[Birdbrain]

I'm curious how much power an Insight+ Double 240 puts out. And how much is that power increased if you use it with an AVA preamp with the phase inverter option. Would such a set up be suitable for, say, a pair of Magnepan MG12s?

[Lefty052347]

A double 240 in a AVA chassis will develop around 125 watts per channel.  The amp will drive a 2 ohm load or higher.  I would recommend the large chassis for driving the MG12s (more heatsink and heatsink is outside chassis).  The small chassis will work fine.  Just make sure there is enough room around the chassis to allow the internal heatsinks to dissipate enough heat.

To increase power using a phase inverter requires 2 amplifiers.  That will essentially triple the power.  This is accomplished by summing the voltage output of both channels of each amp.

Regards,
Dean

[kip_]

A double 240 in a AVA chassis will develop around 125 watts per channel.  The amp will drive a 2 ohm load or higher.  I would recommend the large chassis for driving the MG12s (more heatsink and heatsink is outside chassis).  The small chassis will work fine.  Just make sure there is enough room around the chassis to allow the internal heatsinks to dissipate enough heat.

To increase power using a phase inverter requires 2 amplifiers.  That will essentially triple the power.  This is accomplished by summing the voltage output of both channels of each amp.

Regards,
Dean

The double die option doesn't put out any more watts? Really???

[floresjc]

Its not all about watts. The double die option ups the amount of current the unit can handle, and the more current the more difficult load it can handle.

[kip_]

Its not all about watts. The double die option ups the amount of current the unit can handle, and the more current the more difficult load it can handle.

So the upgrade is pointless if you don't have 2ohm speakers?  I'm not trolling just trying to understand why someone would use the double die upgrade on normal impedance speakers if the wattage is the same.

[rlee8394]

Impedance isn't constant. Depending on how robust the power supply is, you may get a few more watts. I believe that Frank actually quoted specific power increases for one or more of the amps that use Double Die option. Given that the 240 provides 125 watts with the single die MOS-FETs, you might get around 140 watts with the double die option, although you won't notice the difference. Doubling the power from 125 watts to 250 watts would provide a 3 dB increase in sound level. It takes 10 dB increase to provide twice the sound output and that would equate to to 1250 watts. Forego the numbers race and do as Frank says, but the least expensive unit for your requirements. Call him and he will steer you straight. Now since the 240 uses 4 devices, it would only cost you an additional $88 to go the double die route. I think it is worth it. Also, the phase inverter is worth using with a single amp. By running one channel inverted from the other, and then putting both channels back in phase by reversing the speaker connection for the inverted channel, you relieve the common signal stress on the power supply. See the last paragraph on this page for details:

http://www.avahifi.com/index.php?option=com_content&view=article&id=115&Itemid=238

Ron

[floresjc]

kip -

I'm no rocket scientist on this issue, but as rlee stated, impedance isn't constant. Speakers are given a nominal rating, lets say 8 ohms for my SongTowers. During the course of playback, there's going to be times when that dips down, maybe all the way to 2 ohms. As mentioned, it takes a doubling of watts to get 3dB more sound, so the difference between a 125wpc and a 150wpc is peanuts. If your amp can handle more current however (due to double die), its going to handle that dynamic impedance load much better than the wpc would ever tell you about the amp.

[ricardojoa]

How does the ava 240 rated at 120 watts at 8 ohm compares to amp like Rotel 1562 when loaded at 4 ohms. The rotel 1562 is rated 100 watts at 8 ohm and double at 4 ohms. If you would drive both these amp with the same speaker at 4 ohm load, the rotel 1562 will have 75 watts free, that means it is working less hard while the ava is at his limit. Can someone commnet?

[avahifi]

First of all, all of the Insight+ amplifiers put out nearly double 8 ohm rated power into 4 ohms and the "double die option" models do even more into two ohms.  The Insight+ 240 will still have more power than your mass produced made in god know where in the far east Rotel for 25 cents an hour labor by people that will never get to hear good audio equipment.

Second, comparing "raw watts" is very much like comparing cooked meat on a balance scale.  If you put a 20 pound prime rib on one side, and 20 pounds of White Castles, steamed onions and buns and all, on the other side, both sides will balance and you have exactly the same on both sides.

So, for your comments, I will treat you to a White Castle banquet when we next meet.

Best regards,

Frank Van Alstine

P.S. Of course if you serve the White Castles with "Wonderbuns" (which cost $137.50 each), then they will win hands down.

[avahifi]

For any of you that are interested, there is one track on Jim Salk's demo CD that I use often to evaluate the progress of our electrical engineering design work.

It is Track 3: Mary Fahl / Una Furtiva Lagrima [The Other Side of Time]

This track was a "room cleaner" at trade show we were at sharing with SalkSound.  Every time Jim played it loudly I winced and the room cleared out as the high loud "E" sounds of the female vocalist simply were piercingly nasty, ever with the best of our equipment and Jim's speakers.

Finally, with the Vision DAC, AvaStar or Insight+ preamps, and either the Ultra+ or Insight+ amplifiers, the room stays serene and happy.  The high "E" sounds are still too loud (bad recording mix) but the burn your ears out edge is gone, replaced with just much higher resolution and transparency.

The next time you are at an audio show, play that track on both Jim and my equipment and then on anything else at the show.  Listen and you will hear, and know.

Best regards,

Frank Van Alstine

P.S.  My other best "torture" disk is track one on the Clair Marlo, Let It Go CD.  Sheffield Lab #CD-29.  This CD will bring out the worst of any system from top to bottom and sounds completely different on every different system that has any significant weaknesses.

[ricardojoa]

Cool!,
So basically what you are saying is that,the insight+240amp makes roughly 240 watts at 4 ohms, but you simply choose not to post the info on the site. As consumer, when looking for power amps, watts is obvious a little data that they will look for since power amps are design to put out watts to power speakers.
It doesn't matter what brand of amp i put  for reference, my point is, the higher power rated amp simply will work easier and more efficient. I could bring Jeff Rowland for example and simply turn my self into USDA prime rib where as you, who knows mad cow.  But since you have pointed out the power rating, mystery solved.
So I guess all AVA products are made in USA? Great...it is so hard to find American made audio electronics now a days. What about the parts inside?
With all the great review, I was interested in AVA products, but i simply did not think is necessary to knock on some other companies products, i could care less about rotel, but come on, 25 cents an hour people comment? they are just making a living. Last i know this is an audio board, so be focused and keep it simple. Have a good day

[srb]

Speakers are given a nominal rating, lets say 8 ohms for my SongTowers. During the course of playback, there's going to be times when that dips down, maybe all the way to 2 ohms.

Obviously all speakers are different, and each speaker's impedance curve tells the true story.  The SongTowers are 4 ohms nominal, 6 ohms average.
 
They rise to ~14 ohms at 60Hz and ~17 ohms at 1.5KHz, and dip down to ~5 ohms at 40Hz and ~4 ohms at 200Hz and 3KHz.
 
Other speakers may not have such an easy impedance curve and certainly there are ones rated at 4 ohms that do dip down to the 2 ohm range at certain frequencies.
 
Steve

[newzooreview]

Cool!,
So basically what you are saying is that,the insight+240amp makes roughly 240 watts at 4 ohms, but you simply choose not to post the info on the site. As consumer, when looking for power amps, watts is obvious a little data that they will look for since power amps are design to put out watts to power speakers.
It doesn't matter what brand of amp i put  for reference, my point is, the higher power rated amp simply will work easier and more efficient. I could bring Jeff Rowland for example and simply turn my self into USDA prime rib where as you, who knows mad cow.  But since you have pointed out the power rating, mystery solved.
So I guess all AVA products are made in USA? Great...it is so hard to find American made audio electronics now a days. What about the parts inside?
With all the great review, I was interested in AVA products, but i simply did not think is necessary to knock on some other companies products, i could care less about rotel, but come on, 25 cents an hour people comment? they are just making a living. Last i know this is an audio board, so be focused and keep it simple. Have a good day

Unfortunately wattage is not an objective measurement when reported by amplifier manufacturers, and it therefore has no bearing on the relative "power" of a speaker in driving an amplifier.

It's a pretty easy trap to fall into to assume that all 100 watt amplifiers, for example, have the same raw ability to drive a loudspeaker (I used to assume so as well). Please read through the back issues of  Audio Basic Newsletter for a number of articles explaining the problem (and the willful deception within the audio industry on this point): http://www.avahifi.com/index.php?option=com_content&view=article&id=85&Itemid=181

[trebejo]

So I guess all AVA products are made in USA? Great...it is so hard to find American made audio electronics now a days. What about the parts inside?
With all the great review, I was interested in AVA products, but i simply did not think is necessary to knock on some other companies products, i could care less about rotel, but come on, 25 cents an hour people comment? they are just making a living. Last i know this is an audio board, so be focused and keep it simple. Have a good day

<sigh> It is true, if you seek to find slick-marketed, crappy stuff manufactured by hyperexploited labor, you do not need to leave the confines of the good ol' USA. Granted, wages are quite a bit lower in China!

Perhaps it would be more apropos to point out that AVA's stuff is manufactured with craftmanship as in the guild shops of yore--a place where shoddy products would result in unfriendly visits to the shop from the customers. If such excellent products happen to be made in the USA, that's fine, but if it was made in Canada, Mexico, or yes, even China, it would be fine too, if it was made with the same respect for the customer, the laborer, the instrument, and the art behind it.

The last bit of hifi that I purchased satisfying the conditions of "mass-production unit built in China, designed by a company based elsewhere", I opened it up, looked inside and was very very disappointed with the construction quality. After complaining for a couple of months, I finally got an email from that company, explaining that the unit must surely have been fine when it left the factory because the quality control, as well as the assembly, is done robotically.

After that experience, getting something from AVA is a breath of fresh air. Sure, it'll cost a bit more, but it's not like you are going to be throwing it away anytime soon.

Best way to figure out if the AVA amp is a good match for your setup: call Frank and ask him. That option will not be available with the robotic manufacturers.

[gkinberg]

It is Track 3: Mary Fahl / Una Furtiva Lagrima [The Other Side of Time]

This track was a "room cleaner" at trade show we were at sharing with SalkSound.  Every time Jim played it loudly I winced and the room cleared out as the high loud "E" sounds of the female vocalist simply were piercingly nasty, ever with the best of our equipment and Jim's speakers.

Frank, while this track sounds like a useful diagnostic tool, why would you and Jim want to clear the room that you are demoing your gear in?
Garth

[avahifi]

Jim likes to play demo material louder than I do and sometimes goes over the top in that direction in my opinion.  Everyone has somewhat different ideas and judgements about how the best of music is supposed to be presented.

In general we get along very very well.  Perhaps I am more sensitive to that track than he is.  Anyway, its fixed now.

Regards,

Frank