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Posted By: darcman M80 and Yamaha RX-V1900 - 02/22/10 06:43 AM
Hi Im just wondering if anyone has used a Yamaha RX-V1900 with
M80s and what the results were, any problems, overheating, etc?

Thanks
Posted By: alan Re: M80 and Yamaha RX-V1900 - 02/23/10 02:59 PM
Hi darcman,

And welcome. Some years ago, Yamaha AV receivers were not on my list of recommended brands to drive the M80s (the list includes Denon, Rotel, Outlaw Audio, Sherwood Newcastle, NAD).

Recently, however, there have been several of Yamaha's top models that, according to test reports by Audioholics and others, have been stable driving 4-ohm loads and the M80s.

I don't know where your model falls in the Yamaha lineup. Try checking past test reports at Audioholics and SoundandVisionmag.com and see how the Yamahas do when connected to a 4-ohm test load. Some AV receiver brands have overly jittery protection circuitry that will shut them down as soon as they sense increased current flow into impedances below 6 ohms.

Regards,

Alan
Posted By: Sloped Re: M80 and Yamaha RX-V1900 - 02/23/10 05:36 PM
You'll be fine with the 1900 and the M80's. The 1900 is towards the top of the Yamaha receivers and uses full push-pull circuit configuration instead of an all on a chip solution that the less expensive Yamaha model line utilizes.

I believe that is why manufactures such as Denon, Rotel, Onkyo can be blanket recommneded as they never use an all in one amp design for any of their models.

Chris (ClubNeon) should be along shortly to correct me if I'm wrong or expand with explanations if I'm close to right.

I have a RX-V3800 which is an earlier model with a similar design and it has never had a problem with 4ohms.
Posted By: ClubNeon Re: M80 and Yamaha RX-V1900 - 02/23/10 06:39 PM
For future reference: you must say my name 3 times when you wish to summon me forth. \:\)

Believe it or not, I'm not familiar with the internal topologies of every receiver out there. So I can't confirm your blanket statement of a blanket statement.

That said, you are on the right track. An op amp controlled MOSFET pair (what you're referring to as a push-pull configuration) has a much easier time handling high currents vs. an integrated circuit doing the work. But that's mostly due to the size of the MOSFET components, and the heat handling which comes with scale.

It's worth noting that TI now has a single chip, class D amp, which handles 2 channels of 300 Watts each, and is stable into 4 Ohms. So on-chip amps are coming along. Class D helps a lot, because it is never in the the half-open states that produce the most of the heat. When the "valve" is closed there's no current flow, and little heat produced, when fully open there's actually less heat produced. But in the in between, where AB amps spend most of their time, that's where the excess energy has to be siphoned away as heat.
Posted By: Ken.C Re: M80 and Yamaha RX-V1900 - 02/23/10 06:51 PM
But... but... heat necessitates heatsinks, and heatsinks are what tells you if a given piece of equipment is awesome.
Posted By: fredk Re: M80 and Yamaha RX-V1900 - 02/23/10 07:00 PM
 Originally Posted By: kcarlile
But... but... heat necessitates heatsinks, and heatsinks are what tells you if a given piece of equipment is awesome.

That reminds me of my Mercury Marquis, which had more space between the radiator and engine than most cars now have in the rear seat.
Posted By: Ken.C Re: M80 and Yamaha RX-V1900 - 02/23/10 07:07 PM
No, empty space between the radiator and the engine indicate that an improperly sized engine was chosen. You bought the V6, didn't you? Shame... ;\)
Posted By: darcman Re: M80 and Yamaha RX-V1900 - 02/23/10 07:18 PM
Hey thanks guys, I know Yamaha manual says its ok, but I just wanted to hear from someone with some real world experience. The only thing I could find was on epinions where a guy had bought a Yamaha RX-V1900 and complained about having to really crank it with his 4ohm speakers. He said he talked to Yamaha and they said it was normal. The dealer where the guy bought it from told the guy to not switch the receiver to 4ohm, just leave it set for 8ohm. I dont think Id do that though. I wouldnt be pushing the M80 to hard anyways. I dont have alot of space above the yamaha in the entertainment stand, although it is all open. I was think of getting a small fan (computer type thing) and plug it in the back of the yamaha and mount it somewhere. That way Id always have good ventilation.
Posted By: Ken.C Re: M80 and Yamaha RX-V1900 - 02/23/10 07:25 PM
No, you should definitely leave it on 8 ohm. Switching to 4 ohm limits the current and may end up damaging the speakers.
Posted By: Wid Re: M80 and Yamaha RX-V1900 - 02/23/10 07:25 PM

You do want to leave the switch in the 8 OHM position no matter the rating on the speaker.

It could have been that person had some inefficient speakers unlike the 95DB sensitivity rating of the M80s.
Posted By: SirQuack Re: M80 and Yamaha RX-V1900 - 02/23/10 08:22 PM
The dealer is correct, leave it at 8ohm setting.
Posted By: Murph Re: M80 and Yamaha RX-V1900 - 02/23/10 08:23 PM
And put duct tape over it to prevent tampering.
Posted By: darcman Re: M80 and Yamaha RX-V1900 - 02/23/10 09:56 PM
Hi technically my receiver isnt a RX-V1900, its a HTR-6290, but from what I understand they are identical. Just one is sold at big box stores and one at high end stores. Maybe the HTR-6290 is just a canadian thing.
Well anyways on the HTR-6290 there is no switch on the back. You press and hold the straight button and then press the master on/off then the unit turns on to this advanced menu, then you turn the program button to the desired impedence, then press on/off button.
Im kinda confused as to why yamaha tells you to change the impedence for 4 or 6 ohm speakers. Is it a safety thing? Anyways so if I hook up 4ohm speakers just leave the receiver set to 8ohm.
Posted By: Ken.C Re: M80 and Yamaha RX-V1900 - 02/23/10 09:57 PM
It's a certification thing. You have it right. If you hook up 4 ohm speakers, leave it set to 8 ohm.
Posted By: JohnK Re: M80 and Yamaha RX-V1900 - 02/24/10 03:08 AM
Yes, the manuals have that direction to satisfy UL(Underwriters Laboratories)fire safety requirements. Setting a switch or menu setting to lower than the default(which may be 6 or 8 ohms)simply reduces the voltage which the receiver's power supply section outputs. Following Ohm's Law, when the voltage is reduced, so is the current and power. So, although the possibility of overheating is reduced, tests have shown that the maximum power capability is cut roughly in half. So, regardless of the manual language the lower impedance setting shouldn't be used.
Posted By: darcman Re: M80 and Yamaha RX-V1900 - 02/26/10 06:57 PM
 Originally Posted By: wid

You do want to leave the switch in the 8 OHM position no matter the rating on the speaker.

It could have been that person had some inefficient speakers unlike the 95DB sensitivity rating of the M80s.



I just wanted to thank everyone for the info. I feel certain that the Yamaha RX-V1900 - HTR-6290 will power the M80s with ease. I looked at that epinion review thing again. The guy said he had Totem speakers. I dont know what the models were, but I looked up Totem speakers and they arent very sensitive, only like 87. So I guess that would explain the guy complaining about having to crank it with the yamaha.
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