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 Chip Amps Amplifiers based on integrated circuits

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 27th December 2006, 07:04 PM #21 Eric_B_C   diyAudio Member   Join Date: Dec 2006 Is there someplace on the web that defines each part of these equations and what they correlate to? ie what is P1 and P2? I did some searching and re-read through the thread but do not see where I get those 2 values from. I need to draw it out on paper and that would help me a lot. Power in, what happens to it at each stage, output, etc... I have zero electronics, electrical, etc background. The most math I have employed is a month or so ago at work we all sat down to figure out how wide a 42" 16:9 TV was So I'm afraid I'm going to need a more simple explanation or at least something comparative I can use to draw a parallel to. Eventually the light will click and it'll make sense.
AndrewT
diyAudio Member

Join Date: Jul 2004
Location: Scottish Borders
Hi,
do you have a calculator?
Check to see if it has "log" and "10^x" .
P1=117W
P2=50W
P1/P2=117/50=2.34
Log 2.34=0.369
10*log2.34=3.69.
You can enter this log(117/50)=*10= to see the result. You may be able to omit the first "=" and still get the correct result.

92db speakers and 50W gives 109db.
92db speakers and 117W gives 112.7db.
My answer is that if the volume is set to just below clipping the Yam will sound slightly louder than the chipamp, but only if you can set the volume control accurately enoughto hear that 3.7db difference.
I suspect the two amp will be difficult to determine which is louder due to other differences between the amps, eg, response variations, peak transient power, bass strength on sustained notes etc.

BTW,
subtracting 20db from these near 110db levels to give the average level results in 90db, this is pretty loud.
Quote:
 we all sat down to figure out how wide a 42" 16:9 TV was
you are saying this was a team effort!
__________________
regards Andrew T.

 27th December 2006, 07:47 PM #23 Eric_B_C   diyAudio Member   Join Date: Dec 2006 OK! Thats where you were getting the 117 from, from me...I did not catch that part. Now it makes sense. As far as which is louder your right I won't be able to tell the difference. I've played around with my system when I first got it and found 103db to be its limit before it started to break up. I just sat down while listening to Bob Marley on a very well produced CD and could hit 103db crystal clear...if you can define 103 as clear. Once I got over 103 it started to go into protected mode and shut off. This was at roughly 10' to the right of one of the speakers. At 1 meter it would have been spot on I believe. So I do not reach the limit with what I currently have and won't with the chipamp either. The question more is which is going to sound "better". I can hear a difference between regular mode and PURE mode which turns off all the video processing. I've heard dedicated amps sound better and I guess I'll have to wait until I get it together to see. All the parts should be here by Friday. Thanks again, your last example made perfect sense and filled in a lot of the blanks for me. This is what I ordered from PE, am I missing anything? 060-424 SPDT ROUND SNAP MOUNT ROCKER .. 1 0 \$1.90 \$1.90 070-070 12V RED INDICATOR LAMP .. 1 0 \$1.25 \$1.25 074-022 3A MINI CIRCUIT BREAKER .. 1 0 \$1.95 \$1.95 091-1120 DAYTON RCA-CHRB RCA CHASSIS M .. 1 0 \$5.98 \$5.98 091-1245 DAYTON BPA-38G HD BINDING POS .. 2 0 \$6.88 \$13.76 122-640 AVEL Y236750 330VA 25V+25V TO .. 1 0 \$60.33 \$60.33 090-442 IEC POWER JACK CHASSIS MOUNT .. 1 0 \$1.78 \$1.78 370-038 DAYTON SLDR-S4P-8 4% SILVER S .. 1 0 \$18.00 \$18.00 Those are, rocker switch, 12v LED, 3amp circuit breaker, Dayton RCA connectors(2), Dayton binding posts(4), Avel 330amp transformer, standard 3 prong power input and some 1mm solder. Minus the case itself am I missing anything? I have some heatsinks at home for some old Pentium III's which should work. I decided not to do volume control but will want to add it in the future. I looked at all kind of potentiometers but did not know which one to get. The examples I looked at all looked different that what was offered.
 27th December 2006, 07:53 PM #24 davidlzimmer   diyAudio Member   Join Date: Jan 2006 Location: Fairmount, GA So.... the only way you can tell a difference in volume is to run it at deafening levels. Right? My freinds are confused when I tell them my PA100 LM4780 is not louder than my LM3886 amp. I can't hear any noticable volume difference. But it does seem faster. To me anyway. __________________ Poor stereo mix? Switch to mono! Perfect.
 27th December 2006, 07:54 PM #25 Eric_B_C   diyAudio Member   Join Date: Dec 2006 Based on what Andrew said, no it should sound the same at normal listening levels. When I get everything I might test it at 1 meter with some sound protection. I could barely sit here turning it up to hit 103 on the meter for a few seconds. I could never get that close to the speaker without some good protection.
 28th December 2006, 01:47 AM #26 Eric_B_C   diyAudio Member   Join Date: Dec 2006 Another question...I was looking up my entire speaker set. My fronts are 92db efficiency, my center is 91, and my rears are only 90db. I have the same 135 watts going to each. Is this compensated for in the auto setup by boosting each speaker? The room EQ option that just takes into account room effects or does it also figure in efficiency. It doesn't know the efficiency but the speaker would be quieter for a given voltage correct? I'm talking about Yamaha's YPAO room auto setup. Should I leave the auto values alone or should I go back and add in a set number of db for each speakers efficiency difference?
 28th December 2006, 02:17 AM #27 davidlzimmer   diyAudio Member   Join Date: Jan 2006 Location: Fairmount, GA The best and most real sounding recordings I have heard were those that were made when they had 2 mikes and 2 tracks. It seems the more capable technology allows us to accurately reproduce the original performance, the more we are determined to destroy it with dsp. Sorry if this is OT. __________________ Poor stereo mix? Switch to mono! Perfect.
 28th December 2006, 09:53 AM #28 Eric_B_C   diyAudio Member   Join Date: Dec 2006 David, Outside the realm of DTS/DD I have had far better luck with just pure analog. All I do is run my CD/DVD player through a analog crossover/bass manager and in pure through my receiver. This provides the best sound for DVD-A/SACD/2 Channel stereo. I have not made use of any of the receivers functions for a while now except as an amp and a video switcher. That does however leave the speakers out of balance, I think, in the fact that the fronts are more efficient than the rears/center. If the recording, especially in 5 channel, are produced with the idea of equal output then it will not sound right since I am down a few db on the center/rear. Now the problem is, on the analog side I have no way to compensate. At least not until I get a 5 channel amp I have tried it everywhich way on the analog/digital side and nothing sounds as good as analog. DTS/DD is a different story. The sound levels are equal and sometimes my DVD player does a better job and sometimes my receiver does a better job depending on the movie. When I do it with the DVD player its again out the analog 6 channel outs with it doing the DTS/DD decoding. When the receiver does it then its applying all the DSP adjustments.
 28th December 2006, 01:46 PM #29 davidlzimmer   diyAudio Member   Join Date: Jan 2006 Location: Fairmount, GA Wasn't judging. Just venting. Good luck with your new system! __________________ Poor stereo mix? Switch to mono! Perfect.
CarlosT
diyAudio Member

Join Date: Oct 2006
Quote:
 Originally posted by davidlzimmer ...The best and most real sounding recordings I have heard were those that were made when they had 2 mikes and 2 tracks...
Heck...the best recording I heard was done with ONE mike

I think that this was out of print for a while but check out The Philadelphia Orchestra — Nature's Realm and other Water Lily stuff...awesome.

http://www.waterlilyacoustics.com/main.htm

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