Why all amps and receivers aren't the same. (1 Viewer)

[Seth=L]

Would that be hard on my amp?

 

[Seth=L]

Touché Arthur.

Here is a picture of the Cinema Grand:


Here is a picture of the Cinema Grand Signature:


I guess pretty much 80% of the weight is the Power supply. The Truesubs, however, don't have a power transformer, but rather a small transformer for amp controls.

 

[Chu Gai]

You'd lose some power Seth. Can't just use any resistor though, it has to be able to dissipate the power from your amp.

 

[Seth=L]

Sounds like something I wish I had time to do. My first priority right now is to get my sub fixed, mods and stuff I simply can't do at present.

 

[Seth=L]

This is in my Carver manual.


It has a rated input power of 500 watts. Do all amps share the same policy on rated power input or are they distorted as well? Many recent receivers claiming to have like 500 watts of output power only have around 300 watts input power, stamped on the back.

 

[Arthur S]

Thanks for the pics Seth. Obviously, I wasn't aware that the Sunfires are mostly transformer. Also, the case is used as the heat sink. Bob Carver is a genius. Some of his earliest speakers were quite something.

 

[Seth=L]

Are you refering to the very large magnaplanars?

 

[Arthur S]

Yes, except they had a bunch of 12 inch woofers in them, as well as the planar part.

 

[Chu Gai]

You'd need to define that a bit more. The 300 watts may be simply the power consumption at idle.

 

[FeisalK]

what power spec is usually stamped on the back?

 

[Arthur S]

Feisal

I think he is talking about the power consumption that is noted on the back of the receiver. It is not uncommon for a "600" watt receiver to say, "power consumption, 300 watts" or maybe "2.5 Amps", on the back.

This same information is also noted in the owners manual. For example, the Denon 5805 MKII is rated as consuming (or drawing) a maximum of13 Amps.

 

[FeisalK]

Arthur, yes but 300W at idle sounds a bit, er... warm. i read somewhere that manufacturers need only test at 1/8th peak power for consumption rating

 

[johnADA]

This is a real wild one and I have heard it all!!

Just for simplicity, this needs to have a standard set.

UL, doesnt peg a set standard, but mentions that all equipment must state on its product its max consumption, fuse rating etc. This is so you dont hook it up and fry your wall circuit.

I have heard and had emailed to me from companies when I asked the question, these responses.

Normal listening volumes- What is a normal listening volume?
2 Channels max- OK then we split that same number into 4,5,6,7 channels.
There are more, but those are the top 2 responses.

I really have to believe that the rear panel and or owners manual does in deed state max usage and people are trying to deceive for whatever power reasonings there are out there to think its more in some cases and etc.
If you look at ones rated lest say 300 watts, then one with a 6.5 amp rating, you WILL notice the power cords are of 2 different sizes, why??? The 300 watter one uses a 18 AWG and the 6.5 uses a 12 AWG power cord, but people have you believe the 300 watters is average listening level and will go higher than the 6.5 one!! I smell a rat!!!

 

[gene c]

So where do "amps" fit in?. My H/K 435 advertises +-40 amps and 65 WPC (FTC). Also, 1000 watts power consumption @ rated power. I also think WPC is an overrated number but when evaluating the specifications, knowing how to read between the lines can be useful.

 

[johnADA]

Lets see it the way I'd look at it.
65 and HK is known to go low x 7 channels= 455 watts
Figure the amps are 60-70% eff, so to get 455, you'd need at least 758 input with 60-70% made into useful power, leaving 455 out.
That gives you 242 extra to run the video conversions, led lights, processing boards for sound, head room etc.
Whats often forgotten is all that stuff takes power and lots of it , if alot of its running. You'd need 20 watts plus just to turn it on and operate it, and another 20 watts+ for processing etc.

Some ratings work out fine, others are very suspect.

 

[Arthur S]

gene

40 amps would be 4,800 watts, so take it with a grain of salt. What they are talking about is peak, instantaneous output, maybe for 2 cycles. Like, .001 second. High Current is, well, highly desirable. HK receivers tend to be pretty robust. My Citation 7.1 can put out about 850 watts, and has a max power consumption of 2,500 watts, and yeah it has quite a power cord. And is a pain cause it weighs 70 pounds. When it comes to amps, buying by the pound makes sense, except for switching, (or digital) type amps such as Carver, Sunfire, Panasonic. The only downside to some of the HK designed amps is the fan needed to cool them.

Feisal

Good info, tx.

 

[Seth=L]

Aha, so fuse size can be a more reliable sign of true power, correct. As far as the processing power consumption that sounds about right.

 

[Seth=L]

Fans implemented correctly are necessarily a bad thing.

 

[Chu Gai]

The 40 amps in your H/K comes from the capacitors which among other things, provide reserve power (current). Perhaps if you've seen some high power car stereo systems then you'll also find what's called 'stiffening caps'.

If you open the unit up (don't touch anything) and look inside you'll see some rather large cylindrical objects, possibly with some kind of rating on them e.g. 10,000 uF (microfarads). Even though your wall outlet is say a 15 amp, the IEC plug in the back of your receiver has a maximum rating of 12 amps, hence the receiver or whatever, is precluded from drawing over 12 amps on a sustained basis. Audioholics had some information regarding this if you want to dig around.

 

[Seth=L]

I just took apart my Fisher Integrated amplifier apart. Stamped on the rear it says input power: 700 watts. Inside the amplifier there are 5 fuses. The power supply protect fuse is rated at 8 amps, then there are two more 8 amp fuses and two 500ma fuses. I imagine the pair of 8 amp fuses are for the output stage and the 500ma fuses are for the pre/amplification stage. The Capicators are larger than most 10,000uf caps (I am not sure why, maybe because they are manufactured by Fisher) and it also says 85wv instead of the usual 63v(which also is confusing). I beleive the amp was rated 100 watts per channel output, at least from what little I have found about this amp. I don't know if this affects anything here just thought I would throw it out here and see what comes of it.