[jtwrace]

As the tittle asks, do you use any sort of power conditioning with your Hypex amps?  If so, what?  Please tell us exactly what you use and what you have found. 

 

[Julf]

No, and it seems it is not needed and might actually be harmful. The smps600/nc400 combo has pretty darn good power supply noise rejection ratio, and seems to benefit from as little resistance/impedance in the power supply path as possible.

[roscoeiii]

Jackman and I tried his ncore into my Running Springs Haley and I thought it added a bit more richness and meat on the bones, but the detail, openness, dynamics and magic seemed diminished a touch. Though I could see someone preferring the sound with the power conditioner. And some of the downside could be potentially reduced or eliminated with a power conditioner designed for higher power devices. FWIW.

On the other hand, the Crown XLS we were comparing it to was markedly improved by the Haley.

[Airborn]

No with my NC400.  I tried them into a Belkin PF60 and it quashed all the dynamics and air in the presentation, imo.  So now they are straight into the wall even though I worry about power surges, etc.

[gstew]

I have several power conditioning options... several DIY Hammond 193L & 193M chokes used as parallel filters, a PS Audio Soloist in-wall filter, and most recently, a PS Audio P10.

When I first started using the NC400, I went back and forth between straight into the wall or in parallel with a 193L & a 193M. With the choke filters they were a bit smoother on the high-end, but slightly less dynamic. I left them into the wall at that time.

I added the Soloist in preparation for the P10. I tried the NC400 into it, heard a bit more reduction of dynamics with similar smoothing in the highs compared to the chokes, and again stuck to straight-in.

Once the P10 arrived, I tried the NC400 into it and liked that combo immediately... smoother highs, more detail & articulation across the spectrum, same or greater dynamics, less change from 'good' powerline times to 'bad' powerline times. I also tried the P10 into the Soloist (as PS recommends) and with the two Hammond chokes in parallel on the input. I didn't think the Soloist added much and still diminished dynamics (only slightly now). The Hammond chokes in front of the P10 added their bit of smoothness with no reduction in dynamics and they've stayed in. Still, the effect of each with the P10 is only a fraction of what it does and I could live happily with just the P10.

Yup, the P10 is expensive and heavy. But it was very worthwhile with the NC400 to my ears.

YMMV.

Greg in Mississippi

[barrows]

I use a DIY parallel element only power conditioner for my NC-400 stereo amp.  No chokes.  The filter circuit is tuned so that it does not creat a resonance with the built in filter of the SMPS 600 modules.  Remember, the SMPS 600 already has a built in CLC filter circuit, so additional power filtering can create resonances which could be harmful to the sonics of the system in general if not properly tuned/damped.
Best thing to do is to use a 'scope to check the effects of different power conditioners and their interaction with the built in filter circuit of the SMPS.

[Folsom]

Barrows, is the CLC dampened in the SMPS600? I doubt it. But I also doubt there is any huge resonances either.

The Ncores will always benefit from less noise on the line, in a parallel fashion. They're also going to benefit from PFC. But you bring up a good question, what if CMC's that people try with the Ncore have a problem not because of current, but resonances. That seems more plausible since the resistance of the average CMC that's correctly sized isn't really any more than just having an extension cord.

[occamsrazor]

I live in a place where the electricity is rather unreliable with multi-hour power cuts common, so my house is wired up with a whole-house inverter running off car batteries, which kicks in almost instantly when the power goes off. It's a modified sine-wave inverter. Even when inverter is off and the mains is working the voltage can fluctuate up to 255v, and when the inverter is on it can go down to around 200v.
My Audiolab M-DAC was freaking out at this 200v, so as a result I've been using a transformer based voltage-stabilizer to even out these fluctuations, like this:
http://www.tripplite.com/line-conditioner-1000w-avr-system-automatic-voltage-regulator-power-conditioner-ac-surge-protector~LR1000/
And I also use a surge protector like this:
http://www.micro7.com/products/consumer-applications/electronic/p6ce/
Now I'm about to build a pair of NC400 monoblocks using the SMPS600.
Can anyone advise if they see any negative effects using this setup with the NC400/SMPS600? Or whether you think it is not needed?
Please note that unlike the way some people use line conditioners, I'm not trying to "optimize" the sound but primarily to protect the equipment.

[Julf]

I live in a place where the electricity is rather unreliable with multi-hour power cuts common, so my house is wired up with a whole-house inverter running off car batteries, which kicks in almost instantly when the power goes off. It's a modified sine-wave inverter. Even when inverter is off and the mains is working the voltage can fluctuate up to 255v, and when the inverter is on it can go down to around 200v

The SMPS600 is specified for 180 V to 264 V, with an absolute maximum of 270, so you should be OK.

The power here fluctuates a lot too, and I have not noticed any adverse effect.

[barrows]

Occam:  That sounds like some really bad power there, beware that most inverters are pretty bad, and have high distortion (meaning noise noise harmonics) on their output.  I see that you at least have one which outputs a sine wave, does it have a distortion specification?
I do not think that voltage fluctuations would harm the SMPS 600, as Julf notes they have a wide input voltage tolerance, but, these are not regulated supplies, so voltage fluctuations at their input will result in voltage fluctuations in their output (which would be the case with most any amplifier) and hence amplifier output would vary.
Your situation presents a very strong case for having a really good, high power, AC regenerator like a PS Audio P10 to eliminate noise and stabilize the voltage going to all of your gear.

[occamsrazor]

Occam:  That sounds like some really bad power there

Yeah it is. 90% of the time it is OK - well it's on and doesn't fluctuate that much. But at least once or twice a week we have a cut of an hour or two, and every fortnight or so we have a cut that lasts most of the day. Many people use petrol generators for these outages, but others like me use inverters which are more convenient although duration of continuous operation is limited by your batteries. Pretty much everyone uses protective devices to cut power to fridges during brownouts as otherwise their motors burn out.

The inverter I use is this:
http://www.mdspower.com/trace/drseries.html
And it's connected to 4 x rather large 200VA sealed gel batteries. Each is around double the size of a large car battery.
In addition the house is wired with a whole-house surge protector that also protects against over/under voltage - to some extent, not really tight enough for sensitive equipment. But these are cheap and very good by the way:
http://www.sollatek.com/products/avs30/

beware that most inverters are pretty bad, and have high distortion (meaning noise noise harmonics) on their output.  I see that you at least have one which outputs a sine wave, does it have a distortion specification?

Presumably the "noise harmonics" are only in effect when the inverter is actually operational though, right? Not when the mains power is on and the inverter is in standby.
Well it's a modified sine wave, not a pure sine wave. Pure is obviously better but much more expensive.
http://www.bixmart.com/assets/images/PSCompareMS.jpg
There are some specs here, mine is one of the 1500w models but am not sure which:
http://www.mdspower.com/trace/drseries.html

I do not think that voltage fluctuations would harm the SMPS 600, as Julf notes they have a wide input voltage tolerance, but, these are not regulated supplies, so voltage fluctuations at their input will result in voltage fluctuations in their output (which would be the case with most any amplifier) and hence amplifier output would vary.
Your situation presents a very strong case for having a really good, high power, AC regenerator like a PS Audio P10 to eliminate noise and stabilize the voltage going to all of your gear.

The PS Audio P10 certainly looks totally awesome, but is way above my price range. As mentioned in my previous post the electrical fluctuations mainly happen when the mains is cut and the inverter is operational, or during the split-second handover between them. I can totally live without my hifi during these hours, so I don't need a system that keeps audio optimal during this time. What I need is a system that protects the amplifiers during this time.

My choice really is do I just use the surge protectors to cut power entirely to the amps when it is over/under voltage? But bearing that the surge protector's "acceptable" range can be as wide as 180-255v....
Or is it better to additionally use the voltage stabilizers to keep the voltage at the correct level and the amps running? My inclination is to do this.
But I've heard various stuff about inductive vs capacitative loads, and that the transformer-based voltage stabilizer may affect that in some way, but I don't really understand.....

[barrows]

OK, as long as you do not care about audio performance during the power cut, then your inverter is not a factor.  I bring it up, because I have had some dealings with folks using solar power, and in this case the inverter quality is a huge factor in audio performance, then one needs a true sine wave, very low distortion inverter.
As for the voltage stability, when the incoming voltage fluctuates, any component which runs on non-regulated supplies will be affected.  Low level components, typically, run on regulated supplies, but amplifiers typically do not.  So an incoming voltage variances will affect the amplifier output, and change the dynamics of the system.  If one's AC line voltage is unstable, then some kind of low impedance voltage stabilizer on the incoming AC can be helpful in restoring proper dynamics.  A transformer based approach is inadequate for audio purposes though (these typically tap different windings, switching back and forth, to "stabilize" voltage, hardly accurate). 
A really good AC regenerator is the proper way to stabilize voltage, eliminate noise, and even reduce AC impedance to the audio system (as long as they are used with a fair amount of power headroom).  I understand that good regenerators are expensive, but they are really the only way to take care of voltage stability without compromizing other aspects of AC power delivery, and even AC regenerators have their limitations (ultimate power delivery will be less than what the line can provide).

[cab]

Most modified sine inverters have tons of harmonics and really nasty output; lots of precision electronics won't even run or function properly with them. I can't help but think a quality amp like the ncore wouldn't be anywhere close its best with one of those....

[occamsrazor]

First off thank you for your informative replies.... much appreciated.

OK, as long as you do not care about audio performance during the power cut, then your inverter is not a factor.  I bring it up, because I have had some dealings with folks using solar power, and in this case the inverter quality is a huge factor in audio performance, then one needs a true sine wave, very low distortion inverter.

Yes for sure i can understand that. Inverters are far from ideal, to get quality electricity out you need to spend a lot. On the other hand for 95% of home use (lights, most electronics) they work pretty well, even the modified sine wave ones. But I recongnise quality audio falls well outside of that case scenario.

As for the voltage stability, when the incoming voltage fluctuates, any component which runs on non-regulated supplies will be affected.  Low level components, typically, run on regulated supplies, but amplifiers typically do not.  So an incoming voltage variances will affect the amplifier output, and change the dynamics of the system.  If one's AC line voltage is unstable, then some kind of low impedance voltage stabilizer on the incoming AC can be helpful in restoring proper dynamics.  A transformer based approach is inadequate for audio purposes though (these typically tap different windings, switching back and forth, to "stabilize" voltage, hardly accurate).

Ah... I didn't realise the SMPS600 was unregulated. I see your point now - any voltage fluctuations in input will cause similar fluctuations in voltage output. Given output goes to the speakers, what kind of effect would that have? In this case I imagine a stabilizer has some use. I am assuming mine is a transformer based stabilizer but I've no idea really. The specs are here if it makes any sense to you...
http://www.tripplite.com/shared/product-pages/EN/LR1000.pdf
Either way it seems to me that the voltage regulation it performs, while perhaps less accurate than would be ideal, is certainly much better than using no stabilizer. The other night when the inverter was on and voltage had dropped to 205v I measured the stabilizer output and it was exactly 239v and stable.... so not too bad.

A really good AC regenerator is the proper way to stabilize voltage, eliminate noise, and even reduce AC impedance to the audio system

I will certainly look into this option in the longer term. For now though, I just want to make sure I don't fry my Ncores the day after I complete building them

Most modified sine inverters have tons of harmonics and really nasty output; lots of precision electronics won't even run or function properly with them. I can't help but think a quality amp like the ncore wouldn't be anywhere close its best with one of those....

Certainly, but as I said the majority of the time I'm running off mains, I am not in the solar power+inverter all-the-time type scenario that barrows mentioned. When there's a power outage the last thing on my mind is audio quality
But what you say about modified sine wave output is certainly true. That said I have a house full of mac minis, mac laptops, gigabit switches, routers, access points, NAS devices, etc and in 3 years the combination of the inverter and microprocessor controlled surge protectors hasn't led to any devices being damaged, and they continued to run during the mains outages.

The only devices I have had problems with were: I wanted to run a UPS in addition dedicated solely for my internet router, to keep it going when the inverter batteries were exhausted. It worked fine when the mains was on, but when the whole-house inverter kicked in and the UPS started receiving modified sine wave input, it screeched and got fried - permanently.
The other problematic device was the Audiolab M-DAC which when running on inverter power started flashing the bootup screen and refused to complete boot process, stuck in a reboot loop. This was on the first day I got it, and I thought I had fried it, which led to me buying the stabilizers. That said it's likely the issue was the under-voltage not the modified sine wave. Since then it's been fine.

[BPT]

occamrazor:
Another good product for you to consider is from PurePower http://www.purepoweraps.com/. They build audiophile grade battery backup AC power regenerators.
Chris H.