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Relating power to detail. How much is enough?


wilbucd

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Are some speakers just that power hungry?

 

Klipschorns are more than 100x more efficient than most direct radiator loudspeakers - including the extremely high dollar kind.

 

Trust me - power isn't the answer to the question, "how do I raise the bar on my system's audio detail?"  Better, higher efficiency loudspeakers with very low modulation distortion amplifiers (you can think of this as low THD, but it isn't really low THD) are the elements you need to raise that bar.

 

Chris

Edited by Chris A
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I think you should try different amps. Not for power reasons, but for different "warmth" sounds. And of course I wouldnt just jump out there and get one just because it has XXXX amount of watts. Do you have any friends that you could maybe invite over and have them bring theirs just to sample? That beats the hell out of buyers remorse I tell ya!!!

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If power is not the issue then tell me what constitutes having 1000w mono block home systems? They are surely not playing louder than we are without their ears bleeding. Are some speakers just that power hungry? I spend a lot of time surfing high end systems and many of those mega watt amps are in rooms no bigger than my 19x24 room.

Inefficient speakers or ego....

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Wattage output measured at 1Khz is useless

 

I agree with this whole post. 

 

Don't go by wattage alone, particularly when measured at 1K Hz.  Wattage specs should be at full range (e.g., 20 to 20K) with all channels operating.

 

I don't know, but I think whether or not an amp is too powerful for your efficient speakers has to do with the amp's design, rather than the honestly rated power output.  I don't think there would be too much of a problem with a modern, high quality amp.  I'm biased in favor of headroom. 

 

In the good old days, some people could tell the difference between McIntosh and Marantz tube amps that had almost identical power ratings.  Design makes the difference.

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I'm looking for more detail in my 2 channel music. Mainly vinyl. The vintage McIntosh MC2505 50watt amp I am using sounds good but I am wanting to step up to the next level so to speak. Please don't turn this into a cartridge, turntable, preamp or speaker wire debate . I understand all of that. I'm wondering if there is a point where you can have too much or "wasted" power in regards to headroom and clean volume, relating to a specific speaker, listening at reasonably loud volume. Granted, testosterone dictates that you can never have too much power but really, where is the break even point? I'm interested in electrical algorithm type answers, not "use whatever sounds good to you" or name brand debates.

For reference I'm using the original RF-7's and considering an amp advertised at 300 wpc RMS. The speaker sesnsitivity is 102dB @ 2.83 volts/1 meter. 300wpc sounds like a lot to me but I see where some people use 1000 watt monoblocks. Is that much power an advantage to detail or is it overkill?

Thanks in advance.

 

 

The 2505 is a second gen SS Mac amp. The damping number is lower than 20, which seems to be the magic number. So somewhere above 20.

 

The next step would be eliminating capacitor coupled amps, I think this refers to coupling the transistors.

 

100% power increase gets you 3db, so on a LaScala or K=Horn 2 watts will take your head, to keep it simple 4 watts should do the same on your speakers.

 

Since most of your listening will be at the first ,5 watts or less, this is where you need to focus. There is some argument to be made that the larger SS amps operate in Class A at low watts depending to the design and how they are biased, Pass on his amps published this spec which on his 250s is something like 30 watts class A.

 

I'm not an engineer, but my understanding is that for peaks the amp pulls heavily on energy stored in the caps and if I understand it correctly the Transformers have some reserve too.

 

This is a discussion that crops on the Mac forum on AK regularly. The next gen up from your amp that should be measurably different is the MC 2270, 3rd Gen SS amp.

 

As stated above, the source is GIGO, to me the RF 7s always sound good but I like the Heritage speakers better, probably because that is what I have been using for 40 years.

 

Get a good piano recording to test the amps rise and fall, nothing like a piano strike.

 

For accurate I like female voice smooth and as natural as possible. You can tell if it's life like in seconds.

 

A girl and a piano in a practice session as an example: https://www.youtube.com/watch?v=7Oox5S-HM74&index=1&list=PLgugWBANrQyU39SWyIM6sCIJWo-A3GBlD

 

Another stripped down (minus the orchestra) girl and a piano on an FM promo tour for their LP https://www.youtube.com/watch?v=BljhBQpo9c0&index=19&list=PLgugWBANrQyU39SWyIM6sCIJWo-A3GBlD

Edited by Bubo
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For accurate I like female voice smooth and as natural as possible. You can tell if it's life like in seconds.

Listening to Diana Krall's new album on vinyl just now. Very impressed with the recording. An instant favorite. I agree, female vocals, piano and strings are hard to beat.

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Room Tx will help with reflexions, echos, some bass problems.  Most of this will be at 80 Hz and up.  The Tx's mostly benefit the midrange which is where human hearing is most perceptive.  That is why so many people like Heritage speakers.  Here is a pic of the DIY panels I made today.

 

The sound from the RF 7's can give the Heritage speakers good run on SQ when setup to maximize it reproduction of sound in the room.

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For accurate I like female voice smooth and as natural as possible. You can tell if it's life like in seconds.

Like the second song in this video?

 

 

 

 

 

I agree, female vocals, piano and strings are hard to beat.

:emotion-21:  Last song (2:26) in this video:

 

Edited by Quiet_Hollow
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Detail is lost in the electrolytic coupling caps in any amplifier.

 

This is for the 2100/2105, but the 2505 is the same design with half the number of outputs.

 

Download the schematics for the 2100 and 2505 and reference the numbers.

 

Posted by djk (M) on July 11, 2004 at 04:29:36
In Reply to: Re: MC2105 @ $ 100 even @ 20 yrs old is a best buy for me. posted by julian4@telkomsa.net on July 06, 2004 at 14:58:04:


The sound would benefit greatly from replacing a few dried out electrolytics, and adding a few film types here and there.
C301, 302 is the main input coupling cap. It is a Mylar type so it is likely to be OK, upgrading it to a Polypropylene type with give a smoother sound to the high end (0.47µF).

C307, 308 are emitter bypass caps, 100µF 15V. Replace with same type and add a 0.1µF film bypass.

C309, 310 are the output coupling caps for the pre-driver section, 10µF 25V. While a film type would be better, size is a problem. The DC bias across this cap also helps out with its being an electrolytic. Replace with same type and add a 0.1µF film bypass.

C303, 304 are the DC power supply caps for the front end, 470µF at 25V. Replace with same type and add a 0.1µF film bypass.

C1, 2 are the feedback loop caps, 330µF at 3V. The signal goes through these so replacing these with new ones and adding a 0.1µF film bypass really opens up the sound. Go with as high a voltage as what space permits.

C11, 12 are the DC supply caps for the voltage gain stage, 150µF at 50V. Replace with same type and add a 0.1µF film bypass.

C201, 202 are the main filter caps, 39,000µF at 40V. These may be quite expensive new, although I have seen them surplus for very low prices. I would use then unless signs of leakage or amplifier hum are there. Add a 47µF at 50V cap in parallel with each.

C203 is a multi-section cap that will be very hard to find a fresh date code. New caps are small enough that they may be wired to the terminals of the old one, leaving the old one in place. This cap is important as it provides the current for the diff pairs and the VAS. The sections go 80/80/150/50µF with the voltages being 200/200/150/150V. If you measure the voltages 100/95/90/80V are typical, so 200V caps are not really needed, but 100V is not enough.


 

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