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Who wants to measure how much power (voltage) is REALLY needed?


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2 hours ago, PrestonTom said:

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If this is the signal Pano used, then you are off by x2. Simply measure the test tone at the speaker input and square the value

 

I think Tom is correct here.  For an 8 ohm reference impedance, simply square the measured voltage and you're done.  So, Derrick's required power is 4 watts.  If we look at this differently, we can say the power he measured is 2^2/8= .5W at -12db, -9db would be 1W, -6db would be 2W, and -3db would be 4W.  That's as far as we need to go as a -3db sine wave has a peak of zero db.  I'll ask Albert about this to see if he agrees with this interpretation.

 

Maynard

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7 hours ago, ClaudeJ1 said:

OK, Mr. Advocate. I'm currently listening to the best sounding amp I've ever owned, tubes or SS.

 

It's a First Watt Aleph J which is class A single ended, all FET transistors. It tops out a 40 Watts per channel at 8 ohms........maybe a bit more at 4 ohms. It never clips.

 

How would you say it compares to SET amps if you've had them?

 

The last Pass amp I had was the Aleph 3 which was push pull and had feedback.

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38 minutes ago, jazzmessengers said:

 

How would you say it compares to SET amps if you've had them?

 

The last Pass amp I had was the Aleph 3 which was push pull and had feedback.

Never had a single ended tube amp. I got into my "tube period" in my early 20's then Big Dynaco SS, then my Marantz Model 8B, which PWK said he liked. The went the Hafler MOSFET route for about 20 years after. All of thes amps on Khorns.

 

Yes, the Aleph J has feedback, but about 15 db less than the prior version.

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I can't believe no one other than Derrick has tried this experiment!  

 

That said, the test tones which John posted (same when tried on the DIY site) can't be downloaded by mobile devices like the iPad or Kindle.  And, the CD I burned is giving me a TOC error on the CD player.  Can anyone re-format the test tones so they can be more compatible?

 

To summarize the test procedure since there is a little confusion:

 

1) Pick some music that you like

2) play the music at the loudest level at which you would ever listen to it and LEAVE THE VOLUME CONTROL AT THAT SETTING

3) put your multimeter probes, set to a low AC range (even 20V should be fine), across either the speaker terminals or amplifier output terminals of one channel

4) play the 120 Hz test tone and record the voltage

5) play the 220 Hz test tone and record the voltage

6) square the results at each frequency

7) the results of #6 tell you the maximum unclipped power your amp needs to deliver into 8 ohms for that particular volume control setting.  At that setting, no matter what you play, you will not need more power than that.

 

That's the whole test- it should take no more than 30 seconds per music selection (it's worth trying a few).

 

 

Maynard

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14 hours ago, Coytee said:

 

Does that ironically make you the strongest wimp?

 

Basically, I have already done this test long ago without making the measurements.  I knew I had plenty of power and to avoid hiss/noise I reduced the gains to almost nothing to get the maximum volume of the system to be only what I would ever need.........when it could actually go WAY louder.  So while I don't know what the actually wattage I'm using is, I'm using the minimum that makes me happy and it's probably not much.

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18 hours ago, jwc said:

What is the purpose of this thread....to see who is the biggest wimp?  

Having had McGear (225, 240 tubes, 2100 SS, etc.) in the past and BiPolar Q as well as MOSFETs (VSP Labs, Haflter, etc.) none have ever been Class A.

 

What makes the First Watt offerings is they are super simple topologies using the most LINEAR devices possible.

 

My conclusion is: IF the goal of an ultimate amplifier is "straight wire with gain," then this Aleph J comes closest to that ideal. However, it will only work for those who have 100+ db/Watt speakers (horns) since those pesky "air pushers" (direct radiators with only 88 db efficiency) require a KILOWATT to even attempt the same dynamics, and fall short.

 

I recently contemplated a KRELL KSA-250 on Ebay to try more power, but Holy Crap!!! It chews up 12 Amps at IDLE!!! This is 6X the amount of current that my Aleph needs.

 

Right now I'm doing about 200 Watts at idle. The KRELL would be about 1,320 WATTS at idle.

 

Class A, like tubes, is a real SPACE HEATER that makes Audio Sine waves, so a Krell would only work in Michigan Winters for me and get me frequent flyer miles with the Electric Company. LOL.

 

 

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On 5/11/2017 at 2:51 PM, alzinski said:

Okay lets back track a bit sorry.

 

Derrick measured less thatn 2 volts. Was this the test tone? If so that's -12db and so we must multiply by 4. 

 

2*4=8.

 

So 8 volts would be the max your speakers are seeing when you were listening to music.

 

Now on to power. I am going to assume 8 ohm speakers.

 

8^2=64  

 

64/8=8

 

You can get by with an 8 watt amplifier for your listening preference.

 

 

 

Some of you just input a sine wave and measured until it was unbearable, that's not the best way to do this hence why Pano came up with this method. It's best to listen to multiple music CD's or whatever digital files you have and make note of the max volume setting for how loud you will ever listen to music. The test tones provided should be -12db which makes it easier to tolerate when measuring and easy to calculte 0db (max power).

 

 

Sorry long day yesterday. I was trying to show out the calculations the long way for people to do their own power measurements with any load. I accidentally used peak voltage so I missed a step.

 

So if Derrick measured 2v from the test tone the PEAK voltage would be 4x or 8v.

 

8*.707=5.656

 

5.656^2=31.99

 

31.99/8=3.99

 

3.99 or 4 watts of power he needs.

 

Add your measured voltage and speaker impedance into my calculations to get the results. Or if you have an 8 ohm speaker simply square your measured voltage. But for anyone with an odd speaker impedance this is the math.

 

Sorry for the confusion. I will edit the original post.

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I did this test a long time ago when Pano started that thread. I don't remember my exact results but I know it was low power. I will do the test again and post my results here.

 

I am sure people here don't actually want to do the test because they don't want to know the truth. The truth will make them feel like the made the wrong purchase in buying a big watt arc welder of an amp.

 

I wonder if we could somehow make this thread into a poll?

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28 minutes ago, alzinski said:

I am sure people here don't actually want to do the test because they don't want to know the truth. The truth will make them feel like the made the wrong purchase in buying a big watt arc welder of an amp.

When I got my Khorns (at 23), I had 200 WPC Dynaco power amps. Then I built a 9 inch tall, 2 channel  Red LED peak volage/power meter to track the music up and down.

That was almost 40 years ago and when I actually discovered I had WAY more power than I needed, so I downsized to 75 WPC Dynaco power amps. My mono Center channel LaScala was running about 6 db down from the R and L channels, so it mostly saw 2 Watt PEAKS.

 

When I built my first Quarter Pie Woofer Horn, I used a 6 Watt Tripath Chip amp with it, which had been tested by a Klipsch Engineer in Indianapolis during one of my visits, when I lived in that city.

 

IOW, been there, done that, long time ago. That Real World knowledge by my own measurements has served me well when seeking power amplification, but the INDUSTRY didn't make enough money on small amplifiers, so the "Minimum Standard" during and after the 70's became 100 Watts/ch.

 

Even Paul Klipsch had no choice but to buy what he called a "stove" for his own home system because that 100 Watts per channel was the smallest Low TIM amplifier he could buy after he gave up tubes. I saw and heard that in his living room also.

 

But no matter what we say here, there are those who will still buy more power than they will ever need, much to the detriment of that "First Watt."

 

A possible exception to this is the Hypex amplifier I heard on the Sadurni Horns at Axpona a few years back. Those horns only needed Milliwatts also from a high power switching amp, BUT it sounded just wonderful, gave it "Best of Show," so who knows.................................technology marches forward.

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Great discussion so far.  Now on the next question.  Most amps are voltage driven, how do the high current amps affect the picture.  Many of the top SS amps are current driven.  Should we be talking about the 1st watt or just what an amp can deliver at lower wattage?  How does current influence low watt tube amps?

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I can remember several years ago a forum member asked if he could come over and bring a 2 (two) wpc tube amp he had to try on my Klipschorns.  I had Khorns at the time and said sure come over and we'll give it a try.

 

A friend was over that day and we had my Peach and VRDs cranking when this guy arrived with his little toy.  Had been into it and enjoying the tunes.

 

We shut down and let him connect his little toy.

 

It did just what you guys are saying.  It drove the Khorns...........but it was crap compared to what we had been listening to.  While it was making some volume it wasn't anywhere near the sound stage, detail, and punch of the more powerful tube amps.  In fact in the end I'd say it sucked and I would never have anything like that.  But it did make volume, I'll give it that.

 

Just relating one experience with some low powered tubes after listening to some good tube amps with more power. :D

 

I also tried a couple of those little PWM (TRI-Path) amps.  Same thing.  They make volume and even have some decent clarity until they come apart at top end.  But they are just cheap toys and don't compare in ANY way to something like a 60 WPC VRD in the sound stage, micro detail, and PUNCH.

 

I would love to get a hold of Pass first watt.  I bet some of those do much better on Klipsch than the little 3 watt tube toys.  I'd love to try one of those.

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2 minutes ago, mark1101 said:

I can remember several years ago a forum member asked if he could come over and bring a 2 (two) wpc tube amp he had to try on my Klipschorns.  I had Khorns at the time and said sure come over and we'll give it a try.

 

A friend was over that day and we had my Peach and VRDs cranking when this guy arrived with his little toy.  Had been into it and enjoying the tunes.

 

We shut down and let him connect his little toy.

 

It did just what you guys are saying.  It drove the Khorns...........but it was crap compared to what we had been listening to.  While it was making some volume it wasn't anywhere near the sound stage, detail, and punch of the more powerful tube amps.  In fact in the end I'd say it sucked and I would never have anything like that.  But it did make volume, I'll give it that.

 

Just relating one experience with some low powered tubes after listening to some good tube amps with more power. :D

 

I also tried a couple of those little PWM (TRI-Path) amps.  Same thing.  They make volume and even have some decent clarity until they come apart at top end.  But they are just cheap toys and don't compare in ANY way to something like a 60 WPC VRD in the sound stage, micro detail, and PUNCH.

 

I would love to get a hold of Pass first watt.  I bet some of those do much better on Klipsch than the little 3 watt tube toys.  I'd love to try one of those.

Seems like I saw that you could get those on a week demo or something like that.  You would just be out shipping.   I don't remember where I saw that.  Gotta love those VRD's!

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I have the sense that some think that this thread is about promoting the use of flea power amps with Klipsch speakers.  Nothing could be farther from the reality.  The intent is to allow listeners to determine approximately how much power they need to satisfy their listening levels, regardless of what they may be.  For some, flea power will work fine, while for others it may show the need for even more power than they are currently using.  Generally, however, most will find that they could easily satisfy their requirements with far less power than they are using.  At least that was the case on DIY where most are using speakers far less efficient than ours.  If I were Joe Audiophile, in the market for a new amp, I would be very thrilled to find out that 50 wpc would easily handle my requirements instead of the 250 wpc monster that I was considering.  The former power level opens up many possibilities which may not have been considered otherwise. The same applies to a SS guy who wants to try tubes but doesn't know if the 18 wpc Scott, or 12 wpc console pull, will be enough after using a 500 wpc SS unit. Enough said!

 

On to my own measurements.  I only had time to try it with one selection and used it with the intro to Jackie Evancho's version of Lovers. For those who are curious, I set the volume level for 82 db at the listening position at the opening crescendo.  This is about 7 db higher than my usual maximum listening level.  The amps were Little QTs @ approx. 4 wpc, and my speakers are RF-15s which are rated at 96db.

 

120 Hz test tone:  1.423V translating to 2.02W into 8 ohms

220 Hz test tone:  .6475V translating to .42W into 8 ohms

 

The calculated power also allows for signal peaks which are 12 db above the level of the test tone!

 

So, in my case, flea power amps are more than enough to satisfy listening levels which greatly exceed my usual.  And this clearly explains why flea power is even more feasible for owners of LSs, Belles, CWs, Heresys, and K-horns when they are used in small to medium size rooms (say, under 200 sq. ft) at relatively low levels.  The local guys have all made that determination using only their ears, but this will lend credence to their belief that their ears don't lie.

 

Maynard  

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27 minutes ago, tube fanatic said:

I have the sense that some think that this thread is about promoting the use of flea power amps with Klipsch speakers.  Nothing could be farther from the reality.  The intent is to allow listeners to determine approximately how much power they need to satisfy their listening levels, regardless of what they may be.

This is the way I look at it.  I would say my average listening level peaks at around 85 watts and the main music is less.  I'm into a lot of jazz and easy listening to type music so, no rock'N' out at 115+ db. levels.  The music just won't sound good.

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2 hours ago, derrickdj1 said:

This is the way I look at it.  I would say my average listening level peaks at around 85 watts and the main music is less.  I'm into a lot of jazz and easy listening to type music so, no rock'N' out at 115+ db. levels.  The music just won't sound good.

I am afraid you folks are missing the point. Reading the original description over at DIYaudio is important. 

 

In the test, you listen to music (from a CD of your choice) as loud as you like it (and then some). At this point the "volume knob" is not touched. Now you put in the test tone that has been recorded a specific amount (dB below full scale). This tone simply provides a steady state signal. With this steady state signal, you measure the RMS voltage at the speaker input. The value is squared and the resulting number is equivalent to the wattage the amplifier needs to provide. This number includes "headroom", "transients", "steady state" etc. The amazing thing is the number is small. For high efficiency horns, the number is very small. Again this includes dynamics, head room and all the other stuff. 

 

Unlike what is stated by others above, you really do not need a 100 watts, In fact you only need a few watts (if even that). Ignore all the conjecture about head room etc since that is already rolled into the original "adjustment". This test really is an eye opener. An amplifier with a few watts may be sufficient (high efficiency horns with a reasonable impedance ).

 

IOW, your listening peaks are certainly less than 85 watts ..... much less.

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