Got Onkyo M-504 amp out of repair yay! 2 Q's

[saabracer23]

Hello, I don't know if you guys will remember but I found an Onkyo Integra M-504 dual mobo power amp at goodwill for 20 dollars in like new condition and couldn't get any output. I took it to Innersound in Portland and they desoldered and reflowed the the entire board. That's all it needed, 140 dollars. They then checked every thing else and said all looks mint. It sounds incredible, best amp I have owend.

First question: I don't have a preamp so is it save to plug my ipod into it until I get one?

Question 2: The amp is rated at 165 watts rms at 8 ohms, would someone be able to tell me what it might be rated at 4 ohms. If any additional info is needed let me know because I would really like to know.

Thank you all for any info
Dan

 

[saabracer23]

bump, any help?

Dan

 

[mlloyd1]

dan:
i haven't looked at these amps in quite a while, so don't trust my memory.
often, specs like power into 4ohm loads are included in the users manual.
here is a link to free users manuals if you need it: http://www.retrevo.com/samples/Onkyo-manuals.html

as i recall, they are nice amps! $20 is a steal

mlloyd1

 

[Jan Dupont]

Dan you lucky b......

This was a very famous amp way back (and good looking).

As I recall, the only major problem with this amp is that the max Working Voltage of big power supply caps is almost the same as the rail voltages which have coused several caps to blow up

Many have replaced these to ones with higher WV and higher capacity with good result

 

[saabracer23]

mlloyd1, thank you for the link, good info in there.
I love the way this amp looks. I think I read somewhere about the power supply caps being changed often. I may have to look into that.

Thank you both for chiming in.

Dan

 

[rselby]

this is kinda of an old thread...does anyone know what the 4 Ohm power of this amp is...

 

[Tekko]

If there is no 4ohm spec in the manual, it means this amp is not intended to be used below 8 ohms, and may blow up if tried.

 

[rselby]

strange...says use 4-16 ohm speakers on the back of the amp!

 

[Ian Finch]

4R power rating

You can use most solid state amplifiers down to very low impedances - but not at higher power. (like say, twice the 8R power.)
You are limited by expensive parts like the power transformer, number of output devices and heatsinks, so it was not unusual
to go for just 8R power and sacrifice maximum 4R power at a time when it was not so commonly needed in domestic use.

 

[mcsue22]

I know this is an old thread, but I think they never published 4ohm specs because they weren't that impressive. Like how most people expect a serious power amp to double down as impedance halves.

 

[saabracer23]

Wow, blast from the past!

Dan