Help with Denon 3802 (1 Viewer)

[Richard_M]

I have just installed my new 3802 and would like some help if possible.
1. There is a faint hum coming from all speakers all the time, You can notice it during quite passages or changing dvd's etc. BTW I have just replaced my Yamaha 795, which did not make any noise at all. And yes it also does it with no external components plugged in i.e. earth loop. Now do they all have this noise or have I got a dud?.
2. What level do I put the speakers at i.e. most are set around zero, is it advisable to run them this way or up them to say +10, so the volume control only gets to maybe +4. This I find confusing why the volume reads from -70 to +15
3. How important is the matching up of the rear speakers, I currently have B&W 602's for the rears so do I buy more, or say leave these as the rear centre's and buy some reasonable quality flush ceiling mounts or small wall mounts etc.
Thanks
Richard

 

[Chuck Kent]

Richard: I have been running a 3802 as a pre-amp/processor since early August.
I have the tiny bit of hum too. Mine also is clearly receiver based. In my case, it is so low in level that almost anything will obscure it. But it is there. Do we have "duds"??? I don't know. I decided to keep mine. (And I have to clear that I have been very pleased with my 3802. The hum level is VERY VERY low.)
My advice is to only use the volume readout numbers as a reference and not to worry about what they actually read. (BTW, the actual range of the master control is -70 to +18, if the individual channel levels aren't above zero.) If you still had your old Yammy, I'll bet it was marked as going from minus infinity upward towards zero, just like the Denon. As far as the individual channel settings, I leave the mains set as zero and adjust the others (including the sub) to match. In my system, the master volume control, depending on the source, runs from -20 to -08 or so. Some TV stations are lower in volume than others.
IMO, speaker matching is very subjective. But there is no doubt that having similar or the same speakers can't be a bad thing... Also, many have recommended running dipoles as the rear center(s) and direct types (as with your 602s) for the other surrounds. I'm only running a 5.1 setup so I have no direct in-my-own-home experience with a 6.1 layout.
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[Edited last by Chuck Kent on September 27, 2001 at 05:57 AM]

 

[Peter Overduin]

THX recommends dipole rears and direct radiating for center rears in a 7 speaker set-up.

 

[Richard_M]

Thanks for the replies,
I took my 3802 back the shop and they replaced it with a another new one, have installed it, and the hum is still there although ALOT lower, now you have to put your ear next to the speaker to detect it.
Still I don't think it is right in this day & age they produce amps that have this problem.
Anyway bottom line I will run it for a week to make sure the noise does not get any louder, if it stays the same I will probably keep it as I've grown to like the sound compared to my old Yamaha.
Regards,
Richard

 

[Arthur Legardo]

3. How important is the matching up of the rear speakers, I currently have B&W 602's for the rears so do I buy more, or say leave these as the rear centre's and buy some reasonable quality flush ceiling mounts or small wall mounts etc.

If you can't stay within the same speaker line, try to stay with a speaker built by the same company. I have Paradigms all around (Monitor 9 mains, CC-350 center, PW-2200 subwoofer, ADP-170 surrounds, Atoms surround back) in my 7.1 HT.

 

[Dan Hitchman]

A 60 Hz ground loop hum, perhaps? Do you have florescent lights or cable TV on the same circuit?
Try disconnecting the cable TV cord and see if it goes away.
If that's the culprit you need a cable TV ground isolator.
Dan
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Stop HDCP and 5C-- Your rights are at risk!

 

[Chuck Kent]

Dan: No, the hum is definitely from the 3802. In my case, it's low enough I decided to live with it. The only way I hear it is when the room has absolutely no other noises going on. It is at a constant level, no matter what the volume setting. It does sound like a bit like it could indeed be 60 Hz based, but I have unhooked everything and still get it.
Richard: I agree that it's a tad disappointing (that the hum is there.) It wouldn't have surprised me to have a teeny bit of hiss but hum was unexpected. I'm glad that the swap improved things for you.
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[Richard_M]

Update
The new amp was going very well until the transformer developed a loud buzzing noise!. The noise is alot louder than the hum on the first amp. At least the hum on this amp hasn't change volume. I can hear the buzzing even when there is material playing, mind you if I run the volume from -20 up you don't notice it
I have rung the Hi Fi shop and they are happy to exchange the unit for another brand if I want, my delema is do I stick with this brand or get another Yamaha.
Is this a common problem with Denon or just this model?.

 

[Chuck Kent]

WOW! Talk about bad luck!!! No, I haven't heard of any buzzing transformer laminations before.
Some of the older Denon 3300's (which is what I owned before the 3802) had some cooling fan troubles (noisy bearings that squealed) but mine never suffered from it and your new problem doesn't sound like that at all.
I really like the 3802. I like the Pro Logic II, the Mono Movie mode, the ease of setup and the menus. If it were me, I would probably give it one more chance.
But, I guess that no one could blame you for wanting to jump ship...
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[Richard_M]

Chuck, I have to agree with you about the Sound & features of the 3802. I have grown very fond of this unit.
After about an hour of switching back to TV and listening at lower levels the Buzz in the transformer stopped and as yet hasn't reared its ugly head. I was playing quite a few DVD's at quite high volume's when the problem occurred.
Will give it another marathon run tomorrow to see if the transformer problem comes back. The unit had been running for about 7 hours prior to the transformer problem, and about 6 hours after it subsided.
The only speakers I'm running off the 3802 are the centre rears. The mains, centre, and surrounds are powered by an external amp, therefore one would not expect it to be a problem with overdriving the transformer.
Anyway will keep you informed of any further developments.
Regards,