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Thoroughly confused about power requirements

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charliemike

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I'm looking at an Onkyo TX-SR803 as a replacement for my TX-SR502.

Here are the specs of the 803:

Code:
Power Output* 
(8 ohm, 20 Hz-20 kHz, FTC) 		
6 ohm Capable 		
4 ohm Capable 		
Front L/R 		    105 W/Ch
Center 		             105 W
Surround L/R             105 W/Ch
Surround Back 		105 W/Ch (L/R)

Dynamic Power** 		
3 ohm (Front) 		240 W/Ch
4 ohm (Front) 		180 W/Ch
8 ohm (Front) 		125 W/Ch 
Extended Frequency Response (+ 1 dB, - 3 dB)    10 Hz-100 kHz
I have a pair of SL3s I just bought used and haven't hooked them up yet because of some renovations I'm doing to my condo. My 502 will only do 75w/ch and won't do less than 8ohms.

Basically, I'm hoping (praying) someone with some patience and free time (*grin*) will explain to me what I need to look for in a receiver in terms of power output.

Perhaps an Onkyo isn't the best solution (especially compared to some of the amps/receivers I've seen mentioned here) but it's in my price range and I am familiar with Onkyo in terms of performance.

I'm looking at probably a 50% Music - 35% TV - 15% DVD usage for my system. I don't need it to be loud because I do live in a condo but I'd like to get something that will be able to power the SL3s enough to sound good.

Thanks for everything :)
 

Robin

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Separates...

Charliemike,

Welcome to the ML Club!

I would recommend going with separates. IMHO finding an excellent amplifier, through careful auditioning at your home with the rest of your gear would be ideal. "Trust your ears."

IMHO, I think your Onkyo 803 receivers watts/channel are skewed, it probably would run ML's at less than half of 105 watts/channel
(probably about 30-50 watts/channel). What you need in a SS amplifier for ML's is real current and peak-to-peak amperes, down to one ohm, to make your ML's sing... ;)
Having said all that I would try out Sunfire, Rotel you should be able to find a good deal on Audiogon, hopefully in your price range. But I would trail them at your local audio stores first. Bring them home to audition. Remember you have to live with the sound, so choose what your ears like the best. You should be able to use your old Onkyo receiver as a processor, in the mean time, at least until you can find a processor to your liking... As I am doing myself currently with my A/V Reciever.

Good luck on your audio quest... :D

:D It is good to have you here.
 
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tonyc

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Welcome charliemike! I would go with a separate amp. Good deals are available used on audiogon. Enjoy the hunt.
 

twich54

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Charlie, I'm in agreement with Tony and Robin. Depending on your budget(new vs. used) I too would go the seperate route, It gives you greater flexability down the road. Keep this in mind regardless of amp type..... unless it has a rating into a 4 ohm load that is double or at least close to double that of it's 8 ohm rating, stay away !! it would not be happy driving most ML speakers.
 

stesom

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I learned this lesson a long time ago when I bought my first set of good speakers; Thiel 3.5s. I had a high end Yamaha receiver and figured that it should be just fine. I spent a lot of time listening to these speakers set up with properly matching equipment at the dealer. My dealer told me that I would be very unhappy when I get these speakers home and hook them up to my receiver.

At first I did not want to believe him. He challenged me to bring my receiver in and give it a shot. So I did, and I could not believe how poor my receiver sounded using the same source and speakers. It would have been a complete waste of my money.

I learned that systems need to be in proportion and if you get very reveling speakers everything before them will be exposed.

Unless you are looking at one of the new class D amps, power supply is everything in a well designed amplifier. If the amp can’t double down into 4 ohms then the power supply is not very robust. Logan’s can dip down to 1 ohm in the highest frequency range therefore the amp will need to put out 8 watts at 1 ohm compared to the 1 watt it needs into 8 ohms to maintain output level.

You don’t need to buy a monster amp, but you should consider one that is stable below 4 ohms and can double its output into 4 with both channels driven across the full frequency range 20hz – 20khz. This will allow your speakers to perform through their full range without being dragged down by the amps inability to keep up…….Have fun…..Steve
 
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IWalker

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This may be a little heretical...but I am willing to try it out (and have already made the purchase in advance) as I have heard great things about it...

here's the link where I first read about it.
http://www.avsforum.com/avs-vb/archive/index.php/t-418666.html

certain pro amps look like they would do quite well for this task. For $350 you can get a crown xls602 which has ratings of 370w/ch @ 8ohms, 600w/ch @4ohms, and 840w/ch @ 2 ohms. Not doubling the power output, but dishing out plenty of power for any of your needs, I'm sure. I bought one off of ebay brand new for $350. I don't have the system right now to hook it up to...I'm getting all the stuff in advance...but it looks like a low budget way to feed the MLs all the power they need. Read that thread and judge for yourself.

As a preamp, I've preordered an Emotiva UL Preamp (LMC-1 I think) as it should be a good compromise between the stereo sound quality I want, and the ability to have all the bells and whistles+ability to upgrade to 5.1 or 7.1 as I need/desire.

Maybe others who know more can comment on this, but it seems like a good way to go.

You can also get a XLS402 or XLS202 depending on your power desires for even cheaper.

Hope this helps!!!
 

twich54

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IWalker said:
This may be a little heretical...but I am willing to try it out (and have already made the purchase in advance) as I have heard great things about it...

here's the link where I first read about it.
http://www.avsforum.com/avs-vb/archive/index.php/t-418666.html

certain pro amps look like they would do quite well for this task. For $350 you can get a crown xls602 which has ratings of 370w/ch @ 8ohms, 600w/ch @4ohms, and 840w/ch @ 2 ohms. Not doubling the power output, but dishing out plenty of power for any of your needs, I'm sure. I bought one off of ebay brand new for $350. I don't have the system right now to hook it up to...I'm getting all the stuff in advance...but it looks like a low budget way to feed the MLs all the power they need. Read that thread and judge for yourself.

As a preamp, I've preordered an Emotiva UL Preamp (LMC-1 I think) as it should be a good compromise between the stereo sound quality I want, and the ability to have all the bells and whistles+ability to upgrade to 5.1 or 7.1 as I need/desire.

Maybe others who know more can comment on this, but it seems like a good way to go.

You can also get a XLS402 or XLS202 depending on your power desires for even cheaper.

Hope this helps!!!
Hopefully your happy, if not you could pick up a pair of JBL speakers and go back to your highschool and DJ for your class reunion !!
 

IWalker

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Haha. We'll have to see how well it works. I'm a little skeptical too...but going seperates means when I have the cash I can upgrade the amp to something more "respectable." Then people like twitch won't make fun of me anymore ;)

I think there's a lot to be said for raw power (in that even the highest quality amp will distort and clip if beyond it's power limitations), though I think there's little question that a high end consumer amp would do better...but if my choices are a 100-130w/ch receiver or this for the price...this is probably my better bet for the time being. If I have $500 or less to amp (or $1000 if it's an amp+preamp/receiver) 2 channels that might be dropping as low as .7ohms, I don't think your standard options in that price range are going to cut it. I'll let you know my impressions when I manage to get everything together and set up.
 
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twich54

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IWalker said:
Haha. We'll have to see how well it works. I'm a little skeptical too...but going seperates means when I have the cash I can upgrade the amp to something more "respectable." Then people like twitch won't make fun of me anymore ;)

I think there's a lot to be said for raw power, though I think there's little question that a high end consumer amp would do better...but if my choices are a 100-130w/ch receiver or this for the price...this is probably my better bet for the time being.
Just pok'in a little fun, now don't get your britches in an uproar !! The trouble with LOTS of raw power in SS equipment is that it very often comes at the exspense of listenablity (new word), in other words listener fatigue sets in mighty quick, ie. the ringing phone syndrome !!
 

IWalker

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I knew I'd get teased a little when I posted...in fact I was kind of hoping for it, so no worries :p

I can't speak firsthand about the "listenability" of the amp, though I'll make sure to AB it to my friend's brand new Pioneer Elite if I get the chance. I could very well be wrong, but I think that underpowering the speakers would have worse effects on the sound quality in the upper ranges (where impedence drops) than overpowering it would. It remains to be seen! I hope I'm right! *crosses fingers*
 

stesom

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twich54 said:
Just pok'in a little fun, now don't get your britches in an uproar !! The trouble with LOTS of raw power in SS equipment is that it very often comes at the exspense of listenablity (new word), in other words listener fatigue sets in mighty quick, ie. the ringing phone syndrome !!
I can tell you that my Classe CA-400 all 120 pounds of it does not ever induce listener fatigue in me or those who have heard my system. I have also not grown tired of my Rotel 1090 either another high powered beast.

But I will agree that a poorly executed amplifier, no matter how many watts, will sound poor. A well executed amplifier, no matter how many watts, will sound good. Thats my story and I'm sticking to it ;-> Steve
 

Spike

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twich54 said:
Keep this in mind regardless of amp type..... unless it has a rating into a 4 ohm load that is double or at least close to double that of it's 8 ohm rating, stay away !! it would not be happy driving most ML speakers.
stesom said:
Unless you are looking at one of the new class D amps, power supply is everything in a well designed amplifier. If the amp can’t double down into 4 ohms then the power supply is not very robust.
Hmm, I wouldn't make such blanketed, generalised statements like these regarding amplifiers. Each amplifier design is different and should be taken as a whole instead of just specsmanship. Examples? My AES SixPacs (and Cary V12R) are spec'ed at 50wpc, in fact tests showed that they clip at around 60wpc. They only have speaker tabs for 8 & 4 ohms, nothing for 2 or 1 ohms but they do sound MUCH better than my Classe' CA300 which specs out to 'double down' to the 1ohm load! Power supply not being robust enough? Cary has always been known for over-designed and over-built power-supplies. Their focus has never been on the actual output numbers, just the quality of the signal delivered to the speakers. More examples? ARC VT100mkIII, Cary 805C, Conrad Johnson Premier series, etc...
So, if one were to look for an amplifier which "double down" into low impedance, one would have never consider any of the excellent amplifiers just mentioned.

Spike
 

twich54

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Spike, I meant but didn't say "with respect to SS amps", fully understand tube albeit SET or push - pull are diiferent matters all together. And yes I was generalizing !

Steve, My comments to SS robust power was aimed at the "proaudio" market.

Sorry for the confussion, may I be dismissed to go have dinner ??
 

stesom

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Spike said:
Hmm, I wouldn't make such blanketed, generalised statements like these regarding amplifiers. Each amplifier design is different and should be taken as a whole instead of just specsmanship. Examples? My AES SixPacs (and Cary V12R) are spec'ed at 50wpc, in fact tests showed that they clip at around 60wpc. They only have speaker tabs for 8 & 4 ohms, nothing for 2 or 1 ohms but they do sound MUCH better than my Classe' CA300 which specs out to 'double down' to the 1ohm load! Power supply not being robust enough? Cary has always been known for over-designed and over-built power-supplies. Their focus has never been on the actual output numbers, just the quality of the signal delivered to the speakers. More examples? ARC VT100mkIII, Cary 805C, Conrad Johnson Premier series, etc...
So, if one were to look for an amplifier which "double down" into low impedance, one would have never consider any of the excellent amplifiers just mentioned.

Spike
Sometimes I think I/We just get too serious about this stuff but I am really grateful to be able to enjoy this hobby/sport/obsession so on with the show.

I won't get into Tubes vs SS sound quality, but as I stated above, a properly designed and executed amplifier will perform well regardless of its architecture. I did not mean to make a generalization that amp quality can only be derived from specs. I only used double down as an indication that the power supply can deliver into difficult loads.

Tube amps have output transformers that can deliver to a specific impedance range (excepting OTL). SS amps generally don't, so one way to judge the amps ability is to see if the manufacturer states the amps stability into lower impedances as well as to give output readings to 4 ohms or less.

These speakers are not an easy load, so you need to do some experimenting to see what sounds good at the levels that you like to listen to. And even a good amp that cannot meet the demands of the speaker will result in distortion which actually may sound good but is not accurate.

Specs are just an indication, not the only data point to use when buying anything.......Steve

PS Since you mention it, when you say that your tube amps sound better than your SS amp, I would love to know what qualities you hear. Since Classe is known to be a smooth tube like SS amp.....Thanks...Steve
 
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charliemike

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Well, I am very grateful for all the help and suggestions. I will really look into it and do research on it.

Does anyone have links to sites where I can read about the concepts and technologies mentioned?

Thanks!
 

Yang1815

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Hmmmm... I'd use the Onkyo you have for now and spend the money on a good amp. Then upgrade the processor later.

Look on audiogon for some used excellent values.
 

roberto

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Yang1815 said:
Hmmmm... I'd use the Onkyo you have for now and spend the money on a good amp. Then upgrade the processor later.

Look on audiogon for some used excellent values.
Hola...exelent advise...trust your ears and listen more than reading...because you might like things that others won´t or they don´t listen as you do. Happy listening,
Pura vida,
Roberto.
 

charliemike

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roberto said:
Hola...exelent advise...trust your ears and listen more than reading...because you might like things that others won´t or they don´t listen as you do. Happy listening,
Pura vida,
Roberto.
True, but I'm trying to understand why double power at 1 ohm is a good thing :)

Listening makes sense and that's how I narrowed my search down to MLs and then to these SL3s but I need to have a general sense of why I'm looking for certain things. It's just the way I'm built, I guess :)

CM
 

roberto

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charliemike said:
True, but I'm trying to understand why double power at 1 ohm is a good thing :)

Listening makes sense and that's how I narrowed my search down to MLs and then to these SL3s but I need to have a general sense of why I'm looking for certain things. It's just the way I'm built, I guess :)

CM
Hola Charliemike...the impedance (A.C. resistance) of the stat panels drops like a brick as the high frequency is increased. A tweeter, is the opposite, their impedance decrease as the high frequency goes up. The panel at 2OkHz has sometimes less than 1 ohm. This is almost a short circuit for any amp at it speakers binding post, and this amp must be designied to drive this kind of load. So what you are looking for is a high current amplifier, capable to drive this very small, little load impedance. If your amp is not capable to do it, the highs will be rolled off. On the market place today, are many good brands that have being using ML as a tool desing in the test bench. Brands like Mark Levinson, Conrad Johnson, Krell, Jeff Rowland, Cary Audio, Classe, Bryston, Anthem, Spectral, Carver. Sunfire, Aragon, Margules, Audio Analogue, McIntosch, Audio Research, Blue Circle, Manley, VTL, Halcro, Rotel, Adcom, NAD (some models), and there are so many more that I can´t recall, that could drive the panels with no problem. So, as I always say, trust your ears, and the one that you like most...and of course your budget. Power does not means can drive low impedance...look for quality watts than quantity. At www.audiogon.com you can find many of these brands in at fair price. Hope this can help...happy listening,
Pura vida,
Roberto.
 
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Spike

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stesom said:
PS Since you mention it, when you say that your tube amps sound better than your SS amp, I would love to know what qualities you hear. Since Classe is known to be a smooth tube like SS amp
And you had to ask the question, didn't ya? Well, thanks for keeping me up late last night swapping amplifiers around to...refresh my old, fading memory! Let's start with the Classe' to establish a reference point. The Classe' is quite smooth and liquidy in the midrange, with the highs being a tad bit dark (rolled-off). This rolled-off characteristic is only apparent when compared with other solid-state amps in the league of Krell, Levinson, Pass Labs, BAT, etc... On the bass side, Classe' (CA series) have been known to NOT have a grip, and control of the bass like Bryston or Krell. I'm not looking for slamming bass so this is a non-issue with me. Perhaps, the best description I can give to the Classe' is that it was quite close to the ARC VT100 (original series with stock SovTek tubes) that I could not justify the extra cost & headache of retubing and biasing of the ARC. The ARC VT100 had a tad bit more depth, better extended highs but not enough to justify the cost. Heck, that was the main reason I got the Classe' over Krell, Bryston, ARC 10+ years ago!
As good as the Classe' is, the SixPacs are on a whole different level where the difference is quite noticeable. Compared with the SixPacs, the Classe' sounded lean, polite and dare I say, too syruppy. The depth of the soundstage is more forward as well as deeper on the SixPacs than on the Classe'. The width of the soundstage is wider, and there were quite a bit more "air" (separation) between the instruments, musicians. Vocals & highs through the SixPacs have much faster attack and longer decays providing a better sense of immediacy to the music. I was drawn into the music and had the feeling that I was more "involved" with the performance than just sitting back listenning as I was with the Classe'. To sum things up, while the Classe' is an excellent amp in its own right, the SixPacs operate on a whole different level than Classe' or the ARC VT100 mentioned. And to think that this level of performance is achieved at 1/2 the cost of the Classe' is mind-blogling.

Spike
 
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