Balanced Power supply for T8

MarkM · « **on:** 14 Dec 2006, 04:22 pm »

How will my T8 preamp handle being plugged into a balanced power supply? I tried it for a couple of hours and the results were very favorable to my ears, seem to clean up the sound and the background was a tad more silent.

Any potential damage?

BrianM · « **Reply #1 on:** 14 Dec 2006, 05:12 pm »

Yeah, *that's* gonna go over real big around here...

CornellAlum · « **Reply #2 on:** 14 Dec 2006, 05:57 pm »

What could possibly not "go over well" about a power conditioner? That's just dumb.

Toka · « **Reply #3 on:** 14 Dec 2006, 07:38 pm »

Mark,

What is the make/model of your supply? Most will be fine, but there are some that are bit...overzealous.

MarkM · « **Reply #4 on:** 14 Dec 2006, 08:21 pm »

The balanced power supply is from transcendent sound. I built it from a kit and made some minor mods to it. Like I said, this made a difference, I'm not talking about a fancy power cord, so I don't think Frank should get too worked up.

After all, he talks up his new products as having highly regulated power supplies, I see the balanced power supply as an extension of this and made a significant difference to my ears for the $$.

The T8 wasn't designed with the intent of if being fed via balanced power, does this affect the design? Or doesn't it?

http://www.transcendentsound.com/power_supply.htm The price has gone up since I built my kit.

avahifi · « **Reply #5 on:** 14 Dec 2006, 08:59 pm »

Correct me if I am wrong, but this "balanced line" signal conditioner appears to put 60V AC on both the hot and ground side of the AC into the preamp.

This is unsafe, because it defeats the built in fuse protection in the preamp.

The preamp is designed to modern standards with a polarized AC power plug putting the internal fuse first, ahead of everything else on the hot side of the AC line, followed by the switch, transformer, and back to ground. If any internal failure to ground occurs in the preamp, the fuse blows, protecting the user.

With the hairbrained scheme that it appears the balanced line conditioner represents, there would still be 60V AC live in the preamp even after a fuse failure.

How many kids need to be electrocuted for the sake of supposedly "better sound"?

Geeze

Frank Van Alstine

samplesj · « **Reply #6 on:** 14 Dec 2006, 09:24 pm »

Quote from: avahifi on 14 Dec 2006, 08:59 pm

Correct me if I am wrong, but this "balanced line" signal conditioner appears to put 60V AC on both the hot and ground side of the AC into the preamp.

This is unsafe, because it defeats the built in fuse protection in the preamp.

The preamp is designed to modern standards with a polarized AC power plug putting the internal fuse first, ahead of everything else on the hot side of the AC line, followed by the switch, transformer, and back to ground. If any internal failure to ground occurs in the preamp, the fuse blows, protecting the user.

With the hairbrained scheme that it appears the balanced line conditioner represents, there would still be 60V AC live in the preamp even after a fuse failure.

Which is precisely why most balanced power devices are fused and/or GFCI protected.

Balanced Power (technical power) is recognized under NEC code. It is not inherently unsafe, only a particular implementation may/may not be. It is only explicitly prohibited when used in lighting (where "neutral" may be tied to the fixture itself).

It will cancel common mode noise on a power line and that is measureable.

I would suggest that this question be asked in a more open forum like the lab.

avahifi · « **Reply #7 on:** 14 Dec 2006, 11:35 pm »

Gee, the device in question can supply 8 amps at 120V AC, so it, even if it is fused, it would have to be fused heavier than that.

For a preamp, that is like stuffing a penny in the fusebox.

My comments stand, too big a safety risk to use.

Frank Van Alstine

MarkM · « **Reply #8 on:** 15 Dec 2006, 03:48 am »

Guess I shouldn't be surprised by your response.

Some simple mods were implemented before the unit was even plugged in with safety a priority. I got together with some of the clinical engineering guys where I work and we did some fairly simple but necessary mods to the design, even used medical grade devices throughout.

I feel comfortable about the stability and safety of the unit, as Samplesj stated, implemented properly, there are alot of benefits. Your products offer a great value to performance return, thats where I will end. Merry Christmas.

rustneversleeps · « **Reply #9 on:** 15 Dec 2006, 04:24 am »

Quote from: MarkM on 15 Dec 2006, 03:48 am

Guess I shouldn't be surprised by your response. Some simple mods were implemented before the unit was even plugged in with safety a priority. I got together with some of the clinical engineering guys where I work and we did some fairly simple but necessary mods to the design, even used medical grade devices throughout.

.

BrianM · « **Reply #10 on:** 15 Dec 2006, 02:12 pm »

Quote from: MarkM on 15 Dec 2006, 03:48 am

I feel comfortable about the stability and safety of the unit, as Samplesj stated, implemented properly, there are alot of benefits. Your products offer a great value to performance return, thats where I will end. Merry Christmas.

If you already feel comfortable about the stability and safety, and feel it was implemented properly, why did you ask in the first place?

samplesj · « **Reply #11 on:** 15 Dec 2006, 02:31 pm »

Quote from: avahifi on 14 Dec 2006, 11:35 pm

Gee, the device in question can supply 8 amps at 120V AC, so it, even if it is fused, it would have to be fused heavier than that.

For a preamp, that is like stuffing a penny in the fusebox.

My comments stand, too big a safety risk to use.

Frank Van Alstine

I guess I wasn't clear with what I meant by fused. Look at Occam's Felicia project in the lab and notice that they are fused on the input lines like you assumed, but also fused on the output lines. Since the conditioner in question is a DIY design he could easily fuse the specific output line for the preamp line to limit.

CE2 · « **Reply #12 on:** 15 Dec 2006, 08:59 pm »

http://www.furmansound.com/products/pro/blncd/it-20.php But I read somewhere also that in a residential enviorment, it may not be smart to use balanced as it might in fact cause troubles elsewhere in the system. I don't know, I gotta look into this. Since you are applying a voltage on the neutral leg and down wind it may Change a grounded neutral which should not really have a voltage on it to having a voltage, relative to other outlets or something. Looks like a cure for a problem that doesn't exist in home audio. Studios, commercial places, different enviorment. Just get some good Furman line spike etc, it took out all the noise from things turning on in my house, and even from a switch within my system from a CD player. No more snap. I use 6 Furmans total 3 PF Pro R models and 3 PM-8 Series II and a PM-Pro Series II, Well there are 4 OmegaStar EX Hafler Pro 500 and other stuff being fed Off of 3 lines. You should do some reading up on Balanced power in a home system, it might not be a good idea.

Wayner · « **Reply #13 on:** 15 Dec 2006, 10:39 pm »

Quote from: samplesj on 14 Dec 2006, 09:24 pm

Quote from: avahifi on 14 Dec 2006, 08:59 pm
Correct me if I am wrong, but this "balanced line" signal conditioner appears to put 60V AC on both the hot and ground side of the AC into the preamp.

This is unsafe, because it defeats the built in fuse protection in the preamp.

The preamp is designed to modern standards with a polarized AC power plug putting the internal fuse first, ahead of everything else on the hot side of the AC line, followed by the switch, transformer, and back to ground. If any internal failure to ground occurs in the preamp, the fuse blows, protecting the user.

Balanced Power (technical power) is recognized under NEC code. It is not inherently unsafe, only a particular implementation may/may not be. It is only explicitly prohibited when used in lighting (where "neutral" may be tied to the fixture itself).

It will cancel common mode noise on a power line and that is measureable.

I would suggest that this question be asked in a more open forum like the lab.

Which chapter in the NEC says that this kind of power is acceptable in the home, for use with equipment designed for 120 volt line, neutral and ground? You are running 2 phase 60v with one side unprotected. Hopefully the "blanced" power supply is running on a class 2 isolation transformer. The NEC code is for residential wiring that has nothing to do with what you are talking about. Your device is a labratory device ment to be used in fashion associated with test instruments.

I would shut it down, but do as you see fit.

W

pearsall001 · « **Reply #14 on:** 15 Dec 2006, 10:51 pm »

I don't know what all the fuss is about. Here's a link to the guru of the company behind balanced power. I've had their "Son of Q" for over 3 years now, before I have most of the gear I'm running now. Everything is pluged into it & I wouldn't do it any other way. Professional studios & home systems both reap the rewards. Science or Voodoo? You be the judge. I know where I stand.

http://www.equitech.com/

Wayner · « **Reply #15 on:** 16 Dec 2006, 12:16 am »

Well, Frank Van Alstine is an electrical engineer and I'm a electrical machine designer. I guess there is a little to fuss about because we love all of you at AC and we don't want anything to happen to you or your family. If Frank says that a system is unsafe, I would heed his warnings. But then, people ignor their doctors advice as well.

Wayner

pearsall001 · « **Reply #16 on:** 16 Dec 2006, 02:09 am »

Quote from: Wayner on 16 Dec 2006, 12:16 am

Well, Frank Van Alstine is an electrical engineer and I'm a electrical machine designer. I guess there is a little to fuss about because we love all of you at AC and we don't want anything to happen to you or your family. If Frank says that a system is unsafe, I would heed his warnings. But then, people ignor their doctors advice as well.

Wayner

I take it you didn't click on the link. As an electrical designer I think you will find it interesting & a worth while read. You're never too old to learn something new.

xsb7244 · « **Reply #17 on:** 16 Dec 2006, 04:14 am »

Hi CE2. can you give us a review of the furman PF Pro R?

avahifi · « **Reply #18 on:** 16 Dec 2006, 11:36 am »

I went to the link

"touching the chassis would result in a 5 millisecond shock at only 60 Volts before the system sensors detected excess ground leakage and shut the system down."

That's nice, you only get zapped for a short time. Not me.

Frank

CE2 · « **Reply #19 on:** 16 Dec 2006, 12:59 pm »

Too much involved. READ all this. Just plugging it in and using it, AIN'T the way to go. Like I thought, too many other items to deal with, to do it all correctly. Ain't worth the effort, for the minimal probably inaudible improvements. Used in pro situations, where all kinds of noise is an issue, not at home. Improper use of these looks like a disaster waiting to happen. "We wire for fire"? It would seem that if you ain't protecting upstream with a GFCI BEFORE the BP unit, you is asking for toruoble, then you may bet nusiance tripping blah blah blah. Buy a bigger amp, that will improve the sound more than playing with balanced power. Get a good spike supressor to eliminate the anoying and posiblly deadly to tweeters snaps on dirty switches etc. I gots no pops or snaps on anything now with my bunch of Furmans, thre is so much filtering and filtering, the noise is gone. I use the PF units in front of the other Furmans as recomended in their instructions, even though teh PF alone has it's own filters kust like the other distribution/spike/filter units have. Besides they look cool, with their voltage and current read outs...in a small rack assys. My system sucks a lot of current when cranked Furmans show me about 18A total when cranked to about 108dB..I like it LOUD, clean, clear and LIVE..a bunch of OmegaStar EX's in teh Hafler Pro 500 units make it happen at around 4800W RMS capable or more. So does teh Ultra EC pre and Ultra DAC and OmegaStar EX Dyna PAT-5 some Ultra AVA phase inverters, it's all good. Don't think it needs balanced power, too many issues could happen. http://www.equitech.com/support/techgrnd.html