wineslob
Wiping out white van
About the only benefit I can see is if you are having voltage sag when using 110V (aluded to in this thread) other than that.......
220V vs 120V - Any benefit?
- Thread starter jstang
- Start date
About the only benefit I can see is if you are having voltage sag when using 110V (aluded to in this thread) other than that.......
What I would do is temporarily switch the amp to 240v and temporarily hook it up to 240v and see if any difference (be honest because excitement can cloud your thinking 
). If it does show improvement and if justifiable, then route a permanent 240v socket.
From my experience with air compressor, I was able to run my compressor better in 240v configuration than a 120v configuration using the exact same cord. As we know that unlike the amplifier, the motor draws sustained amount of amperage. The cord gets hot using 120v 16a but stays cool at 240v 8a. The same time the motor was struggling at 120v but runs merrily at 240v. Mostly the amperage is the issue.
). If it does show improvement and if justifiable, then route a permanent 240v socket. From my experience with air compressor, I was able to run my compressor better in 240v configuration than a 120v configuration using the exact same cord. As we know that unlike the amplifier, the motor draws sustained amount of amperage. The cord gets hot using 120v 16a but stays cool at 240v 8a. The same time the motor was struggling at 120v but runs merrily at 240v. Mostly the amperage is the issue.
Interesting question -- don't think I've ever seen this one come up on AK. Of course, I have absolutely no idea what the correct answer is...
whoaru99
Epic Member
Again, if the voltage drop on the 120V circuit is relatively high, then yes, there should be a benefit at least in output power under heavy load. That may or may not translate into an audible improvement. All other things equal, doubling the supply voltage cuts the voltage drop in half.
Also, going to a higher voltage facilitates the same amount of power delivered on a thinner cable. So yes, it is possible to have a thinner cord on a 240V unit and still carry the same amount of power. It is the amount of current that dictates wire gauge, not the voltage. Assuming the load is the same the amp will draw about 1/2 the line current operating at 240V vs 120V.
My only suggestion is that if you do make a 240V circuit for the amp, use the correct type of receptacle and change the plug on the amp. That way, nobody will accidentally plug a 120V device into the 240V circuit.
Also, going to a higher voltage facilitates the same amount of power delivered on a thinner cable. So yes, it is possible to have a thinner cord on a 240V unit and still carry the same amount of power. It is the amount of current that dictates wire gauge, not the voltage. Assuming the load is the same the amp will draw about 1/2 the line current operating at 240V vs 120V.
My only suggestion is that if you do make a 240V circuit for the amp, use the correct type of receptacle and change the plug on the amp. That way, nobody will accidentally plug a 120V device into the 240V circuit.
jstang
Honey,I can't hear you...
I am also thinking about short transient loads.....and the affect there. Speaker wire always seems to be a discussion that invokes doubt, hear say and other emotions.... But for sure I can not use 18 gauge lamp cord on my system.... So the main job of the filter caps are provide DC power as required.... But can they be helped by re-enforcing the AC supply side? I think so, but I don't know how much can be helped by it.....
The Filter caps are like a Flywheel and the transformer is the motor that keeps the flywheel spinning ( charged...)
Only two ways to prove the affect of 220v....find someone that has tried this before or to try it myself.
There are so many things in the audio field that are meaningless hear say and some that you just scratch your head & say "How the hell did that make such a difference....."
thanks,
jk
The Filter caps are like a Flywheel and the transformer is the motor that keeps the flywheel spinning ( charged...)
Only two ways to prove the affect of 220v....find someone that has tried this before or to try it myself.
There are so many things in the audio field that are meaningless hear say and some that you just scratch your head & say "How the hell did that make such a difference....."
thanks,
jk
whoaru99
Epic Member
It's the same. Current and voltage drop.
If you look at the Square D circuit breaker tables, the standard QO-type breakers will pass many times their rated current for short periods. For example, a 15A breaker will pass ~70A to 150A for one second before the breaker trips. It will pass even more current without trip if the duration is less. For up to 0.25 second, that 15A breaker could pass approximately 105A to 300A before it trips out. Anything beyond these levels just seems to drive the breaker to trip more quickly.
So, as you see, supplying instantaneous current itself isn't really a problem for transient loads, it is the voltage drop incurred in the wiring that is really the issue, IMO. There are two ways to reduce the voltage drop, use a higher supply voltage or increase the wire gauge of the circuit. Doing both, of course, builds upon the effect of either alone.
If you look at the Square D circuit breaker tables, the standard QO-type breakers will pass many times their rated current for short periods. For example, a 15A breaker will pass ~70A to 150A for one second before the breaker trips. It will pass even more current without trip if the duration is less. For up to 0.25 second, that 15A breaker could pass approximately 105A to 300A before it trips out. Anything beyond these levels just seems to drive the breaker to trip more quickly.
So, as you see, supplying instantaneous current itself isn't really a problem for transient loads, it is the voltage drop incurred in the wiring that is really the issue, IMO. There are two ways to reduce the voltage drop, use a higher supply voltage or increase the wire gauge of the circuit. Doing both, of course, builds upon the effect of either alone.
Don't forget a third factor...length of the circuit.
jstang
Honey,I can't hear you...
Well.... physics coming into play.
Voltage is ElrectroMotive Force.... More Voltage is more force that is available to be used.....
Provided an unwanted resistive load does not get in your way.....
Honestly this might one of those things like Spreaker wire Stand offs ( I have a hard time buying into that one...)....or it might have some real positive affects for extreme systems....
jk
Voltage is ElrectroMotive Force.... More Voltage is more force that is available to be used.....
Provided an unwanted resistive load does not get in your way.....
Honestly this might one of those things like Spreaker wire Stand offs ( I have a hard time buying into that one...)....or it might have some real positive affects for extreme systems....
jk
whoaru99
Epic Member
Yes, very true. The wire gauge and length factor into resistance which impacts the voltage drop.
Arkay,
To deliver the same power, a higher voltage (220v) would need less current than at a lower voltage. If a cord has to carry less current, it can have less copper cross section. If it has to withstand a higher voltage, it will have thicker insulation (assuming the same insulating material.) For common 220/240v cables, they are usually industrial strength in the US so have higher current ampacity, thicker electrical insulation, and protective jackets.
This is why the transmission lines coming out of a power plant are the same thickness as a local distribution line but carry a whole lot more power. In general, the wire size on a transmission line is determined by the tensile strength of the wire given a specific desired span length.
The power plant output wires operate a a much higher voltage, maybe 500,000 volts. while a local distribution line might be 4,160 volts. In fact that's why we have transformers iall over our the power system - Edison's direct current system couldn't step up or step down the generator voltage while Westinghouse's alternating current system could. When Westinghouse showed he could build a power plant at Niagra Falls and ship the power to NYC (and Edison couldn't), J. P. Morgan fired Edison.
This would be an interesting experiment but if I'm close to correct about the issue being in the transformer, any result would not be generally applicable to other devices.
To deliver the same power, a higher voltage (220v) would need less current than at a lower voltage. If a cord has to carry less current, it can have less copper cross section. If it has to withstand a higher voltage, it will have thicker insulation (assuming the same insulating material.) For common 220/240v cables, they are usually industrial strength in the US so have higher current ampacity, thicker electrical insulation, and protective jackets.
This is why the transmission lines coming out of a power plant are the same thickness as a local distribution line but carry a whole lot more power. In general, the wire size on a transmission line is determined by the tensile strength of the wire given a specific desired span length.
The power plant output wires operate a a much higher voltage, maybe 500,000 volts. while a local distribution line might be 4,160 volts. In fact that's why we have transformers iall over our the power system - Edison's direct current system couldn't step up or step down the generator voltage while Westinghouse's alternating current system could. When Westinghouse showed he could build a power plant at Niagra Falls and ship the power to NYC (and Edison couldn't), J. P. Morgan fired Edison.
This would be an interesting experiment but if I'm close to correct about the issue being in the transformer, any result would not be generally applicable to other devices.
jstang
Honey,I can't hear you...
The key at this point is the specs for the transformer.... Least that is my take.... But this amp has plenty of transformer....
Oh as side note.... It was Tesla that figured out most of the power distribution methods....oddly enough...He lived in my town here in NJ and is buried here.... Tesla worked for Edison and then Westinghouse when he got pissed at Edison.... Tesla was the real brains.... Ah yes, another Jersey Boy hard at work....
jk
Oh as side note.... It was Tesla that figured out most of the power distribution methods....oddly enough...He lived in my town here in NJ and is buried here.... Tesla worked for Edison and then Westinghouse when he got pissed at Edison.... Tesla was the real brains.... Ah yes, another Jersey Boy hard at work....
jk
ByteWrangler
Active Member
This may be worth doing if you know how to rewire the power transformer for 240V operation. The power transformers in equipment made for both 120 and 240V markets often have two primary windings; the two primary windings are wired in parallel for 120 V use and in series for 240 V. If that's the case, it's an easy mod, but you'd better be DARN SURE you know which lead is which!
I'd say it may help because:
If the load you're putting on the house wiring, power cord, etc. is causing a significant voltage drop, then setting it up to use double the voltage should help by a factor of four, not two, because the voltage drop will be half, and, since the primary is stepped down by a factor of two more, that voltage drop of half as much is reduced by another factor of two.
To illustrate:
To make the math easy, say the output of the transformer is supposed to be 90V with an input of exactly 120 or 240V, depending on how it's wired, and the input power is 1200W. Say that all the wiring from pole to transformer primary has a resistance of 0.2Ω, and the return side of the circuit is another 0.2Ω (that's a lot, but makes the math easy and illustrates the point).
It's drawing exactly 10 Amps at 120 V (that's 1200 Watts); the wire resistance of 0.2 Ω on the hot side causes a drop of 2V. The resistance on the return (neutral) side costs another 2V, so the voltage at the transformer primary is 120 - 2 - 2, or 116V, a 3.3% drop. The 4:3 transformer reduces 120V to 90V, so 116V at the primary produces 87V in the secondary.
Now, if we rewire the PT to double the length of the primary winding, and double the voltage, it will now draw 5 Amps (5A X 240V is still 1200W). 5A through .2 Ω is a 1V drop. Another Volt is lost in the other half, so the voltage at the primary is now 240 - 1 - 1 = 238V, (a 0.83% drop, half the previous drop from a higher starting point). It's now an 8:3 Transformer, (240 in gives 90 out), so 238 in gives 89.25 Volts at the secondary.
In the example, you've lost 0.75 V instead of 3V.
Give it a try and report back, please.
[edit] Nikola Tesla, "the man who invented the twentieth century", was THE MAN!
I'd say it may help because:
those lamps dimming means something is causing a significant voltage drop. Can you run it without any extension cord and see if that is contributing to the problem? If that is really a 2.2 KVA tranny I doubt it's saturation, although that could be an issue.
If the load you're putting on the house wiring, power cord, etc. is causing a significant voltage drop, then setting it up to use double the voltage should help by a factor of four, not two, because the voltage drop will be half, and, since the primary is stepped down by a factor of two more, that voltage drop of half as much is reduced by another factor of two.
To illustrate:
To make the math easy, say the output of the transformer is supposed to be 90V with an input of exactly 120 or 240V, depending on how it's wired, and the input power is 1200W. Say that all the wiring from pole to transformer primary has a resistance of 0.2Ω, and the return side of the circuit is another 0.2Ω (that's a lot, but makes the math easy and illustrates the point).
It's drawing exactly 10 Amps at 120 V (that's 1200 Watts); the wire resistance of 0.2 Ω on the hot side causes a drop of 2V. The resistance on the return (neutral) side costs another 2V, so the voltage at the transformer primary is 120 - 2 - 2, or 116V, a 3.3% drop. The 4:3 transformer reduces 120V to 90V, so 116V at the primary produces 87V in the secondary.
Now, if we rewire the PT to double the length of the primary winding, and double the voltage, it will now draw 5 Amps (5A X 240V is still 1200W). 5A through .2 Ω is a 1V drop. Another Volt is lost in the other half, so the voltage at the primary is now 240 - 1 - 1 = 238V, (a 0.83% drop, half the previous drop from a higher starting point). It's now an 8:3 Transformer, (240 in gives 90 out), so 238 in gives 89.25 Volts at the secondary.
In the example, you've lost 0.75 V instead of 3V.
Give it a try and report back, please.
[edit] Nikola Tesla, "the man who invented the twentieth century", was THE MAN!
jstang
Honey,I can't hear you...
No problem for me on the Transformer rewire.....I was born with a soldering in my hand.... 
....on the 500 it is just moving some wires on a screw terminal strip under the amp.
Hey thanks for the Math...good simple math always helps straighten out the thought process.
Could be the extension cord...but a new12 gauge cord and new outlet that its plugged into should be ok....but if I get a chance I will give it a try. It will require rolling the rack over there... Oh the wiring....
I really am not overly concerned with lamps as the 12 gauge reduced it and a new direct outlet behind the unit will reduce it further, once I rebuild the listening room.
I am trying to decide if the 220v outlet is worth the effort as part of the room rebuild. But I most likely will run both if I have room in the breaker Box for the extra breakers....
I am more thinking along the lines of transformer efficiency is improved at 220v and that audio output surges are better handle that way.
jk
....on the 500 it is just moving some wires on a screw terminal strip under the amp.Hey thanks for the Math...good simple math always helps straighten out the thought process.
Could be the extension cord...but a new12 gauge cord and new outlet that its plugged into should be ok....but if I get a chance I will give it a try. It will require rolling the rack over there... Oh the wiring....
I really am not overly concerned with lamps as the 12 gauge reduced it and a new direct outlet behind the unit will reduce it further, once I rebuild the listening room.
I am trying to decide if the 220v outlet is worth the effort as part of the room rebuild. But I most likely will run both if I have room in the breaker Box for the extra breakers....
I am more thinking along the lines of transformer efficiency is improved at 220v and that audio output surges are better handle that way.
jk
ByteWrangler
Active Member
If it's as easy to rewire the transformer as you say and you're comfortable running new house circuits, here's what I'd do (although I doubt this is UL approved or NEC compliant):
As an experiment, rewire the Marantz transformer for 240, but leave the cord and plug as-is for the time being. Tag the plug as 240V only. Run a circuit to the location the amp will be, using ordinary techniques and material, but make it a 240V circuit using a two-gang breaker instead of the usual single-pole breaker and neutral. Label the receptacle as 240V (in case you drop off the face of the earth before finishing). Give it a try. If you like what you hear, replace the receptacle, cord and plug with proper 240V fittings. If there's no obvious difference, convert the circuit to 120V, and rewire the transformer, so you don't have this non-standard (potentially dangerous and certainly non-compliant) stuff.
As an experiment, rewire the Marantz transformer for 240, but leave the cord and plug as-is for the time being. Tag the plug as 240V only. Run a circuit to the location the amp will be, using ordinary techniques and material, but make it a 240V circuit using a two-gang breaker instead of the usual single-pole breaker and neutral. Label the receptacle as 240V (in case you drop off the face of the earth before finishing). Give it a try. If you like what you hear, replace the receptacle, cord and plug with proper 240V fittings. If there's no obvious difference, convert the circuit to 120V, and rewire the transformer, so you don't have this non-standard (potentially dangerous and certainly non-compliant) stuff.
jstang
Honey,I can't hear you...
All else fails "Google search time"....
http://www.audioasylum.com/scripts/t.pl?f=tubediy&m=89790
http://www.sweetwater.com/expert-center/techtips/d--09/22/1999
This one is related to getting the best performance testing numbers
from a Krell would need a special AC supply...
http://www.stereophile.com/solidpoweramps/191krell/index4.html
May not answer the question but a good read ... I have not read it
completely yet...
http://www.smartdev.com/pdf/ac_power.pdf
Will continue to google....
http://www.exactpower.com/assets/pdfs/EP15A_Flyer.pdf
From the above URL.....
"Big load on the output
The first is when the load has very high peak current demands. For example, a large audio power amplifier may demand 45 amps of peak current. It is plugged into an outlet that is connected to the breaker panel by wires. When the amplifier demands current, these wires unavoidably create a voltage drop over their length. For a 15 amp branch circuit, Ohm’s law dictates that a peak current of 45 amps would produce a 18 volt drop! In other words, an outlet that measured 120 volts with no load would deliver only 102 volts under this brief overload condition. The EP15A uses its Reserve Power to satisfy the peak current demands of the amplifier, while correcting the peak voltage to its full value. Reserve Power effectively compensates for voltage drop from losses in the wiring allowing the power amplifier to deliver its full dynamic capability and to fill in the missing audio details."
If accurate, I would have to say there is "SEEMINGLY" some benefit from 220V for large amps..... UNTIL IT IS PROVEN OR DIS PROVEN WITH A REAL TEST.... Its speaks to transient response issues which is specifically what I was interested in.
I am thinking that monitoring the +/- Rail voltage with a scope for ripple or other variations might be a way to determine if the Transformer and AC supply are keeping up with the power demands of the amp.....then measure again once converted to 220.
thanks,
johnk
http://www.audioasylum.com/scripts/t.pl?f=tubediy&m=89790
http://www.sweetwater.com/expert-center/techtips/d--09/22/1999
This one is related to getting the best performance testing numbers
from a Krell would need a special AC supply...
http://www.stereophile.com/solidpoweramps/191krell/index4.html
May not answer the question but a good read ... I have not read it
completely yet...
http://www.smartdev.com/pdf/ac_power.pdf
Will continue to google....
http://www.exactpower.com/assets/pdfs/EP15A_Flyer.pdf
From the above URL.....
"Big load on the output
The first is when the load has very high peak current demands. For example, a large audio power amplifier may demand 45 amps of peak current. It is plugged into an outlet that is connected to the breaker panel by wires. When the amplifier demands current, these wires unavoidably create a voltage drop over their length. For a 15 amp branch circuit, Ohm’s law dictates that a peak current of 45 amps would produce a 18 volt drop! In other words, an outlet that measured 120 volts with no load would deliver only 102 volts under this brief overload condition. The EP15A uses its Reserve Power to satisfy the peak current demands of the amplifier, while correcting the peak voltage to its full value. Reserve Power effectively compensates for voltage drop from losses in the wiring allowing the power amplifier to deliver its full dynamic capability and to fill in the missing audio details."
If accurate, I would have to say there is "SEEMINGLY" some benefit from 220V for large amps..... UNTIL IT IS PROVEN OR DIS PROVEN WITH A REAL TEST.... Its speaks to transient response issues which is specifically what I was interested in.
I am thinking that monitoring the +/- Rail voltage with a scope for ripple or other variations might be a way to determine if the Transformer and AC supply are keeping up with the power demands of the amp.....then measure again once converted to 220.
thanks,
johnk
whoaru99
Epic Member
I don't see anyone disagreeing about potential benefits.
The Krell, being a large Class A amp, always presents the worst case load. It draws full power regardless of output/volume level so it's not really an apples-to-apples comparison with your situation.
There will be benefits if all the worst case assumptions are satisfied. What more is there to ponder?
All that's left is to do it/try it...
The Krell, being a large Class A amp, always presents the worst case load. It draws full power regardless of output/volume level so it's not really an apples-to-apples comparison with your situation.
There will be benefits if all the worst case assumptions are satisfied. What more is there to ponder?
All that's left is to do it/try it...
electroking
a- v- karma member
Don't forget to replace the line fuse with one of half the current rating, and to
use a fuse rated for 250 V.
By the way, this smaller fuse will have a bit more resistance, so it could eat up
the (very small) benefit you are expecting. Just my two cents' worth...
use a fuse rated for 250 V.
By the way, this smaller fuse will have a bit more resistance, so it could eat up
the (very small) benefit you are expecting. Just my two cents' worth...