220V vs 120V - Any benefit?

[jstang]

So I am planning my final install of my system..its been temporary up to now. The Marantz Model 500 amp can run on 220Vs.

So the question is - If running the power amp on 220 can provide any benefit in sound quality? 220V should be able to provide more POWER at lower current loads on the supply side.

But I have never tried this.....I am sure our overseas friends can comment....


Any thoughts?

jk

 

[jamesrpm]

Thought about the expense of adding the 220 outlet ?It could be a big deal to get one installed. About sound quality , you would be raising voltage to lower amp draw, I can't see it adding to sound quality.

 

[jstang]

I can handle the circuit install myself....so not to much of an issue there...just cost me da parts...

The Model 500 can suck up power....it is close to 600WPC into 4 ohms, so power delivery might be helpful.....


jk

 

[Endspec]

The problem is that our 220 is two legs of 120 and over there it is one leg of 220, you would need a expensive transformer to do it.

 

[jstang]

My understating is that 220 is made up form the two 120 hots being delivered out phase.... U use the two hots.....


jk

 

[whoaru99]

My understating is that 220 is made up form the two 120 hots being delivered out phase.... U use the two hots.....


jk

Partially correct. It's only single phase power so there can't really be any out of phase.

The 120/240 simply comes from a center-tapped transformer. 120 is from center tap ("neutral") to either end tap ("hot"), 240 comes from using both end taps.

The only reason there should be an expectation of sonic improvement would be, IMO, if the 120V circuit was incapable of supplying adequate current, i.e. too much voltage drop. Generally this would be a concern only at extreme listening levels, and maybe not even then. With a power amp, the result of a bit more voltage drop is probably only that the output power would be somewhat reduced.

 

[jstang]

Well here's the reason I am thinking about this.... I run the system fairly hard and with some very demanding loads.

The Model 500 has a huge 2.2 KVA transformer with 100,000uf of capacitance in the supplies.

I have found that a high quality extension cord and even a new wall outlet made small but noticeable improvements in the sound quality. The amp is a beast.....

Pic of the transformer and the four main filters next to it...

Like to hear what the overseas folks have seen with 220/240 and big amps...

jk

 

[Stanga]

My, my, my. Those are some luvely 21,000uF caps you got there. Just the sort of values to deliver and maintain low frequency base.

As far as the 220/240V issue is concerned: the transformer you got there is the blades type. Some schools of thoughts reckon that the saturation voltage of that transformer design tends to impede performance at higher mains inputs. I have yet to nail that one as factual, but it has some credibility in it based on the transformer design rules I remember from my days at uni.

In terms of my own feeling, I would prefer to stick with what you are using it on. If you do get any improvements they are likely to be too small to impress your speakers with. Your time could be better spent replacing those carbon resistors for 1% metal types. Don't replace the fusible ones though!

 

[whoaru99]

Many overseas folks won't have the 120V experience because some places are 220/240V only. Of course, this depends on the country/region.

Also, keep in mind that even though your amp may be nearly 600W @ 4 ohms, it's not going to ever put out much more than probably 200W (if even that much) on a continuous basis with music because of peaks. If you try to push more continuous power than that with music, you'll drive the amp into clipping on the peaks. The exact ratio between how much usable continuous power and headroom there is depends also on the nature of the music.

 

[Stanga]

600W @ 4 ohms is 300W @ 8 ohms if your amp is a proper linear output design.
With the 85V caps ratings I reckon that the supply line must be between 65V to 75V. At that sort of supply line 300W @ 8 ohms continuous is possible. Even 400W@ 8 ohms continuous is possible.

 

[whoaru99]

No dispute on the rating of the amp.

However, continuous unclipped power measured with sine wave test tones in a lab setting is different than the continuous unclipped power you can get using music because of the difference in crest factor (peak to average ratio).

 

[kcollins4]

Two out of three audiophiles prefer crest factor.

 

[whoaru99]

Two out of three audiophiles prefer crest factor.

I'm a Colgate man myself.

 

[jstang]

There are four of those caps total plus another 16,000uFs on the board in the center...

I just recapped, film bypassed, re-output X-tored, resoldered connections and replaced some resistors... Next winters project would be metal film resistors where necessary...

The amp is linear in the power delivery and has 80V rails, but is SOLimited to just under 600WPC for 4 Ohms.

I was able to dim the meter lamps with heavy bass passages ( which is a second output winding on the transformer for the lamps ) which started me thinking about this.... So I ungraded from a 14gauge 10 foot extension to a 12gauge 10 foot extension... this improved the sound and reduced the dimming some....

I don't think the dimming is an indicator of anything wrong with the AMP, as I restored and test it throughly... I think dimming is a indicator of the AMP's need for lots of clean AC power. I have seen dimming lamp issues vastly improved by cleaning up the AC power with other systems.

Now when I start work on refinishing the basement listening room, I will put an dedicated outlet right behind the unit/system... question is would a 220/240 make difference for the amp.....?


So I know this is a "Shavings make a pile" game.... But after all that is usually where we find a lot of smaller improvements..... I am using OHM Fs, which require tons of amp damping... I have found that any improvement in low freq control can readily be heard. I was using a Soundcraftsmen which is no slough of an amp, but does have about little less than half the damping of the Model 500 ( 180 vs 400+ )and that difference can be readily heard with the Fs.

Your point on transformer saturation is excellent...I am going to read up on transformers...

jk

My, my, my. Those are some luvely 21,000uF caps you got there. Just the sort of values to deliver and maintain low frequency base.

As far as the 220/240V issue is concerned: the transformer you got there is the blades type. Some schools of thoughts reckon that the saturation voltage of that transformer design tends to impede performance at higher mains inputs. I have yet to nail that one as factual, but it has some credibility in it based on the transformer design rules I remember from my days at uni.

In terms of my own feeling, I would prefer to stick with what you are using it on. If you do get any improvements they are likely to be too small to impress your speakers with. Your time could be better spent replacing those carbon resistors for 1% metal types. Don't replace the fusible ones though!

 

[Whitehall]

Since the nominal rail voltages are the same no matter what, a power transformer will use fewer primary windings for the 220v input than for the 120v input. It will be the same winding but likely with a middle tap for the 220v and end-to-end connections for the 120v. The 120v will therefore better couple with all the secondary windings but will draw more current and so might run a tad hotter. The power cord for the 220v would need less copper.

Guess it comes down to the internal design of the transformer. One could screw it up either way but my blind preference would be for the 120v primary.

 

[jstang]

I am thinking that the standard copper AC lead gauges and all the house wiring will be able to better supply instantaneous surges with 220V....

But who knows for sure.....point of looking at the transformed behavior is a great one.

I doubt I will be able to find the specs for a 35 year old custom design, although there is a manufacturer's name and part number on it ... But looking at specs for a similar current design should be helpful.... Maybe.... Meaning some things were just plain build better back then.... Copper cost a lot less back then.....allowing things to be build differently....


Thanks for all the input so far, I greatly appreciate it...and I will continue to post as I read up on the transformer specs and designs....

jk

Since the nominal rail voltages are the same no matter what, a power transformer will use fewer primary windings for the 220v input than for the 120v input. It will be the same winding but likely with a middle tap for the 220v and end-to-end connections for the 120v. The 120v will therefore better couple with all the secondary windings but will draw more current and so might run a tad hotter. The power cord for the 220v would need less copper.

Guess it comes down to the internal design of the transformer. One could screw it up either way but my blind preference would be for the 120v primary.

 

[Mattwizz3]

I live in Australia and the AC here is 'one leg' of 240V, in most industrial workshops and warehouses we have '2 Phase' 415V AC also available for larger equipment - Thats about the only helpful input I can give.

Upon reading the first bit and having no Idea about your Amp I was gonna suggest beefing up the power supply of the unit.... then I saw the pics, HOLEY CRAP! Those are some big caps! Maby checking the quality of the cabling in your house may help, some places have some very interesting DIY handy work done.

 

[jstang]

Actually this amp is rated/speced/tested for continuous 500WPC into 4 ohms, hence the 2.2KVA transformer. Not that it would ever see that other then on a test bench.... Real world power for music is dependent on the caps, diode bridges and the transformer... All of which are really serious stuff on this unit...

Hence the thought of 220V may be helpful....

Remember the Star Trek episode where the "Multitron Unit" Refused to be shut off...and actually connected itself directly to the ships power source.... Same idea here....

jk

600W @ 4 ohms is 300W @ 8 ohms if your amp is a proper linear output design.
With the 85V caps ratings I reckon that the supply line must be between 65V to 75V. At that sort of supply line 300W @ 8 ohms continuous is possible. Even 400W@ 8 ohms continuous is possible.

 

[Arkay]

Since the nominal rail voltages are the same no matter what, a power transformer will use fewer primary windings for the 220v input than for the 120v input. It will be the same winding but likely with a middle tap for the 220v and end-to-end connections for the 120v. The 120v will therefore better couple with all the secondary windings but will draw more current and so might run a tad hotter. The power cord for the 220v would need less copper.

Guess it comes down to the internal design of the transformer. One could screw it up either way but my blind preference would be for the 120v primary.

The power cord for the 220v would need less copper.

I don't quite understand this. The power cords for 220V gear are almost universally thicker/heavier than the cords for 110V gear. I've never seen nor heard of anyone even suggesting that 220V gear doesn't need heavier (thicker) copper wiring than 110V.

Here in Hong Kong, much of my gear is multi-voltage, and it sometimes sounds better --or most often, sounds identical-- when run on the local 220V grid voltage. Some gear is ONLY for 110V (US) or 100V (Japanese), and I run those using step-down transformers. Of course, there is no way to make any comparisons for those. I can't see the point in adding an extra step-down transformer when it isn't necessary, except for the extreme isolation transformer, which obviously I use for different reasons.

I really don't know which would be better in your situation, but the thread and the question sure is interesting! If/when I ever move back to the States, I would plan to take at least some of my present gear back with me, and have always assumed I would run a 220V line to power them with.

 

[jstang]

Arkay...Thanks for chiming in....


Sometimes sounds better on 220V ? You mean a switchable unit that is being run as 120 but with your step down transformer... then switch it to 220V and remove the step down?

And you have heard a difference?

That could be due to removing the step down....or could be better power delivery by the AMPs transformer....

thanks,
johnk