You can use a toothpick to clean out the jacks. I would do that before doing any signal testing.
Hum and no audio
- Thread starter ryburdman
- Start date
OK, post the make and model of your meter and I can give you some follow up instructions.
-PB
-PB
OK, find a device (phone/tablet) with a headphone jack and download either a signal generator app or a 60Hz tone. With an 1/8" TRS to RCA cable, you should be able to measure the AC voltage coming out of the RCA jacks and turn the device all the way down, then up one step on the volume control. Let us know what AC voltage this is.
Plug the RCA cables into your Reduction with the Reduction off an measure the AC voltage across each RCA jack and let us know what it is.
The Fluke 115 has a mV range and it looks like it will default to AC mV, which is what you want. I would expect your phone to put out maybe 300mV at max volume and somewhere between 5 and 10mV one step above mute.
Plug the RCA cables into your Reduction with the Reduction off an measure the AC voltage across each RCA jack and let us know what it is.
The Fluke 115 has a mV range and it looks like it will default to AC mV, which is what you want. I would expect your phone to put out maybe 300mV at max volume and somewhere between 5 and 10mV one step above mute.
Plug the TRS to RCA into your device, download a signal generator app and play a 60Hz tone. Put your black meter probe on the shell of one RCA plug and the red probe on the center of one RCA plug, set your meter to AC millivolts, then adjust the volume all the way down on your device, then up one click. Let us know what that AC voltage is that you see.
You're not quite following what I'm asking you to do.
1. Put the Reduction in another room, close the door, leave it alone for now.
2. Plug the 1/8" TRS to RCA cable into your phone/tablet/whatever.
3. Download a signal generator app.
4. Play a 60Hz tone though it.
5. Turn the volume all the way down, then up one click.
6. Now measure the AC voltage across each RCA plug at the end of your TRS cable.
The minimum AC voltage that can come from most devices will be a lot lower than 50mV. Be aware that your meter has a different setting for AC millivolts that will give you more stable readings.
1. Put the Reduction in another room, close the door, leave it alone for now.
2. Plug the 1/8" TRS to RCA cable into your phone/tablet/whatever.
3. Download a signal generator app.
4. Play a 60Hz tone though it.
5. Turn the volume all the way down, then up one click.
6. Now measure the AC voltage across each RCA plug at the end of your TRS cable.
The minimum AC voltage that can come from most devices will be a lot lower than 50mV. Be aware that your meter has a different setting for AC millivolts that will give you more stable readings.
Perfect, now grab your Reduction and plug those RCA cables into the inputs. You don't need to apply power to the Reduction, just the RCA cables.
Now read the AC voltage across the input jacks.
Now read the AC voltage across the input jacks.
OK, that tells you that the input jacks aren't clogged with debris.
Power the Reduction up and play that tone into the inputs. You can just anchor your black meter probe to the grounding screw if that's easy for you, then measure the AC voltage at:
6
10
19
23
Power the Reduction up and play that tone into the inputs. You can just anchor your black meter probe to the grounding screw if that's easy for you, then measure the AC voltage at:
6
10
19
23
6 really can't be 0V if 10 is 2.5. You're also missing units, is that 2.5V or 2.5mV?ryburdman said:
Ditto here, 10V? 10mV? What AC voltage do you see at terminal 27?ryburdman said:
You have a loose connection, that causes the LED to blink.ryburdman said:
No, you have a loose connection making the LED flash. There isn't anything about what the meter is up to that will cause that.
Ok if that's the case, when I measure with the meter in ac mv heres where leds blink
2- led to 3
7- both leds
13-led to 3
14 led to 3
15 both
---------
18 both
19 led to 9
20 led to 9
26 both
29 9
31 9
Sorry this is taking so much of you time and such a pain, I really appreciate the help.
2- led to 3
7- both leds
13-led to 3
14 led to 3
15 both
---------
18 both
19 led to 9
20 led to 9
26 both
29 9
31 9
Sorry this is taking so much of you time and such a pain, I really appreciate the help.
