Do your lights dim when your amp powers up?

YouTuber XrayTonyB has a video on how to add a Pioneer-style soft start to any amp; it includes a relay and a hefty power resistor that functions as described above by Larryi. The current to initially charge the capacitor power bank runs through the power resistor until the capacitors approach full charge and then the relay contacts change state and the power resistor is dropped from the circuit.
 

The circuit works well because of the way capacitors charge. The curve is exponential, so that, if memory serves, 4/5ths of the current is consumed in the first 1/5th of the time it takes to charge them fully, then 4/5ths of the remaining current in the next 1/5th of the charging cycle. The power resistor is dropped out of the circuit well before it reaches full charge, but well after the capacitor bank has received the bulk of the current it needs. This way, it doesn’t kick back in during normal operation when the capacitors may need to be resupplied after heavy transient responses. At least that is my understanding.

The circuit is fairly simple and I think Tony even went so far as to come up with a small circuit board that can be installed in nearly any power amp or receiver short of a design like Devaliet (if I’ve spelled their name correctly). 

I have a 1957 house with 100 amp breaker.  I have a 20 amp line for stereo.  When I turned on the big Yamaha amp turning that on dimmed the lights.  Running the Vitamix blender made light above the sink flickered.

 

My insurance company put a monitor on my power to monitor for fire hazards.  I noticed voltage drops down to 106V.  Called the utility.  Turned out there was a bad ground after the transformer.  They called it a neutral.  They fixed that. Problem solve

 

 

 d.

 

 

My insurance company put a monitor on my power to monitor for fire hazards.  I noticed voltage drops down to 106V.  Called the utility.  Turned out there was a bad ground after the transformer.  They called it a neutral.  They fixed that. Problem solve

@daledeee1 - EXACTLY.  And a neutral is not a ground, but a lifted neutral (bad connection from center tap of utility transformer to your panel neutral) is exactly the sort of thing that would cause this.

If you noticed in my earliest reply, I suggested a cheap AC voltage meter with a built in N-E voltage display for just such a reason. 

Even with a dedicated 10 gauge outlet, if your panel's connection to the utility neutral is bad you get all sorts of issues.  The biggest issues come when we try to fix significant home electrical problems with power conditioners.  You ignore a real issue or make it worse. 

 

The lack of resistance in the 10 gauge wiring is INCREASING the inrush current and dropping the voltage at the panel until that current is reduced.   A loose outlet screw (unsafe!) or 12 gauge/14 gauge wiring would all increase the R slightly and REDUCE the inrush current. 

Agree.

I wouldn’t want any resistance/impedance in an audio equipment branch circuit wiring to limit inrush current. Ideally you do not want any voltage drop in the branch circuit wiring caused by any audio equipment load condition . 

I have a couple of ARC VT50 tube amps that draw over 50 amps each of inrush current from a cold power on. ( Across the AC mains power on circuit).  Dedicated Branch circuit wiring is 10 gauge copper. 

Lights in the audio room are can lights with GE Profile BR30 65 watt 130V lamps. (Controlled by a Lutron dimmer.)  Branch circuit wiring for the two ARC Vt50 amps are fed from Line 1 to neutral. The 120V can lights are fed from Line 2 to neutral.  A cold power on from either of the VT50 amps causes a quick flicker in the ceiling lights.

Electrical service is 120/240V single phase 200 amp. Panel, Square D QO, plated copper mains bus, with 200A main breaker. Wire from meter socket to panel main breaker and neutral bar is 3/0 copper.

Electrical problem with wiring in the house? None. 

Quick short duration voltage drop on the electrical service that causes the ceiling lights in the room to flicker when turning on one amps at a time?  Normal, IMO.

I am pretty sure it is due to the Utility Power Company’s aluminum underground wiring that feeds the meter socket on the side of the house. Another factor could be the Utility Power Company’s transformer. The Power Company deliberately under sizes the transformer. Economics... Also worth noting the Power company requires only aluminum wire to be used from their power transformer to the electrical meter socket if the underground wiring is installed by others. The power Company wants the impedance of the aluminum wiring. Also worth noting, the impedance in the aluminum wire increases in the event of a sort circuit fault or ground fault event. Thus, limits current in the faulted circuit.

And then there could be a lose and or corroded aluminum wiring connection(s), Especially where the connections are overhead and exposed to the environment. 

As for a lose and or corroded main service neutral conductor. That can indeed cause electrical problems. 

Example of something drawing a lot of current when switching on causing 120V incandescent lights to dim and or continuing to be dimmed while the load is on, that are fed from the same AC mains Line, leg. 

 Or,

Example of something drawing a lot of current when switching on causing 120V incandescent lights to get brighter. That indicates the higher current load(s) are on one AC mains Line, leg, and the Lights are fed from the opposite AC mains Line, leg. This example can damage electronic equipment.

The higher current loaded Leg, Line, voltage to neutral bar at the panel will measure less than half the HOT Line to HOT Line voltage. And the lower current loaded Leg, Line, will read a higher voltage to the neutral bar than half of the Hot Line to Hot Line voltage.  

Example if the Hot L1 to Hot L2 measures 240Vac then ideally from either L1 or L2 to neutral bar will measure 120Vac. 120V + 120V = 240V.  (  120V loads are somewhat equally balanced on each leg, Line.)

IF the service mains neutral conductor is lose and or corroded causing a series resistance, impedance, in the connection to the power transformer neutral bus you will get measurements, for example something like this.

Hot L1 to Hot L2 measures 240Vac.

Line 1 to neutral bar measures 100Vac. Line 2 to neutral bar measures 140vac

Line 1, leg, has a greater current load than L2, leg.

Note: it is normal to measures a few volts deference from L1 to neutral bar and L2 to neutral bar. The difference could be as simple as the center tap on the secondary winding of the split phase winding of the utility power transformer causing the difference. 

Never move all 120V high current loads to one leg, Line, in a panel. That’s a No, No. 

120V loads are constantly turning on and off throughout the day. The known loads should have been somewhat balanced on L1 to neutral loads and L2 to neutral loads by the electrician that wired the panel . Only the imbalanced 120V loads of L1 to neut and L2 to neut load current returns on the service neutral conductor to the Utility Power Transformer. The 120V balanced 120V of L1 to neut and 120V of L2 to neut load current are in series with one another and are being fed by 240Vac

Example: IF L1 to neut has 30 amps of combined 120V load, and L2 to neut has a combined 120V load of 30 amps, then zero amps of current will travel on the electrical service’s neutral conductor back to the Power Transformer’s neutral bus.

Only the unbalanced 120V loads of L1 and L2 will return on the neutral conductor to the Utility Power transformer. Balanced loads are in series and are being fed by 240V, nominal.

.