Denon 1708 blown fuse -- are they all this sensitive?

[dvolk]

I had my Denon 1708 hooked up in my living room working fine and disconnected everything to move it downstairs in our main media room. Suddenly it didn't work -- just a flashing red light which the user manual indicated could be a cross connected wire. After disconnecting everything and checking again, it turned out to be a fuse (?) that had blown. I went back to the audio store where I had purchased and they said all "high-end receivers have circuitry like this -- only the "mid tier models" like Sony have extra protection, but that impacts sound quality." That sounds a little odd.

I'm a little concerned that if I happen to have a bare wire touch the wrong post my whole receiver will be in the shop again for a month. Is it true that better receivers are this sensitive? I'm even more concerned now that I picked up last year's model (Denon 1707) to fill the void in the living room.

I'm using an APC power supply/surge protector so all my gear is protected, but the speaker cable thing seems far too flaky to be standard. Any comments or other experiences?

 

[markw]

I'm still not sure why the fuse blew, but ashort in a speaker wire should trip the protective circuit.

A tiny short in a speaker wire, even for a split second, can take out several transistors and perhaps other parts (read: very expensive repair) and good receivers will offer some sort of protection, either by a fuse which is cheap to incorporate easily replaced, or by some other, more elaborate and expensive protection circuit that may automatically reset itself.

Odds are that the more you pay for a receiver, the more elaborate it's protectiove sircuits will be, and some can be reset by merely correcting the short and rebooting the receiver.

 

[Midcow2]

Sounds like pure bunk

...and they said all "high-end receivers have circuitry like this -- only the "mid tier models" like Sony have extra protection, but that impacts sound quality." That sounds a little odd.

You really want a fuse or protective circuitry to blow if you cross connect or short out; eletronic circuitry especially the power transistors is very expensive to replace, both labor and down time. I am surprised though that protective circutry did not kick in maybe the Denon uses fuses instead of protective circuitry.

Denon 1708 has protection circuitry:

But it appears i may be only for low ohm ( 4) speakers in conjunction with tmeprature rise ( page 9)

Page 57 also talks about the protection circuitry it two speaker wires touch. Talks about power indicator flashing red.

There is no mention of fuses in your manual. The only reason to use a fuse and maybe why Denon did, it a fuse is sometimes the only way to stop a high immediate current surge from damaging electronic equipment. It is more of an active protection that a more passive protective cicuitry. Like, for instance if you connect a 12 gauge directly accross the postive and negative of an AVR speaker output.


My advice is to always check your speaker conenctions a second time on new installations or moved or rewired installations.

 

[Haoleb]

There is no mention of fuses in your manual. The only reason to use a fuse and maybe why Denon did, it a fuse is sometimes the only way to stop a high immediate current surge from damaging electronic equipment. It is more of an active protection that a more passive protective cicuitry. Like, for instance if you connect a 12 gauge directly accross the postive and negative of an AVR speaker output.

There is no mention of fuses in the manual mainly because they dont want people taking off the covers and digging around in there. Every product I have worked on has internal fuses. However they are only meant to be serviced by a trained technician.