amp running without speaker load?

[Sanitarium]

Question:
I have an old Hifonics Jupiter VIII 30x4. Currently I am running
infinity 6.5s off 2 of the channels while I search for a center
channel. Will I damage this amp with line level inputs connected to the
2 unused channels with no speakers loaded?

I know a tube amp will fry the output transformer... How about a solid
state circuit? Will I fry mosfets?

thanks,
Garrett

[Kevin McMurtrie]

In article >,
Sanitarium > wrote:

>Question:
>I have an old Hifonics Jupiter VIII 30x4. Currently I am running
>infinity 6.5s off 2 of the channels while I search for a center
>channel. Will I damage this amp with line level inputs connected to the
>2 unused channels with no speakers loaded?
>
>I know a tube amp will fry the output transformer... How about a solid
>state circuit? Will I fry mosfets?
>
>thanks,
>Garrett

It's no problem for it.

[Jeff]

"Sanitarium" > wrote in message
...
> Question:
> I have an old Hifonics Jupiter VIII 30x4. Currently I am running
> infinity 6.5s off 2 of the channels while I search for a center
> channel. Will I damage this amp with line level inputs connected to the
> 2 unused channels with no speakers loaded?
>
> I know a tube amp will fry the output transformer... How about a solid
> state circuit? Will I fry mosfets?
>
> thanks,
> Garrett

Some solid state amplifiers can go into thermal
runaway if left unloaded, depends on the design.
I have seen this more in IC output car radios than
any other types.
Jeff

[Scott Johnson]

"Jeff" > wrote in message
...
>
> "Sanitarium" > wrote in message
> ...
> > Question:
> > I have an old Hifonics Jupiter VIII 30x4. Currently I am running
> > infinity 6.5s off 2 of the channels while I search for a center
> > channel. Will I damage this amp with line level inputs connected to the
> > 2 unused channels with no speakers loaded?
> >
> > I know a tube amp will fry the output transformer... How about a solid
> > state circuit? Will I fry mosfets?
> >
> > thanks,
> > Garrett
>
> Some solid state amplifiers can go into thermal
> runaway if left unloaded, depends on the design.
> I have seen this more in IC output car radios than
> any other types.
> Jeff
>
>

it should be just fine.

[Eddie Runner]

> "Jeff" > wrote in message
>
> > Some solid state amplifiers can go into thermal
> > runaway if left unloaded, depends on the design.

Where would it run to if you had the amp bolted down?
Same reason I keep a leash on my dog when I walk her.

> > I have seen this more in IC output car radios than
> > any other types.

I think your dreamin, I have hooked up 1000s of car radios
with only two speakers, leaving the other two speaker leads
unloaded and I have NEVER had any problems, much less
had one RUN AWAY!

If this just a rumor you heard Jeff or an old wives tale or what?


Eddie Runner
installin since 1974
http://www.installer.com/tech/

[chris lewis]

I too have seen thousands of amps on my service bench diagnosed with no
load attached.
never a problem.
that rumour goes back to early tube days when TUBE amps driven w/o load
did have run away


Jeff wrote:

> "Eddie Runner" > wrote in message
> ...
> > > "Jeff" > wrote in message
> > >
> > > > Some solid state amplifiers can go into thermal
> > > > runaway if left unloaded, depends on the design.
> >
> > Where would it run to if you had the amp bolted down?
> > Same reason I keep a leash on my dog when I walk her.
> >
> > > > I have seen this more in IC output car radios than
> > > > any other types.
> >
> > I think your dreamin, I have hooked up 1000s of car radios
> > with only two speakers, leaving the other two speaker leads
> > unloaded and I have NEVER had any problems, much less
> > had one RUN AWAY!
> >
> > If this just a rumor you heard Jeff or an old wives tale or what?
> >
> >
> > Eddie Runner
> > installin since 1974
> > http://www.installer.com/tech/
> >
>
> Hi Eddie
> "No" speakers connected, some amps or ICs will get
> hotter and hotter over time. (its rare, not common)
> Loading 2 channels of a 4 channel IC is enough to stop
> this if it was going to happen. (or 1 of a 2 )
> Some companies have a switch to cut signal or turn on
> to the outputs if not used.
> I have assumed this is why, although it may or may not
> be the reason.
> I have seen it happen several times on my bench and
> had several customers that had bad outputs after a
> while of not using them. (no other problems found)
> Old car radios are known to have this problem.
> No fridge jokes.
> Jeff

[Jeff]

So have I Chris but I do not mean tube amps and I do
not mean every amp but there are a few that can.
Saying it can not happen ever would be incorrect.
Jeff


"chris lewis" > wrote in message
...
> I too have seen thousands of amps on my service bench diagnosed with no
> load attached.
> never a problem.
> that rumour goes back to early tube days when TUBE amps driven w/o load
> did have run away
>
>
> Jeff wrote:
>
> > "Eddie Runner" > wrote in message
> > ...
> > > > "Jeff" > wrote in message
> > > >
> > > > > Some solid state amplifiers can go into thermal
> > > > > runaway if left unloaded, depends on the design.
> > >
> > > Where would it run to if you had the amp bolted down?
> > > Same reason I keep a leash on my dog when I walk her.
> > >
> > > > > I have seen this more in IC output car radios than
> > > > > any other types.
> > >
> > > I think your dreamin, I have hooked up 1000s of car radios
> > > with only two speakers, leaving the other two speaker leads
> > > unloaded and I have NEVER had any problems, much less
> > > had one RUN AWAY!
> > >
> > > If this just a rumor you heard Jeff or an old wives tale or what?
> > >
> > >
> > > Eddie Runner
> > > installin since 1974
> > > http://www.installer.com/tech/
> > >
> >
> > Hi Eddie
> > "No" speakers connected, some amps or ICs will get
> > hotter and hotter over time. (its rare, not common)
> > Loading 2 channels of a 4 channel IC is enough to stop
> > this if it was going to happen. (or 1 of a 2 )
> > Some companies have a switch to cut signal or turn on
> > to the outputs if not used.
> > I have assumed this is why, although it may or may not
> > be the reason.
> > I have seen it happen several times on my bench and
> > had several customers that had bad outputs after a
> > while of not using them. (no other problems found)
> > Old car radios are known to have this problem.
> > No fridge jokes.
> > Jeff
>

[Scott Johnson]

>
> Hi Eddie
> "No" speakers connected, some amps or ICs will get
> hotter and hotter over time. (its rare, not common)
> Loading 2 channels of a 4 channel IC is enough to stop
> this if it was going to happen. (or 1 of a 2 )
> Some companies have a switch to cut signal or turn on
> to the outputs if not used.
> I have assumed this is why, although it may or may not
> be the reason.
> I have seen it happen several times on my bench and
> had several customers that had bad outputs after a
> while of not using them. (no other problems found)
> Old car radios are known to have this problem.
> No fridge jokes.
> Jeff
>
>
>


Sounds like the product of an already efective output chip/transistor. or
the speaker wire is grounding out somewhere.