No voltage across power out terminals and speaker playing

[[email protected]]

Hello!

I have a Marantz SR4600 receiver.I wanted to measure it's approximated
performance
with an excellent quality sound card and RightMark AudioAnalyzer.

I have a neccessary voltage divider for speaker-to-line levels
conversion.
My other amp, Technics SU-V4X works ok.No problems at all.

With Marantz, I have no voltage reported across speaker terminals
when measuring with a multimeter and playing a sine tone through
speaker.

Still the speaker is playing very loud.

To be assured, I also connected the receiver to pc's line in.
Here a signal is not sensed too, although I've fiddled with volume.
So, I doubt it is a multimeter's fault.

I don't have much experience with various exotic amp designs...
So possibly I'm missing something.

Maybe, this has something to do that (perhaps) Marantz used
switching mode discrete amps?

With sincere greetings,
Daniel K.

 

[John Fields]

Hello!

I have a Marantz SR4600 receiver.I wanted to measure it's approximated
performance
with an excellent quality sound card and RightMark AudioAnalyzer.

I have a neccessary voltage divider for speaker-to-line levels
conversion.
My other amp, Technics SU-V4X works ok.No problems at all.

With Marantz, I have no voltage reported across speaker terminals
when measuring with a multimeter and playing a sine tone through
speaker.

Still the speaker is playing very loud.

To be assured, I also connected the receiver to pc's line in.
Here a signal is not sensed too, although I've fiddled with volume.
So, I doubt it is a multimeter's fault.

I don't have much experience with various exotic amp designs...
So possibly I'm missing something.

Maybe, this has something to do that (perhaps) Marantz used
switching mode discrete amps?

 

[[email protected]]

It is on AC... I said I have measured Technics amp with no problem.
I only have problem with the receiver.

 

[Homer J Simpson]

It is on AC... I said I have measured Technics amp with no problem.
I only have problem with the receiver.

Measure across the active speaker terminals. Expect to see less than one
volt AC.

 

[[email protected]]

Homer J Simpson wrote:
Measure across the active speaker terminals. Expect to see less than one
volt AC.

I do it all the time.There is 0 ac volts across active speaker
terminals.

 

[Chris]

I do it all the time.There is 0 ac volts across active speaker
terminals.

You're saying that you have a speaker output with no voltage being
applied to the speaker. There's something wrong with your
measurements. Period. Can't have a speaker output without voltage.

Try measuring another voltage source with your DMM on AC volts, and see
if your meter is working. Try measuring another voltage source with
your sound card and voltage divider, and see if it's working, too.

Own the problem. Use your head.

Good luck
Chris

 

[[email protected]]

You're saying that you have a speaker output with no voltage being
applied to the speaker. There's something wrong with your
measurements. Period. Can't have a speaker output without voltage.

Try measuring another voltage source with your DMM on AC volts, and see
if your meter is working. Try measuring another voltage source with
your sound card and voltage divider, and see if it's working, too.

Own the problem. Use your head.

Good luck
Chris

The DMM is working.I've tested it again with a line out signal from cd
player.
And about your statement "You're saying that you have a speaker output
with no
voltage being applied..." I think we got misunderstood that time.
What I meant was, that I read 0 volts across active speaker terminals,
with DMM.
All the time.Even when there is sound in the speaker.
I always try to use my head first, before I post.
But this time, I got owned by physics.
This is very mysterious problem for me.

 

[Don Bowey]

The DMM is working.I've tested it again with a line out signal from cd
player.
And about your statement "You're saying that you have a speaker output
with no
voltage being applied..." I think we got misunderstood that time.
What I meant was, that I read 0 volts across active speaker terminals,
with DMM.
All the time.Even when there is sound in the speaker.
I always try to use my head first, before I post.
But this time, I got owned by physics.
This is very mysterious problem for me.

Pay attention to what Chris told you - You cannot measure zero Volts AC AND
have sound from the speaker. If your meter is ok, your test is faulty.

 

[Greg Neill]

[snip]

Pay attention to what Chris told you - You cannot measure zero Volts AC AND
have sound from the speaker. If your meter is ok, your test is faulty.

Or the meter is insensitive to audio frequencies.

 

[Lord Garth]

[snip]

Pay attention to what Chris told you - You cannot measure zero Volts AC AND
have sound from the speaker. If your meter is ok, your test is faulty.

Or the meter is insensitive to audio frequencies.

Or it's a crappy connection with the meter probes.

 

[[email protected]]

How can it all be, if I play *exact* same signal (calibration signal
from RightMark AA)
and on every device, but the Marantz, it all works! Should I assume my
receiver is damaged? (Irony warning)

 

[Lord Garth]

How can it all be, if I play *exact* same signal (calibration signal
from RightMark AA)
and on every device, but the Marantz, it all works! Should I assume my
receiver is damaged? (Irony warning)

Hook it to a scope and see for yourself. If you think there is 0 volts,
there should be no vertical
deflection.

 

[Roger Dewhurst]

How can it all be, if I play *exact* same signal (calibration signal
from RightMark AA)
and on every device, but the Marantz, it all works! Should I assume my
receiver is damaged? (Irony warning)

Disconnect the supply connections to the speaker, first one, then the other
and see what happens to the sound. Connect the meter across the amplifier
outputs without the speaker connected and see what happens. Connect up
everything and measure the voltage between each speaker input and ground.

R

 

[John Fields]

How can it all be, if I play *exact* same signal (calibration signal
from RightMark AA)
and on every device, but the Marantz, it all works! Should I assume my
receiver is damaged? (Irony warning)

---
Think about it for a minute. If you have sound coming out of the
speaker then you _must_ have current in its voice coil, and in order
to drive current through the voice coil there _must_ be a voltage
across it.

So either there's something you're not telling us, something you're
telling us which is wrong, something you're doing in your
measurement which is wrong, or you've just discovered a source of
perpetual motion.

Why not post a schematic of your test setup so we can see what's
_really_ going on?

 

[Jamie]

Hook it to a scope and see for yourself. If you think there is 0 volts,
there should be no vertical
deflection.

Most Likely he's using a DC volt meter, the Marantz being the most
likely device that is generating a perfect AC sine through out and
nulling it.
just a thought!

 

[John Fields]

---
So, by thinking that you had made an error, but hadn't, you were
wrong in thinking that and have made at least one error, no?

 

[Lord Garth]

Most Likely he's using a DC volt meter, the Marantz being the most
likely device that is generating a perfect AC sine through out and
nulling it.
just a thought!

Ahh! Of course, that makes the most sense. It never occurred to me that
one might
read the output with DC set on the meter.

 

[Lord Garth]

What was it that Kirk said....
oh yes, "Jackson Roy Kirk, your creator is dead! You have mistaken me for
him....
You have made an error! You are flawed and imperfect...You did not detect
your
mistake, YOU have made two errors...and you did not correct by
sterilization, you
have made three errors!"

"Execute your primary function"

(excerpt from 'The Changeling')

 

[Michael Black]

Hook it to a scope and see for yourself. If you think there is 0 volts,
there should be no vertical
deflection.

Of course, if it's a bridged output amplifier, then that will short out
part of the output stage.

I don't have a clue how common bridged output amplifiers are in home
stere amplifiers.

Michael

 

[Lord Garth]

"Lord Garth" ([email protected]) writes:
Of course, if it's a bridged output amplifier, then that will short out
part of the output stage.

I don't have a clue how common bridged output amplifiers are in home
stere amplifiers.

Object lesson, get an isolation transformer...