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Discussion Starter #1
Hi
Recently bought the Amphony 1800 wireless kit. It consists of a single transmitter with 2 receivers over 2.4 ghz. Transmitter input can be either from receiver speaker outputs or line level RCA. I'm using the RCA inputs. Output level is set at 50% as are the receiver volumes. They were then calibrated using YPAO on my RX-A3080 as surround back speakers. The speakers are Elac Debut 2.0 bookshelfs.

Here are the problems:
Units have no standby mode or power off. If I manually turn them off there is a loud pop which could damage my speakers. Design flaw?
There is a lot of noise. With every piece of electronics powered off including my router, they still have line noise and buzz. Closest thing is a tube guitar amp with the cable plugged in but not the guitar.

Any thoughts of what I can do? Experimented with basic Ferrite Chokes but I have no idea of what rating to use. Re-purposed them off old audio cables. What about PA noise gates? Have no access to the schematics but I'm sure nothing is shielded in these units. Their tech support hasn't been much help.

Thanks for any help.
 

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Have you tried a Ground Loop Isolator? I have had luck with them in the past, not brand specific.


 
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Discussion Starter #3
Been researching them tonight. Looks it would be in line between the AV receiver line out and the transmitter. Is the noise at the wireless receiver end or the transmitter? Just wondering because there is no way to connect it between the wireless receiver and the speaker. Isolators seem to only be line level and not for amped outputs. How have you configured yours? Thanks JetRanger.
 

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When I used one, it was in a vehicle. I used to install car stereos back in the day and never had any trouble until one day when I was putting one in my own car. There was a hum I couldn't get rid of no matter what I did or tried between the head unit and main amp. Then a friend suggested an isolator and voila, problem solved.

In your case, the wireless component opens the system to all manner of interference but, if there happens to be an imbalance on your source side, this might just solve it. They don't cost much so you won't be hurting too much if it doesn't happen to work for your problem.

Thinking about it a bit more after re-reading your post; is the buzz still there if you unplug the transmitter? If yes then your problem is definitely in the receiver(s). Have you tried plugging the receivers into a different power outlet? Maybe try an extension cord if there isn't one close enough?
 

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Another though might be a lamp with either a fluorescent bulb or maybe one on a dimmer circuit? Just spitballing here.
 

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Discussion Starter #6
Tested and yes it's the transmitter side. Just ordered a GLI. We'll see what happens. Thanks again.
 

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This device appears to be using bluetooth or wifi so it is highly unlikely that the receiver is picking up wireless hum. I wouldn't rule out noise from the audio source. The hum could because the RCA cable is defective or has a bad ground contact. Another thing to check is the audio output level of the connected source device on the transmitter end. If it's line level, then the volume should typically be fixed at full volume. If it's an amplified output, that could be the issue as sound levels can be quite low for speaker outputs and noise levels can be relatively high. The other thing I would do is set the transmitter level to maximum. Low levels at the audio source or transmitter end would lead to overly high settings at the receiving end and over-amplification of any noise in the source audio. If possible, I would use an optical audio cable instead of RCA.

Another possible source of hum are power adapters. That's especially true if they are transformer models. 60Hz hum could be due to poor filtering in the adapter or the device. Switching power supplies are unlikely to create 60Hz hum. Small 'wall wart' power adapters are unlikely to cause ground loop issues as they typically have ground loop isolation built in.
 

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The speaker wires coming from your stereo sound source into the amphony transmitters might be picking up noise when the stereo source is off, after all the speaker wires are not shielded so they could act as an antenna.

you could try disconnecting the speaker wires from the transmitter and leave the speakers on and see if the noise is gone or reduced. Also the stereo system itself could be inducing some noise onto the speaker wires when its off depending on how well its built, give this a try too.

Yeah the fact that theyre always on and transmiitting even when the stereo is off, does bother me. it means theyre acting as an amplifier always connected and turned on with nothing plugged in.
 

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That amp has an OK but not very good SNR of 91dB as well. While that shouldn't be a big issue it might be audible if the gain is turned up very high. Again, that could be a result of low input levels caused by low volume settings on the components feeding it. The cure could be to turn levels up on those units and down on the amp.
 

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Discussion Starter #10
Installed the Ground Loop Isolator last night. Actually made the noise worse so I took it out. Very frustrating. The noise is like having a fly or mosquito constantly buzzing your ears. So I took out the RCA line level cable and used the speaker connections from the receiver. It seems quieter. I'll see after I rerun the YPAO. Should I be concerned that running the speaker outs into the transmitter will cause the receiver to work harder and run hotter? It bothers me that these run 24/7 and have no power off or standby modes. Pretty sure it will reduce the product lifespan.

Anybody have any ideas? Thanks for any help.
 

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Discussion Starter #12
Re-ran YPAO a few times with transmitter at 50% and receivers at full volume. Noise is still there. Have emailed their support wanting a resolution as it’s now been a month. Have asked for another transmitter and power supply. Any ideas on how to power off the receivers without popping the speakers?
 

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Discussion Starter #14
Yes and it made the noise worse which seemed to further verify the transmitter as the problem. I'll see what happens with their support. Problem is I need a 1 transmitter 2 receiver compliment as I can't run wires from a single receiver to separate speakers. Few options out there as most have 1 transmitter and 1 receiver.
 

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Analog RCA audio can be split so two transmitters and 2 receivers may be an option provided they can simultaneously operate without interference.
 
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