Axiom Home Page Forums General Discussion Technical Questions Amp Question (4ohm stuff)

Fred I can check the local retailer here to see if I can still get the 2808 for $800 and I could ship it to you, most likely only another $20. And no I am not treating, you still have to pay me first.

Where can you get the 663? It isn't even on the Yamaha canada site?

OK, I just read the review Mark linked to. From what I had read, I didn't think that the 661 would even drive the M80. I must say I am encouraged. The 663 is supposed to be quite a bit heavier and some are assuming this means it has the same power supply is the 659.

I was wondering if I could go with the 663 for now and use it as a pre-amp later if I feel I need more power. From the review (and the tests published on S&V) it looks like this is a very reasonable option. Hmm... encouraging.

Thanks for the offer Jason. Let me know what you find. I will look around here too. I seem to remember several Denon units on sale locally last month.

No, the 663 is not on their site yet. I hate the way Canada gets treated like a second rate market by many manufacturers.

I wasn't planning on buying for a couple of months yet (still saving my pennies) so maybe the 663 will be out and reviewed by then.

Actually Fred I just started playing around with a search and up popped the 663 on the Yamaha canada site under legacy receivers, weird.

Hmm... I tried and nothing showed up.

Fred, all these details are described on the Yamaha site, including those for the 663 . Among other things, the 663 is a few ounces heavier than the 661, but this is a trivial matter. It also has a power rating 5 watts higher, but this is similarly trivial. There wouldn't be any apparent reason to suspect that the 663 wouldn't be at least as capable as the 661(i.e., as measured in the S&V lab test)and probably a slight bit better.

As was said before, any amplifier can drive 4ohm speakers and almost any amplifier can be forced to shut down if driven hard enough and long enough with either 4 or 8 ohm speakers. The M80s are a relatively easy 4ohm load and, for example, at any given sound level require less power and about the same current as the M3s, and therefore are a bit easier on the amplifier than the M3s are.

Yep, looking at the graphs, the 80's never really dip below 4ohm across the range.

OK, now you guys are confusing me. There's M80 graphs on the Yamaha site??

John. I can be quite OCD like in my pursuit of details. I have gone over stuff in the Yamaha US site quite a few times, but it doesn't provide any details on 4ohm loads.

I wish someone would hurry up and look under the hood of this amp. OTOH, it looks like my Saturday overtime has dissapeared so I will have to wait a little longer before buying. Sigh...

On a related note, what does getting really hot do to the components on an amp? Back when I worked for a custom application crt manufacturer, we swapped out components due to heat issues at times.

Fred,

My cheap Denon isn't rated for 4 Ohms either but I've tried blowing the damned thing up a few times by playing it loud into the 80s and it won't quit. It doesn't even get hot.Even when they are set to large.

Now your Yammie may get hot if you push it which I doubt you will unless you have hearing disabilities. Heat reduces the lifetime of your components. By how much I can't tell you unless you contract me to develop an MTBF model for your Yammie. PM me if you are interested in a quote for this service .

I'm talking about the 80's. The problem with other 4 ohm speakers is that they dip below 4 ohms across the frequency spectrum. The 80's do not dip below 4 ohms. That is why they are easy to drive.