Power amps peak demand?... thinking about power regenerators
Posted by: goldfinch on 25 September 2008
Hi, I would like to know how much current can demand my power amp (nap 250.2).
I have very bad quality mains, with some interferences with my fridge and even lights. These cause noise through speakers and music dropouts with digital signals via coax. digital.
I am not sure a dedicated mains spur will solved the problem. Other mains problems are not local (cuts, variable quality depending on the time of the day...).
For these reasons I have decided to try a power regenerator. There are some beasts that claim being able to deliver even more current than a standard spur.
Can anyone give me this spec.?
Any experience with power regenerators?
Posted on: 25 September 2008 by Adam Meredith
quote:
Originally posted by goldfinch:
There are some beasts that claim being able to deliver even more current than a standard spur.
Why do I feel a little suspicious of this?
I believe the figure you seek is printed on the rear panel of the amplifier, just by the mains input socket. In the case of the NAP 250.2 the rear panel image I have indicates 480VA for Input Power. You should check this on your unit.
Posted on: 25 September 2008 by Lightkeeper
Goldfinch,
from what you describe, you have just an ordinary "mains quality" like most of us here
Oz
Posted on: 25 September 2008 by goldfinch
quote:
Originally posted by Adam Meredith:
quote:
Originally posted by goldfinch:
There are some beasts that claim being able to deliver even more current than a standard spur.
Why do I feel a little suspicious of this?
I believe the figure you seek is printed on the rear panel of the amplifier, just by the mains input socket. In the case of the NAP 250.2 the rear panel image I have indicates 480VA for Input Power. You should check this on your unit.
Thanks Adam, do you know if this figure is an average measure or is the maximum the power amp can demand?, do you know the maximum amps can demand a nap 250.2?
I would like to demo at home a purepower regenerator and I don´t know which one could match my system, specs are usually given in Amps, rms amps and peaks of maximum amps.
I know this sort of products promise too much but mains regeneration technology sounds very attractive,
Posted on: 25 September 2008 by goldfinch
OzrenH,
Yes, but maybe a power regenerator can solve it,
Posted on: 25 September 2008 by spacey
i really wouldnt bother. i have tried a few and they all did something. not an inprovement but kind of change things. i found it became flatter and boring with the ATC kit i had. the best one i found was an mains isolation transformer form trichord. its the powerblock500 which has a 2500VA tranformer.
it took the mains buzz in the kit. but then buzzed itsself.
Posted on: 26 September 2008 by djftw
I messed around with this a lot, some of it worked with my old kit - or at least I thought it did and got left in place at first when I first started getting Naim stuff. However, my dealer advised me to go back to completely standard mains (except for the dedicated radial & Hydra), and it really does sound loads better, the mains filters really were messing up everything. It was probably more significant than adding the Flat-Cap to the CD5x!
The only guy I know on here who is really happy with his mains filtering is using a 10KVA balanced mains transformer, as he's in a 110v area so that will allow him to pull around 91A. However, r-tee's 2.5KVA isolation transformer relates to about 10A on his 230v mains supply, I would have gone for something higher spec as I suspect there is a good reason Naim tell UK costumers with plug top fuses to use 13A fuses, and adding a 10A bottleneck would seem counterintuitive if I was trying to improve the supply!
Posted on: 26 September 2008 by G4RKO
quote:
Originally posted by djftw:
I messed around with this a lot, some of it worked with my old kit - or at least I thought it did and got left in place at first when I first started getting Naim stuff. However, my dealer advised me to go back to completely standard mains (except for the dedicated radial & Hydra), and it really does sound loads better, the mains filters really were messing up everything. It was probably more significant than adding the Flat-Cap to the CD5x!
The only guy I know on here who is really happy with his mains filtering is using a 10KVA balanced mains transformer, as he's in a 110v area so that will allow him to pull around 91A. However, r-tee's 2.5KVA isolation transformer relates to about 10A on his 230v mains supply, I would have gone for something higher spec as I suspect there is a good reason Naim tell UK costumers with plug top fuses to use 13A fuses, and adding a 10A bottleneck would seem counterintuitive if I was trying to improve the supply!
Maybe 'cause the next smaller mains fuse is rated at 5A?
Posted on: 26 September 2008 by goldfinch
quote:
Originally posted by djftw:
I messed around with this a lot, some of it worked with my old kit - or at least I thought it did and got left in place at first when I first started getting Naim stuff. However, my dealer advised me to go back to completely standard mains (except for the dedicated radial & Hydra), and it really does sound loads better, the mains filters really were messing up everything. It was probably more significant than adding the Flat-Cap to the CD5x!
The only guy I know on here who is really happy with his mains filtering is using a 10KVA balanced mains transformer, as he's in a 110v area so that will allow him to pull around 91A. However, r-tee's 2.5KVA isolation transformer relates to about 10A on his 230v mains supply, I would have gone for something higher spec as I suspect there is a good reason Naim tell UK costumers with plug top fuses to use 13A fuses, and adding a 10A bottleneck would seem counterintuitive if I was trying to improve the supply!
If Naim recommends 13A fuses why is also recommended installing a dedicated mains spur of 16A or even higher?
Posted on: 26 September 2008 by Analogue
quote:
Originally posted by goldfinch:
quote:
Originally posted by djftw:
I messed around with this a lot, some of it worked with my old kit - or at least I thought it did and got left in place at first when I first started getting Naim stuff. However, my dealer advised me to go back to completely standard mains (except for the dedicated radial & Hydra), and it really does sound loads better, the mains filters really were messing up everything. It was probably more significant than adding the Flat-Cap to the CD5x!
The only guy I know on here who is really happy with his mains filtering is using a 10KVA balanced mains transformer, as he's in a 110v area so that will allow him to pull around 91A. However, r-tee's 2.5KVA isolation transformer relates to about 10A on his 230v mains supply, I would have gone for something higher spec as I suspect there is a good reason Naim tell UK costumers with plug top fuses to use 13A fuses, and adding a 10A bottleneck would seem counterintuitive if I was trying to improve the supply!
If Naim recommends 13A fuses why is also recommended installing a dedicated mains spur of 16A or even higher?
Goldfinch,
The higher the amperage = lower impedence.
ATB
Chris N
Posted on: 26 September 2008 by goldfinch
Thanks Chris, this seems to complicated for me!
Posted on: 26 September 2008 by djftw
quote:
Maybe 'cause the next smaller mains fuse is rated at 5A?
Nope, the next smallest standard plug top fuse fuse would be 10A.
quote:
If Naim recommends 13A fuses why is also recommended installing a dedicated mains spur of 16A or even higher?
Really? The UK manual reads
quote:
ideally with a 30 or 45 Amp rating
Posted on: 26 September 2008 by Fossil
quote:
Originally posted by djftw:
quote:
Maybe 'cause the next smaller mains fuse is rated at 5A?
Nope, the next smallest standard plug top fuse fuse would be 10A.
quote:
If Naim recommends 13A fuses why is also recommended installing a dedicated mains spur of 16A or even higher?
Really? The UK manual reads
quote:
ideally with a 30 or 45 Amp rating
The priority with a spur is to minimise the voltage drop along the spur. In general the lower the amp-rating the higher the voltage drop will be. In UK a 16amp spur would be inadequate. 40 or 45amp would be far better. In the USA I would expect to double these figures.....110V requires twice the current of 220V....
In UK a NAP250 can blow 3amp plug fuses at power-on. This seems to indicate that the maximum power draw of a NAP250 is in excess of 3x220=660VA....maybe casting some doubt on the 480VA labeling ?
I believe that Isotek claim that a power amp can have instantaneous peak-demands in excess of 15000VA - which can be supplied from a standard ring-main but not from most mains-regenerators.... Except, of course, those made by Isotek...
Posted on: 27 September 2008 by Derek Wright
The HiTUF calculator at
heremight be of interest in calculating voltage drops.
Posted on: 28 September 2008 by David Sutton
Goldfinch,
I have been driving my 555/LP12/552/ATC50ASL through a regenerator (PS Audio P500) for some years now. With our mains supply here in Abu Dhabi, it works fine with a noticable improvement in presentation.
An interesting aspect of these units is the ability to monitor peak power output from the regenerator. Despite being rated at only 500Watts, I have struggled to need more that about 375-400W when listening to very loud music (552 at beyond 10 o'clock).
You need to audition one and decide for yourself. Like most things to do with hifi, one mans meat is another mans poison.
david
