Guest
Suppose an av receiver needs to be run with some channels missing speakers
during remodeling.
Will this damage the outputs?
--
Skip
during remodeling.
Will this damage the outputs?
--
Skip
S
Sofie
Guest
Skip:
NO..... absolutely not a problem with solid state amplifiers......
....back in the vacuum tube days, a load was needed on the outputs..
--
Best Regards,
Daniel Sofie
Electronics Supply & Repair
----------------------
<Skip> wrote in message news:bvtmf0027cu@enews3.newsguy.com...
NO..... absolutely not a problem with solid state amplifiers......
....back in the vacuum tube days, a load was needed on the outputs..
--
Best Regards,
Daniel Sofie
Electronics Supply & Repair
----------------------
<Skip> wrote in message news:bvtmf0027cu@enews3.newsguy.com...
S
Steve(JazzHunter)
Guest
On Thu, 5 Feb 2004 07:44:01 -0800, "Sofie" <sofie@olypen.com> wrote:
I inadvertently turned on a Sony 60 watt-per-channel receiver and
turned up the volume with the speakers disconnected.. not only did
the output IC's fail but they shorted and fried a section of the
circuit board. NOT recommended in other words. If I have to run an
amp without speakers I put on some sort of dumping load, say 20 to 50
Ohms at 10 watts.
. Steve .
I inadvertently turned on a Sony 60 watt-per-channel receiver and
turned up the volume with the speakers disconnected.. not only did
the output IC's fail but they shorted and fried a section of the
circuit board. NOT recommended in other words. If I have to run an
amp without speakers I put on some sort of dumping load, say 20 to 50
Ohms at 10 watts.
. Steve .
S
Sofie
Guest
Steve (JazzHunter).....
Turning up the volume to excessive levels even with a load connected can
cause failures.
A "dumping load" is not needed and is superfluous, irrelevant and immaterial
with solid state amps that do not use an audio output transformer.
How many folks run surround sound receivers without rear channel speakers
connected or center channel speakers connected...... and they have
absolutely no problems..... unless someone turns the volume way up...... at
that point, the channels that fail will probably be the ones with a speaker
or "dumping load" connected thus causing that channel's power output stage
to draw more current and dissipate more heat while the output stages without
any kind of load will not draw much current and will run cool.
--
Best Regards,
Daniel Sofie
Electronics Supply & Repair
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
"Steve(JazzHunter)" <jazzhunterNotHere@internet.com> wrote in message
news
kr4201r8qjc8iae8lcr2bg8u7kslp0dmv@4ax.com...
Turning up the volume to excessive levels even with a load connected can
cause failures.
A "dumping load" is not needed and is superfluous, irrelevant and immaterial
with solid state amps that do not use an audio output transformer.
How many folks run surround sound receivers without rear channel speakers
connected or center channel speakers connected...... and they have
absolutely no problems..... unless someone turns the volume way up...... at
that point, the channels that fail will probably be the ones with a speaker
or "dumping load" connected thus causing that channel's power output stage
to draw more current and dissipate more heat while the output stages without
any kind of load will not draw much current and will run cool.
--
Best Regards,
Daniel Sofie
Electronics Supply & Repair
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
"Steve(JazzHunter)" <jazzhunterNotHere@internet.com> wrote in message
news
kr4201r8qjc8iae8lcr2bg8u7kslp0dmv@4ax.com...
A
Alex Bird
Guest
"Sofie" <sofie@olypen.com> wrote in message news:<1024pb51mj1n28f@corp.supernews.com>...
new as you describe will be fine.
When I used my yamaha without speakers a couple of years ago, I could
hear the wobbly inductors in the output stage singing along. Maybe
they do when the speakers are connected too, but are drowned out?
Alex
I've seen solid state amps that advised against this, but anything as
new as you describe will be fine.
When I used my yamaha without speakers a couple of years ago, I could
hear the wobbly inductors in the output stage singing along. Maybe
they do when the speakers are connected too, but are drowned out?
Alex
J
Jerry Greenberg
Guest
You can run a solid state amplifier with no load, as long as it is not
driven to clipping levels. When clipping, it can be damaged with or
without any load.
We run amplifiers at some locations with no load on them for long
periods of time, and never had a failure from that.
Only amplifiers with an output transformer such as tube amplifiers,
and some specialized transistor amplifiers that use an output
transformer should have a load.
Jerry Greenberg
http://www.zoom-one.com
--
<Skip> wrote in message news:<bvtmf0027cu@enews3.newsguy.com>...
driven to clipping levels. When clipping, it can be damaged with or
without any load.
We run amplifiers at some locations with no load on them for long
periods of time, and never had a failure from that.
Only amplifiers with an output transformer such as tube amplifiers,
and some specialized transistor amplifiers that use an output
transformer should have a load.
Jerry Greenberg
http://www.zoom-one.com
--
<Skip> wrote in message news:<bvtmf0027cu@enews3.newsguy.com>...
S
Steve(JazzHunter)
Guest
On Thu, 5 Feb 2004 11:54:37 -0800, "Sofie" <sofie@olypen.com> wrote:
Again my experience belies that. The Sony wasn't driven to excessive
levels, just what was achieved after the startup muting had
disengaged. A fellow with a Cambridge amp also lost most of the
output transistors on one channel when his cat pulled the wires off
the speaker during regular listening. Even quite modern amps can
break into RF oscillation due to a residual phase shift in the
negative feedback loop with no load whatosever. Another fellow in
this thread was referring to that when he mentions a "singing" sound
from the unit
The question was whether it was OK to leave a power amp unterminated.
The responsible answer is "No", Period. Particularly if there can be
any doubt about the stability of the amp in question. It's just plain
bad practice.
. Steve ..
Again my experience belies that. The Sony wasn't driven to excessive
levels, just what was achieved after the startup muting had
disengaged. A fellow with a Cambridge amp also lost most of the
output transistors on one channel when his cat pulled the wires off
the speaker during regular listening. Even quite modern amps can
break into RF oscillation due to a residual phase shift in the
negative feedback loop with no load whatosever. Another fellow in
this thread was referring to that when he mentions a "singing" sound
from the unit
The question was whether it was OK to leave a power amp unterminated.
The responsible answer is "No", Period. Particularly if there can be
any doubt about the stability of the amp in question. It's just plain
bad practice.
. Steve ..
S
Sofie
Guest
Bad practice???
When you shut the speakers off with the front panel speaker switch on a
solid state modern home consumer model stereo receiver or amp I have yet to
see a design that switches in a proper high power handling load in place of
the speakers...... now the older tube type amps with an output transformer
usually provided that ability if they had a speaker switch. The headphone
don't provide much of a load because of series resistors in the order of 68
to 330 ohms..
--
Best Regards,
Daniel Sofie
Electronics Supply & Repair
----------------------
snipped:
"Steve(JazzHunter)" <jazzhunterNotHere@internet.com> wrote in message >
..
When you shut the speakers off with the front panel speaker switch on a
solid state modern home consumer model stereo receiver or amp I have yet to
see a design that switches in a proper high power handling load in place of
the speakers...... now the older tube type amps with an output transformer
usually provided that ability if they had a speaker switch. The headphone
don't provide much of a load because of series resistors in the order of 68
to 330 ohms..
--
Best Regards,
Daniel Sofie
Electronics Supply & Repair
----------------------
snipped:
"Steve(JazzHunter)" <jazzhunterNotHere@internet.com> wrote in message >
..
..
D
Daniel L. Belton
Guest
Sofie wrote:
without a load. Solid state amps need some type of load on the output.
Some amps have a load built in that switches in when the spaekers are
disconnected to prevent blowing the output transistors.
Actually, it's the other way around. Tube amps could handle being run
without a load. Solid state amps need some type of load on the output.
Some amps have a load built in that switches in when the spaekers are
disconnected to prevent blowing the output transistors.
C
CJT
Guest
Daniel L. Belton wrote:
without a load can cause the output transformer to ring and generate
voltages high enough to arc and self-destruct. Transistor amps are
pretty tolerant of running without a load.
Actually, I think the other guy has it right. Running a tube amp
without a load can cause the output transformer to ring and generate
voltages high enough to arc and self-destruct. Transistor amps are
pretty tolerant of running without a load.
L
Leonard Caillouet
Guest
"Steve(JazzHunter)" <jazzhunterNotHere@internet.com> wrote in message
news:477620h5115jpd05fjhcm1q69j7cm69stb@4ax.com...
attached or not. No modern consumer products have problems running unloaded
at nominal levels.
the most common reason that we reapir most brands of amlifiers. Even a
brief short on many will kill an output pair.
products this is very unlikely at a level that will cause problems unless
there is a defect.
themselves as audible effects and it does not mean that there are problems
that relate to loading. Audible ~=> RF, BTW.
Leonard Caillouet
news:477620h5115jpd05fjhcm1q69j7cm69stb@4ax.com...
Your Sony likely had other problems and would have failed whether a load was
attached or not. No modern consumer products have problems running unloaded
at nominal levels.
Obviously there was likely an short term short between the leads. This is
the most common reason that we reapir most brands of amlifiers. Even a
brief short on many will kill an output pair.
Name one, other than a few more esoteric designs. Among mainstream consumer
products this is very unlikely at a level that will cause problems unless
there is a defect.
So what, lots of products exhibit sympathetic vibrations that manifest
themselves as audible effects and it does not mean that there are problems
that relate to loading. Audible ~=> RF, BTW.
Bullshit, except in very specific cases.
Leonard Caillouet
S
Steve(JazzHunter)
Guest
On Fri, 6 Feb 2004 07:56:16 -0500, "Leonard Caillouet"
<lcailloNOSPAM@devoynet.com> wrote:
thirty-five years of servicing, you expressed an opinion also.. There
is no need to call my opinion "bullshit."
Since there is no harm in any situation with having a load on an amp,
then that is preferred to NOT having a load on the amp - which is bad
in "esoteric" cases and for older equipment. On the balance of safety
the amp should be loaded.
. Steve .
<lcailloNOSPAM@devoynet.com> wrote:
The poster asked for an opinion. I expressed my opinion based on
thirty-five years of servicing, you expressed an opinion also.. There
is no need to call my opinion "bullshit."
Since there is no harm in any situation with having a load on an amp,
then that is preferred to NOT having a load on the amp - which is bad
in "esoteric" cases and for older equipment. On the balance of safety
the amp should be loaded.
. Steve .
L
Leonard Caillouet
Guest
"Steve(JazzHunter)" <jazzhunterNotHere@internet.com> wrote in message
news:nj6720li7gajgfs6r79lqba4sjb0oo8th2@4ax.com...
very much overstating the possibility of there being a problem, particularly
with modern mainstream consumer products. Other than in specific cases
where the design requires a load, I have the opinion that your statement is
bullshit, particularly in the context of the other comments that you made in
the same post. You make the mistake that many people do, taking a view that
has some correctness, exaggerating its importance and trying to back up the
opinion with points that are irrelevant, ignore the obvious, or are just
plain wrong in application to the current discussion. I think bullshit was
a good description. Sorry if it dented your ego or offended your delicate
sensibility.
Leonard Caillouet
....I'd like to find you inner child and kick its little ass. Get over it...
(The Eagles)
news:nj6720li7gajgfs6r79lqba4sjb0oo8th2@4ax.com...
It is my opinion that to call it "bad practice" to run an amp unloaded is
very much overstating the possibility of there being a problem, particularly
with modern mainstream consumer products. Other than in specific cases
where the design requires a load, I have the opinion that your statement is
bullshit, particularly in the context of the other comments that you made in
the same post. You make the mistake that many people do, taking a view that
has some correctness, exaggerating its importance and trying to back up the
opinion with points that are irrelevant, ignore the obvious, or are just
plain wrong in application to the current discussion. I think bullshit was
a good description. Sorry if it dented your ego or offended your delicate
sensibility.
Leonard Caillouet
....I'd like to find you inner child and kick its little ass. Get over it...
(The Eagles)
K
Ken G.
Guest
Those newer Sony receivers were really bad at blowing amps for no reason
anyway
anyway
A
Alan Peterman
Guest
On Fri, 06 Feb 2004 08:49:29 -0500, "Steve(JazzHunter)"
<jazzhunterNotHere@internet.com> wrote:
will not need to dissipate power, and will not run warm or hot. And the load
resistor will also need to be cooled. While there MAY be some unstable amps
that need a load, in my 40+ years of selling and servicing audio gear I don't
think I've ever seen a solid state amp that needed a load - including the
notoriously unstable early amps from the late 60's.
Tube gear of course did need a load.
<jazzhunterNotHere@internet.com> wrote:
Actually there are reasons to NOT load a solid state amp. Without a load it
will not need to dissipate power, and will not run warm or hot. And the load
resistor will also need to be cooled. While there MAY be some unstable amps
that need a load, in my 40+ years of selling and servicing audio gear I don't
think I've ever seen a solid state amp that needed a load - including the
notoriously unstable early amps from the late 60's.
Tube gear of course did need a load.
S
Steve(JazzHunter)
Guest
On Fri, 6 Feb 2004 09:09:46 -0700 (MST), goodguyy@webtv.net (Ken G.)
wrote:
for about ten minutes while I was out of the room. I came back in
realizing I'd not connected the speakers and I smelt burning. Both
channels had failed, one had done so dramatically, frying the foil.
There was no previous history of problems with this two-year old
receiver. The volume was not excessive, the ONLY circumstance was that
there was no load.
. Steve
wrote:
It was a 1985 model. The amplifier was run at normal dialogue volume
for about ten minutes while I was out of the room. I came back in
realizing I'd not connected the speakers and I smelt burning. Both
channels had failed, one had done so dramatically, frying the foil.
There was no previous history of problems with this two-year old
receiver. The volume was not excessive, the ONLY circumstance was that
there was no load.
. Steve
S
Steve(JazzHunter)
Guest
On Fri, 6 Feb 2004 09:09:59 -0500, "Leonard Caillouet"
<lcailloNOSPAM@devoynet.com> wrote:
with no load, The Cambridge failed when the cat pulled out twinned
banana plugs while loud classic music was being played. there was no
possiblity of a short. I have had a Denon amp in with one failed
channel, the owner forgot to select speakers with the front panel
switch. Every bloody unit failed due to NOT having a load!! I used
to design and build vacuum tube amps, strangely enough I have never
had a Tube amp damaged by lack of loading.
Get off your high and mighty and consider that experience beats
anal-retentive name calling just for the sake of disagreeing and
trying to be right. Say all you like about "modern design" many amps
may indeed be perfectly ok since they can operate truly as a voltage
amplifier. However many of "esoteric design" such as the Cambrideg can
NOT safely operate without damping. However a SHORTED amp will
usually be protected and shut down safely, except by being operated
beyond thermal rating for too long. But of course a short is not good
idea either. I've had unconnected amps fail, due to not having a
load, units which were fine up to that point. ergo the open load
caused the failure. Logic, the best tool for troubleshooters.
. Steve ..
<lcailloNOSPAM@devoynet.com> wrote:
I have had a receiver fail while run at normal volume for ten minutes
with no load, The Cambridge failed when the cat pulled out twinned
banana plugs while loud classic music was being played. there was no
possiblity of a short. I have had a Denon amp in with one failed
channel, the owner forgot to select speakers with the front panel
switch. Every bloody unit failed due to NOT having a load!! I used
to design and build vacuum tube amps, strangely enough I have never
had a Tube amp damaged by lack of loading.
Get off your high and mighty and consider that experience beats
anal-retentive name calling just for the sake of disagreeing and
trying to be right. Say all you like about "modern design" many amps
may indeed be perfectly ok since they can operate truly as a voltage
amplifier. However many of "esoteric design" such as the Cambrideg can
NOT safely operate without damping. However a SHORTED amp will
usually be protected and shut down safely, except by being operated
beyond thermal rating for too long. But of course a short is not good
idea either. I've had unconnected amps fail, due to not having a
load, units which were fine up to that point. ergo the open load
caused the failure. Logic, the best tool for troubleshooters.
. Steve ..
S
Steve(JazzHunter)
Guest
On Fri, 06 Feb 2004 18:03:31 GMT, Alan Peterman
<alnospam@nospamscn.rain.com> wrote:
such. I've never had a tube amp damaged by lack of loading but of
course that's not a good idea. Tube equipment is just plain more
robust than solid sate. You can fool with biasing and voltages all
you like with no more than a temporary bit of excessive Plate curent,
- a transistor, too much forward bias on the Base and Poof!
. Steve .
<alnospam@nospamscn.rain.com> wrote:
I mean just 20 or 30 Ohms or so, not a full-current load of 4 Ohms or
such. I've never had a tube amp damaged by lack of loading but of
course that's not a good idea. Tube equipment is just plain more
robust than solid sate. You can fool with biasing and voltages all
you like with no more than a temporary bit of excessive Plate curent,
- a transistor, too much forward bias on the Base and Poof!
. Steve .
L
Leonard G. Caillouet
Guest
"Steve(JazzHunter)" <jazzhunterNotHere@internet.com> wrote in message
news:7on720h22qhaieljaiudo6dmj7ma4s60u4@4ax.com...
and effort. That does not mean that logic is bad, it is absolutely
required. The problem is that many techs make assumptions that are poorly
founded. In fact, most people make such assumptions and end up with very
erroneous results using logic. Any good tech knows that he has to be wary
of the assumptions that he makes at every step along the way. When your
experience, based on a few episodes that could be attributed to other
causes, is vastly different than most others, you need to self-check.
I think my years of repair experience are as valid as yours and I never
called you names. I just refuse to make the assumptions you do and can see
no reason for unloading to cause a problem for most transistor amps that are
otherwise working normally. You have provided nothing but a few
circumstantial experiences to support your assertions and no logic at all.
Leonard
news:7on720h22qhaieljaiudo6dmj7ma4s60u4@4ax.com...
Logic, when based on faulty assumptions leads to a great deal of wasted time
and effort. That does not mean that logic is bad, it is absolutely
required. The problem is that many techs make assumptions that are poorly
founded. In fact, most people make such assumptions and end up with very
erroneous results using logic. Any good tech knows that he has to be wary
of the assumptions that he makes at every step along the way. When your
experience, based on a few episodes that could be attributed to other
causes, is vastly different than most others, you need to self-check.
I think my years of repair experience are as valid as yours and I never
called you names. I just refuse to make the assumptions you do and can see
no reason for unloading to cause a problem for most transistor amps that are
otherwise working normally. You have provided nothing but a few
circumstantial experiences to support your assertions and no logic at all.
Leonard
D
Daniel L. Belton
Guest
CJT wrote:
stuff at 1am anymore <g>
yea.. I thought about it after I wrote this... remind me not to write
stuff at 1am anymore <g>