I have 2 digital designs amps hooked up in my truck .
1 of the amps is hooked up to the midrange speakers and the other map is hooked up to the tweeters .
When the amps are hooked up in the truck the amps do not work they don’t power up I checked the voltage at the amps terminals and I get 5 volts .
If I unhook the amps and I test the power and ground wires I get 14.4 volts .
I pulled the amps out of the truck and bench tested them and they work perfectly fine .
I went back and tested the battery and ground wire measuring the voltage on the power wire with the black probe to the ground wire and it reads 14.4 volts . If I hook the amps back up I get 5 volts on the power wire .
Any ideas what might cause this ?
1 of the amps is hooked up to the midrange speakers and the other map is hooked up to the tweeters .
When the amps are hooked up in the truck the amps do not work they don’t power up I checked the voltage at the amps terminals and I get 5 volts .
If I unhook the amps and I test the power and ground wires I get 14.4 volts .
I pulled the amps out of the truck and bench tested them and they work perfectly fine .
I went back and tested the battery and ground wire measuring the voltage on the power wire with the black probe to the ground wire and it reads 14.4 volts . If I hook the amps back up I get 5 volts on the power wire .
Any ideas what might cause this ?
You have a resistive connection somewhere. It could be virtually any point where a connection is made, or even a fuse or fuse holder. Measure the DC voltage on each side of every connection (amps in the circuit) to find the fault.
Are you using agu fuses? If so then change them even though they look fine, otherwise inspect the power and ground from end to end.
I have a 100x4 and a 75x4 amp what size power wire should I use from front battery to the back of the truck for these 2 amps ?
What's the actual current draw from the two amps?
What's the acceptable voltage drop along the length of the wire? 0.5v?
What's the acceptable voltage drop along the length of the wire? 0.5v?
Well I found the issue with the voltage my ground wire came disconnected. I had it screwed to the frame of the truck with a self tapping screw and the screw fell out and the ground wire is just hanging there .
I will have to find a better way or bolting it to the frame
I will have to find a better way or bolting it to the frame
You might try using a 3/8" bolt and nut on a place where the metal is sanded to bare metal on both sides so both sides conduct well to the bolt/nut.
Have you upgraded the body to battery and the body to engine cables?
Have you upgraded the body to battery and the body to engine cables?
Re did the ground and installed the amps adjusted the gains and everything works .
I noticed an issue with 1 of the amps .
The amp is Digital Designs 4.75 .
This is a 4 channel amp .
I’m only running 2 of the channels right now to some tweeters .
If I plug in the rca cables to channels 1 and 2 I get audio but a loud hissing noise along with audio and sounds distorted. If I plug in the 2nd set of rca cables to channels 3 and 4 so I have 2 sets of rcas going to the amp supply signal to all 4 channels the hissing goes away and it plays clean audio .
Any ideas ?
I noticed an issue with 1 of the amps .
The amp is Digital Designs 4.75 .
This is a 4 channel amp .
I’m only running 2 of the channels right now to some tweeters .
If I plug in the rca cables to channels 1 and 2 I get audio but a loud hissing noise along with audio and sounds distorted. If I plug in the 2nd set of rca cables to channels 3 and 4 so I have 2 sets of rcas going to the amp supply signal to all 4 channels the hissing goes away and it plays clean audio .
Any ideas ?
Post a photo of the board in the amp.
The amp may be oscillating or it could be like some of the older Rockford amps that had grounding issues for 2 channels in 4-channel amps. Have you looked at the output when the amp had the noise/distortion?
The amp may be oscillating or it could be like some of the older Rockford amps that had grounding issues for 2 channels in 4-channel amps. Have you looked at the output when the amp had the noise/distortion?
I’m just gonna take them back out of the truck and send them back to DD since both amps have issues and they are covered under warranty
I sent the amps that were having issues in the vehicle back to DD they said they couldn’t find any issues with the amps and cannot get them to make the hissing noise when testing . They will play perfectly fine on a bench but when installed in the vehicle that’s when they act up .
could the issue still be the amps or should I be looking elsewhere in the system?
I already took the headunit out to check the rca ground shields are they are intact
could the issue still be the amps or should I be looking elsewhere in the system?
I already took the headunit out to check the rca ground shields are they are intact
Why don't you plug all 4 RCA connectors in and simply not use 2 channels?
Can you use the channels that stop the hissing (when plugged in) instead of the other 2 channels?
Can you use the channels that stop the hissing (when plugged in) instead of the other 2 channels?
I can use all 4 channels with all 4 rcas plugged in . The only reason I sent them into DD audio is becomes the amps were brand new and I had hissing and engine noise like crazy through the speakers .
since these are new amps I don’t think they should act this way in the vehicle so I sent them in to see if they could find any issues with them I didn’t wanna open them myself and void the warranty
since these are new amps I don’t think they should act this way in the vehicle so I sent them in to see if they could find any issues with them I didn’t wanna open them myself and void the warranty
This is a problem on other amplifiers as well. I think it's partly due to the noise cancelling circuit that tries to deal with two different grounds for front and rear. They may expect two of the channels to be the most likely to be used and are the reference ground. When those two channel alone are used, there is no problem but when the other 2 channels are used alone, you could have a noise problem.
You have interference somewhere in your wiring. I'm not sure who DD uses for these smaller amps but they are extremely touchy. Make sure power wire is away from the RCAs. Your mention of truck, twice I've had DD amps in silverados that were noisy. 1 was the ground was not sufficient and I need to ask the owner of the second one which I'll send a message to that i figured out why. I know his regulator went out in the alternator but I don't recall if that was the issue.