help with A/B amps working verse D amps not working.

[garychoffmann 10+ year member]

Oddest thing I've ever come across. Is there a certain parameter that will cause a class D not to work while A/B's will. It seems every class D I put in my truck it will not work. Are they more susceptible to electrical noise that could throw them into protect. I have checked everything and all seems good. Any input would be greatly appreciated. Thanks

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[los33]

Where are you grounding and what vehicle is it?

 

[Spl4200]

Make sure all ur connections are solid (grounds and positives)(then double check) when you say ithe class d won't work do you mean not at all? Possibly something with the amp itself?

 

[garychoffmann 10+ year member]

2010 ram quad cab. I have a ground to chassis on floor board, that ground is the linked to the frame. From there I have a a ground running from that spot on the frame to the front frame which ties into a ground on the battery ground. Those are all ring terminal grounds. Sanded, bolted and painted. Ground shouldn't be a problem. But maybe over grounded lol

 

[garychoffmann 10+ year member]

Make sure all ur connections are solid (grounds and positives)(then double check) when you say ithe class d won't work do you mean not at all? Possibly something with the amp itself?

Here are my amps I have tested in my truck:

Soundstream tra560.2 works

Dd c4a works

Diamond d3 300.4 works

Diamond d6 300.4 300.4

Skar 80.4ab works

Ppi pc 2300 works

Ppi a 40 works

Directed 1100d5 4 channel side works, d side does not (5 channel)

Directed 600d protect

Ab 100.1 protect

Dd cm1000 protect

Alpine pdx f6 protect

Db drive a5 90.4 protect

Rockford 1001bd hums sporadic output till protect.

 

[garychoffmann 10+ year member]

Power is 2 runs of 0 gauge, both fused at 100 amps. Remote is 10 gauge off a bosch relay

 

[Jepalan]

So, in every case the A/B amps are driving your cabin speakers and the D amps are driving your sub(s) ?

I don't think this is an A/B versus D issue. It sounds like an issue with your sub, or gain settings, or sub wiring?

 

[garychoffmann 10+ year member]

No subs hooked up at the moment. Just using a sub to test output. Goes into protect without a sub hooked up. Have tried all 3 sets of rca's. All the same. I just ordered a cz702 to rule out the head unit (alpine 149bt) already swapped out rca's. If no subs are connected and no rca's it will stay powered on. Hook up rca's and it goes into protect. I need to try another source but my rca's seem good. I can run an a/B amp to my subs without an issue but I'd rather figure this out.

 

[garychoffmann 10+ year member]

Oh yeah, a/B amp drives the sub just fine.

 

[gckless 5,000+ posts]

Your issue is not with amp topology.

 

[los33]

No subs hooked up at the moment. Just using a sub to test output. Goes into protect without a sub hooked up. Have tried all 3 sets of rca's. All the same. I just ordered a cz702 to rule out the head unit (alpine 149bt) already swapped out rca's. If no subs are connected and no rca's it will stay powered on. Hook up rca's and it goes into protect. I need to try another source but my rca's seem good. I can run an a/B amp to my subs without an issue but I'd rather figure this out.

If you are running two runs of 0 gauge have you tried just one as you may have bad wire or there is an issue with ground once the amp is trying to receive signal and get more power.

 

[garychoffmann 10+ year member]

Yes, not saying the topology, curious if the class d is more susceptible to electrical "noise" or dirty power vs an AB. Any idea what to look into? The only thing I haven't changed is the power in the vehicle. Everything else has been tried another way.

 

[garychoffmann 10+ year member]

Yes, they are separate runs. I've swapped amps back and fourth multiple times. All amps have been tested in my rav 4 to be working. Unhooked one power from the battery. Un did each ground point starting at the battery and backing all the way up to the chassis.

 

[trumpet 5,000+ posts]

If you are running two runs of 0 gauge have you tried just one as you may have bad wire or there is an issue with ground once the amp is trying to receive signal and get more power.

The amps are going into protection as soon as RCAs are connected. This would not indicate a problem with current delivery.

 

[garychoffmann 10+ year member]

It really is baffling to me that this problem has popped up. I can't figure out why the ab amps play while the d's don't. It is the oddest problem I have come across. Going to try and swap out my relay tonight so we will see. That's about the only thing I can think of left to try except the head unit itself. But if the head unit is faulty why do the a/b amps work and not go into protect....