Superfi or madness

[Pharos]

It's a preference for many.

[Macca]

Maybe some, I think it is a practice that is dying out.

I think any amp that takes more than a couple of minutes at most to reach optimal performance is worth avoiding. Assuming there are any, which I doubt.

[Macca]

Actually thinking about it the speakers do have to warm up, which actually might be audible and could be why people think it is the amplifier warming up instead. But that's still only a few minutes tops.

[Barry]

Class A amplifiers can only be 50% efficient at most, and since they draw constant current, what you are not using to power your speakers comes out as heat. Thus if left idling, or playing music quietly most of the power is dissipated as heat in the amplifier.

My Levinson Class A monoblocks are 25W (into 8 Ohm) and during the summer months they are too hot to use. In winter it's a different matter!

[AJSki2fly]

My Levinson Class A monoblocks are 25W (into 8 Ohm) and during the summer months they are too hot to use. In winter it's a different matter!

They sound very inefficient,, the Krell is quite happy ticking along a -35dB giving of a little warmth.

[Pharos]

Class A amplifiers can only be 50% efficient at most, and since they draw constant current, what you are not using to power your speakers comes out as heat. Thus if left idling, or playing music quietly most of the power is dissipated as heat in the amplifier.

My Levinson Class A monoblocks are 25W (into 8 Ohm) and during the summer months they are too hot to use. In winter it's a different matter!

My college notes say 45% max, and my Nelson Jones 10+10 used to only just 'bubble' spit

[Barry]

My college notes say 45% max, and my Nelson Jones 10+10 used to only just 'bubble' spit

The theoretical figure is 50%, the figure in practice is likely to be a little lower.

[Barry]

They sound very inefficient,, the Krell is quite happy ticking along a -35dB giving of a little warmth.

They were designed to be used with Quad ESLs, which should see no more than about 30V peak. I believe the Levinsons use +/- 25V rails. Anyway they put out:

25W (continious sine wave) into 8 Ohm
50W into 4 Ohm
100W into 2 Ohm
200W into 1 Ohm

https://www.marklev.com/2013/04/ml-2...amplifier.html
https://stereonomono.blogspot.com/20...nson-ml-2.html

And they do run hot - each drawing 400W from the mains, most of which will be turned into heat.

[AJSki2fly]

They were designed to be used with Quad ESLs, which should see no more than about 30V peak. I believe the Levinsons use +/- 25V rails. Anyway they put out:

25W (continious sine wave) into 8 Ohm
50W into 4 Ohm
100W into 2 Ohm
200W into 1 Ohm

https://www.marklev.com/2013/04/ml-2...amplifier.html
https://stereonomono.blogspot.com/20...nson-ml-2.html

And they do run hot - each drawing 400W from the mains, most of which will be turned into heat.

Thanks Barry, I was being a numpty, I had completely forgotten about Mark Levinson, as soon as I saw the link I remembered them, highly regarded amps considered to produce a purity of sound. I bet they sound lovely, what speakers do you drive with them?


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[Firebottle]

Barry is a dyed in the wood Quad 57 man, like myself.