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Power, noise and summertime
Old 19th May 2003
  #1
Gear Nut
 
stuntmixer's Avatar
 
🎧 15 years
Power, noise and summertime

Hi everybody,

A couple of semi related questions:

1) It's getting hot as it is want to do this time of year in South Austin, Tx and for some reason this year I am experiencing troubling power woes. Most afternoons for the past 10 days or so, I have been seeing AC voltage readings of 115v-116v(!!??) This is according to a cheapo Rackrider in the first FX rack. Now, I am assuming that this is due to the heat and my neighborhood's collective air conditioning use, which I certainly contribute to. Usually by midnight the voltage reads back up at 120v-122v.

I have investigated enough to rule out my own power consumption as the cause. The studio is on a dedicated breaker and turning almost everything else in the house does not effect the reading. This concerns me. I don't mind a volt or two here and there, but....

What should I do about it? Conditioning seams in order. Does anybody have any experience or recomendations about how to deal with this?

2) On a semi-reated note, I finally tracked down a variac to borrow and as per recomendations from other posts here hit my little Ghost's power supply with 126v (not on topic here, but WOW, what a difference) and in doing so introduced a noticable noise floor. I'm sure there is a better device than an industrial/tech grade power regulator.

Thanks for any help here. I really want to resolve these issues and get back to thinking about Making Music!
Old 19th May 2003
  #2
Lives for gear
 
pounce's Avatar
 
🎧 15 years
although i cannot help with the power issue, i'd like to hear any reports as to weather the variac ends up helping your ghost much or not. i have a ghost, and i'll get a variac if it's truly ends up making a difference. eventually a beefier console, but for now a variac is my last and only hope...oh sorry launched into star wars for some reason. anyhow, i'll take my cue from you on this. please do follow up or pm me. thanks.
Old 20th May 2003
  #3
Gear Nut
 
stuntmixer's Avatar
 
🎧 15 years
The difference is not subtle. It is wonderful. A client who has been slowly mixing his CD here a song at a time noticed in the first 30 secords last night. He described the sound as bigger. Mind you, I hadn't told him there was any change. He called it blind - "Wow, that sounds a lot bigger than the other day, what did you do.."

C
Old 20th May 2003
  #4
Gear Maniac
 
psytechguy's Avatar
 
🎧 15 years
Re: Power, noise and summertime

Quote:
Originally posted by stuntmixer
Hi everybody,

A couple of semi related questions:

1) It's getting hot as it is want to do this time of year in South Austin, Tx and for some reason this year I am experiencing troubling power woes. Most afternoons for the past 10 days or so, I have been seeing AC voltage readings of 115v-116v(!!??) This is according to a cheapo Rackrider in the first FX rack. Now, I am assuming that this is due to the heat and my neighborhood's collective air conditioning use, which I certainly contribute to. Usually by midnight the voltage reads back up at 120v-122v.
Hey neighbor!

I've lived in South Austin on and off for the past 25 or so years and the power grid definitely has it's peaks and valleys.

For years I've been in the habit of occasionally sticking my Fluke meter in wall outlets and watching this. (mostly only on really slow weekend nights)
What you're seeing is just one of those common urban things that happens on the grid in any city you care to choose.

Very typical summer pattern:

Folks get off work and come home, turn on the TV, A/C, electric ovens, microwaves, etc. and the power drops all along the chain. Later they start going to bed and turning off appliances and the power comes back up a few volts.

I used to get a 20 volt swing in one house I lived in.stike

At some point I'm going to buy an Equitech balanced power rig. Having perfect, constant power makes a big difference in how your gear sounds and how long it lasts in some cases.

If you're over in the Slaughter Lane/Manchaca area, those brownouts you're experiencing are probably just me powering up my gear!

Southbound and down,

Mike
Old 20th May 2003
  #5
Lives for gear
 
pounce's Avatar
 
🎧 15 years
stuntmixer - could you recommend a make, model, and or supplier for this variac dealio. i haven't used one before, but i'm willing to give it a go. any info appreciated - plus i will buy the thing, so i'm not just a timewaster...i'm ready to giddyup and see if i can take things up a notch like that. thanks in advance.
Old 20th May 2003
  #6
Gear Nut
 
stuntmixer's Avatar
 
🎧 15 years
psytechguy,

Howdy neighbor! This is weird you are probably only a mile or two from here. e-mail me.

There is WAY to much variance in voltage here to satisfy me. How do you deal with it or do you just do most of your work at night like me? The level usually hits 120 about 10 pm and stays there or above untill morning.

I don't know much about types or brands of variacs. I borrowed one from my tech. If you do a search you will quickly find out as much as I know. Hell, search e-bay and you can learn a lot.

Is Equitech the only good game for good "clean power"?
Old 20th May 2003
  #7
Lives for gear
 
Mario-C.'s Avatar
aaah Austin.....
you couldn't get me out of "las manitas" last time I visited...
way off topic I know, I could not resist...
Old 21st May 2003
  #8
Lives for gear
 
pounce's Avatar
 
🎧 15 years
http://recpit.prosoundweb.com/viewtopic.php?t=5630

here is a great thread warning against the use of a variac on a power supply. i felt obligated to share the same info here.

sometimes upgrading or modding the actual power supply is a good option, and changing some of the components in the mixer might require the extra power, however using a variac seems to be more likely to damage the power supply than add any sonic anything.

lets call it a variac urban legend and not blow up our power supplies on account of it. (i have, however, heard of benefits of a newer/more powerful ps for the ghost as it originally shipped with some lesser ps that the later ps improved upon).

my ghost happens to sound decent, so i am not going ot mess with it. however, bad power supplies could be the cause of noise issues and this is especially true of the older version of the power supply that came with the ghost. hth.
Old 21st May 2003
  #9
Gear Maniac
 
fishtop_records's Avatar
 
🎧 15 years
Your 115v level doesn't even count as a brownout.
Power companies do brownouts all the time when
the weather is very hot (or very cold).

If you are having audible problems with 115vac,
you have other problems.

Arround here, the power company won't tell
people when they drop the power to 100vac.
That is more than 15% down. I could understand
that making a difference on sensitive gear with
tube powersupplies, or underdesigned powersupplies.

Now most of the mass market pro audio stuff
uses powerbricks. They are switching powersupplies
that can work, without any change, from about 80vac to
260vac. Cool for overseas travelers. Some have
a switch, and others skip even the $0.03 that the
switch costs.


Related to this topic, good PC UPS systems are
more than powerful enough to drive a decent
sized project studio, and you could get two more
more. But most of them do _not_ put out nice
sine wave power, it has lots of notches like
an undersampled digital audio signal.

Has anybody tried feeding their studio through
mid-tier UPS systems?
Old 21st May 2003
  #10
Gear Maniac
 
🎧 15 years
Quote:
Originally posted by fishtop_records


...Has anybody tried feeding their studio through
mid-tier UPS systems?...

I use (almost exclusively) the "Smart UPS" line from APC

{ www.apcc.com }

The output is sinusodial.

NYC Drew
Old 21st May 2003
  #11
Lives for gear
 
sonic dogg's Avatar
 
🎧 15 years
For those of you contemplating using the Variac on your power supply, please be aware of these facts taken directly from the Soundcraft Power Supply Manual for the PS250/PS275...

quote:
This unit is capable of operating over a range of mains voltages by means of a four-position mains input fuse carrier.It is important to ensure that the correct voltage setting is selected for the level of local mains voltage supply,for safe,uninterrupted operation of the unit.Voltage selection is achieved by positioning the fuse carrier so that the required voltage appears next to the arrow which is molded in the connector.In this way the unit is set up for operation at one of the following ranges of mains supply:

NOMINAL VOLTAGE OPERATING VOLTAGE RANGE
(+10/-15%)

Vrms AC Vrms AC

230 196-253
115 98-126
100 85-110
85 73-93


So, my suggestion of using a Variac to up the input voltage to the Power Supply to 126 Voltsrms, is simply saying that the Ghost likes the little extra voltage and according to my research and the factory manual, is within the guidelines set down by the Factory themselves. Most house current in the U.S. is anywhere from 114 to 122 volts depending on your area and the types of loads prevalent there. How do I know this? I'm a Journeyman Electrician and have been for 25 years. I would not suggest you run any power supply above its rated ability nor below it either.As was stated in the PSW thread, this has nothing to do with how Ed Van Guitar ran his marshalls, and while those over at PSW think they have the market on knowledge, most are simply bitter jackasses that dont get out enough or simply talk thru their hats without thinking or reasearching their pronunciations. Its why most of us came here ,aint it.

The fact is, I personally have tried this with MY Ghost and have gotten great results with it.I have had a Variac on my power supply for about four months now and have experienced no problems of the immediate kind nor the creeping in kind.The board is powered up 24/7 and sounds great. Charles mentioned that the difference was immediately apparent, and it is.I could only recommend this to users with the PS275 supply since that is the only one i have. It is also the only piece of equipment i have on this set-up and has appropriate metering,fusing and switching.
I would never put my DAW or any outboard piece of gear on any voltage other than the supply to the building and I would always use regulated power for larger setups involving many multiples of supplys simply for the grounding and filtering. As Fletcher would say YMMV.....One other thing....be absolutely sure that your Power Supply is quite well vented....Mine used to be on the floor under my desk but i mounted it up alone in a rack so that now it has airflow above and below it.This is in my opinion another contributing factor to the better sound...it seems to run cooler even with more voltage and seems much smoother and quieter when many inputs are used at once. Peace
Old 21st May 2003
  #12
Gear Nut
 
stuntmixer's Avatar
 
🎧 15 years
Urban Legend

Thanks everyone for replying,

Fishtop, I guess I am learning that this kind of 6v swing in voltage is "normal". I was incorrectly assuming that 120v was supposed to be 120v, no less or more. I have never had this issue come up before (ignorance can be bliss after all).

While I haven't yet noticed any obvious change in the over all sound of my gear due to voltage swings, last week I thought everything I was mixing sounded "soft" and kind of "sluggish" like a tube amp with an over-worked rectifier. It makes sense that older/tube pieces are the ones that will suffer the most. Still, I can see no harm in trying to regulate the power as much as I can afford to.

NYC Drew, to this end I am still interested in overall power conditioning for the studio. Thanks for the tip, the APS stuff looks cool. What size or amp rating would you recommend for a small/mid sized hybrid project studio?

pounce: As far as the Ghost PS thing goes. I was as skeptical of this as anyone. It still makes no sense to me. While this may have all the ear marks of being an "urban legend," it works! (Quick note: I have absolutely no interest in even considering this as any kind of GS/PSW debate as it isn't. I hang in both places and respect all of y'all).

I didn't have any problems with the sound of my Ghost before, other than it isn't a Neotek, or Trident. I am actually very happy with it for the cost. I like pushing the 2-bus pretty hard and it can take it pretty well. But at some point, especially with rock mixes, just as I feel like I'm starting to feel the mix start to gel, it kind of folds in on itself, flattens out. The bottom goes a little soft and the mids loose their growl. Not badly, I just always feel like it's "almost there" but I have to play it a little safe due to the headroom, or lack thereof.

Before I tried the variac I did enough research to feel confident that I wouldn't be damaging my board as I use it everyday to make my living. I found several folks, including sonic dogg who have done this with good results and found nobody reporting any ill-effects.

The improvement is noticable. I have blind tested this now, having a friend switch it back and forth, carefully and without telling me which setting the variac was on. I chose the PS fed with 126v everytime...... I don't get it either, but there it is. So far there is no smoke coming from the machine room, it has been on for three days. The PS doesn't feel any warmer to the touch, nor does the board.

The variac is borowed and has to go back soon. I will have a chance to sit with the board afetr it goes and figure out if I want to take the chance (this still makes me nervous) and buy one.

Thanks for listening, back to your regularly scheduled work break.

C
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