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Onkyo DYNAMIC FOUR 800 AM FM stereo receiver



Onkyo DYNAMIC FOUR 800 AM FM stereo receiver


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Re: Onkyo DYNAMIC FOUR 800 AM FM stereo receiver

Does anyone know what the output per channel is for this unit?

Re: Onkyo DYNAMIC FOUR 800 AM FM stereo receiver

Schematic shows a single rail of 34 volts. This means it can swing a peak of around 15, so 10.6 volts rms, or about 14 watts. It appears to be similar to D F 700, which is specified as producing 14 watts into 8 ohms.

Re: Onkyo DYNAMIC FOUR 800 AM FM stereo receiver

I contacted the website that sold the unit in the advert I saw.

They said it’s 25watt peak power output and about 12 watts continuous per channel.

So seems you’re estimates were about right.

Re: Onkyo DYNAMIC FOUR 800 AM FM stereo receiver

Physics dictates what available power is delivered. With a single 34-volt rail, the peak output is theoretically 17 volts (output has to swing both positive and negative --- +17 and -17 is 34 total). However there are losses due to transistor junctions and resistors, so typically knocking off a few volts is within reason. Based on the 12 watts claimed, this puts the rms at 9.8 volts, therefor peak is 13.86, typical for the design. Peak audio watts have limited value for musical purposes and specifying audio equipment. 25 watts peak is 3 dB dynamic headroom for 12.5 watts. 3 dB is commonly claimed amount, albeit under best testing conditions, (purely resistive load, sine wave, pink noise, etc.). Get some sensitive loudspeakers, (92 dB SPL or greater) and that rig will reproduce loudly with reasonable headroom.

Re: Onkyo DYNAMIC FOUR 800 AM FM stereo receiver

Thank you very much for the comments

Re: Onkyo DYNAMIC FOUR 800 AM FM stereo receiver

Thanks for the reply.

After I found this page, I did some more (a lot more) googling and found an advert for one for sale (not private sale) which listed various specs including:

“Dynamic Power: 50 watts (25 watts x 2)”

14 watts seems in line with earlier amps but is there any chance / thing that would suggest the adverts claim of 50 watts is accurate?

Thanks again,

Re: ONKYO DYNAMIC FOUR 800 AM FM stereo receiver

Hi,

Need schematics for this model. My tuner section died after 40 years of faithful service ;(

Carlos

Re: ONKYO DYNAMIC FOUR 800 AM FM stereo receiver

I repaired one of these yesterday; no AM or FM. The issue was Q100, but I replaced most of the other transistors and electrolytic capacitors on that board as well. Hope that helps someone.

Re: ONKYO DYNAMIC FOUR 800 AM FM stereo receiver

Hi Carlos,
Mine is no longer working either?! Did you manage to find the schematics anywhere?
Thanks,
Ivana

Re: ONKYO DYNAMIC FOUR 800 AM FM stereo receiver

Uploaded schematics today...in case you're still looking!

Re: ONKYO DYNAMIC FOUR 800 AM FM stereo receiver

Hi there

I'm curious to know what speakers you guys are using with this receiver?

I have one of these that is in good condition along with the matching 100v turntable, but it has the original onkyo speakers that sound a bit washed out and muddy. I've had no luck whatsoever finding a better quality pair of loudspeakers that match this amp. I've tried Dali concept1, richter harlequin speakers and some paradigm atom monitor speakers which all sound good until I turn the volume up over a third of the way and things start to distort. The amp has been serviced and runs well but I think the issue stems from the low power and its inability to drive the speakers.

Just wanted to know if you had anything you'd recommend?

Thanks

Adrian

Re: ONKYO DYNAMIC FOUR 800 AM FM stereo receiver

Hi Adrian
I've still got the original Onkyo speakers which sound ok to me. But then again I'm getting old and deaf so I'm not really in a position to make any worthwhile suggestions regarding alternative speakers.
Sorry.