Hi all. I run this little Magnavox amp on my desk. Just recently, I started hearing different frequency sounds coming out of my speakers. The frequency is higher pitched at lower volumes and goes lower as I turn up the volume. Any ideas what going on?
I am sure that you have tried turning ALL electronic devices off so that there is the interference problem sectionalized. And as you know, it usually means lights too these days. Didn't you have a ham radio in the mix in your shop or was that someone else?
Not a HAM radio but a Collin’s R390 receiver I sat at all night long when I was a Radioman in the Navy. I didn’t think to disconnect everything but I’ll do that next time I’m in my office.
Does the amp work ok when it's not connected to the FX-Audio preamp?The frequency is higher pitched at lower volumes and goes lower as I turn up the volume. Any ideas what going on?
jeff
I'm still laughing. I knew that I smelled ham or something like it (ok, not like it per se, but you see where it led). I know, you got the cord pulled, right? My point is that maybe a certain combination of equipment in the room as mentioned in the above post or something changed in the last few hours/days that you might not know about or thought about. You know better than I do how much more vibrations are in the air these days. Back in the day, I would visit microwave sites to do installation of some new equipment, and I even wonder if it changed me. Something was happening in those sites.
I haven’t disconnected anything yet. I won’t be back at the office until Monday. I’ll do it then.Does the amp work ok when it's not connected to the FX-Audio preamp?
jeff
In Band, On Channel (IBOC) system used in North America to transmit better fidelityJust recently, I started hearing different frequency sounds coming out of my speakers.
while using existing AM & FM transmitters. Not used in Europe tho.
The side bands developed sometimes interfere with the main channel.
Look it up in Wiki 🙂
I don’t know if this matters in regards to IBOC, but I am running Qobuz from my computer to the amp.
No connexion there at all. Many commercial NA broadcasters have
an IBOC signal piggybacked on to their transmitter. Some older receivers
have a problem, especially if their IF BW does not reject the IBOC sidebands.
Not sure from your leadin comments, I thought you were using
a receiver of some kind as your program source. Maybe not? 🙂
an IBOC signal piggybacked on to their transmitter. Some older receivers
have a problem, especially if their IF BW does not reject the IBOC sidebands.
Not sure from your leadin comments, I thought you were using
a receiver of some kind as your program source. Maybe not? 🙂
No, when I disconnected it from all inputs. I have the same issue. But I want to say, it sounds so much more dynamic with the FX pre. Great investment!Does the amp work ok when it's not connected to the FX-Audio preamp?
jeff
Thanks J. No radio, just digital from computer to DAC to preamp to amp to speakers.No connexion there at all. Many commercial NA broadcasters have
an IBOC signal piggybacked on to their transmitter. Some older receivers
have a problem, especially if their IF BW does not reject the IBOC sidebands.
Not sure from your leadin comments, I thought you were using
a receiver of some kind as your program source. Maybe not? 🙂
I’ll look at them today. Thanks for the tip.View attachment 1466346
Cute looking amplifier, underside of a similar model that's had some work done. those four brown capacitors have been changed make sure the one's in yours are changed to polypropylene
You certainly don't want old electrolytic capacitors in those Four positions. It would help if you post a picture of the inside when you have time and I'm sure others will help you to get back up and running very soon.
Disconnect the computer wire to the dac or the dac.
Maybe your neighbors installed solar panels , maybe someone bought an electric car and charges it.
A few months ago my electricity became very dirty and I had no choice to place isolating transformers, DC stoppers, and EMI filters everywhere for feeding equipment with real transformers.
If you place an incandescent bulb near the electrical panel you can hear it buzzing with the dirty electricity!
Maybe your neighbors installed solar panels , maybe someone bought an electric car and charges it.
A few months ago my electricity became very dirty and I had no choice to place isolating transformers, DC stoppers, and EMI filters everywhere for feeding equipment with real transformers.
If you place an incandescent bulb near the electrical panel you can hear it buzzing with the dirty electricity!
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