Amps and watts

idc

Well-known member
Watt is a measure of power, amp is how much electrical current is flowing.

The watt is more important in hifi as it is used to measure the power output of amps and input capability of speakers, usually shown as decibels per watt, or how much power is needed to create a certain volume.

The only issue I can think of do do with amps is not over loading your fuse with too much equipment.
 
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Anonymous

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Thanks for the reply idc.

does the rule of watts being more important in hifi also stand true for low impedence speakers or would you say that current becomes more important as impedence drops?
 

idc

Well-known member
Aw crap! I was hoping to bluff this one and already question 2 is too complicated for me!

Have a read of this <<<clicky>>> which explains headphones and amps and sensitivity, ohms ratings and how they work together. It should help with regards to understanding more about speakers and amps.
 
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Anonymous

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Cheers matey thanks for the link. I will have a read and see if it will shed any light my question.
 

oldric_naubhoff

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let me try. as been said watt is the unit of power. but there is connection between power and current:

power = current * voltage

there's also another crucial connection between current and voltage. it's called Ohm's law and goes:

impedance = voltage/ current

implication of these two equations is another golden rule of amp emgineering; in order to maintain stable supply of electricity to the speakers power must double when impedadance halves. unfortunatelly this rule is not always followed that's why you get power specs like: 70Wpc into 8 Ohm / 110Wpc into 4 Ohm (where it should be 140Wpc ito 4 Ohm for a perfect situation). you also need to know impedance plot of your speakers if it dips low (below 4 Ohms) in any part of frequency bandwidth you'd do well to get an amp efficient in 4 Ohm loads. in other words one which power doubles when impedance halves.

I know it may be difficult to comprehend at the beginning but it's not that difficult in the end. and it's good to know what engineers mean by all those numbers given in spec sheets.
smiley-wink.gif
 

jiggyjoe

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This is a bit of a generalisation but for:

A. low sensitivity, speakers require watts.

B. low impedance, speakers require amps.

Combine these two lets say an Apogee Scintilla and you need a Krell!
 
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Anonymous

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jiggyjoe said:
This is a bit of a generalisation but for:

A. low sensitivity, speakers require watts.

B. low impedance, speakers require amps.

Combine these two lets say an Apogee Scintilla and you need a Krell!

Cheers jiggyjoe. What would be considered high amps? Not sure what peak to peak figure I should be looking for in order to know if an amp can provide plenty of current.
 

CnoEvil

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I'm not at all technical, but an amps ability to double its Watts as the Ohms halve, is a sign that it has decent current ie. MF M6i: 200W (8 Ohms); 400W (4 Ohms); 800W (2 Ohms).

My AMS 35i sounds way louder than it looks on paper because of this.

Cno
 
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Anonymous

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Thanks guys. I understand more about it than I did earlier but I think I will have to do some reading up. Only asking as my plan to get a Bryston has recently gone out the window due to the funds being needed elsewhere but I am still unhappy with the way my A3 drives my model twos so was just curious to see if there are any other amps for less than Bryston money that would do a decent job of driving my speakers but I was more than a little confused by all the numbers on the spec sheets.

Oh Cno I am liking the toys more and more every time I listen to them. I still haven't got stands for them yet but they really are a lovely sounding little speaker!!!
 

jiggyjoe

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As cnoevil says.

look for amplifiers that double their power output when impedance halves.

Not many amps do this as they need big expensive power supplies.

Think, Krell, Mark levinson, Chord, Boulder, Big Bryston's, and I think the big Naims get close.
 
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Anonymous

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jiggyjoe said:
As cnoevil says.

look for amplifiers that double their power output when impedance halves.

Not many amps do this as they need big expensive power supplies.

Think, Krell, Mark levinson, Chord, Boulder, Big Bryston's, and I think the big Naims get close.

In my current financial position that is not a list of names I was hoping to see... oh well!!! I've heard kidneys are going for good money at the moment... i'm sure I could spare an arm and a leg too...
 

CnoEvil

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james_LR90 said:
Thanks guys. I understand more about it than I did earlier but I think I will have to do some reading up. Only asking as my plan to get a Bryston has recently gone out the window due to the funds being needed elsewhere but I am still unhappy with the way my A3 drives my model twos so was just curious to see if there are any other amps for less than Bryston money that would do a decent job of driving my speakers but I was more than a little confused by all the numbers on the spec sheets.

Oh Cno I am liking the toys more and more every time I listen to them. I still haven't got stands for them yet but they really are a lovely sounding little speaker!!!

:)

I had a feeling you might like the combo....just as well by the sound of it. :(

I wouldn't consider an amp of a lesser quality than M6i, or possibly Quad Pre 99 / 909 (140w/8ohm; 250w/4ohm)..... if you can get one going a begging.

Cno
 
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Anonymous

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CnoEvil said:
james_LR90 said:
Thanks guys. I understand more about it than I did earlier but I think I will have to do some reading up. Only asking as my plan to get a Bryston has recently gone out the window due to the funds being needed elsewhere but I am still unhappy with the way my A3 drives my model twos so was just curious to see if there are any other amps for less than Bryston money that would do a decent job of driving my speakers but I was more than a little confused by all the numbers on the spec sheets.

Oh Cno I am liking the toys more and more every time I listen to them. I still haven't got stands for them yet but they really are a lovely sounding little speaker!!!

:) I had a feeling you might like the combo....just as well by the sound of it. :( I wouldn't consider an amp of a lesser quality than M6i, or possibly Quad Pre 99 / 909 (140w/8ohm; 250w/4ohm)..... if you can get one going a begging. Cno

I'm really happy with the toys and I am sure I will be happier still when I put them on decent stands. I have just been looking at Quad stuff on ebay and price wise the combo you mention seems reasonable. I am just a bit worried that even if I went for something like that I would always have that voice in my head telling me that I have short changed my speakers by not giving them the amplification they deserve! As it is I am very happy with the toys and they are seeing much more use than the Kefs at the moment so I think I will use them for my main system until I can afford the amplification to do the Kefs justice.
 
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Anonymous

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jiggyjoe said:
A big Rotel or Nad power amp would probably drive the Kefs well but might not be a big step up in sound 'quality'.

That is my worry really. I don't want to be spending money on something that isn't going to make me feel satisfied. As it is I think I am better off using my second system as my main until I can afford something that will be a real step up from the A3.
 

CnoEvil

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james_LR90 said:
CnoEvil said:
james_LR90 said:
I am just a bit worried that even if I went for something like that I would always have that voice in my head telling me that I have short changed my speakers by not giving them the amplification they deserve! As it is I am very happy with the toys and they are seeing much more use than the Kefs at the moment so I think I will use them for my main system until I can afford the amplification to do the Kefs justice.

...baby steps, my friend. :)
 
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Anonymous

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CnoEvil said:
james_LR90 said:
CnoEvil said:
james_LR90 said:
I am just a bit worried that even if I went for something like that I would always have that voice in my head telling me that I have short changed my speakers by not giving them the amplification they deserve! As it is I am very happy with the toys and they are seeing much more use than the Kefs at the moment so I think I will use them for my main system until I can afford the amplification to do the Kefs justice.

...baby steps, my friend. :)

Haha I know... unfortunately patience is not one of my strong points! I need to ponder over the situation...
 

CnoEvil

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james_LR90 said:
CnoEvil said:
james_LR90 said:
CnoEvil said:
james_LR90 said:
I am just a bit worried that even if I went for something like that I would always have that voice in my head telling me that I have short changed my speakers by not giving them the amplification they deserve! As it is I am very happy with the toys and they are seeing much more use than the Kefs at the moment so I think I will use them for my main system until I can afford the amplification to do the Kefs justice.

...baby steps, my friend. :)

Haha I know... unfortunately patience is not one of my strong points! I need to ponder over the situation...

Spend...or ponder and spend....it all amounts to the same thing. ;)
 
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Anonymous

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CnoEvil said:
james_LR90 said:
CnoEvil said:
james_LR90 said:
CnoEvil said:
james_LR90 said:
I am just a bit worried that even if I went for something like that I would always have that voice in my head telling me that I have short changed my speakers by not giving them the amplification they deserve! As it is I am very happy with the toys and they are seeing much more use than the Kefs at the moment so I think I will use them for my main system until I can afford the amplification to do the Kefs justice.

...baby steps, my friend. :)

Haha I know... unfortunately patience is not one of my strong points! I need to ponder over the situation...

Spend...or ponder and spend....it all amounts to the same thing. ;)

True true. If I were to go for a Quad 909 do you think my A3 would be a suitable pre amp until I could get a 99 pre?
 

CnoEvil

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If I gave an answer, it would be a total guess...it's one for the dealers on here.

If you get it cheap enough, try and see.....and then you can either live with it for a while, or sell it on. "Ponder and spend".... with self convincing logic. :)
 
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Anonymous

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My (humble) advice would be to not let yourself get blinded by the technical specifications. Although they do reveal information about the amp, they will not tell you how it will sound. And if you do want to look at specs, then don't neglect frequency response and damping factor because they tell you more about how an amp behaves than only wattage.

To give my impressions (in order of importance):

- amperage/capacity
the amount of "headroom" an amplifier has. Not only important for low-impedance speakers, but especially for speakers that are classified as "difficult to drive" (and that term usually means low-impedance for certain frequencies only, or erratic impedance).

- damping factor
tells you how firm the amp can grip a speaker ("control"). Higher damping factor means less distortion from speaker design/placement.

- wattage
tell you how loud an amplifier can go. Only marginally important, only tells you whether speakers/amps are in the same league; for example don't connect speakers with 80dB sensitivity to a 15W amp, and don't connect speakers that are rated for 15-75W to a 200W amp.

- frequency response
gives an impression of the overall design quality of an amplifier. Wider frequency response = higher quality ("faster" sound).
 

idc

Well-known member
I will be a better bluffer in the future
smiley-tongue-out.gif


Something else to take into consideration is voltage and now I going back to how the source, assuming it is a CDP reacts with the amp. It would appear many CDPs output voltage is higher that amps input and the best situation is where they match.

One audiophile gadget I bought that really did work was attenuated interconnects, where the cable's phono reduces the CDPs voltage output. (You can also buy connectors to go onto an existing cable that do the same job, such as Rothwell or Golden Jacks) I found by attenuating the voltage the amp had better volume control and you would get better sound at lower volumes.
 
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Anonymous

Guest
james_LR90 said:
CnoEvil said:
james_LR90 said:
CnoEvil said:
james_LR90 said:
CnoEvil said:
james_LR90 said:
I am just a bit worried that even if I went for something like that I would always have that voice in my head telling me that I have short changed my speakers by not giving them the amplification they deserve! As it is I am very happy with the toys and they are seeing much more use than the Kefs at the moment so I think I will use them for my main system until I can afford the amplification to do the Kefs justice.

...baby steps, my friend. :)

Haha I know... unfortunately patience is not one of my strong points! I need to ponder over the situation...

Spend...or ponder and spend....it all amounts to the same thing. ;)

True true. If I were to go for a Quad 909 do you think my A3 would be a suitable pre amp until I could get a 99 pre?

Very much so. The A3 pre-amp section was claimed by some to be better than the actual dedicated A3 Pre-Amp. I know form using it as a pre-amp myself that it is very good. Do yourself a favour though and get something far more substantial than a quad 909. Think MF again, only bigger.
 

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