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Bring down high wall voltage. Variac or buck transformer?


avguytx

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My wall voltage in my house stays at the 125 to 126v range per my Tripplite HT7300PC power conditioning center, which my Dynaco VTA ST-70 is not tied into.  Currently, I'm using a basic variac that was recommended by Bob Latino to dial the voltage back to 117v and was measured via my Fluke as I don't trust all built in meters.  I have not seen line voltage drop below 125v since I've lived in this house the last 4.5 years, either.  Would I be better off with a variac dialing back voltage or getting/building a buck transformer for use with the ST-70?  I know the filaments like to see a certain voltage, around 6.3v I think it is, and without the variac, it's into the 7 range.  So, this is what I've been using since the first of the year.

 

Any advice, thoughts, or otherwise?

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My wall voltage is in the same range as yours.  I don't have any problem with any of the electrical device in the home, HT, 2ch system with several different amps over the years.  I have a new amp.  I have heard that amps from the 50's, 60's and early 70's were made for 110 volts.  Here is something off the internet:https://www.quora.com/Can-low-voltage-damage-home-appliances

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Check plugs on both phases of your breaker box.  Be sure they are the same.  If they are not the same chase your neutral connection for continuity, or call your power utility and have them do it.  It *can* be dangerous if your don't know how to do it safely. 

 

I thought I saw a spark at my pole one windy day.  Weeks later I was checking voltages at a plug (don't know why) and found one at ~109V and another at 126V.  The power company found my neutral broken near the transformer pole. 

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12 hours ago, avguytx said:

Anyone? @tube fanatic maybe? :)

I think a variac is fine and have never found its use to be detrimental in any way.  You are correct about the tube filaments.  A major cause of premature tube failure is excessive filament voltage (7+ volts is definitely excessive).  So, keeping it at 6.3 maximum is a good measure.  If normal line voltage variations should cause the voltage to run even 5% low that should not affect emission to any significant degree .  Same for plate and screen voltages.  Running a little low isn't going to change the operating parameters to the point that the sound of the amp will be degraded.  And an added advantage is that the tubes will run a bit cooler which can only help longevity.

 

Maynard

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Ok...thank you for the information, Maynard.  As long as it's not hurting anything, I'll leave it be.  I ordered a Kill A Watt P4400 to plug into it so I can see the actual voltage at the plug instead of using the Fluke on it.  I did that one time checking voltage and it seemed to have opened up the terminals so much that any plug that goes into it is loose and won't hold a solid connection and will make the amp power off.  I've got to see if that'x fixable this weekend and maybe put a new plug on it.

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10 hours ago, JohnA said:

Check plugs on both phases of your breaker box.  Be sure they are the same.  If they are not the same chase your neutral connection for continuity, or call your power utility and have them do it.  It *can* be dangerous if your don't know how to do it safely. 

 

I would call the electric company no matter.  To me, 125V is too high.  The electric companies like to run it high because then you use more electricity, in this case 4% or so.

 

I noticed the same thing here, always 125V or so, and I talked to the head guy of the company.  It was soon corrected back to 119V to 120V.  So if they say they can't do anything about it I'd be highly skeptical.

 

It really isn't necessary, but you could also think about a Brultech GEM or EC1240 if you'd be happy monitoring just a few circuits.  I have the GEM and it has been helpful at times, but it was what I would consider a bit high priced, about $450 or so.  But I saved a bit by installing it myself, and now I have every circuit in the house monitored.  I've got 4.7kw of PV solar, so I'm very focused on electricity usage.  During the four days without power after Hurricane Irma, we were able to live fine, hot water, A/C (daytime only due to degrading batteries), ran the dishwasher, lights and TV (thank goodness, but no Internet for a week), and also charged the EV Nissan LEAF, so we weren't concerned with the gasoline shortages or the hour wait others had do do.  I even kept up the mowing schedule with my electric EGO lawn mower.

 

 

 

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15 minutes ago, ksquared said:

 

I would call the electric company no matter.  To me, 125V is too high.  The electric companies like to run it high because then you use more electricity, in this case 4% or so.

 

 

 

Using ohm's law please explain how you would use more electricity.

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5 minutes ago, jimjimbo said:

I have to say that's a pretty ridiculous statement.

 

Says the guy who stated it is perfectly fine for some unscrupulous seller (not jimjimbo to clarify) to claim something was purchased for $5000 when the truth is it was $880, in order to try to justify a higher selling price.  The person potentially overcharged would have most likely also have been a member of this forum.

 

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17 minutes ago, ksquared said:

 

Says the guy who stated it is perfectly fine for some unscrupulous seller (not jimjimbo to clarify) to claim something was purchased for $5000 when the truth is it was $880, in order to try to justify a higher selling price.  The person potentially overcharged would have most likely also have been a member of this forum.

 

Dude, get a grip.  I never said that.  

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That would be correct! I've never been in a house here where it is lower. I used an old light dimmer from a theater when I had my ST-70 hooked up. The original power transformer would run rather hot on 125, and it helped when I cut it back.

 

Bruce

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4 hours ago, Davis said:

Using ohm's law please explain how you would use more electricity.

 

I knew I had read it somewhere, but a long time ago:

https://www.greentechmedia.com/articles/read/120-to-118-will-dropping-our-voltage-save-power#gs.R12QP9c

 

It involves Conservation Voltage Reduction.  There is more information in the comments section than the actual article, but I did remember the snippet about Ohm's law from this guy (bold added):

"

Greg W  7 years ago

I've been involved with CVR research for the last 10 years, and aside from a few knowledgable comments this is mostly a wounderful compulation of all the ignorant reactions to CVR I've heard for the last 10 years! Voltage Optimization is real. As long as you reduce the voltage to the low end of the ANSI 84.1 voltage delivery standard, it works. For anyone that is truly interresting in expanding their knowledge base, there have been years of research on the topic by the CEC, EPRI, NEEA, BPA and a host of utilities dating back to the early 1980s that you can study up on. Ohms law is not the bible - it is only the tip of the iceberg when it come to what actually happens when the voltage moves up or down. By the way EPRI (the Electric Power Research Institute) named CVR as their #1 topic for continued research this year."

 

Also, this person wrote an interesting article too:

https://blogs.dnvgl.com/energy/is-conservation-voltage-reduction-truly-energy-efficiency

 

I will definitely admit that this is pretty far above the limited knowledge I have in this area, and over time I have muddled the information.  I mostly was studying to design, get permitted, and be code compliant for the 4.7kw PV system with battery backup that I installed here.  

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