Voltage stabilizer for audio system. Which one?

SDhawan schrieb:

Dear Neutral, The reccomendation here is to total all the max power requirement of your current & future components and then add 50 % to it to determine what you should go for. Regards Sanjay

Present components:
Computer: 300W
Artis HT: 100W
Amp: 300W

Future components:
TV: 165W

Total: 865W
Needed VA = 865 x 1.5 = 1300
So I'm safe

Neutral schrieb:

SDhawan schrieb: Dear Neutral, The reccomendation here is to total all the max power requirement of your current & future components and then add 50 % to it to determine what you should go for. Regards Sanjay Present components: Computer: 300W Artis HT: 100W Amp: 300W Future components: TV: 165W Total: 865W Needed VA = 865 x 1.5 = 1300 So I'm safe :prost

W = VA * PF

PF == Power factor. For most load it is around 0.8.

So your basic requirement of VA for 865 W load could be 865 W /0.8 = 1081 VA.

Then apply your safty factor of 1.5 times the VA rating, so in this it becomes: 1081 * 1.5 = 1621 VA.

So plan for 2 KVA if you really want to be safe.

SuhasG schrieb:

Neutral schrieb: SDhawan schrieb: Dear Neutral, The reccomendation here is to total all the max power requirement of your current & future components and then add 50 % to it to determine what you should go for. Regards Sanjay Present components: Computer: 300W Artis HT: 100W Amp: 300W Future components: TV: 165W Total: 865W Needed VA = 865 x 1.5 = 1300 So I'm safe :prost W = VA * PF PF == Power factor. For most load it is around 0.8. So your basic requirement of VA for 865 W load could be 865 W /0.8 = 1081 VA. Then apply your safty factor of 1.5 times the VA rating, so in this it becomes: 1081 * 1.5 = 1621 VA. So plan for 2 KVA if you really want to be safe.

I need a spanking for forgetting my electricical fundamentals! Yes, the PF for inductive loads (I guess everything except incandescent lamps) is less than one. So the division by the PF is called for.
However, my supplier gave me a 2KVA as I mentioned earlier. I had initially asked him for a 1KVA as 865W < 1KW but he rightly did his arithmetic and said that 2KVA is better as starting current has to be taken into account, not just the running current.

He specifically mentioned that cathode ray tubes (TVs and computer monitors) consume 2-3 times more current at start up. And I know that amps take more current at start up. My HT doesn't have a soft start and starts with a thump! I guess all motor windings take higher current at start up. As do tubelight chokes.

I have connected my entire HTS setup with a LOGICSTAT 4KVA stabilizer (earlier it was used with a an AC).

1) is 4KVA = 4KW
2) according to you is it a normal stabilizer or is it a servo stabilizer.

SUNILYO schrieb:

I have connected my entire HTS setup with a LOGICSTAT 4KVA stabilizer (earlier it was used with a an AC). 1) is 4KVA = 4KW 2) according to you is it a normal stabilizer or is it a servo stabilizer.

The formula is KW = KVA * PF .

4 KVA = 4 KW is possible only in ideal condition when the load connected is having Unity power factor.

Normal domestic loads are inductive in nature and hence has a power factor ranging from 0.7 to 0.9 lagging.

(There are certain electrical loads which have leading power factor. But it is rare to find such loads in our normal domestic applications)

Low power factor (lagging) means that appliance draws more current than otherwise suggested by its KW rating. That's why Electicity board charges penalties if the load has poor power factor and forces user to install power factor improvement devices such as capacitor banks, AC synchronous Motors etc.

Normal stabilizer (realys based) won't serve any purpose , it is just waste of money. Servo stabs can correct voltage in 2-3 milliseconds and can maintain voltage within 1-2%. But electical noise spikes are very fast (nano second) and before sevo can act , damage is done!

To protect from spikes you need to have different protection device/s while you will still need a Servo stab to maintain supply voltage within a safe operating band.

So that means we have add something that suppresses those spikes to the output of servo stab.

In that case can a power strip with spike suppressor be helpful??

I think mine is a relay-based (so less helpful ) how do i know if it is a relay-based? do i open it or is there any indication on the stab (like at the back)???

as per some folks a not so clean power is generally preferred over a fully regulated power source as the second usually falls short in terms of dynamics. realistically the cost of providing clean power with enough rating is usually too high to justify for most folks (definitely for me).

of course components like cdps, pre amps and most importantly turntables really benefit a lot from clean ower as their dynamic requirement is not so high..


But again most of the really good amps are built with good psu to take care of dirty power and a good power chord usually makes sure that the supply of power is good !

Of course a good spike buster is always a prerequisite for any electrical component.

i have a nice utilitarian power conditioner of the passive type which just does the basic polarity test and the basic RFI cleanup and that has been pretty useful..although i have been having improper thoughts on the PS audio series of regenerators;).another one is by ISOCLEAN ...one model by exactpower actually corrects the waveform rather than regeneration as by the former two..

My vendor claims that spike suppression (as in a spike-buster strip) is built into his servo stabiliser. But he warns that there is no protection against lightning (very high voltages).

Sunil, I am not sure if the electronic AC stabiliser you are using is suitable for audio purposes. Technical folks (Amp Nut, Suhas, Sachi) please help here. I would generally prefer a CVT to an electronic stabiliser (maybe just my prejudice, but I feel that it is built more sturdily.)

Hi !

There is an Indian company who is importing German lightening & surge protection devices which is installed at the mains power supply.

Cape India

The combo device cost about 23K - takes care of you entire household - as per the company claim.

Neutral schrieb:

My vendor claims that spike suppression (as in a spike-buster strip) is built into his servo stabiliser. But he warns that there is no protection against lightning (very high voltages). Sunil, I am not sure if the electronic AC stabiliser you are using is suitable for audio purposes. Technical folks (Amp Nut, Suhas, Sachi) please help here. I would generally prefer a CVT to an electronic stabiliser (maybe just my prejudice, but I feel that it is built more sturdily.)

Avoid CVT for powering Audio equipments. The "Ferro" or CVT works on the principle of Saturated Core. This is once again a transformer sort of thing, which creates a magnetic field, or flux, that is a function of the (input)voltage applied . This magnetic flux is more or less proportional to the voltage EXCEPT at the high or low voltage extremes. At these extremes, a relatively large change in voltage will result in little change in the magnetic flux, with the high voltage extreme described as being the "saturation" region.

CVT can provide good noise attenuation and are very reliable (as there are no moving parts or any electronic circuit to fail)

On the downside, CVTs can add significant harmonic distortion (Do you want them ride on your music?), have a serious problem with high inrush currents (And we know our amps draws a heavy in rush current), have very poor efficiency at less than full load (our power requirement varies) and tend to be very hot and noisy (We say No to even a ceiling fan and talk about sound-proofing the music room) in operation. Say NO to CVT.

Neutral schrieb:

I am not sure if the electronic AC stabiliser you are using is suitable for audio purposes.

Electronic Voltage Stabilizer is quite a vague description. It could be:

1>A voltage stabilizer with taps changing technology:

Instead of using conventional electromechanical relays it might be using solid state relays (SCR/ TRIAC based) and thus labeled as an Electronic Voltage Stabilizer’. Well, but this won’t solve the problem as it still a tap changing technology (4 to 6 available); voltage regulation is still sluggish and less accurate. Even solid-state Relays take time to operate so correction is still slow. For voltage transients, surges, and spikes this technology serves no good as by the time correction mechanism kicks in the, damage is already done!

This means that you are buying another piece of junk at a higher price under the name ‘ Electronic / Solid state Voltage Stabilizer’!


2>A voltage stabilizer based on waveform shaping technology:

In this technology, input power source waveform is continuously monitored and compared with a highly accurate and stable reference waveform. Based on this comparison, it then adds or subtracts exactly the required amount of correction. The compensation required by this method is only a fraction of overall power. Such stabilizer operates with high efficiency and produces little heat, and are fairly compact and lightweight. Since all circuitry is analog and there are no oscillators or switches, the unit itself does not act as a source of spurious high-frequency noise.

This is a serious piece of equipment and of course pretty expensive, this may cost more than your Stereo Integrated amp!

I think no body in India makes this type of Voltage Stabilizers. (At such a cost , who will buy it?) . There was a model offered by Aplab , Mumbai based on Single cycle correction principle but again it was using Solid state switching and needed 20 millisecond to correct. Damage Done ! Aplab no longer sells this.

Hi !

Can any of the "Tech" guys here look at the new power supply oferings from Sonodyne and let us know what would be suitable for what kind of system?

Sonodyne

Thanks

SuhasG schrieb:

Avoid CVT for powering Audio equipments. The "Ferro" or CVT works on the principle of Saturated Core. This is once again a transformer sort of thing, which creates a magnetic field, or flux, that is a function of the (input)voltage applied . This magnetic flux is more or less proportional to the voltage EXCEPT at the high or low voltage extremes. At these extremes, a relatively large change in voltage will result in little change in the magnetic flux, with the high voltage extreme described as being the "saturation" region. CVT can provide good noise attenuation and are very reliable (as there are no moving parts or any electronic circuit to fail) On the downside, CVTs can add significant harmonic distortion (Do you want them ride on your music?), have a serious problem with high inrush currents (And we know our amps draws a heavy in rush current), have very poor efficiency at less than full load (our power requirement varies) and tend to be very hot and noisy (We say No to even a ceiling fan and talk about sound-proofing the music room) in operation. Say NO to CVT.

Thanks a ton Suhas for the detailed reply
At my home in Bombay, a 500VA CVT used originally for a fridge was lying around. So my mother connected all our equipment: 21" TV, Sony music system and my 300W (input) amp to it. I invited Observer (a Mumbai forum member) to my place for an audition. He turned up the amp volume while listening to Dire Straits.

He complained that there was distortion at higher volumes and the system wasn't sounding the way it should. Something just wasn't right. In hindsight, I realise that the CVT (that too overloaded) might have played the devil!

Suhas, tell me please, will my 2KVA servo stabiliser also introduce any noise or other artifacts into the music? Or is it a considerably better option than a CVT? As a servo has a motor, how long can I reasonably expect it to last? Is my servo drinking power, even when there is no load on it?

My servo has both a transformer and a motor. How much magnetic interference is it likely to generate? Should I keep the computer, monitor, amp and speakers at a particular distance away from it?

I apologise for asking you so many questions. But, I do need some education!

SuhasG schrieb:

Neutral schrieb: I am not sure if the electronic AC stabiliser you are using is suitable for audio purposes. Electronic Voltage Stabilizer is quite a vague description. It could be: 1>A voltage stabilizer with taps changing technology: This means that you are buying another piece of junk at a higher price under the name ‘ Electronic / Solid state Voltage Stabilizer’!

Suhas, we are talking about an AC stabiliser here. I think it fairly reasonable that it will not handle the requirements of an audio system correctly. The one at my office categorically states "Designed for AC use only". This is in spite of a high stated VA of 4KVA or so.

I had a similar problem with my Pass Labs preamp shutting down due to low voltage. Pass Labs explicitly recommended against using a Servo and advised to use a CVT as well. CVT's control voltage and act as very good surge supressor's. The only problem is they are noisy so you need to have them out of the listening room.

msb1 schrieb:

I had a similar problem with my Pass Labs preamp shutting down due to low voltage. Pass Labs explicitly recommended against using a Servo and advised to use a CVT as well. CVT's control voltage and act as very good surge supressor's. The only problem is they are noisy so you need to have them out of the listening room.

I didn't understand the "noisy" part. They have no moving parts and are very quiet. I guess you mean that they introduce phase shifts and line noise. But how do you get them out of your listening room?

I didn't understand the problem with a servo stabiliser. I just bought one. You are saying that I should not use it for a preamp?