Bottlehead Forum
General Category => Technical topics => Topic started by: ewingfox on November 12, 2016, 06:19:43 AM
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Working on finding a solution to a dirty power issue. At this location, there are voltage fluctuations +-10v, mid 1960's house wiring, FM radio audible through all speakers (even through SS gear), interference audible from cell phone calls, landline calls... And weather.
Have unplugged EVERYTHING in this house, and the issue persists, and is not limited to one circuit. With over 10+ families sharing the same common transformer, we have a problem, Houston.
If I can install a dedicated circuit from the main panel and install hospital grade outlets, etc... Is there an option outside of spending 2-3k on power conditioners? Has anyone here built a Line filter/isolation transformer unit themselves that works well? I have reviewed other threads here where users have rewired their entire house to clean up power, but I am fairly convinced that the issue lies with a neighbor's house. Having my friend relocate isn't an option, and buying the neighborhood out is also out of the question.
Can we dedicate a thread to a conversation about power filtering? Perhaps a new group project could come out of this! I'll happily be the guinea pig for this - my friend is non-technical and is at the end of his rope.
If I failed to go far enough back in the forum, and this has already been solved - just let me know and I'll RTFM!
My personal thought would be a pair of line filters based around Corcom 3EC1 suggested by Paul Joppa, in line with a few hospital grade isolation transformers, and probably a slow start circuit. If there is a better way, gurus please educate me!
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-and to answer the first question everyone will ask - no, a DC only system is out if the question. I'm playing with a DC only system only at my place, but more to come on that in a few weeks as I get the amps knocked together :)
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There are a lot of threads out there on many forums covering this topic. Here's my two cents.
I'm active duty Navy and move every three or so years. In the last 10 years I've went from 100v 50Hz power to 128v 60Hz and currently 115v 60Hz. As I rent and don't own where I'm living the best solution I've come up with is a PS Audio Premier Power Plant. I've had this in my system for the last 10 years or so and it is the single best purchase I've made in audio. It provides consistent regenerated 120v power that I never have to worry about. When in Japan, I used a 20 amp step up transformer from 100v-117v in front of it and it didn't blink. Stateside it handles daily voltage fluctuation with zero hiccups. I've got every piece of audio gear I run plugged into it and with BH tube gear using a 120v primary winding, I never have to worry about too much or two little voltage. Additionally, it has a pretty advance surge protector built in and PS Audio backs it every step of the way. Their engineers personally helped my through the Japanese power conversion questions and I've read of them helping customize power solutions for individuals. I sound like a fan boy and am of this product. Again, just my two cents.
Aaron
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A mains filter and isolation transformer should get you there.
No need to spend big money as i picked up a Belkin PF-60 mains filter for £100 on eBay which all my gear is fed from. The isolation transformer was another bargain i found on eBay for £30, its a 1KVA toroid with x2 120v windings so i have it setup as a balanced 240v output to feed my speaker amps and preamps. Whole setup probably cost me £200.
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Aaron -
First of all, thank you for your service! Your previous posts about your power setup, and your time living with challenging power conditions lead me over the past few days to review and consider the PS regeneration units! If a home option won't work, the strength of your recommendation will likely send us there for sure. A ET "fanboy" turned me on to these crazy bastards up in the NW building $99 tube preamps back in 1999, so be a champion for what works!!!
mcandmar - did you chop up those units to build a home brew box, or are the photos the commercial units?
I have already added a Pyle voltage stabilizer with sequential power on/off for his small setup (some self powered 5" Presonus units and a standalone DAC for use with his computer). This did little to lower the noise floor, but has stabilized the voltage somewhat.
I'll look into adding those two additional units, I assume upstream?
Finally, anyone have any luck building a single homemade unit?
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mcandmar - did you chop up those units to build a home brew box, or are the photos the commercial units?
Finally, anyone have any luck building a single homemade unit?
The PureAV is a commercial unit, the isolation transformer unit i built myself. I did have my own DIY filter box but i dismantled it when i bought the PureAV as its a much better unit.
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Mcandmar-
Consider me a complete and total newbie in all things - any chance you could assist with the layout and parts list for the isolation transformer setup? Not clear on what a "wingding" is!
I'll look into the Belkin PF-60 - the pricing is reasonable and if it doesn't do the job when paired with the ISO, I can buy if back from my buddy and use it at my place where the power is much cleaner!!
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I have not tried this personally but it sounds like it should work. Buy a small used gas generator and remove the gas engine and replace it with an electric motor. That would be about as pure and dedicated as you can get. Shouldn't cost too much either.
Michael
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You might also find some interesting and potentially helpful info by researching Balanced Power. There are many off the shelf units on the market (some may be among the products mentioned above in this thread) but it is also not beyond DIY-ing. See the linked thread for a discussion here on the topic; lots more is JAGA (just a google away).
http://bottlehead.com/smf/index.php?topic=3443.0
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I've not had this problem and am not technically adept enough to address it, but to me, all of the replies are geared to giving you clean, stable voltage. This is fine, but am I wrong in thinking that this won't help you with the FM, cell phone and other interference?
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Thanks everyone!
i am looking into a balanced power setup for his main listening room (under construction at the mo) and I'll attack the isolation transformer setup this week. I know a guy who knows a guy with a stack of 'em.
I am hoping most of the noise is coming in over ac - to your point Deluk - anything that is actually riding in on RCA's and through the rest of the signal path, well - that is just a return to best practice - shorten cables, keep things neat, use floor offsets, shielding, etc, etc.
One remaining question - other than being an annoying font, what is a whingding?
Thanks in advance,
Ewing
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A wingding is the same as a winding, only spelt wrong. I would like to know what auto-correct thinks it is...
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Caffeinator -
Thank you for sending me over to the balanced power thread - reading through it, I wonder how much of the benefit from balanced power comes through the fact that there are transformers in the mix - essentially isolating the power. I have added some line filtering and voltage stabilization already with a 1U Pyle conditioner (purchased more for the sequential soft start than anything, as the speakers in his office are self powered and are a pain to turn on manually.)
I think next steps is probably to build a isolation transformer setup, or try one of the commercial units - I can always deploy it elsewhere if it turns out to be half-measures, and will likely employ a soft start. Many people forget that even if there is no load connected, inrush current on large transformers can actually damage a ton of gear upstream - I once saw an electrician down (my) datacenter by powering up a 400VA transformer, then before allowing it to stabilize, energize the next one in the line. Even though there was no load on either, it caused a massive sag and not only popped the upstream UPS, it also damaged quite a bit of gear.
I'll do more googling - but in BH forums I trust, so expect me to dupe-check things here before I make any bold moves :)
E
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mcandmar -
wow - Apparently i misread your initial post lol -
I completely understand what you are talking about - thank you for the dope slap. I won't admit how long I spent researching "power conditioning" and "wingdings" :)
Thank you everyone for your expertise and patience!
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Hi ewingfox,
I think the idea behind balanced power is that by splitting the transformer secondary and returning each of its halves to ground, a lot of AC-borne noise is thus split, opposed, and cancelled. The transformers used for balanced power are often isolation transformers if they aren't purpose-built for balanced power. This makes me wonder if an isolation transformer would add more to a balanced power setup.
The other parts of a typical balanced power setup - a power line filter, for example, and maybe a ferrite ring or tube - can also help with a variety of power line noise.
Good luck!
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The isolation transformer is most certainly what's called for in your application. There are also some designs out there that can block DC before it comes into your isolation transformer.
Do your best to find an isolation transformer that isn't toroidal. You want absolutely horrid bandwidth more than a decade or two over 60Hz. That will knock out the RF/AF bleed pretty substantially. List off all the gear you want to put on this thing, then we can help you size the transformer properly.
If you want balanced power, your isolation transformer needs a center tap on the secondary.
Filtering before the isolation transformer can be obtained simply by buying a fancy IEC receptacle that has it built in and sized according to your approximate draw. More filtering can be added after the ISO transformer, and you may find that specific filtering for outlets feeding switch-mode power supplies or digital devices is a nice idea. Frankly, after you've bought the enclosure and isolation transformer, none of this other filtering stuff is going to seem particularly expensive.
Something like a Hammond 169G will do 4A of current at 120V, and it has taps at the output that can help you dial in 120V regardless of what's coming into the primary. It will not, however, provide balanced power. Putting a Hammond 1182N60 after the 169G will give you the center tap you need to obtain balanced power. Such an arrangement has been suggested in the past, and if your wallet can afford it and your floor joists can support it, it seems to be worth a shot!
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FWIW, I went to a TRIPP-LITE LCR-2400 a few years back and I have been very pleased with it's performance vs. cost. (<$300)
https://www.tripplite.com/2400w-120v-3u-rack-mount-power-conditioner-automatic-voltage-regulation-avr-ac-surge-protection-14-outlets~LCR2400/ (https://www.tripplite.com/2400w-120v-3u-rack-mount-power-conditioner-automatic-voltage-regulation-avr-ac-surge-protection-14-outlets~LCR2400/)
When we lived in El Paso, particularly during the "hot" months, the load on the transformer that serviced 5 houses fluctuated greatly, as AC units and pool pumps kicked in and out. This unit significantly improved line voltage stability performance, and related spike and noise suppression.
I added a PS Audio IPS-9000 after the LCR-2400, but that was mainly for outlet control, and the geek factor of being able to set delay turn off and turn on times, as well as monitor performance, with a web interface. The LCR-2400 does the line voltage heavy lifting ...... I believe the IPS-9000 has been retired by PS Audio http://www.psaudio.com/wp-content/uploads/2011/11/PowerPlay-80001.pdf
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Thank you everyone for the input!
We worked pretty hard to try ensure that the loud hum (100-120hz) and a bit of high frequency fizz was coming from the power and wasn't a source issue. This is for a pretty low-fi active studio monitor system that is taking signal directly from an SMSL M8 DAC with linear power supply. The house power is completely atrocious, but for now (and with no tubes in the mix yet) we have gotten it to a livable level
Turns out the Presonus 5" active monitors have a case of bad case of gain-itis - the line level from the SMSL DAC was hot enough that using the default gain (it is a rotary adjustment on the monitor) it was amplifying some signal noise (the fizz) and the ~100hz noise from the power supply, and the local country music station. By dropping the gain setting on the monitors to nearly off - when you back the dial all the way back it goes from low to off - and using a much higher source setting (at the digital level) we were able to improve the signal to noise ratio. Combining this with a Pyle 10 outlet, 2U sequential power /voltage stabilizer/ line filter that we had on hand seems to be enough.
Still a bit of hum when there is no music playing out of one channel (the amp is not the best quality for sure in those, but for under $200/per what do you want?) and he is a happy camper.
What does this mean? Was this thread for naught? NO!
Once we build the tube setup, we are going to have to address the power quality issues. I'm thinking medical grade outlets on a dedicated circuit, home brew IS Trans, center tapped for balanced power as an option, with something like a PS unit for outlet control and additional filtering ahead of the BeePree (on order) , DAC and SS amp. Once we have a better handle on the power draw for the system, expect me to be back kneeling at the BH alter :)
I am a pretty smart guy - I spend most of my day being a trusted expert at work, and people pay me to be trusted expert in my consulting business. I come here, and I am instantly reminded how phenomenal the talent, intelligence and experience the Bottlehead Community has collectively in its ranks. It is humbling and I am incredibly thankful for how generous everyone is with their time and knowledge. I am happy to take the title of permanent Newb :)
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It's a pretty good creative community. One of the characteristics of good creative communities is "each one teach one" - you may start as a noob, learning from the more experienced. But as soon as you learn something, you will recognize when someone else is in need of what you have learned, so you share your knowledge. The return on investment in sharing knowledge is a robust community, where everyone is both learning and teaching.
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I've been lurking around here for a while, mostly trying to learn about tube amps and just found this thread. I've already learned quite a bit from many of you, so thank you.
It seems that this problem has been solved, but wanted to share my effort at power filtration for others. My power box serves a number of functions for my theater system. It is installed on its own dedicated 30A feed from my breaker box, powers my entire theater system, has a two-stage remote control power up, features two separate turn on delay circuits, has multiple AC line noise filters, has four stages of spike and surge protection, and provides balanced power to the preamp, CD, DVD, and DAC.
[edit] Hmmm... looks like I'm not allowed to post external links on my first post... I edited my profile to include the URL of my webpage, click on the "AC Power Distribution, Sequencer, and Filter" link.
Eric
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Interesting update to the power conditioning issues!
So - it turns out that the power in the house in question was DEAD SILENT. The issue was a component in the room that was pumping out RF and also some line noise back into the house circuit - some third party phone system gadget for internet phone service that ties back into the home POTS lines. This in combination with a pair of presonus studio monitors that have a track record for a nasty high Frq hiss lead us down this long road.
Thank you everyone for the fantastic information - I always say the only stupid question is the one you have to ask twice!! I am still keeping my eye out for a honking isolation transformer at local swaps and online so I might build up a power conditioning setup anyway just for the experience if I can find the parts on the cheap.
Take care,
Ewing