AC Power Voltage Regulation

Musica Amantem · « **on:** 14 Feb 2015, 07:20 pm »

Hi!

I need some orientation on this subject of which I'm not familiar. I've been using an Isolation Transformer for almost three years now, without any noise issues. Lately, the power company in the town I live in is experiencing some issues and I have noticed voltage fluctuations, mostly during peak demand times. Although my system continues to enjoy a very quite background, my system's SPL drops when the Mains AC voltage is failing.

Since I'm happy with my Isolation Transformer, I was wondering if it would be advisable to connect a Voltage Regulator to my Isolation transformer and feed my system's components from it, or viceversa, plug the Voltage Regulator to the wall instead and connect my Isolation Transformer to it, and distribute power from the transformer to the system's components.

I hope I'm not intruding in the wrong forum with this new thread. Thanks in advance for any candid and informed opinion.

PS.: I have a tube integrated amp with tube input and output voltage regulation, but when the mains are unstable, I loose significant SPL at same volume dial settings. The sound may suffer plus my DAC is probably not liking it either.

I asked the manufacturer of my Isolation Transformer for one of his Voltage Regulators but he said these are not designed to be coupled with the Isolation Transformer, as each need to be plugged directly to the wall outlet. Go figure!

Any suggestions?

dBe · « **Reply #1 on:** 16 Feb 2015, 07:38 pm »

Getting on an airplane in 5 minutes. I'll write more when we get on shipboard tomorrow.

paul79 · « **Reply #2 on:** 16 Feb 2015, 07:42 pm »

I too have issues with power in the summertime, sometimes gets as low as 110 Vac. I just sweat it out, and when fall hits, I'm all good again...

I sure would love a good regulated power solution, so I am interested in some info here as well. The sound absolutely suffers from the summertime blues also....

Enjoy that trip Dave! Very much envious I am... I am so due for a vaca...

rollo · « **Reply #3 on:** 16 Feb 2015, 08:24 pm »

Quote from: dBe on 16 Feb 2015, 07:38 pm

Getting on an airplane in 5 minutes. I'll write more when we get on shipboard tomorrow.

Aye Captain.

charles

Musica Amantem · « **Reply #4 on:** 18 Feb 2015, 11:49 am »

Still no replies, Huh? I'm so lucky I chose the exact time the most knowledgeable member is on vacation ... Good for him! Anyone else?

dBe · « **Reply #5 on:** 18 Feb 2015, 05:18 pm »

WiFi on the shop is .75 a minute... yikes! Methinks the reply is yet to come. Stay.tuned... the tight wad WILL answer eventually.

paul79 · « **Reply #6 on:** 18 Feb 2015, 06:36 pm »

I say this can wait! Enjoy that there trip man. We'll be here when you get back.

woodsyi · « **Reply #7 on:** 18 Feb 2015, 06:48 pm »

Enjoy the cruise. Voltage will still fluctuate when you get back to something cheaper than $45/hour internet.

Musica Amantem · « **Reply #8 on:** 18 Feb 2015, 07:24 pm »

No worries, I'll wait.

Musica Amantem · « **Reply #9 on:** 20 Feb 2015, 06:16 pm »

Speedskater · « **Reply #10 on:** 20 Feb 2015, 09:46 pm »

Do you have a 'Kill-a-Watt' meter or similar that you could log the voltages? My voltage varies in steps from time to time. I think the power company switches taps on a transformer. It varies ±5% for no visible reason. This afternoon with record low temperatures it's at +4%.
But in any case I would never notice a 0.5dB change in loudness.

Musica Amantem · « **Reply #11 on:** 20 Feb 2015, 11:56 pm »

Well, any and all voltage fluctuations (which occur constantly in most mains, to varying degrees) are bad for your sensitive electronic equipment, especially a DAC. Also, the DAC may not behave optimally, thus not offering its best analog conversion. This applies to most digital audio components.

One would neeed to plot voltage samples during several days to get a notion of the voltage distributions, and these may even change from week to week.

I think it is just good profilaxis to aim at the best and most stable power conditions if you care for sound.

Just the way I see it.

MtnHam · « **Reply #12 on:** 21 Feb 2015, 12:20 am »

In areas where voltage fluctuations are problem, a regeneration unit is probably the best solution.

dBe · « **Reply #13 on:** 21 Feb 2015, 06:21 pm »

We are back on land at FLL waiting for our flight home, so now is a good time to answer.

This is a difficult question for me to answer. I used a Topaz 2.5kVA Ultrat Isolation Tx for some time before I developed the BUSSes. I had a PS Audio PowerPlant that I used in conjunction with it. My system at that time was comprised of a much modified Cary SLP50B, Cary CAD572SEMkII mono blocks and a Cary 306CD player. The system was very quiet. Even so, it lacked a bit of dynamics with that configuration. The best combo was with only the CD player plugged into the PP. Everything else into the Tx. Even so, the system was not as dynamic as plugged straight into the wall.

I guess the answer depends upon what you value most: noise reduction or consistent volume. While you can obtain consistent SPL with a regenerator or autoformer, the trade-off in dynamics might be off putting. It is like everything in life. There are very few absolutes and compromise is something essential.

That being said, if I were in your position with a preference for consistent levels and knowing what I know about this power thing, I would would sell the Tx and buy the largest capacity regenerator I could find. So, I would find a regenerator to borrow or with a 100% return policy and try it with and without the transformer in tandem, with the Tx first in the power chain.

I am blessed with consistent-ish voltage, so this is definitely a YMMV situation.

Digital sources are usually very tightly voltage regulated and could care less about +/- 10% fluctuations.

Back to you in the discussion.

DaveBSC · « **Reply #14 on:** 21 Feb 2015, 09:23 pm »

Most power amp manufacturers strongly recommend against plugging their products into voltage regulating autoformers not just because of the loss of dynamics that can result by these relatively slow reacting devices but because of serious issues that can occur. There was a reviewer who plugged his subwoofer into one of the relatively cheap VR devices made by APC (but that still claimed something like 1.5kVA capacity). When the sub powered on, the current in-rush caused a momentary voltage sag that the APC interpreted as an under-voltage condition. It boosted voltage to compensate, and the result blew the fuse in the sub.

So called AC regenerators like those made by PS Audio are probably a better bet, but my experience with the previous generation Power Plant Premier was that as a line conditioner device, it was much less effective than passive types like the UberBuss. The PPP was also incredibly unreliable, but I think the newer models are better at that.

TheCableCo should be able to lend you one to try at home for a small fee, or a PS dealer may be willing to do it.

Musica Amantem · « **Reply #15 on:** 22 Feb 2015, 12:24 pm »

Thanks for the valid feedback. I had considered a regeneration plant for a while, but found it too expensive for the relatively minor need I'm facing. In addition, my Isolation Transformer is doing everything else, except voltage regulation (at least to the extent needed during demand peak times in my place).

I would not be too concerned with limited dynamics from a second device in tandem, since my amp is a SEP class A, running at only 4 Watts/Ch RMS @ 8 Ohms of speaker impedance (consumption of 70 Watts/Hr) and my speakers are 98 dBs @ 1 W/1 M.

I do not think voltage fluctuations are only affecting SPL. Even though well designed digital components are well protected against voltage fluctuation damage, the statement would imply all power cords are the same and all conditioners are also the same, as each component has its own inner protection devices ... Not in my view. I expect their 'performance' not to be affected either, as it would in turn impact sound quality.

I'll probably live with the issue, avoiding as much as posible peak demand periods when I listen, since apparently the potential solutions are not really feasible. My system sounds great as it is, I just wanted to make sure I'm not loosing sound quality stemming from voltage fluctuations.

I may also consider a dedicated circuit only for my audio gear, although this would not prevent voltage fluctuations coming from the power supplier.

Thanks again for the pointers.

HAL · « **Reply #16 on:** 22 Feb 2015, 12:40 pm »

For certain types of power line noise, like light dimmers, the PS Audio PPP has been a very good piece with my Pass Labs Aleph 2 monoblocks, Rythmik 370PEQ servo amps and digital front end. So far the PPP has been very reliable in my setup over many years of use. I sold my PS Audio P300 to a friend who now runs his analog front end with it.

Only device that killed the dimmer noise when my wife uses them throughout the house.

I also use an UberBUSS with the setup feeding the PPP. Use a MiniBUSS for extra distribution.

dBe · « **Reply #17 on:** 22 Feb 2015, 05:30 pm »

Quote from: Musica Amantem on 22 Feb 2015, 12:24 pm

Thanks for the valid feedback. I had considered a regeneration plant for a while, but found it too expensive for the relatively minor need I'm facing. In addition, my Isolation Transformer is doing everything else, except voltage regulation (at least to the extent needed during demand peak times in my place).

I would not be too concerned with limited dynamics from a second device in tandem, since my amp is a SEP class A, running at only 4 Watts/Ch RMS @ 8 Ohms of speaker impedance (consumption of 70 Watts/Hr) and my speakers are 98 dBs @ 1 W/1 M.

I do not think voltage fluctuations are only affecting SPL. Even though well designed digital components are well protected against voltage fluctuation damage, the statement would imply all power cords are the same and all conditioners are also the same, as each component has its own inner protection devices ... Not in my view. I expect their 'performance' not to be affected either, as it would in turn impact sound quality.

I'll probably live with the issue, avoiding as much as posible peak demand periods when I listen, since apparently the potential solutions are not really feasible. My system sounds great as it is, I just wanted to make sure I'm not loosing sound quality stemming from voltage fluctuations.

I may also consider a dedicated circuit only for my audio gear, although this would not prevent voltage fluctuations coming from the power supplier.

Thanks again for the pointers.

Now it is time for the sales pitch. Using an Uber or a RevB AFTER the ISO Tx will provide a current well and improve the dynamics as well as further lower the noise floor. The increase in micro as well as macro dynamics is worth the cost even with low current demand systems.

Curious: what speakers are you using?

Musica Amantem · « **Reply #18 on:** 22 Feb 2015, 06:02 pm »

I have the new Tekton Lore 2.0 floorstanding speakers. I alternate these with my Decware DM945 monitors on stands. Both speaker sets are used in conjunction with a Velodyne SUB (DLS 3500), evidently with quite different crossover cut settings.

I appreciate your sales pitch, but there's something that does not ring a bell in my mind:

How can the dynamics improve beyond what I have now (with only the IS Tx in place), if, in the best scenario, the current draw is limited by the IS Tx, and the Power Conditioner would not overcome this limitation if connected after the IS Tx (best scenario = IS Tx is the current flow bottleneck).

Unless you are implying that further noise reduction stemming from the added filtering of the Power Conditioner allows for better micro and macro dynamics, somehow? I would expect higher levels of detail by lowering the floor noise and sort of lifting a 'veil' from the presentation, but dynamics?

Could you explain the basis of your claim, please?

Thanks, and enjoy your well deserved vacation.

brj · « **Reply #19 on:** 22 Feb 2015, 06:21 pm »

Quote from: Musica Amantem

Even though well designed digital components are well protected against voltage fluctuation damage, the statement would imply all power cords are the same and all conditioners are also the same, as each component has its own inner protection devices ... Not in my view.

I would recommend not reading that implication into the original statement. Voltage stability is only one factor of many that impact electrical performance. For power cords and conditioners, I tend to pay more attention to their impact on instantaneous current draw, not to mention overall RLC properties.