Effects of running av recvr with speakers missing

[jakdedert]

"Steve(JazzHunter)" <jazzhunterNotHere@internet.com> wrote in message
news:uko720dfk33kbrje4d6j06i304ibok0sjd@4ax.com...

On Fri, 06 Feb 2004 18:03:31 GMT, Alan Peterman
alnospam@nospamscn.rain.com> wrote:

On Fri, 06 Feb 2004 08:49:29 -0500, "Steve(JazzHunter)"
jazzhunterNotHere@internet.com> wrote:

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.

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.

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 .

Tube gear of course did need a load.

Back in the 70's I built a demo switching unit for a small stereo store.

Using push buttons, one could select any of 12 receivers into a similar
number of speaker pairs. Sometimes we'd have the entire dozen units powered
up for the entire day so that we could switch any unit in to demo mode with
no delay. We switched at will, back and forth between amps, receivers and
speakers...never had any of them fail due to being unloaded..or for any
other reason. The car stereo demo unit I built was similar, with similar
results.

jak

 

[Sofie]

jakdedert:
How interesting....... one of my first electronics jobs as an A/V repair
tech in the very early 70's (1971) was to build a couple of 10x 1 switching
arrangements for an independent stereo store switching any combination of
receivers/amps with any combination of speakers and any combination of tape
decks. (no CD players back then) ....... never once did we have a blown
receiver or amp because of a "no- load" condition..... and most of the time
they were left on at a fairly loud volume as the speakers and amps were
"hot-switched"...... and there were no provisions for dummy loads to the
amps that weren't connected to speakers..... usually only one amp was
listened to at a time so that means that 9 amps were running unloaded.
Gosh, I didn't know that I was building things that are considered "just
plain bad practice"........ I guess I just lucked out.
--
Best Regards,
Daniel Sofie
Electronics Supply & Repair
----------------------


"jakdedert" <jdedert@bellsouth.net> wrote in message
news:2YfVb.16991$8a5.9741@bignews1.bellsouth.net...

Back in the 70's I built a demo switching unit for a small stereo store.
Using push buttons, one could select any of 12 receivers into a similar
number of speaker pairs. Sometimes we'd have the entire dozen units
powered
up for the entire day so that we could switch any unit in to demo mode
with
no delay. We switched at will, back and forth between amps, receivers and
speakers...never had any of them fail due to being unloaded..or for any
other reason. The car stereo demo unit I built was similar, with similar
results.

jak

 

[jakdedert]

Obviously we both did. Whew! Glad to have dodged 'that' bullet!
Think...if every amp in the store had gone up in smoke in front of a
customer....

jak

"Sofie" <sofie@olypen.com> wrote in message
news:102bk353hlbra17@corp.supernews.com...

jakdedert:
How interesting....... one of my first electronics jobs as an A/V repair
tech in the very early 70's (1971) was to build a couple of 10x 1
switching
arrangements for an independent stereo store switching any combination of
receivers/amps with any combination of speakers and any combination of
tape
decks. (no CD players back then) ....... never once did we have a blown
receiver or amp because of a "no- load" condition..... and most of the
time
they were left on at a fairly loud volume as the speakers and amps were
"hot-switched"...... and there were no provisions for dummy loads to the
amps that weren't connected to speakers..... usually only one amp was
listened to at a time so that means that 9 amps were running unloaded.
Gosh, I didn't know that I was building things that are considered "just
plain bad practice"........ I guess I just lucked out.
--
Best Regards,
Daniel Sofie
Electronics Supply & Repair
----------------------


"jakdedert" <jdedert@bellsouth.net> wrote in message
news:2YfVb.16991$8a5.9741@bignews1.bellsouth.net...

Back in the 70's I built a demo switching unit for a small stereo store.
Using push buttons, one could select any of 12 receivers into a similar
number of speaker pairs. Sometimes we'd have the entire dozen units
powered
up for the entire day so that we could switch any unit in to demo mode
with
no delay. We switched at will, back and forth between amps, receivers
and
speakers...never had any of them fail due to being unloaded..or for any
other reason. The car stereo demo unit I built was similar, with
similar
results.

jak

 

[JW]

On Sat, 7 Feb 2004 21:57:20 -0800 "Sofie" <sofie@olypen.com> wrote in
Message id: <102bk353hlbra17@corp.supernews.com>:

jakdedert:
How interesting....... one of my first electronics jobs as an A/V repair
tech in the very early 70's (1971) was to build a couple of 10x 1 switching
arrangements for an independent stereo store switching any combination of
receivers/amps with any combination of speakers and any combination of tape
decks. (no CD players back then) .......

Spooky x 3 - I worked as a tech for a company that made those car stereo
demo displays as well, in the 80's, however. Spectro Logic was the
companies name.

 

[Sofie]

...... and guess what.... when a set of speakers were "hot switched" between
car stereos, the only amp that had any kind of a load was the one with the
speakers switched in..... all the others ran at the volume level that they
were left on (probably high) .... with no load. ..... and no damage..... NO
PROBLEM.
I think that this posting among the last few pretty well makes the point
that solid state amps will NOT be damaged without a speaker load or without
any load what so ever.
--
Best Regards,
Daniel Sofie
Electronics Supply & Repair
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -


"JW" <none@dev.nul> wrote in message
news:fkji20dnv0d5i83bt79gd05hn6qtt897ps@4ax.com...

On Sat, 7 Feb 2004 21:57:20 -0800 "Sofie" <sofie@olypen.com> wrote in
Message id: <102bk353hlbra17@corp.supernews.com>:

jakdedert:
How interesting....... one of my first electronics jobs as an A/V repair
tech in the very early 70's (1971) was to build a couple of 10x 1
switching
arrangements for an independent stereo store switching any combination of
receivers/amps with any combination of speakers and any combination of
tape
decks. (no CD players back then) .......

Spooky x 3 - I worked as a tech for a company that made those car stereo
demo displays as well, in the 80's, however. Spectro Logic was the
companies name.