Author Topic: when or how can you say that an AVR or amp is enough to drive a set of speakers (Read 17886 times)

ATJr. · « **Reply #60 on:** Jul 05, 2011 at 08:06 PM »

^come to think of it, it is never a good practice to short out the secondary of any power traffo, and 60 seconds at that! fuses will blow and breakers will trip....unless your traffo is severly current limiting type with an air gap at the center leg!......

folks do not do this at home......

sovrain · « **Reply #61 on:** Jul 06, 2011 at 08:28 AM »

Quote from: TonyT on Jul 05, 2011 at 04:57 PM

to the average user, damping factor is the least of your concern.......you can forget about it....just endjoy the music....

said it right there Sir TonyT, at least, have known about it, maybe I can use this little learning about DF for future upgrades, he he. tnx

badoy · « **Reply #62 on:** Jul 06, 2011 at 09:44 AM »

Quote from: TonyT on Jul 05, 2011 at 06:10 PM

a solid state amp for example can be simplified for analysis as a Thevenin voltage source, consisting of an ideal voltage source and an internal resistance.....

ok but everything was varying as the freq also varying. it is not also constant voltage and current source. internal resistance is constant but the actual impedance is varying..correct me if i'm wrong...this means that the lower the output impedance the higher your amp can deliver maximum power beyond recommended rms power without breaking down the components. (you must consider also heat transfer)

Quote from: TonyT on Jul 05, 2011 at 06:10 PM

output power and frequency response has nothing to do with damping.....it is about amplifier topology and its power supply....that results in damping factor....

yup thats right. amp circuitry and supply has to do with power. but internal impedance will also vary as the freq vary when we apply AC circuits analysis.

Quote from: TonyT on Jul 05, 2011 at 06:15 PM

rails of +/-85 volts at idle dropping to +/-75 volts at full power.....filtered by 56,000ufd/100volt computer grade caps...

compared to commercial amps like the Pioneer Spec2, it has an unloaded rails of +/-91volts dopping to +/-71 volts at full power....

is this class AB circuitry?

Quote from: TonyT on Jul 05, 2011 at 06:10 PM

take my 250 watter for example. it is a 45volt ac source, a damping factor of 200 at 20hz means that at 8ohms, its internal resistance is 0.04 ohms...

how did you get the internal resistance? is this also class AB amp? so your amp can drive a load of 2 ohm at full power?

ATJr. · « **Reply #63 on:** Jul 06, 2011 at 10:25 AM »

Quote from: badoy on Jul 06, 2011 at 09:44 AM

ok but everything was varying as the freq also varying. it is not also constant voltage and current source. internal resistance is constant but the actual impedance is varying..correct me if i'm wrong...this means that the lower the output impedance the higher your amp can deliver maximum power beyond recommended rms power without breaking down the components. (you must consider also heat transfer)
yup thats right. amp circuitry and supply has to do with power. but internal impedance will also vary as the freq vary when we apply AC circuits analysis.

you are confused....

the internal impedance of the amp itself is a constant......it is the damping factor that changes with frequency...

Quote

is this class AB circuitry?

yes, the super leach amp is a class AB........class A drivers, classB output stage...

Quote

how did you get the internal resistance? is this also class AB amp? so your amp can drive a load of 2 ohm at full power?

if you have to ask........

the super leach can drive 2 ohms, but just because it can does not mean i will use it at 2 ohms....the 2 ohm territory is a dangerous territory as far as the life of your amp is concerned.....i will never go there...
if you know how amps are tested then you will understand......

ATJr. · « **Reply #64 on:** Jul 06, 2011 at 12:28 PM »

^this is a good read: http://sound.westhost.com/amp-basics.htm

this too: http://www.rocketroberts.com/techart/amp.htm

oweidah · « **Reply #65 on:** Jul 06, 2011 at 03:00 PM »

Quote from: badoy on Jul 05, 2011 at 05:48 PM

In the real world, a speaker's impedance curve is not ﬂat, therefore the actual DF is higher or lower at certain frequencies. as i understand in general, the higher the DF, the stronger the ampliﬁer's "grip" on the woofer the higher the DF, the more control the ampliﬁer has over the woofer. lower DF when it comes in frequency response your system bass is not deep (walang gapang ang bass kasi wala nang reserve power kung baga hangang 50hz lang kaya ng amplifier mo for maximum bass gain)unlike in higher DF your amplifier can deliver up to 30Hz or lower of bass at maximum gain.
wow nice amp....ilang volts yung supply nya..split dc ba yan..

sir,

ok po ba amp Damping factor: >20,000, 10–200Hz; 1800 at 1kHz ?
anong pagkakaiba neto sa mga amp na usually 60-100 lang ang DF

tia

badoy · « **Reply #66 on:** Jul 06, 2011 at 06:01 PM »

Quote from: TonyT on Jul 06, 2011 at 10:25 AM

you are confused....

the internal impedance of the amp itself is a constant......it is the damping factor that changes with frequency...

you said that DF is about internal impedance of amp. why then DF is lower at higher freq? is this means the DF is in function of internal impedance? in my point of view internal resistance in amp is constant but..the actual impedance is not. if we apply thevenin's theorem in AC source we found out that there is a varying impedance with respect to the freq. in point of view also practical amp is not only composed of internal resistance since the power transistor is considered simiconductor and it is not purely resistive or conductive in nature.

when the ac signal pass through a purely resistive conductor the current will not change regardless of freq. but if it is composed of inductor, capacitor and resistor then the current will vary with respect to the freq. so as i understand this was DF was derived.

ATJr. · « **Reply #67 on:** Jul 06, 2011 at 06:18 PM »

Quote

why then DF is lower at higher freq? i

read my earlier post for the answer....

badoy · « **Reply #68 on:** Jul 07, 2011 at 09:47 AM »

More about damping factor..share ko lang..

http://www.crownaudio.com/pdf/amps/damping_factor.pdf

reynold · « **Reply #69 on:** Jul 07, 2011 at 11:02 AM »

Quote from: TonyT on Jul 05, 2011 at 04:57 PM

to the average user, damping factor is the least of your concern.......you can forget about it....just endjoy the music....

I agree

...actually ngayon ko lang mas naintindihan ang DF dahil sa thread na 'to... but in a real world (meaning, in a less-technical life), what is always important is how your amp/speakers will perform and the sounds that they will produce... but it's nice to have a topic like this, maraming natututo

btw, 20 to 20KHz, 8ohms = 200 is the DF of my Yamaha DSP-A1 pala, so is that a Wow-DF ba?

ATJr. · « **Reply #70 on:** Jul 07, 2011 at 12:27 PM »

Quote

btw, 20 to 20KHz, 8ohms = 200 is the DF of my Yamaha DSP-A1 pala, so is that a Wow-DF ba?

in all probability, walang "magic coils" yan kaya constant ang DF from 20hz to 20khz......

badoy · « **Reply #71 on:** Jul 07, 2011 at 12:49 PM »

Quote from: reynold on Jul 07, 2011 at 11:02 AM

btw, 20 to 20KHz, 8ohms = 200 is the DF of my Yamaha DSP-A1 pala, so is that a Wow-DF ba?

just like may old yamaha 992 release in 1997. normal load at 4 ohms still kicking until now..lol...

reynold · « **Reply #72 on:** Jul 07, 2011 at 01:41 PM »

^^^ Nice to hear it from you guys

Sir Tony, noob question po... what's a "Magic Coils" ba?

ATJr. · « **Reply #73 on:** Jul 07, 2011 at 02:43 PM »

Quote from: reynold on Jul 07, 2011 at 01:41 PM

^^^ Nice to hear it from you guys

Sir Tony, noob question po... what's a "Magic Coils" ba?

yung naivento ni mel aka rascal101, pm mo sya, baka makatulong sa amp mo...

badoy · « **Reply #74 on:** Jul 08, 2011 at 05:52 PM »

@TonyT
na confuse kasi ako sa leach amp mo. 45-0-45 V or 85-0-85 V ba yung supply nya?
kung ok lang sayo anu yung part number ng power transistor?

curios lang kasi ako...

markcrenz · « **Reply #75 on:** Jul 08, 2011 at 07:38 PM »

do i smell a flame bait?

ATJr. · « **Reply #76 on:** Jul 08, 2011 at 07:41 PM »

Quote from: badoy on Jul 08, 2011 at 05:52 PM

@TonyT
na confuse kasi ako sa leach amp mo. 45-0-45 V or 85-0-85 V ba yung supply nya?
kung ok lang sayo anu yung part number ng power transistor?

curios lang kasi ako...

ang power traffo nya ay 60-0-60 volts secondary kaya ang unloaded rails nya ay +/-85volts.....

ang output power transistor nya ay Mj15003/Mj15004....eto ang link.........http://users.ece.gatech.edu/mleach/superamp/

http://www.youtube.com/v/9c2Sj-sqWk4&hl=en_US&feature

ATJr. · « **Reply #77 on:** Jul 08, 2011 at 07:43 PM »

Quote from: markcrenz on Jul 08, 2011 at 07:38 PM

do i smell a flame bait?

wag naman sana.......game ako.....hehehehe......

badoy · « **Reply #78 on:** Jul 09, 2011 at 09:09 AM »

Quote from: TonyT on Jul 08, 2011 at 07:41 PM

ang power traffo nya ay 60-0-60 volts secondary kaya ang unloaded rails nya ay +/-85volts.....

ang output power transistor nya ay Mj15003/Mj15004....eto ang link.........http://users.ece.gatech.edu/mleach/superamp/

http://www.youtube.com/v/9c2Sj-sqWk4&hl=en_US&feature

improved class AB. di ba pede convert sya sa darlington..takaw naman sa transistor kasi. mukhang pede yata sa 4 ohms yan. nasubukan mo na ba?

ATJr. · « **Reply #79 on:** Jul 09, 2011 at 03:20 PM »

Quote from: badoy on Jul 09, 2011 at 09:09 AM

improved class AB. di ba pede convert sya sa darlington..takaw naman sa transistor kasi. mukhang pede yata sa 4 ohms yan. nasubukan mo na ba?

the leach superamp made use of bert locanti's Tripple darlington output configuration....the basis for many of today's power amps....

this is an 8ohm, 250watts power amp, although it can handle 4 ohms and occasionally 2ohms, i did not dare use it for speakers other than 8 ohms.....imho it is foolish to subject amps to low impedances....

panzer · « **Reply #80 on:** Jul 09, 2011 at 05:45 PM »

mga masters tanong lang po whats the difference between damping factor and high current? which one is important to drive speakers ? one time kasi a friend of mine compared the following amplifier adcom gfa 555mk2 200watts, denon avr 5802 170 watts, plinius integrated 100 watts, mark levinson 100 watts, pioneer avr 130 watts to drive a dynaudio contour floorstander. nagtaka ako yung pinaka magandang tunog yung mark levinson at plinius na lower wattage samantalang yung 200 watt na adcom or denon sounds weak and maipinis . sounds thin naman yung pioneer . sabi ng technician high current daw yung ml at plinius. anu ibig sabihin nun?

ATJr. · « **Reply #81 on:** Jul 09, 2011 at 06:40 PM »

Quote from: panzer on Jul 09, 2011 at 05:45 PM

mga masters tanong lang po whats the difference between damping factor and high current? which one is important to drive speakers ? one time kasi a friend of mine compared the following amplifier adcom gfa 555mk2 200watts, denon avr 5802 170 watts, plinius integrated 100 watts, mark levinson 100 watts, pioneer avr 130 watts to drive a dynaudio contour floorstander. nagtaka ako yung pinaka magandang tunog yung mark levinson at plinius na lower wattage samantalang yung 200 watt na adcom or denon sounds weak and maipinis . sounds thin naman yung pioneer . sabi ng technician high current daw yung ml at plinius. anu ibig sabihin nun?

it would help if you can give the model numbers also for those different amps.....

let us lay the premise for our discussions.....we are talking high fidelity and not public address....

first, any power amp is only as good as its power supply, the power delivery to the load depends a lot on the power supply, that is why in several occasions i have asked for the amplifiers' weight as this aspect can be a determinant of a powerful amp....
second, wattage rating alone does not tell you how powerful the amp really is, i look at the power supply transformers, the size of its rectifiers and filter capacitors, the heat-sinking used, these are unmistakable yardsticks to amplifier power....

as to your query about damping factor and high current, this partly answered above, but there is more....

to be able to deliver high current, your output stage should be capable(robust), using high current output devices, this also leads to very low output impedance and thus high damping factor...

but any amp can have high damping factor and yet low current capability, and vice-versa....
amplifiers with high amounts of negative feedback also achieves very low output impedance and therefore high damping factor....

finally, the class of operation has a lot to do also, the Mark Levinson has a very big window wherein it operates classA, the Plinius amp is also a class A amp.

all the others are classAB probably lightly biased because they may not have big heatsinks required to sustain the heavier bias.....and more likely smaller power supply as it typical of many commercial amps..

panzer · « **Reply #82 on:** Jul 09, 2011 at 07:12 PM »

thanks master tony for a technical explanation .the ml 331 and plinius 9100 . yung pioneer i'm not familiar but its thx. yung friend ko sinubukan din yung pro audio na amp crest rated 1000 watts pero comparable lang cya sa adcom .

ATJr. · « **Reply #83 on:** Jul 09, 2011 at 08:41 PM »

^this just goes to show that power rating is never a qualifier for sound quality......so i stopped looking at power specs of the amps and just looks at the actual amp, how it is built and most importantly, how it sounds....

badoy · « **Reply #84 on:** Jul 11, 2011 at 10:17 AM »

Quote from: TonyT on Jul 09, 2011 at 03:20 PM

the leach superamp made use of bert locanti's Tripple darlington output configuration....the basis for many of today's power amps....

based on the link you gave the output stage configuration was cascode. i can't understand how they became darlington.

edison · « **Reply #85 on:** Jul 11, 2011 at 11:22 AM »

Quote from: TonyT on Jul 09, 2011 at 08:41 PM

^this just goes to show that power rating is never a qualifier for sound quality......so i stopped looking at power specs of the amps and just looks at the actual amp, how it is built and most importantly, how it sounds....

Tama ka Sir, built and the resulting sounds na naaayon sa taste ng makikinig. Kaya pala marami na rin ako na try na integrated amp tapos madali ako masawa sa tunog. Kasi manipis ang bass

audiojunkie · « **Reply #86 on:** Jul 11, 2011 at 11:37 AM »

Quote from: TonyT on Jul 09, 2011 at 08:41 PM

^this just goes to show that power rating is never a qualifier for sound quality......so i stopped looking at power specs of the amps and just looks at the actual amp, how it is built and most importantly, how it sounds....

yes sir! you're absolutely correct...

have 60w/c power amp that outperformed the 85w/c int. amp not in sound output but in sonic quality that the int. amp failed produce.... (tested side-by-side) now, I sold the int. amp and kept the small amp....

ATJr. · « **Reply #87 on:** Jul 11, 2011 at 12:59 PM »

Quote from: badoy on Jul 11, 2011 at 10:17 AM

based on the link you gave the output stage configuration was cascode. i can't understand how they became darlington.

of course, you don't understand anything, that is why the foolish questions....

you got a long way to go boy......study harder....and keep an open mind.....

i can not baby sit you all the time....

ATJr. · « **Reply #88 on:** Jul 11, 2011 at 01:06 PM »

to further illustrate the 8 ohm 4 ohm or even 2 ohm loads spec.....

let us say you have car that can go 200 kms per hour....i am pretty sure you are not going to run your car full throttle all the time.....most likely you are going to cruise along at 60~80 kms per hour....

the same with amps, just because you have an amp that can drive 2ohms, it doesn't mean you will load your amp with these speakers.....

badoy · « **Reply #89 on:** Jul 11, 2011 at 05:53 PM »

Quote from: TonyT on Jul 11, 2011 at 12:59 PM

of course, you don't understand anything, that is why the foolish questions....

you got a long way to go boy......study harder....and keep an open mind.....

i can not baby sit you all the time....

so you call me baby or idiots..review your amp circuits and that is not darlington as you said. it is cascode output stage.

Quote from: TonyT on Jul 11, 2011 at 01:06 PM

to further illustrate the 8 ohm 4 ohm or even 2 ohm loads spec.....

let us say you have car that can go 200 kms per hour....i am pretty sure you are not going to run your car full throttle all the time.....most likely you are going to cruise along at 60~80 kms per hour....

the same with amps, just because you have an amp that can drive 2ohms, it doesn't mean you will load your amp with these speakers.....

your amp is weak...joke..joke... I witnessed my self how my friend loaded a speaker to his customized amp. there are 4 18" speaker in a box. the amp drive the 2 box at almost 24 hours because it is a sound system...lol but after the fiesta its still kicking...the amp is only medium power but customized with 16 triple diffused transistor per channel and supply of 110 volts...its not a joke men that an amp driving 2 ohm. they also tried to load at bridge of 2 ohms....so your amp is low power only...