Wondering if there is anyone out there using balanced AC in your studios? If so, did you ever make a comparison in terms of the noise floor improvement? Was there an improvement? Ground loops mysteriously disappear? 60Hz hum gone?
I'm looking at one of the Furman balanced AC units for my studio. But at around a $1K, it's a difficult decision. Would like to know if any of you have any experience with this. Thanks!
BTW: a link to some info on the subject...
http://www.equitech.com/articles/articles.html
<font size=-1>[ This Message was edited by: krizrox on 2002-06-16 07:52 ]</font>
Balanced AC
IMHO, balanced is required on stages etc, where's a lot of interference: loads of lights, amps, long cables etc. For short distance and home/small studio works, I would not consider balanced necessary. A good placement of equipment and wiring can prevent most hum. Ie. Do not run audio cables parallel to screen cables, place power supplies away from connections and cables etc.
Hmmm...
Well, these aren't the responses I was hoping for but I appreciate the feedback. I've decided to see for myself. I ordered a Furman IT-1220 from Musician's Friend. Hopefully, should have it here in a few days. I'll do a comparison and see if it makes any noticable difference or not. I have 45 days to decide if I want to return it. I'll let everyone here know what I find out.
Well, these aren't the responses I was hoping for but I appreciate the feedback. I've decided to see for myself. I ordered a Furman IT-1220 from Musician's Friend. Hopefully, should have it here in a few days. I'll do a comparison and see if it makes any noticable difference or not. I have 45 days to decide if I want to return it. I'll let everyone here know what I find out.
Well, there is an ending to this story.
I bought a "blem" unit from Musician's Friend only to have it arrive in a very damaged condition. This unit must weigh around 60 or 70 pounds (very heavy).
They simply threw it into a cheezy cardboard box with almost no padding to speak of and it must have been dropped (a few times) because the entire front face plate was bashed to shit.
That didn't stop me from plugging it in and trying it out. Luckily, it seemed to work.
I noticed absolutely no change in the noise floor of my equipment. At least nothing obvious to my ears. After reading some of the articles on the subject, I was hoping for something a bit more, well, obvious to justify the $1K price tag.
Needless to say, the unit is going to be returned and I doubt I will pursue buying another unit. The sad part is that shipping costs will kill me on this thing because it's so heavy. Oh well...
I bought a "blem" unit from Musician's Friend only to have it arrive in a very damaged condition. This unit must weigh around 60 or 70 pounds (very heavy).
They simply threw it into a cheezy cardboard box with almost no padding to speak of and it must have been dropped (a few times) because the entire front face plate was bashed to shit.
That didn't stop me from plugging it in and trying it out. Luckily, it seemed to work.
I noticed absolutely no change in the noise floor of my equipment. At least nothing obvious to my ears. After reading some of the articles on the subject, I was hoping for something a bit more, well, obvious to justify the $1K price tag.
Needless to say, the unit is going to be returned and I doubt I will pursue buying another unit. The sad part is that shipping costs will kill me on this thing because it's so heavy. Oh well...
Here's a very useful discussion on the origins and benefits of balanced power:
http://www.circumtech.com/development/t ... gy/default
Now the only difference between using their expensive systems and an ordinary isolating transformer, is that they centre-tap the secondary of the isolating transformer. This centre-tap is wired away to equipment, and becomes a wired earth to the various loads.
Now , for gear with no filters, or no switchmode power supplies, ie straight into a mains transformer, there is no filter or hash currents going to chassis or power lead earths. Balanced power would seemingly be of nil advantage.
However, with filters or switchmodes (which inevitably have filters in them) the balanced supply mode will give a centrepoint ground that the filter currents can pass to.The filters are always a balanced arrangement. Each half of the filter (Phase and Neutral-both are equally alive under balanced power arrangements, so there is no neutral, rather two supply conductors) will bypass/filter the same as the other half is doing . The result is that there should be no out-of-balance ripple/hash/harmonic currents running on the earths.
So there may be advantages in this, especially when you are running unbalanced audio feeds.
With balanced/isolated/transformer coupled audio feeds at +4, I can't see that you will hear or see much improvement.
So again, yer pays yer money and takes yer pick....
http://www.circumtech.com/development/t ... gy/default
Now the only difference between using their expensive systems and an ordinary isolating transformer, is that they centre-tap the secondary of the isolating transformer. This centre-tap is wired away to equipment, and becomes a wired earth to the various loads.
Now , for gear with no filters, or no switchmode power supplies, ie straight into a mains transformer, there is no filter or hash currents going to chassis or power lead earths. Balanced power would seemingly be of nil advantage.
However, with filters or switchmodes (which inevitably have filters in them) the balanced supply mode will give a centrepoint ground that the filter currents can pass to.The filters are always a balanced arrangement. Each half of the filter (Phase and Neutral-both are equally alive under balanced power arrangements, so there is no neutral, rather two supply conductors) will bypass/filter the same as the other half is doing . The result is that there should be no out-of-balance ripple/hash/harmonic currents running on the earths.
So there may be advantages in this, especially when you are running unbalanced audio feeds.
With balanced/isolated/transformer coupled audio feeds at +4, I can't see that you will hear or see much improvement.
So again, yer pays yer money and takes yer pick....
but your stuff may not really be grounded well,which can cause problems.at least make sure you have a good ground.(big metal deep in ground) first.also,if you only need power conditioning(rf,spike/surge and undervoltage correction,i.e. clean consistant power),a line conditioner or ups of 1000-1500va will be plenty for a home studio and will cost about $200-300.$1000 is crazy.spend $300 on a good electrician and $300 on a line conditioner and still save $400.hey! with that $400, upgrade the cableing in your studio.(monster studio grade mic cable $200) if hum is the problem and you're just looking for a quick and dirty fix,many cable manufacturers such as whirlwind,hosa,horizon etc. sell isolation transformers as "hum eliminators". money spent on an electrician who has some experience with studios(local recording studios should be able to refer someone),will probably give you the best sounding results.
Yeah - thanks for the responses guys. The bit about the electrician is probably the best suggestion and, in fact, I have one coming in to rewire some outlets for me. I'm not sure this is going to improve things however. I am getting hum from my PC and also my Triton. The Triton was easy to fix: I just installed an Ebtech Hum eliminator.
The PC is a bigger issue. The problem is hum from the analog outputs - also noted through the SPDIF input. PC and mixer moved to other locations in the home and same result. Perhaps the ground in my entire home is suspicious.
Is there any specific grounding magic I can work on Pulsar or the motherboard which might have an effect? I tried grounding the mixer chassis and the PC chassis together but that seemed to make the noise worse. Something clearly amiss. Any ideas?
The PC is a bigger issue. The problem is hum from the analog outputs - also noted through the SPDIF input. PC and mixer moved to other locations in the home and same result. Perhaps the ground in my entire home is suspicious.
Is there any specific grounding magic I can work on Pulsar or the motherboard which might have an effect? I tried grounding the mixer chassis and the PC chassis together but that seemed to make the noise worse. Something clearly amiss. Any ideas?
fix the ac ground on the house first and see what's up.this could be related to how well the power supply in you computer was sheilded...a little noise is normal with good power and proper cabling,but a very little noise.it is the ratio of signal to noise that is important.(more signal less noise)all electronic components generate noise.if it's a hum however,it's a ground loop.there are ways to isolate grounds if you use balanced cables.beware,the ground loop may not be from the computer if you have several devices connected together.(including midi)
you need a heavy ground strap into substantial metal going well into the ground.it needs to be well connected to the lines in your house.(better than code)
it helps to have a separate breaker for your studio and the have ALL connected gear on that breaker(15-20 amp is ok if your setup is small,30 amp if you're running a sideshow)
<font size=-1>[ This Message was edited by: garyb on 2002-06-27 00:23 ]</font>
you need a heavy ground strap into substantial metal going well into the ground.it needs to be well connected to the lines in your house.(better than code)
it helps to have a separate breaker for your studio and the have ALL connected gear on that breaker(15-20 amp is ok if your setup is small,30 amp if you're running a sideshow)
<font size=-1>[ This Message was edited by: garyb on 2002-06-27 00:23 ]</font>
Ideally, you should also put your analog and digital equipment on different power lines. Switched power suplies, as found in computers and similar equipment, cause interference on power lines that could affect your analog equipment depending on their power supplies design.
You could also build your own <a href="http://www.dansdata.com/diyups.htm">dual convertion UPS</a> with separate inverters for your digital and analog equipment...
You might also want to take a look at this article: <a href="http://www.sospubs.co.uk/sos/aug99/arti ... ing.htm</a>
RedSun .:.
<font size=-1>[ This Message was edited by: redsun on 2002-06-27 11:12 ]</font>
You could also build your own <a href="http://www.dansdata.com/diyups.htm">dual convertion UPS</a> with separate inverters for your digital and analog equipment...
You might also want to take a look at this article: <a href="http://www.sospubs.co.uk/sos/aug99/arti ... ing.htm</a>
RedSun .:.
<font size=-1>[ This Message was edited by: redsun on 2002-06-27 11:12 ]</font>
I have everything in my studio connected via a Furman AR1215 - and 2 powerstrips of wallwarts connected to it as well. This eliminated clicks caused by large draws on the circuit (refrigerator, A/C, etc). It won't fix ground loops though, but I did get everything connected via the same ground path this way.
A special home-made ground-lift cable(s) may do the trick for you, particularly if you're going balanced -> unbalanced, or have powered speakers.
A special home-made ground-lift cable(s) may do the trick for you, particularly if you're going balanced -> unbalanced, or have powered speakers.
If I would buy an UPS or power conditioner for $100-$300, which brands would you recommend?
I live in a rented apartment so rewiring is not an option. When I'm using SP/DIF I get spikes from the fridge and the gear gets out of sync. Irritating...
BTW, should monitors (screens) be connected to other sockets then the studio gear?
<font size=-1>[ This Message was edited by: Need on 2002-07-02 20:08 ]</font>
I live in a rented apartment so rewiring is not an option. When I'm using SP/DIF I get spikes from the fridge and the gear gets out of sync. Irritating...
BTW, should monitors (screens) be connected to other sockets then the studio gear?
<font size=-1>[ This Message was edited by: Need on 2002-07-02 20:08 ]</font>
UPS: APC makes some good stuff (www.apc.com)
Conditioning: Furman, ETA or APC
Your SPDIF problem: doubtful it's related to AC. I have the same problem. Some eq works fine, some doesn't. I think it's just poor programming.
Monitors: get an LCD display and that will take care of your monitor hum. Otherwise, just keep the monitor as far away from your audio gear as possible.
Conditioning: Furman, ETA or APC
Your SPDIF problem: doubtful it's related to AC. I have the same problem. Some eq works fine, some doesn't. I think it's just poor programming.
Monitors: get an LCD display and that will take care of your monitor hum. Otherwise, just keep the monitor as far away from your audio gear as possible.
For UPS/conditioning there is also http://www.liebert.com
If anything it's good to get an ups/power conditioner just to protect the $$$ invested in your cards from power surges and spikes etc.
If anything it's good to get an ups/power conditioner just to protect the $$$ invested in your cards from power surges and spikes etc.
Guess I shouldn't put it in the closet either as it gets to warm for the UPS...