Troubleshooting DMM not reading voltage

[mylows10 5,000+ posts]

really couldnt tell you now.sounds like you are doing everything right ,only thing i can think of is either the deck not set right ,rca bad or amp

 

[sjv13 10+ year member]

really couldnt tell you now.sounds like you are doing everything right ,only thing i can think of is either the deck not set right ,rca bad or amp

man, that *****. It's really near impossible to hear sub distortion isnt it? I could just try to set it by ear.

 

[mylows10 5,000+ posts]

its hard really unless you are clipping really bad .just set the volume to your highest listening level and turn the gain up til start to clip then back it down

 

[sjv13 10+ year member]

its hard really unless you are clipping really bad .just set the volume to your highest listening level and turn the gain up til start to clip then back it down

Should I do that with the 60hz sine wave? Or just a really bassy song? What will the clipping sound like?

 

[vaiboy 10+ year member]

Sounds like you have a problem with your DMM, do you have the red probe plugged in to the fused side of the DMM?

 

[maylar 10+ year member]

Sounds like you have a problem with your DMM, do you have the red probe plugged in to the fused side of the DMM?

I'm wondering that too. OP's pic doesn't show what input jacks the probes are connected to. Also, that DMM gets lousy reviews on Radio Shack's site.

OP, there's a fuse in that meter. Check it. Also verify that the thing works by putting it on DC volts and measuring a battery.

 

[sjv13 10+ year member]

Sounds like you have a problem with your DMM, do you have the red probe plugged in to the fused side of the DMM?

I'm wondering that too. OP's pic doesn't show what input jacks the probes are connected to. Also, that DMM gets lousy reviews on Radio Shack's site.

OP, there's a fuse in that meter. Check it. Also verify that the thing works by putting it on DC volts and measuring a battery.

Yeah, the positive is on the fused side. And I looked it up and saw those reviews too. I just found it out in the garage, so my dad must have bought it a while ago.

How do I check the fuse?

 

[vaiboy 10+ year member]

Yeah, the positive is on the fused side. And I looked it up and saw those reviews too. I just found it out in the garage, so my dad must have bought it a while ago.
How do I check the fuse?

You will have to take the meter apart, there is probably a spare fuse inside, unless this isn't the first blown fuse.

 

[Kingstroker 10+ year member]

does the volume on the phone have any effect on the reading?

 

[LBC]

does the volume on the phone have any effect on the reading?

yes that's why you can't use that phone. you need to use something else. iphones, ipods, or any external player is garbage for setting your gain. you need a disc, or thumb drive, or something with no volume/gain control of it's own.

 

[mat3833 10+ year member]

the volume on the phone should have an effect. "generally" the second highest volume level is close to 0db gain on newer phones, but my current phone doesnt even break -10db gain... i actually have an old samsung phone set up just to play test tones. i went into the phones settings and set the gains for all 7 volume levels to diferent DB levels. "1" is -6 "2" is -3 "3" is 0, etc. works out quite well since i can just plug in the phone and i have tones from 20hz to 160 hz and sweeps ranging from 180hz down to 15hz to 80hz down to 30hz. the wife hates it when i do a tone sweep on the home theater. lol

Matt

 

[sjv13 10+ year member]

does the volume on the phone have any effect on the reading?

yes that's why you can't use that phone. you need to use something else. iphones, ipods, or any external player is garbage for setting your gain. you need a disc, or thumb drive, or something with no volume/gain control of it's own.

the volume on the phone should have an effect. "generally" the second highest volume level is close to 0db gain on newer phones, but my current phone doesnt even break -10db gain... i actually have an old samsung phone set up just to play test tones. i went into the phones settings and set the gains for all 7 volume levels to diferent DB levels. "1" is -6 "2" is -3 "3" is 0, etc. works out quite well since i can just plug in the phone and i have tones from 20hz to 160 hz and sweeps ranging from 180hz down to 15hz to 80hz down to 30hz. the wife hates it when i do a tone sweep on the home theater. lol
Matt

Guys, when I use my phone I connect it through the USB input. It's an iPhone so the HU sees it like an iPod. There is never volume control on the phone when you use the USB interface with any product. The iPhone should only be sending the digital signal through the USB cable (same as a flash drive would I think). I also tried using the flash drive, as you would all see if you read the other posts, and it made no difference.

My guess right now is that the DMM is faulty. If the fuse was blown I don't think it would have any reading.

 

[mat3833 10+ year member]

try connecting it through the headphone jack and see if you can get a reading. cant hurt.

Matt

 

[sjv13 10+ year member]

try connecting it through the headphone jack and see if you can get a reading. cant hurt.
Matt

Yeah, I'll try that later. If my theory about the DMM being faulty is correct, then it shouldn't make a difference. It's a pain unhooking, inserting leads, changing all the settings, and then undoing it all after the test. I've done it like 5 times already.

For now, I just have the gain at half and use my bass remote to adjust it to a sane level.

 

[LBC]

Guys, when I use my phone I connect it through the USB input. It's an iPhone so the HU sees it like an iPod. There is never volume control on the phone when you use the USB interface with any product. The iPhone should only be sending the digital signal through the USB cable (same as a flash drive would I think). I also tried using the flash drive, as you would all see if you read the other posts, and it made no difference.
My guess right now is that the DMM is faulty. If the fuse was blown I don't think it would have any reading.

Ipods and iphones transcode on the fly adjusting for their own gain. This is why you can play flac even when cd players don't support flac. So no, it doesn't just open a data connection and stream files to the cd player. It has it's own gain adjustment that it makes during the transcode. Don't give snotty replies like "if you had read". You're the one doing something wrong. Humbly take advice of the people trying to help you.