Axiom Home Page Forums General Discussion Technical Questions Question about sperates vs. receivers

I read in the newsletter that a receiver will not have as much power as seperates, and that the receiver generally is limited to 110 to 120 watts total power. Is this because of the amount of power being received from the plug?

If this were so, would a multi channel amplifier also have the same restrictions or woud it belt out more power than a receiver?

is what Alan meant by 'go seperates for the most amount of power' to go with monoblocks?

I know some receivers do give more power than others. Wouldn't the power supply in the receiver determine how much power it can generate to the speakers?

Ravi,

It's limitations on the size of an A/V receiver's power supply as well as cooling/heat-sinking issues when you cram seven amplifiers into a receiver chassis along with all the other video and audio switching circuitry. An A/V receiver manufacturer has to meet cost targets vs. physical size limitations--the thing has to be able to fit on a standard shelf! As it is, a few flagship A/V receivers (Denon, H/K) have become almost unmanageably large. Several of these will produce greater output (Denon and the H/K 7300). I would have gotten the earlier model, the H/K 7200, but it wouldn't fit onto my equipment shelf.

A designer of a basic power amp has far more room on the chassis for robust power supply, big capacitors and lots of heat-sinks, even with a multi-channel basic power amp. Since there are no controls, you can stick the power amp out of the way so physical size isn't a big deal.

With advances in digital amplifier designs (on-going), which run cool and do not require huge heats sinks, some of these limitations of analog power amps in receivers may be overcome. In Axiom's EP600 and EP500 subs, we use a 500-watt digital amplifier that runs cool with a massive analog power supply so that there will be headroom.

But there are shielding issues and many others that have to be addressed if digital amps are to be used successfully in an A/V receiver.

Regards,

>>I read in the newsletter that a receiver will not have as much power as seperates, and that the receiver generally is limited to 110 to 120 watts total power. Is this because of the amount of power being received from the plug?

[BBIBH] No, the limitations are that of designs that will fit into enclosures used for electronic equipment. Any electrical input can be altered to the required levels using circuitry and components. There are trade offs when designing amplifiers, and there is typically a target for the amplifier – usually a market segment and price point to be hit. Stating that receivers will not have as much power as separates is a generalization, and is not always true.

>>If this were so, would a multi channel amplifier also have the same restrictions or woud it belt out more power than a receiver?

[BBIBH] It depends on the design, and the target the designer was trying to hit. Generally speaking, there is more flexibility to produce a more powerful amplifier in a unit that has the goal of simply amplifying the input signal. Without having to include the processing sections that are required in receivers, there is more physical room, and quite possibly money available to produce an amplifier section. However, that may not be the goal. Power is sometimes thought of as the measuring stick – as in Bigger is Better. That would depend on the goal of the amplifier, and the target market. I have heard smaller output amplifiers that VASTLY outperform larger output amplifiers.

>>is what Alan meant by 'go seperates for the most amount of power' to go with monoblocks?

[BBIBH] Not necessarily monoblocks, although you could go that route. I believe he means that a preamp/processor section, coupled with amplifiers driving speakers. This could be a pre/pro using a number of 2 channel amplifiers to drive the speakers. Monoblocks would be a method of achieving the same thing (pre/pro => amps => speakers) if this is desired. Again, there are tradeoffs to be dealt with in terms of design specs, price points, etc.

>>I know some receivers do give more power than others. Wouldn't the power supply in the receiver determine how much power it can generate to the speakers?

[BBIBH] There are several limiting factors at play. Some amplifier sections (transistors, tubes, or Op Amps) are capable of delivering a certain limit of output REGARDLESS of the stability and capability of the power supply. When the amplifier is driven beyond its capabilities, it can be traced to the circuits being at their limit, or the power supply being at its limit. The differences you mention in power output would be more the limitation of the amplifier circuits or limiters within the amplifier. If the amplifier section IS capable of delivering more power, then the power supply could be the limiting factor. It again goes back to the design and target of the product

One approach that gets mentioned frequently is to use a medium-powered receiver then add a stereo power amp for the front speakers. Adding a power amp for the front speakers also frees up more power supply capacity for the center and surrounds, although you still won't get MORE power than the receiver is rated for.

Most receivers seem to be designed to run the same power into all channels which seems wrong to me since the fronts (and maybe center) seem to carry most of the signal.

Sent you an email.
CAV104

I had a Sony STRDB1070 receiver rated at 100 watts x 6 channels. This rating was very misleading as it certainly did not put out anything like that with all channels driven. It probably put out more like 30 wpc all channels driven. So, although it is unlikely that by freeing up the front L/R channels will get you more than rated output for the remaining channels, you may get actual output closer to rated output.

A receiver is an integrated amp and a processor combined in a single box. They tend to be jacks of all trades ... masters of ... A dedicated processor will probably do its job better than the processor section of a receiver. A dedicated multichannel amp, or IMHO, even better, a gaggle of 2 channel amps will do their jobs better than what you'll find in most receivers.

I used the Sony STRDB1070 as a processor - preouts to 3 pair of Onkyo M282 2 channel amps. This resulted in an enormous improvement in sound quality. I then swapped the Sony STRDB1070 for a dedicated Sony processor and WOW, this resulted in an incredible improvement in sound quality.

I have (and love) my Rotel RSP-1066 and RMB-1075 combo. The amp is terrific, and now that the newer RSP-1068 has come out there are some good deals to be had on the 1066. (I've seen some sold for $900 and under!)

I agree, Rotel makes some outstanding amps. I had been using one of their THX 5ch models several years ago, before I went with B&K mono's and 2ch amps, and it was a huge step up from just using my HK alone.

I hesitate to ask, because I'd hate to start a battle, but why is it that so many people place their amps on a stand all by themselves in the middle of the room? Couldn't your B&K amp fit nicely on the rack with everything else? Or even it if didn't fit on the rack, start a new rack on the other side of the TV?

Personally it would drive me nuts to have the big thing sitting right in front of the TV. I know you're not alone in doing this. Nearly every "high end" setup I've ever seen has it this way. I can't fathom why it'd need to be all alone in the middle of the room.

It's a legitimate question spiff. I can't speak for other people, but the reason I have mine between my speakers in front of the RPTV is to reduce the length of speaker wire used. As everyone knows the longer the speaker wire used, the better the chance for interference to occur. That is also why I have the Outlaw M-200 placed on top of the RPTV, behind and to the left of the center speaker. Hope that helps. Edit* BTW, if you don't like the way it looks now, just wait until I have three Outlaw M-200's down there.

Since you dig the good stuff...have you ever tried out an Odyssey Audio amp? I had a 2 channel Silver Stratos with cap upgrade and loved it. I simply ended up without a use for it, and decided to sell it. Sounded pretty darn sweet though...give one a shot. (They make mono's as well.)

Yeah, I have heard of them. What speakers did you have them paired with?

The Stratos powered my M60ti's. Call me nuts, but I think it sounded better than the RMB-1075. Though to be fair, I didn't do a side-by-side comparison. Just by going by memory. (Which we know is pretty terrible when it comes to audio.)

You can usually find a Stratos with cap upgrade on audiogon quite often for a pretty good price. If you call Klaus (the Odyssey guy) he'll often hook you up with a great deal as well. I got mine as a b-stock unit for an unreal price. The b-stock was due to a slightly scratched cover, and one of the screws on the top was slightly stripped. There was nothing at all wrong with the electronics, and from any further than 3 feet away, you'd never know it had any issues at all.

Some day I'd love to have another Stratos amp powering a pair of Veritas 2.2's in my bedroom.

I can dream, right?

In reply to:

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from any further than 3 feet away, you'd never know it had any issues at all.

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I've known some people like that.

THAT'S the kind of useless posts I'm talking about Peter! Yes! Love it!

I dragged the old Peter out of the hole in the basement just for you, spiff.

This is a limited engagement, so get your kicks while they last.

I second the Odyssey suggestion. I've had my Stratos for about 3 years and still love it. It drives my Maggies with ease (no small feat) with plenty of power to spare. This thing is utterly quiet/transparent and it never runs hot (always room temp even when driven hard). It is big and heavy and I suspect that it won't fit many racks. This it truly one of high-ends best bargains.

I'm looking at the Stratos HT3 now. It's a possible alternative to using the three mono's.