After many hours of listing I'm pleased to say Hypex have another very satisfied customer. They really are all they're cracked up to be!
On first listening I found something lacking in the bass power and control. So I swapped out the 3 fairly thin solid silver/gold plated wires per binding post that were used initially to some very thick Chord Odyssey which is silver plated OFC. I was stunned to hear so much difference from changing just 3cm of wire. As mentioned previously on this thread, the ncore does seem sensitive to its output wiring.
I want to set mine up with a +12v trigger as posted a on here a while ago. As discussed I might have to make a basic transformer, BR & relay box to switch over my control output from +12v when on, to +12v when off to keep the SMPS in standby.
But did anyone ever find out if the SMPS has a constant output that could be used or adapted to keep it in standby?
On first listening I found something lacking in the bass power and control. So I swapped out the 3 fairly thin solid silver/gold plated wires per binding post that were used initially to some very thick Chord Odyssey which is silver plated OFC. I was stunned to hear so much difference from changing just 3cm of wire. As mentioned previously on this thread, the ncore does seem sensitive to its output wiring.
I want to set mine up with a +12v trigger as posted a on here a while ago. As discussed I might have to make a basic transformer, BR & relay box to switch over my control output from +12v when on, to +12v when off to keep the SMPS in standby.
But did anyone ever find out if the SMPS has a constant output that could be used or adapted to keep it in standby?
Good to hear!
The ncores do benefit from low-impedance, high-current speaker cables - the less "audiophile magic" the better, it seems
Yes - the answer is "no". When the SMPS goes into standby, it really goes into standby. No voltages available.
OK thanks. Looking at the datasheet, to put the SMPS into standby; I need to apply +3.3 to 12Vdc to J1:1.
But I'm not sure where to connect 0v?
Maybe J1:5?
So your grounds wouldn't connect anywhere else? As long as there is some connection somewhere, you are OK using a single pole relay, as the standby signal doesn't cause any significant ground current.
Right - that is the usual case, and with that setup, a single-throw relay is enough.
Yes I'm using the recommended ground wiring but with a single ended cable to each amp so the shield carries all ground currents to the source which is mains grounded. If I run an additional connection between J1:5 of each amp, I'll create 'triangle' grounding (if there is such a thing).
Since the standby current is so low, and there should only be current flowing when the amps are on standby, are we saying its OK to strap 0v of the standby psu to ground of the source? That way the return path for the standby current is the shield of the single ended cable. Then I connect J1:1 of each amp together with a single wire, which is connected in the middle to an SPST relay that switches the +v standby signal?
Sorry if I'm over thinking this but I'd hate to spoil the audio performance through lack of knowledge!
Since the standby current is so low, and there should only be current flowing when the amps are on standby, are we saying its OK to strap 0v of the standby psu to ground of the source? That way the return path for the standby current is the shield of the single ended cable. Then I connect J1:1 of each amp together with a single wire, which is connected in the middle to an SPST relay that switches the +v standby signal?
Sorry if I'm over thinking this but I'd hate to spoil the audio performance through lack of knowledge!
So don't!
Is your standby psu grounded? If so, your 0v is already connected to ground, and no additional ground connection is needed. If not, connect 0 v to J1:5 to *one* amp, still no ground loop.
I'm trying to find information about a settling time for NCore, but it is not mentioned in official materials or this thread.
I've found a requirement that it "must be less than 1µs (microsecond), to maintain high quality audio" -- KV2 Audio
Have anyone tried to measure settling time for NCore?
EDIT: I've found something in AES118BP whitepaper from 2005 at page 5 suggesting it might be around 20us, but this is old paper and NCore might be different.
I've found a requirement that it "must be less than 1µs (microsecond), to maintain high quality audio" -- KV2 Audio
Have anyone tried to measure settling time for NCore?
EDIT: I've found something in AES118BP whitepaper from 2005 at page 5 suggesting it might be around 20us, but this is old paper and NCore might be different.
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to my best knowledge, no independent measurements of NCOREs are available as of yet. Bruno does not believe in the relevance of square-wave response. FWIF I don't either.
that webpage kind of reminds me of those "a very well hidded secret about weight loss" ads.
and remember that there's a 400kHz carrier always riding on your signal, kind of makes you wonder about the relevance of 1us settling times. the FR plot of the NCORE (the small post 20kHz bump) indicates that there is some ringing, if that helps you in any way.
I'd stay away from webpages telling you that the response to something that never actually exists in music is relevant, but that's just me and my opinion.
that webpage kind of reminds me of those "a very well hidded secret about weight loss" ads.
and remember that there's a 400kHz carrier always riding on your signal, kind of makes you wonder about the relevance of 1us settling times. the FR plot of the NCORE (the small post 20kHz bump) indicates that there is some ringing, if that helps you in any way.
I'd stay away from webpages telling you that the response to something that never actually exists in music is relevant, but that's just me and my opinion.
I've found two reviews from USA Tour of NC400 that suggest there might be a problem with shortened/blurred decays of instruments:
- "Its almost like the Ncore sound is too fast and leaves the stage before the notes have time to 'shimmer' away in the distance. I feel as though the Ncore shortens the decay time of the instruments, resulting in a slightly smaller music space."
- " That said, and despite other things the Ncore does well, I find its presentation a little flat, and leaves me wanting more. It's as if the Ncore, like you said, drops the finer leading edges of the music---almost as if I'm listening through a cloth that veils high frequency decay, ambiance and subtle detail."
Source: Hypex NCore NC400 - USA Tour Listening Impressions
- "Its almost like the Ncore sound is too fast and leaves the stage before the notes have time to 'shimmer' away in the distance. I feel as though the Ncore shortens the decay time of the instruments, resulting in a slightly smaller music space."
- " That said, and despite other things the Ncore does well, I find its presentation a little flat, and leaves me wanting more. It's as if the Ncore, like you said, drops the finer leading edges of the music---almost as if I'm listening through a cloth that veils high frequency decay, ambiance and subtle detail."
Source: Hypex NCore NC400 - USA Tour Listening Impressions
I think you are trying to relate two things which aren't so. I have no reason to believe that a shortened decay correlates with settling time, it's just an "antropomorphic" way to view things. IMO that could be a matter of frequency response and/or distortion. also, that is a stranger's opinion which might be just personal preference. you'll only know if you listen to it yourself.
one more thing. at some point I think that Bruno said something along the lines of being reluctant to post square wave plots because they are often misiterpreted. we should all remember 2 things. first is that you can make a very simple circuit with 2 passive components (I'll leave you to guess what it's called) which displays a "ringing" behavior in response to square wave signals, but manages to pass sines completely unaltered. second is that as long as you're feeding the amp the output of a CD player, the "worst" thing that it will ever output is a peak-to-peak 22.05kHz sine. so maybe it's better to look at an amp's behavior in response to something that resembles what your CD player outputs when it's not malfunctioning (and that is not fast-slewing sines).
one more thing. at some point I think that Bruno said something along the lines of being reluctant to post square wave plots because they are often misiterpreted. we should all remember 2 things. first is that you can make a very simple circuit with 2 passive components (I'll leave you to guess what it's called) which displays a "ringing" behavior in response to square wave signals, but manages to pass sines completely unaltered. second is that as long as you're feeding the amp the output of a CD player, the "worst" thing that it will ever output is a peak-to-peak 22.05kHz sine. so maybe it's better to look at an amp's behavior in response to something that resembles what your CD player outputs when it's not malfunctioning (and that is not fast-slewing sines).
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IMO what's being reported there has nothing to do with settling time. Its modulation noise - the leading edge softening effect is the same as given by analogue tape to the abrupt percussive sound of a firmly struck piano key.
This is a classic distortion artifact, often associated with digital reproduction. It may be hard to track down the precise cause and effect, but is most certainly something in the overall reproduction system that is misbehaving ...
The symptoms do rather sound like power supply noise is creeping in. I'd suggest making a recording of the power supply noise while playing out music as I've done here: Possibly the most frugal high-end sounding amp? - Page 3
You might have noted that there is a specific section in the nc400 datasheet with "frequently asked numbers" that don't influence sound quality directly...
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