Denon 3800 with B&W 606’s - blown center and right front channels - 1 year apart

[crusherks1988]

Just got my Denon 3800 back from warranty service for a second blown channel - first was center last year, this year right front. Denon warranty tech in KC recommended to set receiver to 4 ohm to maybe protect it. A lot of these receivers are blowing channels - he had 22 of them - he said Korean components (replaces with Japanese). Does it make sense with these speakers to set receiver to 4 ohm? I trust him, but seems like more heat from receiver - no issue on my end on clearance for heat, etc. Any thoughts? Running B&W 606s center and surrounds.

 

[Chrispy]

The 4 ohm setting could restrict things somewhat. Perhaps you're overdriving the unit to begin with? Is it well ventilated? B&Ws can be rough for amps, tho. Are you using external amps? Might be a consideration....

 

[Keith Flanker]

Set it to 4 Ω mode only if the unit runs hot, since it caps current but treats the symptom. The 606s are 8 Ω nominal, dipping toward 3-4 Ω in the bass, not an extreme load. Two blown channels a year apart points to heat or unit reliability, not your speakers. Good ventilation helps; an external amp for the front stage is the durable fix if you listen loud.

 

[OldHvyMec]

The deal is that you can have a component set on a desktop with all sides plus the top and bottom open. If the ambient air is not cool enough, or not circulating enough from outside that box to inside the box and back out again. You are basically preheating an oven.

You need to circulate cool air around any AVR if you are pushing high-watt-makin' speakers to high SPL. I'll tell you something else about AVRs: they don't like vibration, like having heavy vibration on the gear and no decoupling from heavy subs or speakers.

Heat
Circulation
Vibration
Make darn sure if you're using bare wire to do a clean hookup, no stray strands at all on either end of the AVR or the speaker.

Good luck.

 

[ryanosaur]

Can’t let the denon off the hook completely, but I do agree that the B&Ws are known for low impedance and usually hitting that minima at the worst phase angle.

If you have a Sub and are crossing over before those Speaker's hit their minima, that shouldn’t be a problem, though, as long as you are crossing high enough.

Old mec is right in commenting about possible setup issues as well: make certain you have a good 6” of open air on both sides and above the Denon, as well as not being in a closed back cubby, etc.

Denon and Marantz AVRs are well known for running warm, and heat build up is a killer, just as certain as pushing low impedance at higher volume can be…

AC Infinity fans can be a very inexpensive way to help prolong your AVR. Also, if the Amp channels are being taxed, adding more robust external Amps for those channels can be a lifesaver.

Until then, watch your SPL. Maybe consider Speakers with a higher sensitivity or which present an easier load at impedance minima.

 

[Steve Dallas]

My 4700 did pretty much the same thing. I 'upgraded' to a 4800 hoping Japanese manufacture would make a difference. It has been a little over a year. Fingers crossed.

My left and right were on an external amp with those amps turned off in speaker layout the entire time it was in service. The warranty repair shop never told me which amp boards died, just that they did. I also had a AC Infinity fan on top for forced cooling. Two amps still failed.

I run my 4800 with LCR farmed out to an external amp to further reduce heat hoping that may also help.

Toes now crossed too.

 

[Miker 1102]

Just got my Denon 3800 back from warranty service for a second blown channel - first was center last year, this year right front. Denon warranty tech in KC recommended to set receiver to 4 ohm to maybe protect it. A lot of these receivers are blowing channels - he had 22 of them - he said Korean components (replaces with Japanese). Does it make sense with these speakers to set receiver to 4 ohm? I trust him, but seems like more heat from receiver - no issue on my end on clearance for heat, etc. Any thoughts? Running B&W 606s center and surrounds.

Mine went into protection mode. Its just sitting there. I bought the 3900 but am thinking about selling it because I think the amp design is the same. These are just cheaply designed where the 4500 is a beast.

The deal is that you can have a component set on a desktop with all sides plus the top and bottom open. If the ambient air is not cool enough, or not circulating enough from outside that box to inside the box and back out again. You are basically preheating an oven.

You need to circulate cool air around any AVR if you are pushing high-watt-makin' speakers to high SPL. I'll tell you something else about AVRs: they don't like vibration, like having heavy vibration on the gear and no decoupling from heavy subs or speakers.

Heat
Circulation
Vibration
Make darn sure if you're using bare wire to do a clean hookup, no stray strands at all on either end of the AVR or the speaker.

Good luck.

Good advice. I have killed some receivers with wire that costs nothing.

 

[crusherks1988]

Can’t let the denon off the hook completely, but I do agree that the B&Ws are known for low impedance and usually hitting that minima at the worst phase angle.

If you have a Sub and are crossing over before those Speaker's hit their minima, that shouldn’t be a problem, though, as long as you are crossing high enough.

Old mec is right in commenting about possible setup issues as well: make certain you have a good 6” of open air on both sides and above the Denon, as well as not being in a closed back cubby, etc.

Denon and Marantz AVRs are well known for running warm, and heat build up is a killer, just as certain as pushing low impedance at higher volume can be…

AC Infinity fans can be a very inexpensive way to help prolong your AVR. Also, if the Amp channels are being taxed, adding more robust external Amps for those channels can be a lifesaver.

Until then, watch your SPL. Maybe consider Speakers with a higher sensitivity or which present an easier load at impedance minima.

Thanks everyone for the ideas - just ordered the fan, gonna check the sub crossover as well - hope it works!

 

[peng]

My 4700 did pretty much the same thing. I 'upgraded' to a 4800 hoping Japanese manufacture would make a difference. It has been a little over a year. Fingers crossed.

I hope you are right though I am not a believer of the made in Vietnam vs made in Japan making much of a difference, maybe a tiny bit. Having worked in heavy industry for too many years, I do know and trust QS/QA systems are really good but there are always going to be a % of products that would be more prone to failure (prematurely) of some sorts regardless. Denon's 3000/4000 series likely are big sellers in big box stores including Amazon, Crutchfield, probably have hundreds of thousands being used by now, there bound to be enough failures reported on forums, more so than brands that have much smaller user base.

My left and right were on an external amp with those amps turned off in speaker layout the entire time it was in service. The warranty repair shop never told me which amp boards died, just that they did. I also had a AC Infinity fan on top for forced cooling. Two amps still failed.

I run my 4800 with LCR farmed out to an external amp to further reduce heat hoping that may also help.

Toes now crossed too.

Now as you have had two failed, that's highly unusual in the first place, so your 3rd unit will most likely last for very long time.