# onkyo vs. marantz



## Guest (Apr 8, 2008)

simply put the onkyo tx-nr905 or the marantz sr8002?
i can get them both for about the same price, any other suggestions would be great too. :bigsmile:


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## tonyvdb (Sep 5, 2007)

Thats a tough choice, The one big thing is the Onkyo has more power per channel and has a Toroidal Power Supply. The Marantz also doesn't mention if it uses the HQV Raon chip for upscaling video where the 905 does.


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## Sonnie (Apr 11, 2006)

I'd go 905 all the way. 

Of course I gave you my thoughts on your other thread.


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## Guest (Apr 8, 2008)

your opinion is always valued, even if you say it twice. :bigsmile:
i'm purdy new at all this so every bit helps. :bigsmile:


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## warren112 (Feb 27, 2008)

I looked at the Marantz SR8002 because it was heavily pushed by a dealer who higly recomended it. It is rated at 125 watts x 7 channels. It only weighs 33.1 pounds. Maximum power consumption is 780 watts. It does 480i to 480p upconversion. And its dimensions (whd) are 17 5/16" x 7 1/4" x 15 5/8". The dealer said it would sound really good with the Paradigm Studio speakers he was also selling.

The Onkyo TX-NR905 is rated at 140 watts x 7 channels. It weighs 54 pounds. Maximum power consumption is 9.8 amps (1176 watts). Its dimensions (whd) are 17 1/8" x 7 5/8" x 18 1/16". It is thus 21 pounds heavier, 2 11/16" deeper, and can use about 400 watts more AC power than the Marantz.

My understanding is that amplifiers are rated as stereo amplifiers only. So in most of the ratings for 7 channel amplifiers or receivers they are testing the amplifier with only 2 channels at a time. Thus an underpowered powersupply would not be noticed by any measurement in the ratings. 

I suspect that a big heavy transformer will output more power than a smaller lighter transformer. And big larger conventional aluminum heatsinks will dissipate heat better than small light copper plated ones will. 

I don't know the exact improvements that a toroidal transformer has over a more conventional cheaper transformer except that they are probably a little more power efficient and dissipate less heat. They are also much more expensive to manufacture. A necessary improvement for marketing with no real improvement for the customer.

I also believe that much of the maximum power that a unit will consume will be an indication of how much power could go to the speakers. Of course a class D switching amplifier will be more efficient than a non switching amplifier. However, at higher frequencies the class D will have more distortion. Subwoofers commonly have class D switching amplifiers but they only amplify low frequencies.

The dealer told me that the Integra DTR-7.8 receiver ($1200) that I was thinking of buying had a harsh and bright high end. This would make the Paradigm speakers sound harsh and bad. He said that the Marantz would make the speakers sound smooth and clear.

I ended up buying the Integra receiver and the Paradigm speakers from another dealer whose advice I trusted more. The sound is clear, flat, accurate, detailed, and there is plenty of power. Integra is a division of Onkyo. So I am sure that the sound from Onkyo TX-NR905 will also be excellent. And it has the HQV reon-VX which upscales to 1080p. The reon is worth $700 alone.


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## tonyvdb (Sep 5, 2007)

warren112 said:


> The Onkyo TX-NR905 is rated at 140 watts x 7 channels. It weighs 54 pounds. Maximum power consumption is 9.8 amps (1176 watts). Its dimensions (whd) are 17 1/8" x 7 5/8" x 18 1/16". It is thus 21 pounds heavier, 2 11/16" deeper, and can use about 400 watts more AC power than the Marantz.


That alone is a big factor in going with an Onkyo, the build quality over the other receivers in this class is allot better.



> My understanding is that amplifiers are rated as stereo amplifiers only. So in most of the ratings for 7 channel amplifiers or receivers they are testing the amplifier with only 2 channels at a time. Thus an underpowered power supply would not be noticed by any measurement in the ratings.
> 
> I suspect that a big heavy transformer will output more power than a smaller lighter transformer. And big larger conventional aluminum heatsinks will dissipate heat better than small light copper plated ones will.


Yes this is usually the case. 



> I don't know the exact improvements that a toroidal transformer has over a more conventional cheaper transformer except that they are probably a little more power efficient and dissipate less heat. They are also much more expensive to manufacture. A necessary improvement for marketing with no real improvement for the customer.


A toroidal power supply is a huge advantage one being quality. The toroidal PS will give you cleaner power and is far more stable than a standerd power supply. All Onkyo receivers from the 805 and up use larger transformers in them and use a push pull amplification section giving superior sound quality.



> And it has the HQV reon-VX which upscales to 1080p. The reon is worth $700 alone.


That is a HUGE advantage over the Marantz.


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## lcaillo (May 2, 2006)

tonyvdb said:


> That alone is a big factor in going with an Onkyo, the build quality over the other receivers in this class is allot better.
> 
> Yes this is usually the case.
> 
> A toroidal power supply is a huge advantage one being quality. The toroidal PS will give you cleaner power and is far more stable than a standerd power supply. All Onkyo receivers from the 805 and up use larger transformers in them and use a push pull amplification section giving superior sound quality.


I work on all brands of receivers. I cannot conclude the same about build quality. It would be more correct to describe the brands in this class as more similar than different. I have actually seen more build quality related issues with Onkyo than with others in its class (I consider those to be Yamaha, Denon, Marantz, and maybe HK). The Marantz has a longer warranty and we rarely see any problems with them at all. I'd say that in terms of reliability, Yamaha has likely been the best over many years, with the rest coming in behind, and Onkyo and HK taking up the rear of this group. I have never been impressed with anything about Onkyo as a company in terms of service and customer support. Marantz is marginally better in this respect, but Denon and Yamaha definitely beat them both in tech support and Yamaha customer relations is easily the best.

The primary advantage in a torroidal transformer is the efficiency. You can build a smaller, lighter device to get the same current. They are quieter as well, but the difference in how "clean" the power might be is marginal.


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## bobgpsr (Apr 20, 2006)

Torroidal transformers are self-shielding (they contain their magnetic fields better). This can reduce the amount of 60 Hz hum (when using a linear design power supply) induced in other circuits. For higher frequency switching power supplies, a torroidal transformer does a better job of containing EMI.

Harder to wind though.


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## warren112 (Feb 27, 2008)

Plitron is a company which makes toroidal transformers. This information is from their web page: http://www.plitron.com/advantages.asp

High efficiency of around 95% at load versus 80% for a standard transformer.

Size can be 50% smaller and lighter than conventional transformers.

Toroidal transformers are acoustically silent with very low mechanicl hum compared to conventional transformers.

The windings of the toroidal transformer act as magnetic shielding and they radiate 1/10 the magnetic field of conventional transformers.

The toroidal transformer uses 1/16 the power when no load is being driven. 

All of these factors should be of greater importance when larger loads such as 1000 watts or more are required to drive the speaker output amplifiers.


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## MatrixDweller (Jul 24, 2007)

I'm pretty sure that both of these amps have toroidal transformers. Copper is a better conductor of heat than aluminum so a smaller copper heatsink would be more efficient than a larger aluminum one. Excess weight can also mean poor design or heavy use of older (heavier) components or materials.

I think it would boil down to features, which the Onkyo has more. You get network capabilities (streaming, internet radio), THX Ultra certification as opposed to THX Select, a little more wattage and much better video upconversion. 

The 905 has the upper hand in pretty much every category, looking at the specs. You might want to audition them though to see which one sounds better in you opinion. On paper the 905 is a clear winner.


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## thxgoon (Feb 23, 2007)

MatrixDweller said:


> THX Ultra certification as opposed to THX Select


That would do it for me:bigsmile: This says a lot about the power stage of the receiver.


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