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Audio Systems/keeping 2 amps to one set speakers


QUESTION: I have a question, and don't know to whom I should pose it, so I'll take a =
chance and ask you.
For LPs/CDs, the 33s are driven by a tube preamp/amp combination. But most =
of the time, I run the audio from my TV into a solid state amp which drives=
Accustat Spectra 33s.
Would there be an harm in hooking both the preamp/amp and the solid state a=
mp to the 33s, but only power them when I am using either the LP/CD setup a=
nd turn off the solid state amp to the TV, and vice versa?
It is possible to purchase a device that I could switch the power sources, =
but since I am only going to have one power source driving the speakers at =
a time, that seems to be an unnecessary solution. Currently I disconnect th=
e speaker cables from the solid state amp to the TV, and then connect the c=
ables from the preamp/amp combo when I wan't to listen to music. Obviously =
an inconvenient solution, but don't want to take a chance on blowing fuses,=
etc. What do you think?

ANSWER: You must not, as a general rule, unless you know the science of the output circuitry of the electronics, connect two amplifier outputs to the same set of speakers whether the amps are active or not. (And it is not a fuse blowing that is the greatest possible trouble but damage to the power amplifier section.)

Yes, you would be better off either having individual speaker systems connected to each amplifier or use a speaker switch which allows the speakers to be connected to only one amplifier at a time.

You can buy speaker switches easily and they are not difficult to hook up.

If you have another question, don't hesitate to send me a followup.

Have a nice day.

---------- FOLLOW-UP ----------

QUESTION: Following the above good advice, I bought a Niles DPS-1 Amplifier-Speaker A-B Selector.

But my issue this time is different. Two years ago, Roy Esposito restored/updated a pair of Accoustat Spectra 33s for me, and I was very pleased with the results.

I have not used them much, but now that I am back into music, one of the speakers is not putting out sound.

I've tried changing inputs to the amp and switching the wires from the amp to the speaker, but the problem appears to be the speaker/interface. I tried to email Roy, but my email got kicked back as undeliverable.

Any suggestions you might have would be most helpful.

Thank you,


Ugh.  Bad problem.

First, you MUST determine conclusively if the problem is a bad speaker or not.  To test, if you have one speaker working then merely disconnect the good speaker and move the wires from the bad speaker and connect where the good speaker was.  If the dead speaker is still dead when connected to the good terminals you must determine what is going on with the dead speaker.

Second, assuming the dead speaker is bad (based on your testing) check the terminals at the connection points to make sure you are getting a good connection.  Sometimes you can easily break the binding post and the if the connector is wobbling it may be bad.  Also, check for a short across the terminals.

Lastly, you may have an open connection inside the speaker itself.  The update you mentioned could have left something with weakened or poorly soldered joint or something like that. Unless you are pretty skilled at electronics you better let an expert get inside the speaker to do the troubleshooting.

Hope this helps.  

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Audio Design Engineer; systems, loudspeakers, cd/dvd players, etc. I am knowledgeable in all high end audio equipment and installations. MAKE SURE YOU GIVE A MAKE AND MODEL NUMBER AND CAR IF IT IS AN AUTO QUESTION. Note: I am getting some who ask good questions that take a lot of time to research but then the questioner fails to read the answer. Please don't ask questions unless you are seriously looking for an answer. If you find an answer to your question otherwise then let me know with your reply. Thank you.


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