The fact that it didn't happen in the first 6-8 months of owning it leads to me disagree with your assumption.

I agree with Tkam, I can crank my Denon3808 to +18 (the max) and get almost no audible hiss with my Pass pearl phono hooked up, and totaly silent with my Denon 3930 hooked up.

So the Denons can be dead silent.

No possible way. Denon designed their high end receivers to have hum from the video section. There is no other explanation.

The fact that it didn't happen in the first 6-8 months of owning it leads to me disagree with your assumption.

Sure, I'd have disagreed with myself too if I had known the problem appeared so many months later. I must have skipped it in your OP I'm assuming nothing else changed in your system a few days or even weeks before noticing the hum, and that it could have passed unnoticed until that moment.

I didn't try to mean that being a common issue with AV receivers it's correct, right or even acceptable, but when used as sources/preamps for good sets of amps and speakers those devices get noisy. I read a lot of messages about similar issues at AA when I was more active there.

the 4308ci is a $3000 receiver, it's not some piece of shit.

That's what I've been trying to say.

A high price doesn't make a product any better, and all you know it well. I'm also not saying that the Denon used alone driving speakers would suffer some hum, it's probably dead silent. Those receivers show hum issues when used as sources or preamps. That's my experience and other people's too, but this doesn't mean Tkam's unit "has to" be huming necessarily and he should accept it as is. Specially after knowing the device didn't hum previously. However I'm prone to believe that he hardly will get rid of the hum when using the receiver as source or preamp. In any case I wish him the best of lucks

Glad I'm not the only one who thinks so.

Sure a receiver may not be 'purist' enough for 2 channel snobs, but I have a Denon that is much lower down the chain from Todd's, and I have ZERO hum. We're not talking some Kenwood or Phillips Kmart special receivers here. Mine has a retail tag of $1.3k and todds is in excess of $3k. It may not be as quiet as DuAlMonoZ setero audiophail amps, but to say that we should be hearing and living with excessive hum is a bit of a stretch.

Whatever

Well I think I figured it out tonight. Still have to test out a few more components to make sure they weren't adding anything to it but seems to be related to my cable box after all. Either the Jensen VRD-1FF catv isolator doesn't work for shit or there's an issue with the hdmi out on the cable box.

Ok so there is still a little bit of hum there, I'm going to try disconnecting everything and see what happens.

Have you disconnected your Cable Tv incoming cable before your cable box completely?then listen to see if the hum is gone.

Well I've done some testing and it looks like my ps3 might be the culprit. Time to try a cheater plug on it.

Ok it's final my hum issue is solved!!!!!!

Turned out to be a combination of the cable and the ps3. With the cable box disconnected from the tv and the ps3 using a cheater plug it's now dead quiet.

Until I figure out a way to solve the cable issue I'll just have to remember to disconnect it from the TV anytime I want to watch a movie or game. Not a big deal.

Ok it's final my hum issue is solved!!!!!!

Turned out to be a combination of the cable and the ps3. With the cable box disconnected from the tv and the ps3 using a cheater plug it's now dead quiet.

Until I figure out a way to solve the cable issue I'll just have to remember to disconnect it from the TV anytime I want to watch a movie or game. Not a big deal.

I have a somewhat high noise floor when listening to my SACDmods Denon using the Denon 3808 Reciever as the pre-amp to an outboard amp. If I unplug the hdmi cable going from the receiver to the TV most of the noise goes away. Now what do I do to fix it?

The noise is not really audible at normal listening settings.

What else do you have connected to the receiver?

Edited December 31, 200817 yr by tkam

What else do you have connected to the receiver?

Cable box, HD DVD, Panny Bluray, Denon DVD-3930CI

The pre-outs of the Denon 3808CI cause some noise when going to my Odyssey Candela Preamp and Odyssey Stratos Amp, verified when I disconnected the pre-outs from the Candela inputs, the noise went away and I was left with just some low level hiss.

I'd try disconnecting the cable box and see if that helps at all.

Ok it's final my hum issue is solved!!!!!!

Turned out to be a combination of the cable and the ps3. With the cable box disconnected from the tv and the ps3 using a cheater plug it's now dead quiet.

Until I figure out a way to solve the cable issue I'll just have to remember to disconnect it from the TV anytime I want to watch a movie or game. Not a big deal.

A cheap fix for your cable problem,get 2- 75ohm to 300 ohm adapters at radioshack. Connect the 2 -300 ohm wires from each adapter together & insert the adapters in your incoming cable before your cable box.

Basically you are converting your 75 ohm cable to 300ohm back to 75ohm by doing this. I got this tip from a cable tech & it works.

There are some high end adapters that do the same thing I beleive Madigral(Levinson made one year back) for about 100 bucks.

A cheap fix for your cable problem,get 2- 75ohm to 300 ohm adapters at radioshack. Connect the 2 -300 ohm wires from each adapter together & insert the adapters in your incoming cable before your cable box.

Basically you are converting your 75 ohm cable to 300ohm back to 75ohm by doing this. I got this tip from a cable tech & it works.

There are some high end adapters that do the same thing I beleive Madigral(Levinson made one year back) for about 100 bucks.

I did that years ago. Totally forgot about it. Good tip.

you have to be careful with the 75 to 300 ohm transformers, some

of them actually have a common ground. You don't want those.

This is the right thing

DIGITAL CATV ISOLATOR

but i have seen them for only $9.95...

That's exactly the part I have that doesn't work at all. Or I suppose I could have just got a bad one.

Tkam,

The tube pre-amp with no inputs connected, is making some noise I can hear through the speakers at about 3 feet away. Sounds like hiss with some gunk thrown in as well (tube noise?)

Turn off the preamp and there is just the faintest noise coming from the bare amp connected to the speakers, when listening at maybe 2-3 inches from the speaker cones (sounds like very faint ac hum and hiss).

I will add in the preouts from the Denon Receiver next to see what added noise comes in.

Ok, I figured out that the HT bypass on the Candela Preamp hums when I plug in the pre-outs from my Receiver. But if I plug the the pre-outs from my Receiver into another input on the Candela Preamp no hum, no noise either if I plug in the pre-outs directly into the amp.

Ok, I figured out that the HT bypass on the Candela Preamp hums when I plug in the pre-outs from my Receiver. But if I plug the the pre-outs from my Receiver into another input on the Candela Preamp no hum, no noise either if I plug in the pre-outs directly into the amp.

So the Candela Preamp is going back due to a bad ground in the HT input rca module causing buzz, and to correct a high level of hiss present whenever the unit is on