2. amps-preamps
  3. 137209-3022

Line Magnetic 518ia - How Much Heat Does It Produce?

Hello, and thanks for any help with this. I'm helping a very dear friend, who loves music, and good audio equipment, put together a system. He has suffered some very serious personal setbacks of late, and one of the key things he has turned to, is putting together an audio system as a means to attempt to move forward. He is trying to put together a nice audio system in what he has available, a small room.

He travels a fair bit for work, and has had two recent experiences listening to the exceptional Line Magnetic 518ia, and was blown away by it. I can guarantee you that he has heard some very good audio components, but has been captivated by the 518ia. If you have heard it, or read the reviews, you understand, as I do. That's a truly amazing piece of gear, especially for the price.

Here is my concern, Because of serious budget deficits related to his other problems,  he can only afford one of these wonderful integrated amps, used. Okay, they are available  in his price range. I have him set up with speakers and everything else to maximize the quality of his system. But, this is a Class A amp, even if relatively low wattage. He would be using this in a 10x10 room, with the integrated amp only 2.5 feet away from where he sits. There is no other available placement. Is this going to overheat him, and/or the room? 

Any input would be appreciated. If he cannot make use of this amp he loves so much, it could get very difficult to find anything else, given it's price performance capabilities. 
nightfall
almarg's avatar
Ag insider logo xs@2x
almarg
9,670 posts
 
I agree with the conclusion that "this solution won’t work."

For a class A amp the calculation is simple. The amp is spec’d as consuming 320 watts, and given that it operates in class A virtually all of that power will be converted to heat and radiated into the room whenever the amp is powered up, regardless of whether music is being played or not. And in this case into a 10 x 10 room at a distance of only 2.5 feet from the listener. That seems to me to be completely untenable.

A small handful of those 320 watts will be sent to the speakers when music is playing, but the great majority of even those few watts will then be converted to heat by the speakers. The rest of the 320 watts will be radiated into the room by the amp.

Also, based on the specs I’ve seen for various Line Magnetic models their power consumption generally seems to be particularly high relative to their output power ratings and class of operation. In the case of the 518ia, for example, 320 watts input divided by 44 max watts of output for the two channels is a ratio of 7.3, very high even for class A operation.  Or putting it another way, 44/320 = 13.7% efficiency, very low even for class A operation.

What speakers are being used? Perhaps less power than 22 watts per channel is necessary, especially since the listening distance will be minimal?

Best of luck in this endeavor.

Regards,
-- Al
charles1dad's avatar
charles1dad
10,250 posts
 
Yeah,
I find it rather strange (bizarre?) that some are discounting the close sitting proximity to amplifiers dissipating 320 watts!!! (Essentially a room heater in a tiny space). As Al mentioned regarding speakers, more efficient models could possibly mate with a 300b SET. Far less heat generated compared to the 845.
Charles
nightfall OP
188 posts
 
Thanks again for everyones thoughts. Now the struggle is finding any integrated amps that will satisfy my friend (based on his loving the sound of the 518ia). It clearly needs to be something  that won't overheat him, and the room, is available for  $3-3500.00, used, and is somehow comparable to the sound of the Line Magnetics.

I've already discussed it with several audiophile friends that are familiar with the sound of the 518ia, and they too, are having difficulty coming up with something that meets all of the above. One initially suggested a Unison S6, which does sound like a real possibility, but I think that might  also present a heating issue. Its a Class A amp, only moderately powered, but in the Stereophile review, John Marks notes that, " The S6 performed flawlessly, though it did throw off a lot of heat.". That surprises me since it uses EL34 tubes. 
almarg's avatar
Ag insider logo xs@2x
almarg
9,670 posts
 
The Unison S6 has a specified power consumption of "265 VA max." Given that it is a class A design that probably means a continuous draw of not a great deal less than 265 watts, which in turn is not greatly less than the 320 watts drawn by the LM-518ia.

An EL34 requires close to 10 watts just to heat the filament, and I'm guessing that in this design each of the six EL34's consumes something like 25 watts in total. So that's 150 watts just for the power tubes, plus additional consumption by the power supply, the small signal tubes, and other circuitry.

I don't have a solution to propose, but as Charles and I stated earlier perhaps the answer involves going to a less powerful amp than the ones that have been mentioned.

Good luck. Regards,
-- Al 
charles1dad's avatar
charles1dad
10,250 posts
 
Nightfall
Unison Research is an Italian company that has a reputation for good sounding tube amplifiers. My suspicion is that it will fall in somewhere between the Prima Luna (class A/B push pull) and the LM 518a (class A SET) . The S6 model is class A and parallel SET with 3 el 34 per channel.

I bet this amplifier sounds really good given the design, circuit and topology. Don’t know if it will equal what your friend heard with the 518a but you never know until you’ve actually listened . As Al noted heat output is still a concern. I sympathize with your fiend, he has good taste/ears but limiting circumstances.
Charles
More to discover