Can someone tell me about the "quality first watt" theory?

[erdric]

I was following a thread over in the updating older speakers section "Forte II's getting long in the tooth".

http://forums.klipsch.com/idealbb/view.asp?topicID=31357&sessionID={11F76D17-B2C3-4D30-BBC2-E8BCEC11BA6C}}

Dndphisin brought up the point that Klipsch are so efficient and therefore don't demand a lot of power output. Because of this characteristic, it's important to have an amp that puts out a good first watt. I posted in that thread to get some more info but I think the thread has died. I thought I'd repost what I asked over there to see if I could get some more info.

" I was wondering about the "quality first watt" theory. How does one tell if an amp has a "quality first watt"? Is it a spec issue? Is it something that's easily looked up or do you have to demo and listen for distortion? Are there manufacturers that are known to have this quality?

I'm using my system for HT so I want SS amp. I've been planning on picking up a Rotel amp when I get some more cash. Does anyone know if Rotel has a "quality first watt"?"

So, does anyone have info on this topic? Dndphisin, are you out there?

[Audible Nectar]

I will quote verbatim the specifications printed on the back of my McIntosh Mc 250 amplifier:

"Rated power band 20 hz to 20,000 hz

TOTAL HARMONIC DISTORTION

.25% maximum harmonic distortion at any power level from 250 milliwatts to 50 watts from 20 to 20,000 hz, both channels driven"

The critical element of this spec is "at any power level from 250 milliwatts to 50 watts". It will perform well and give quality clean full bandwidth power at any output level.

If you start looking at spec sheets for amplifiers (and especially current home theater amplifiers), you might read for a month before you find a spec that reads this way. There's a reason for that - the amplifier simply cannot do the low power equally as well as the high power. To place 5 channels of such quality amplification in one chassis would be very expensive and large (the Mc 250 weighs about 37 lbs, and that's just 50w x 2).

You cannot hear an amplifier from it's specs, though, so listening becomes the best test. It is "trial and error", however the collective experiences of this forum are very helpful (especially for purposes of eliminating the obvious junk). So we settle on several options in solid state amps well known for that good "first watt", based on recommendations I've seen here on the forum, as well as from a bit of experience.

McIntosh: This is the obvious "first mention". Mac solid state is very tubelike and smooth - a match made in heaven for Klipsch, IMO. While many feel that the earliest Mac 2 channel solid state units are the most tubelike (mc 250, mc2100, mc 2505, mc 2105), the newer units offer multichannel configurations too, if you want it all in one chassis. A bit pricey, but hold resale value VERY well. The Mc 250 is an OUTSTANDING value (available used for $350-600 each, based on condition).

Monarchy Audio SM 70: These are 2 channel amps rated at 25 wpc, which operate in class A. Buy three for 6 channels in the HT. These run about $550 each new, and are also sold for less on the used market. So for about $1650, you've got 6 channels of smooth, quality power.

Classe: This particular brand of amps have a reputation for being very smooth as well, and are available in multichannel configurations.

Any amplifier that operates as true "class A" would be worth investigating.

I've also read many very good comments on the Sherbourn home theater amplifiers - when these show up on the used market, they never seem to last more than a day or two. If I remember correctly, the company founder worked for Macintosh at one time. This is an amp I would very much like to demo.

I have no personal experience with the Rotel, but from what I've read, they tend to be fairly "laid back" or "british" in sound, which is encouraging for use with Klipsch. I've had no personal experience with them, but have heard many good comments - especially for HT use.

Another point: I have found (as have many forum members) that it is very difficult (if not impossible) to set up a system that is ideal for both 2 channel and HT. We tend to ask different things of the HT vs. the 2 channel system, so 2 systems tend to address ALL of the issues pertinent to both. It may seem crazy, but it is actually more cost effective to set up 2 systems (and get good results) than to try to do HT and 2 channel in one setup and get comparable 2 channel performance. The reason is that most pre/pros are below par in the 2 channel area (unless you spend big bucks on a Theta, Meridian, Lexicon, etc).

Ultimately, it is your ears that will have to decide. Hope this helps some.

[erdric]

Thanks, it helps a lot.

I had a feeling you wouldn't be able to find this information easily in a spec. It sounded to me that this characteristic would be difficult to achieve in a mass market amp/receiver, especially multi-channel.

I'm going to check out some of your recommendations. I'm familiar with Classe and McIntosh by name only. I've haven't had a chance to listen to them, though. Monarchy Audio is new to me.

I've listened to Rotel with Paradigm speakers but not with Klipsch yet. However, Paradigm is known to be a bit bright so I considered it a reasonable demo. I loved the sound. I've read that Rotel is considered warm but I found it to be more neutral/slightly warm to my ears. A number of people here and at HTF use Rotel with Klipsch so I suspect it's a good match.

I may eventually end up with a system for 2 channel music that is independent of the HT setup (in the same room). I currently have a 2 channel setup in my studio with KG-4's and NAD separates. Very nice to my ears.

Thanks again.

[JohnA]

I have La Scalas. Under normal conditions (84 dB average), my amps are running at 0.01 watts average. When I turn them up loud, I'll average 1 watt and peak around 10 watts. Most of my listening is at small fractions of a watt, so this is where the amp needs to sound best. I will hit 100 watts once a year, so the first watt is by far the most important.

[erdric]

Stupid question...How do you know how much wattage is being used? Is there a meter of some sort on the amp? I know that some power conditioners have voltage meters on them.