That's a class A/B amp by any definition, and sounds like you are happy with the sound.  Just keep them!

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