What 200 WPC power amp??

[Cal Blacksmith]

Well I have NAD AV Pre/Pro and I

certainly don't get any noise or distortion so what do you base your

opinion on, the one NAD amplifier you heard!!!

I thought you would enjoy noise and distortion since you using low level tube amplification.

I am also tiring of his posts but give him some slack, he is only a kid

with limited exposure to life. He is the perfect example of why I got

tired of the constant praising of only two amps, as good as they are.

It is all he has heard and is not aware of the other outstanding or

even very good equipment out there.

[dougdrake]

I am using an Acurus 200x3 with my Chorus mains (and a Forte

center). You can also find it as a 200x2 configuration. I

like it - clean, powerful, quiet.

[DaleR]

I'll throw my $.02 in for the Rotel amp. I have it's predecessor, the RB-980BX, which is rated at 200 wpc as well. It does well with both rock and classical music. If you're into volume, you'll be very happy. I can't crank mine much past 3-4 on the knob. Rotel makes some really good stuff for the price.

Dale

[rplace]

What was you budget again?

If you want headroom check out the Carver TFM line. The TFM-25 is 240 WPC and I think the TFM-35 is 350. Both are on ebay all the time.

I used a single TFM-25 with my Forte IIs for many many years and think they mate very well together. Recently I picked up a 2nd from ebay (about 300 bucks) and ran them each in mono mode trying it with both my Forte IIs and Chorus. Talk about power to spare and ear splitting volume if you want it. Way more power then you could ever want with Klipsch speakers.

[psg]

Tony, It's a 15x15 room with angled ceiling and an alcove. I just wanted more headroom. Mt Rotel 3 channel is 150WPC.

You are not going to see much change in headroom going from 150W to 200W; that's a 1.2 dB increase.

[colterphoto1]

I was talking to a Forum member on the phone the other day (yes that works to), and he had an interesting point. If the RF7 is nearly as efficient as the Klipschorn, why do users of the former seek 200 wpc+ amps and users of the later gravitate towards 25 watt tube amps. Is there a definite difference in listening levels as far as user's age, style of music and preference of 2 ch vs HT is concerned. Seems a somewhat bizarre trend.

Michael

[cjgeraci]

Michael, actually, it is not really that much of a bizarre trend. The issue of 200 watt amps, and RF-7s has been discussed and debated many times in 2-channel and HT. I encourage you to do a search in both sections because the issue has been discussed. I can share my experiences, having listened to many Klipschorns on various amplification - and having owned RF-7s and Belles. The following, with respect to RF-7s being demanding speakers, was an experience echoed by a number of RF-7 owners.

Yes, some owners of RF-7s like to listen to music louder than Klipschorns' owners, on average, but that does not seem to account for the main difference in amp choice. I believe the primary difference in amp choice has to do with the difference in the two speakers. These two speakers are different beasts.

First, despite their "ratings," you know that K-horns are more efficient than RF-7s. There was a provocative thread in the Tech section some time ago with numbers bearing that out. More importantly, RF-7s are simply more picky and demanding when it comes to amplification. In my experience, their low impedence dip, combined with asking a lot of a two-way design with one horn and two woofers, left me dissatisfied when I tried lower amplification with my RF-7s (even nice quality 20-35 watt tube amps). In comparison, I have never had a problem running Belles with the same tube amps (which are nearly as efficient as K-horn and have nearly the same drivers) - and at the same higher volumes. As a result, to get moderate to higher volume levels, with clean output, I preferred at least 100 watts solid state with RF-7s, and preferably 200 watts (better bass control with the dual woofers and less strain on the amp at higher volumes). And, of course, even though watts are watts, tube watts are different than ss watts due to the respective nature of clipping between the two devices.

And finally, with respect to HT, I run Belles with a 35 watt push-pull tube amp when running movies. Again, I would never do that with RF-7s.

RF-7s can sound just incredible with the right amplification. But, with the wrong amp, they can sound like &$%&*. I think Klipschorns are a bit more flexible in that regard.

Carl.

[MrMcGoo]

I have to agree with Carl about the RF-7 needing at least a 200 wpc SS amp to get near optimal sound. The RF-7 is rated as 102 db at 2.83 volts, not 8 ohms. The RF-7 is not an 8 ohm speaker. It was rated at 6 ohms by Sound & Vision. In the bass frequencies, the RF-7s are a 4 ohm speaker IMO.

S&V rated the sensitivity of the RF-7 as 99 db/1w/1m. It also measured the minimum impedance at 2.8 ohms. The ideal amp for the RF-7 requires very high current capability. In solid state amps, such amps usually start at about 200 wpc. The wattage is only needed if you like to listen to loud explosions (movies or the 1812) at higher listening levels.

The Crown amp company has an amp size calculator. Reference level at home is 75 decibels with up to 30 decibel peaks. Run the calculations with 99 db sensitivity and see what you get in your room: http://www.crownaudio.com/apps_htm/designtools/elect-pwr-req.htm

Bill

[Duke Spinner]

the Crown calculator is handy ...

as a matter of fact, it shows my amplifier needs ..going from 99 dB/watt/meter to 93 dB/w/m/

my amp size just went from 127 watts to 506 ...

no wonder i just bought a Crown K-2 ...[]

[MrMcGoo]

The Crown calculator can give surprises in both directions. Klipsch surrounds do not have the sensitivity of their bigger brothers, yet they are an important part of movie reproduction.

Bill

[Dylanl]

Dynaco S410. Great SS amp for the cash. Very rebuildable. Other forum members run them and like them.

[edwinr]

For some reason, I find the sound of very powerful S/S amplifiers to be much more pleasent to listen to, than their lower powered brethren. It's not that you actually listen at higher levels. Although you can if you want. It's just that at normal listening levels, the powerful S/S designs tend to offer a larger listening level 'sweet spot'. Some lower powered S/S amplifiers, like the Sugden A21a and some NAD's, also offer a very smooth sound that matches nicely with horns, but these lower powered S/S amplifiers are few and far between. The big Rotels are very nice. Great value for money and the RB1080 would match nicely with a tube preamp. The other alternative is to go tube. Not the wimpy, anaemic, single ended triode designs [], but the superior, push pull designs like the Mac MC275 or maybe the VRD monoblocs.

[MrMcGoo]

Edwinr,

I agree that the big SS amps sound better on RF-7s, provided the first watt is clean. There are many benfits to the bigger amps. It's more than just headroom. The bigger amps are usually built better all around, have more output devices per channel and spend more time playing in the linear zone of the output devices. The impedance curve of the RF-7s in particular seems to benefit from the big amps, much more so than Heritage that can run on tube amps.

Modern movies have extreme dynamics that will clip smaller amps. Then there is some music that will clip as well. Clipping a solid state amp can sound terrible.

Bill

[Strabo]

I was talking to a Forum member on the phone the other day (yes that works to), and he had an interesting point. If the RF7 is nearly as efficient as the Klipschorn, why do users of the former seek 200 wpc+ amps and users of the later gravitate towards 25 watt tube amps. Is there a definite difference in listening levels as far as user's age, style of music and preference of 2 ch vs HT is concerned. Seems a somewhat bizarre trend.

Michael

I have been noticing this trend recently too. It seems that the forum has been taken over by the wattage wars lately. I've been trying to figure out if it really is the new Reference style speaker, or if the forum has become inundated with newer/younger listeners with different musical tastes. To be honest, I keep checking this thread looking for someone to be blunt and answer "there is no good 200+ wpc SS amp for Klipsch and music reproduction."

It seems like the older more experience members have either given up or have been shouted out by these wattage war listeners whose main requirement is that a system must be loud and have lots off bass.

I put the recommended 75db with 30db headroom and 99db/m/w example into the calculator listed above. It said at 10 feet I need a 36 watt amp. Seems silly to me to use 30 dbs of headroom for music since most CDs today only have a couple of db of dynamic range but ok. Either way, the numbers are the same using 100db with 5db dynamic range. We should be able to agree that 100dbs can be considered loud.

The scenario does change considerably if you are listening 20 feet from the speakers and maybe I'm naive, but I don't know anyone that sits that far from their speakers. I'm sure their are some but they would be the exception to the rule. At 15 feet you still only need 81 watts to fulfill the scenario.

So physically, the 200+ watt requirement doesn't add up unless the listener is requiring much higher levels or he is fixated on bass reproduction. If the former, then I recommend a simple fix, turn it down or risk not being able to hear a normal conversation in 20 years.

If the latter than I recommend these listeners find out what stage they are in on the pursuit of audiophile nirvana and adjust their recommendations accordingly.

Step 1, music must be loud.

Step 2, music must have accurate bass reproduction, or worse, an inordinate amount of fake bass.

Step 3, volume is sacrificed for better imaging.

Step 4, bass is sacrificed for better midrange and an even better soundstage.

Giving Klipsch the benefit of the doubt that they still make a good, efficient speaker leaves me to believe that the membership on this board has turned over, reverting back to steps one and two above.

Where have the old timers gone to correct this lad before he continues down the path of the wattage wars?

[Frzninvt]

To me its about clarity, accurate dynamics, and headroom, even the mighty Klipschorn can absorb some power to get to reference levels. For my listening habits even though I normally listen in the lower ranges, DVD soundtracks can be brutally demanding and it takes an amplifier with a very stout power supply and stiffening capacitors! There is no replacement for displacement.

Here is what I use and they can run any speaker on the planet and do not add any coloration at all. Clean and clear in the low ranges with the balls to drive anything to insane levels without breaking a sweat.

I have had the crazy notion of selling them both and buying a B&K 200.7 S2 but haven't for fear of losing the awesome sound I am currently getting. While they are rated at 400W X 2, I run one in 4-channel mode (125W X 4) and the other in 3-channel (125W X 2 + 400W X 1). They sound great with the speakers I am using below.

[colterphoto1]

Lightened it up a bit for ya.

AND thanks Carl, that post summed up the debate very well for me. I understand now.

I think many members might be trying to do 120db in their homes. Not recommended for anything but short bits of time, but when I'm watching a DVD concert, sometimes I do enjoy concert levels. My Yamaha receiver just doens't have the balls sometimes.

Michael

[Duke Spinner]

[

try plugging 105 dB into the calculator ...

it don't come up with 25 watt's ...................[:^)]

[cjgeraci]

Heh, heh, heh...... No flames from me - just different viewpoints. Ah, the revisited argument that the old timers must instruct the lads on the finer points of audio nirvana. Unfortunately, the "lad" who started this thread is not really a lad at all, but a nice gentleman who plays a bass in a nice little 'ol band.

And, I'm not sure if I qualify as a "lad" - I guess I'll have to look at my incoming grays to decide that. I enjoy listening to music at moderate levels, and I have some wonderful tube amps for relaxing and listening to glowing midrange and nuances. Those tube amps can also get up and get with with it at times. Over the years, I have also enjoyed solid state amps at moderate and high volume levels, and I guess maybe I am one of the few that actually enjoys both tubes and solid state. Yes, they are certainly different sounds.

But I am also fond of really letting it rip, probably to Dean's levels, and some larger solid state amps can do that pretty well. Yes, America, you can listen to music loud and still retain midrange, imaging, clarity, and separation. You can get clarity with some larger solid state amps, and it is just not about bass and loudness. Of course, the quality of the preamp is the most important factor in achieving clarity and separation at high volume levels, and I am truly blessed to own two really nice ones (Peach and a Classe). But the right amp is still an important part of the equation and with RF-7s, even more so.

So, from this middle-aged graying lad who still likes to crank music (and also relax at lower volumes), I stand by my prior post. If you like to crank it at least infrequently with RF-7s, demanding speakers, the amp selection is important, and larger solid state amps are pretty good choices. These amps also sound pretty good at low and moderate levels. Not sure why RF-7s demand more power than some other Klipsch speakers (for similarly clean output) because they are supposedly efficient, but I have heard them distort and scream on a variety of lower wattage solid state and tube amps when laying into them just a little bit. And no, not even at levels close to 120 db.

On the other hand, if you never want to get into it a little bit with your RF-7s, go with lower powered amps.

Heritage is another animal altogether. But, we'll save the flea amp vs. pp debate for another day.

Carl.

[Strabo]

[

try plugging 105 dB into the calculator ...

it don't come up with 25 watt's ...................[:^)]

Agreed. Anytime you go above the efficiency rating of the speakers you will exponentially increase the power requirement. The same goes for distance. Per that chart, 105dB at 15 feet (4.5 meters) with 5 dB of headroom on 99 dB/M/W requires 255 watts, versus 102.7 dB's at 150 watts.

As mentioned before, does the listener really notice that 2.3 dB increase in volume? Probably not. For him to receive a perceived doubling in volume he would need to go to 110 dB which would require 806 wpc (assuming the same parameters).

So the question becomes either,

a.) what amp will give me more bass slam over my current 150wpc amp, or

b.) what amp will give me better sound over my current 150wpc amp. Note that this is not necessarily the same as a.)

Given the figures above, I think he is better served if the answer is to find a higher quality amp rather than buy more watts because as we saw above, watts really won't buy him much unless you equate watts = quality which generally is untrue.

Bill's logic is true. Better/more output devices may equate to better quality resulting in higher wattage as a side effect. But higher wattage does not necessarily equate to better amplification.

[Deang]

But I am also fond of really letting it rip, probably to Dean's levels...

Now what in the hell is that supposed to mean Carl? I hardly think 125dB constitutes "letting it rip."

Folks really need to make a distinction between steady state and peak because there's a world of difference. Also, "loudness" is somewhat linked to the network type you are running. For example: a person running a first order network like the Type A or DHA might find 85-90dB steady state with 100dB peaks extremely loud due to the amount of power being dumped into the drivers. Consider this statement: "A tweeter with a third order high pass filter with a crossover frequency of 5000 Hz driven by the 100 watt amplifier...will receive about 1.6 watts at 2500 Hz versus 25 watts with a first order filter at full output." So, you could take two Klipschorns, load them up with different networks, run each up to 85dB or so, and find that though the volume levels are perfectly matched -- one will sound louder than the other. Incidently, I've done this many times, and can assure you that unless everyone in this thread is using the same speaker/network/driver configuration -- everyone is speaking a different language. There is so much more to this, but I'ze got to git back to work!