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110 (or 120) vs 220

Hi,

IF an amp can operate at both 110 and 220, and a dedicated circuit is being installed for that amp, is there an advantage to a 220 v circuit? Or is the answer "it depends on the amp"? Or is the answer simply "no"?
jimspov
gs5556
769 posts
 
For an amplifier to be designed to run on either 120 or 240 it must have two fuses, one for the hot and one for the neutral. When it is running on 120, the fuse on the neutral is just dead weight and does nothing but provide continuity. When it's running on 240, that "neutral" is now doing duty as a hot conductor and can pull short circuit current under a fault -- hence the reason for the second fuse. Don't forget to change out the fuses to a lower (usually half) amperage since the current draw is now half at 240 volts.

If there in only one fuse then do not run it at 240 regardless if there is a split primary with a switch or jumpers capable of conversion or else you will run the risk of what jea48 outlined above.

Also, you should not run other equipment off a 240 circuit. Theoretically, you can pull power off one leg and feed it to a 120 outlet and run a neutral  back to the panel but that is against code because it unbalances the circuit. The correct way is to leave it dedicated. That circuit will have a 2-pole circuit breaker feeding a 250 volt receptacle (6-15 or 6-20) which has the blades rotated at a 90 degree angle (horizontal) so that you cannot accidentally plug a 115 volt appliance into that outlet, resulting in a pretty fireworks display.

Your electrician knows how to wire everything up if you decide to go with 240.
jea48
2,944 posts
 

A neutral ( The Grounded Conductor) should never be fused. If a breaker is used both poles must be mechanically connected together so both contacts will open simultaneously at the same time.


http://www.audioresearch.com/ContentsFiles/VT50_SchemPL.pdf

Scroll down the page to the drawing of the primary winding side of the transformer.

The primary has dual windings so it can be connected to 120V or 240V mains. (Parallel for 120V. Series for 240V)

Note only one fuse is used. The HOT conductor, be it, 120V or 240V connects to the Line side of the fuse.

The neutral conductor, (The Grounded Conductor), connects to the other Line lead of the of the configured primary winding of the transformer.

jimspov's avatar
jimspov OP
58 posts
 
Ok. If the amp isn't designed to do both with no modifications from me then I don't want to do this. (I have a call in to the manufacturer).

I have a CPAP machine and it will automatically switch from 110 to 220 it I switch the power cord. Guess it isn't so simple for an amp!

For the interconnects, I was referring to a converter that you plug into the wall and then you plug the ancillary equipment into it. The converter takes 220 volts from the wall and converts to 110 for the equipment to use.
jea48
2,944 posts
 

http://www.audioresearch.com/ContentsFiles/VT50_SchemPL.pdf

Scroll down the page to the drawing of the primary winding side of the transformer.

The primary has dual windings so it can be connected to 120V or 240V mains. (Parallel for 120V. Series for 240V. The change must be done internally inside of the piece of equipment.)

Note only one fuse is used. The HOT conductor, be it, 120V or 240V connects to the Line side of the fuse.

The neutral conductor, (The Grounded Conductor), connects to the other Line lead of the of the configured primary winding of the transformer.

>>>>>>>>>>>>>


Some audio equipment have a switch mounted on the back panel to switch from 120V to 240V Can’t get any easier than that.

BUT, BIG BUT.... The AC power that you connect to the equipment must have only one Hot ungrounded conductor and one Neutral conductor, (The Grounded Conductor). That is the AC power system the manufacture, of the equipment, designed it to be connected too. Not 2 Hot ungrounded conductors as your electrical service panel has.

My understanding is the mains power you have in Canada is the same as here in the US.

120/240Vac The Utility power transformer has three output legs, conductors, wires, that feed your home.

At the main service electrical panel you have 2 HOT ungrounded Lines, Legs. They are called Line 1 (L1), and Line 2 (L2). If you measure from L1 to L2 you will measure 240Vac nominal voltage.

The third wire that comes into the electrical panel is called the neutral conductor. This wire is common to both L1 and L2. If you measure from either L1 or L2 to the neutral conductor you will measure 120Vac nominal.

By NEC Code the service entrance neutral conductor must be intentionally connected to earth. This makes it the Grounded Conductor. (There is a lot more that has to be done than just saying it must be connected to earth. For simplicity lets just leave it at that).

>>>>


For you, I see no advantage of feeding 240Vac power to a dual rated 120/240V piece of audio equipment. Even if you use a transformer to create a neutral conductor to feed the 240Vac equipment. It will not sound any better and in fact it could sound worse if the transformer is not sized properly.


Feeding it directly from the main electrical panel with the 2 Hot, L1 and L2 Lines Is, I would guess, a safety code violation in Canada. I don’t know if it is or not though.

Might it sound better? Don’t know. It would be as some call it, fed from balanced power.

Would it be safe? No not in my opinion as well as gs5556, as explained above in previous posts.


jimspov's avatar
jimspov OP
58 posts
 
My reason for doing this is that my tube amp is rated at 35 watts / channel. I'm buying new speakers after having my Paradigm 5se's for over two decades.

I naively thought if I doubled the voltage I could ~double my available power (~quadruple at 4 ohms?) and that would vastly increase the pool of speakers I could choose from (e.g., Totem, Magnapan).
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