Dual power supply amp

 

Gold Member
Username: Hittin1

TEAM REVOLUTION, La. Lake Charles...

Post Number: 4433
Registered: May-07
What problems could you run into if one of the grounds had came off of one of the power supplies to an amp? How would it effect the out of the amp? Thanks
 

Gold Member
Username: Hittin1

TEAM REVOLUTION, La. Lake Charles...

Post Number: 4435
Registered: May-07
Output*^^ of the amp?
 

Platinum Member
Username: Glasswolf

Lexington, SC USA

Post Number: 13437
Registered: Dec-03
no ground = no circuit = infinite resistance = no current = no voltage.
 

Gold Member
Username: Hittin1

TEAM REVOLUTION, La. Lake Charles...

Post Number: 4441
Registered: May-07
My amp is the RD5750. It has 2 pos and 2 neg. If one of the Neg power wire came loose, How whould that effect the output of the mono amp? I understand that one of the power supplys could not have been operating normally, but does that mean that I have been getting 1/2 of the power to my subs?
 

Platinum Member
Username: Glasswolf

Lexington, SC USA

Post Number: 13441
Registered: Dec-03
You most likely, without having seen the inside of that particular amp before, have two lines that go to the same power supply. This is to carry larger amounts of current without needing one larger cable. You would be getting more voltage drop and more heat build up over the one line as the overall current capacity would be reduced with only one ground.

The end result is that the amplifier would clip sooner as it would be starved for adequate current flow to drive the sub(s) at high output or volume levels.
 

Gold Member
Username: Hittin1

TEAM REVOLUTION, La. Lake Charles...

Post Number: 4442
Registered: May-07
This could possibly explain the 151.00 on the TL.. Since discovering the problem, I t "seems" to pressure up better, but that could be in my head... With setups this loud, I guess that it would be almost impossible to tell the difference in a db or so...
Now, seems to me that with more current flow allowed I would get a slight increase in voltage drop with the grounds properly attached. which seems to be the case with my setup.. More current allowed to be used= increase of voltage drop, right?
If not, then how would the addition of current flow capabilities not put a slight increase of voltage drop?
 

Gold Member
Username: Hittin1

TEAM REVOLUTION, La. Lake Charles...

Post Number: 4443
Registered: May-07
Upload

This is what we are dealing with as far as ampguts on the powersupply side. This is not the exact amp, but close... My heatsink actually says atomic AT-5000D.
 

Platinum Member
Username: Glasswolf

Lexington, SC USA

Post Number: 13446
Registered: Dec-03
the only reason that the improved current flow would cause a voltage drop would be if your electrical system isn't up to par for the demands of the audio system. The result of such a scenario would be that the amp is able to draw more current, but since the alternator is already maxed out, then the inability to supply more current would result in further sagging voltage rails. You'd probably gain a bit in SPL if the charging system could match the demands of the amplifiers, too. May not be by much, but it would improve.

I'm only seeing one end of where the ground lines go, but the way they are banded together does lead be to think they are just parallel grounds to allow sufficient curernt flow instead of using one, larger line instead.
 

Gold Member
Username: Hittin1

TEAM REVOLUTION, La. Lake Charles...

Post Number: 4444
Registered: May-07
batts- 6 c+d technology 134 AH UPS AGM connected with bussbars
1 Redd top under hood isolated..
6 runs 0ga. (3-pos-3-Neg)
260 amp DC Power alt (200 amp idle)

we are talking a couple tenths of a volt at the time I was looking at it, but there were other factors that could have hendered my readings at that time as well, so I'll check it out and see how the drop look at different times. I'm not getting below 14.0 at all with the exception on some long sustained high freq notes.. and even then its ~13.8V at its lowest.
 

Platinum Member
Username: Glasswolf

Lexington, SC USA

Post Number: 13448
Registered: Dec-03
then your voltage rails are fine. When you don't have a large enough wire to carry the required current in a circuit, you see voltage drop across the wire itself between the two ends. That what would happen with one of your two ground lines came loose, if and only if you had the amplifier turned up loud enough for it's power supply to draw current in excess of what the single ground wire could carry, for the period of time it had to sustain that increased current flow. (wire length, wire gauge, current flow are the three main factors to contend with here, really.)

At lower volumes, typically those used for sustained in-car listening levels, you probably didn't see that sort of current draw I'd guess. If you were burping at an SPL event, that's another matter.
« Previous Thread Next Thread »



Main Forums

Today's Posts

Forum Help

Follow Us