If you had an spare amp of lesser power but good quality doing nothing.Would you use it over your receiver's amp?

[John Holmes]

Title pretty much tells it all. Do any of you think that a seperate amp will always sound superior? Will it always produce a better soundstage or imaging over a given receiver's interior amps?

Keep in mind, the seperate will give up power to the receiver!




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[KennyG]

This is a loaded question, it all depends on the gear in question, and the load they'd be driving.
Let's say reciever "A" has 150 watts per channel, and power amp "B" has 125 watts per channel...a fact let's use Acurus's 125X5...hands down I take the Acurus, I don't care how big the reciever is, it will not sound as good as the Acurus. (had one at home for a few days)
In all reality the power rating has little to do with the sound. I've heard 25 watts class A amps that can outperform 150 watt recievers.
Since it takes a doubling of power to increase sound levels by 3 dbs, once you get over...maybe 100 watts, it takes alot more power to make much of a difference.
If you had a set of speakers that were a hard load to drive, maybe they drip down to a 1 or 2 ohm resistance, this is another place the seperate amp would outshine the reciever.

[Andrew Pratt]

well obviously it depends on which amp and which receiver but in general there may be other side benefit to using an external amp such as helping to relive stress on the receivers power supply so the other channels its powering might be improved also.

[Mike V]

I would agree with the last 2 posts but lets not forget that the external amp could change the sound "temperature" overall and provide a different listening experience.

[JonMarsh]

I have to go down Kenny's street on this one.

Problem is, amplifier power ratings into 8 ohm loads don't necessarily mean a whole lot about what an amp can do with a real speaker load. Then, add in that most receivers aren't rated for four ohm loads, and for good reasons! Plus many recievers aren't rated with all channels driven simultaneously.

Then, you have the folks making seperates that, how shall we phrase this delicately, sandbag a bit on the ratings? Or more than a bit?

I'll guarantee you that an Aragon 8002 (rated 125 watts, eight ohms) will clean the clock of pretty much any receiver. And I can't explain all the reasons why, either, because it will best many seperates of the same power, both in clarity, naturalness, and subjective power. Then there's amps like my Aragon Palladium class A monoblocks- rated 100 watts per channel. Well, that's what they put out while remaining in Class A mode. They clip at about 450 watts per channel at 8 ohms, and about 750 watts at 4 ohms. Not hardly fair to compare with a receiver, huh?

Now, as soon as I get over the fact that Klipsch has bought Mondial Designs- both Aragon and Acurus, I'll be ready to continue this discussion....


-Jon




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[KennyG]

Excuse me while I pick my jaw up off the floor...Klipsch just bought Mondial/Acurus???
CRAP!!! that is some very good gear for it's pricing point. I just hope it stays that way.
I'm hoping to step into a Aragon 8008X3 in the near future, and it'd better be as good as the "pre-Klipsch" stuff.
Damn, a guy was making a package deal out of his 8008X3 and an 8002, I made an offer on the 8008X3, but he ended up selling them as he wanted...together.
Sorry to get off subject, I'm ok now...

[John Holmes]

All of you pretty much hit what I thought to be the response. Now let's up the kitty a bit...

If this same amp had all the qualities that we love but, was half the power of the reciever, would you still use it?




"I came here, to chew bubble gum and kickass. And I'm all out of bubble gum!!!" My DVD's

[John Holmes]

Jon,

Like Kenny, I hope that they leave well enough alone. If it's not broke...




"I came here, to chew bubble gum and kickass. And I'm all out of bubble gum!!!" My DVD's

[JonMarsh]

Re amplifier at "half the power"

Again, I presume you're talking half the rated power at 8 ohms. Again, with many real speakers, it's not at all the point.

Why?

OK, let's look at it this way. First, lets remember that a 2X difference in power is only 3dB in level. There are a number of well regarded amplifier manufacturers that acknowledge that the first watt from an amp is the most important, since it's the one you use the most.

Receiver X, rated 125 watts per channel at 8 ohms. Minimum safe load impedance 6 ohmns. Old power amp Y, built by yours truly, 20 years old, nominal power per channel at 8 ohms 75 watts. Nominal power per channel at 4 ohms 150 watts. Nominal power per channel at 2 ohms 250 watts. Ability to drive reactive load- in excess of 60 degrees leading or lagging phase.

Speakers: My DIY bedroom set; "Modula III"; consists of two Scanspeak Kevlar 8" woofers, QB3 ported alignmnet, two MB Quart 2" titanium midrange, one MB Quart Titanium tweeter in each cabinet. Nominal impedance varies from 3 ohms to 16 ohms.

The receiver goes into current limiting in midbass and low bass due to impedance and current phase shift at 25-40 watts out. Twenty year old power amp yawns and just drives the load, with up 200 watts clean power into reactive 3 ohm load.

BUT, on paper the reciever is twice as powerful as the old power amp. At least, according to receiver manufacturers.


Re Klipsch buying Aragon-

Well, they talk a good line on the web site, and have some PR talk and interview with the original founder and chief engineer at Mondial, so I'm REALLY hoping they aren't going to mess things up.

I design and build a lot of my own electronics; I've been building power amps since the 70's, and designed several for companies. I still consult in that area, and horse around with both CLASS D and linear designs (I've authored a few papers on CLASS D design, including one presented at AES conference and reprinted in the AES Journal. The last outside design I did was for a high end Pro/Studio monoblock amp that weighs 145 lB per chassis, using a compound MOSFET output stage, outputing 450 W at 8 ohms and over 1.6 kW at 2 ohms.)

Aragon is in my opinion one of the best values in amplifers available, because they offer sound and basic build quality rivaling the big Krells and Levinsons, but in a much more reasonable and affordable package. That's why I own a pair of Palladiums, and have dibs on an 8002 at Tom's that we/he recently acquired used. If he decides to keep that one, I probably will buy a new one this fall. I've used the 8008ST and BB in speaker development, and that's why I bought the Palladiums, since they're basically more of the same, but in monoblocks. I've got my fingers crossed that they'll keep on doing the right thing, but just promote and market the stuff better, using Kipsch's financial clout.

I think the 8008X3 is a cool product, but, if you want to see a real brute, check out the X5! But bring a friend to help lift it!

Regards,

Jon




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[Kevin P]

Back on the original topic, if I had a spare amp lying around, I would try it out and see if it improves the sound. If it does (and isn't overly lacking for power), it stays (with most receivers, chances are it will). If not, the amp goes back to being a paperweight or whatever it was doing before.

This sort of happened to me last summer, though it was between two receivers, and not a receiver and an amp. I had a Yamaha 795 receiver (85 wpc) and was happy with it, until I had a chance to try out an Outlaw 1050 (65 wpc). At first I thought, 65 watts per channel? Can't possibly be enough power for a HT with 89 db efficiency speakers (and at that time, no sub). But I tried it out anyway, and guess what... it trounced the Yamaha in terms of sound quality, and have never found it lacking for power. In the end I sold the Yamaha and kept the Outlaw.

KJP

P.S. In regards to the amp having 1/2 the "power" of the receiver, let me say that the Yamaha replaced a Sony rated at 120 wpc (2-channel mode). The Yamaha blew away the Sony. The Outlaw, at 1/2 the power per channel of the Sony, blows away the Yamaha. So, once again, assuming the reduced "power rating" on the amp doesn't result in clipping, I would certainly use it over the "higher powered" receiver amp.

KJP




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[Lex]

John, I think the answer wil be "it all depends". A lot depends upon the effeciency of your speakers, and wether the lower power is enough to sufficiently drive them. of course, the advantage of more capable power supplies can have the impact of offsetting some wattage loss perhaps. At least when driven hard anyway. If it's lower distortion, which it probably will be, that is a HUGE factor in listening at loud levels. You can blow a speaker with 100 bad watts a whole lot easlier than with 50 clean watts. Of course, by the same token, 25 bad watts will come closer to blowing a driver than 50 good watts as well.

Anyway, gonna have to do some listening to know for sure!

Lex

[John Holmes]

I didn't mention equipment names so not to add bias. With a hi percentile (through the years) stating that a stand alone amp "will" yield better results, I thought it would be good to see/hear opinons when the amp had the "subjective" disadvantage.




"I came here, to chew bubble gum and kickass. And I'm all out of bubble gum!!!" My DVD's

[John Holmes]

Jon,

I noticed that you never once mention the power supply in the equation for either piece. Would I be wrong in assuming that this was on purpose?




"I came here, to chew bubble gum and kickass. And I'm all out of bubble gum!!!" My DVD's

[JonMarsh]

Well, actually I'm implying a fair amount about the power supply by describing how the amps behave with lower impedance loads. And in a sense, my real point is that comparing power output into 8 ohm loads as a metric for how powerful or good sounding an amplifier isn't very useful. In general (mmm, it's dangerous to generalize), quality separate amps have more robust output stages as well as more robut power supplies than recieivers. It's not unusual for a power amp to have 50,000 - 100,000 uF of reservoir capacitance or more. That would be very rare in a reciever, but it has a direct impact on bass quality, and energy reservoir for transients. Remember, a conventional power amp supply only charges the output capacitors from the line for a few milliseconds every sixtieth of a second- unless it uses an inductor input power supply, like Cello amps, Ayre Amps, and some of my homebrew monoblocks do.

I shouldn't be chauvinist, but a lot of the things that contribute to fundamental amplifier quality are transformers, heatsinks, output devices, and capacitors. The thing they have in common is mass and weight. So, while I don't buy amps by the pound, it's certainly something to check for. I've designed Class D amps, as well as switching power supplies (and have AES and other papers published on those topics), those techniques are rarely used in home equipement, because of the expense. Even one of the best commercially available switching amps, the Crown K2, uses a conventional linear power supply.

So, my point is that you'll usually prefer an amp with a stiff clean power supply, able to effortlessly drive low impedance loads, over a conventional reciever approach to audio electronics, even if rated at 2X the eight ohm power (which is, afterall, only 3 dB).

Then too, I just like the flexibility of matching the amplifier to the load requirements that separates gives. The upper modules in my speakers really shouldn't be too difficult to drive, (paralleled Eton 7" drivers 100 Hz to 2.5 kHz, Focal and Audax tweeters above it,) but the speaker IS 3 ohms over much of the frequency range, expect for some rises in the crossover region, which have more current phase shifts associated with them. Most recievers may not be at all happy with a 3 ohm load- they certainly aren't rated for it.

Best regards,

Jon




Earth First!
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[John Holmes]

Okay Jon, I got it all this time! Thank you for taking the time to fully explain as to why.




"I came here, to chew bubble gum and kickass. And I'm all out of bubble gum!!!" My DVD's