Jan Peter,
Thanks for finally saying "no" to my second question in post 4449
About the internal resistance being a lot less compared with a traditional linear supply: that totally depends on the properties of that linear supply.
I agree when you think of a 500VA commercial toroidal power supply transformer and mediocre quality power supply caps for a NC400, but linear supplies can be made to improve on the SMPS600 (however not within the same "form factor").
OK, I stand corrected. My assumption was that the SMPS600 was based on a switching regulator, not just a fixed chopper. Seems I was wrong in my assumption. So the pulse ratio doesn't change at all?
Julf, a fixed chopper is the same as a switching regulator. Indeed the pulse ratio is fixed.
More interesting is that the SMPS600 (and SMPS400, 1200) is that it use synchronical rectifying. The SMPS can source or sink energy, it works bi-directional. So we can place all big caps on the primary side and only small caps on the secondairy. In this case the SMSP transformer will not carry anymore the big charge currents you need if you have big caps on the secondary. For this reason we don't advice to add more caps on the secondary side....
More interesting is that the SMPS600 (and SMPS400, 1200) is that it use synchronical rectifying. The SMPS can source or sink energy, it works bi-directional. So we can place all big caps on the primary side and only small caps on the secondairy. In this case the SMSP transformer will not carry anymore the big charge currents you need if you have big caps on the secondary. For this reason we don't advice to add more caps on the secondary side....
To me a switching regulator is one that actually regulates - as in changes frequency or pulse ratio to maintain a constant output voltage. A fixed-rate, fixed-ratio chopper is a switch-mode power supply all right, but not a regulator.
My Ncores sound just great with the SMPS600's whether it be regulated or not - all happy in my house
I must agree, we could go round in square circles discussing the ins and outs of power supplies of all varieties and forms of regulation.
My UcD's perform well with SMPS, My NCores sound superb with the matching SMPS.
Hypex know a lot more about how to design a matching Class D/SMPS combination than I do - thats why I bought from them.
Jan-Peter,
My apologies for dragging on with this conversation, but I am just trying to understand how the SMPS600 works. What is the difference between the "normal" output voltage (J2:1+2, J2:7+8) and the "unregulated" aux voltage (J1:3, J1:7) apart from impedance/current capability?
It is up to members if they want to discuss the power supply subject.
A discussion on power supplies will always make sense when amplifiers are at stake. Especially in the case of class D and class A/B amplifiers the influence of the power supply on sound quality is big, and can not be underestimated.
My point was that IMO the information provided here by Hypex was misleading.
Not anyone is able to read and interprete datasheets well.
I'm sorry if I gave you the impression I was trying to stop discussion on power supply issues I was not.. Indeed we have a section in the forum to do just that.
You have edited the sentence I used in my post and commented on what is now a distorted view of my response to the previous post
The information provided by Hypex is IMO crystal clear. They state that the main output voltage(s) is proportional to the input mains voltage. ( Note 3 page 4) (Note1 page 8) and that these are fully short circuit protected (Note 2 page 8) one concludes to work with the protection circuitry to avoid damage to a connected loudspeaker. I have unintentionally tried this with a Ucd400 and SMPS400 and it works.
The auxilary voltage(s) is also proportional to the input mains voltage ( Note 1 page 8) but does not include any short circuit protection (note 2 page 8). I used this voltage pair to drive my LED indicators on my chassis.
I have listened to my NCores now for some weeks and in my book they are the best amps Ive owned and the last thing I would want to do is tweak in any fashion the excellent design and marriage of a Power Supply and Amplifier as provided by an NCore and SMPS600.
Its plug and play with some thought given to the layout.
No doubt there will be those who think they can and build power supplies like generating stations which will also heat their homes.
Listen listen listen
enjoy enjoy enjoy
the only downside is they may highlight the weak links in your Hi Fi chain
Ian,
The misleading information is about the power supplies to be of the voltage regulating variety, or not.
Once more, Hypex SMPS's are unregulated power supplies, which is clear when checking the datasheets. Some members believed the supplies to be voltage regulated.
About heat generating power supplies: based on the feedback here I guess that the SMPS600 generates more heat than a linear power supply.
I have revisited the Hypex data sheets and the only issue I can see is that they call the Auxillary Voltages unregulated. Perhaps implying to some that the main voltages are regulated. It may be a term to describe the lack of S/C protection and auto shut down has been mixed up with unregulated?
I have commented before that I thought the Hypex data sheets would benefit from a simple schematic showing all the interconnects and options - to me a drawing speaks a thousand words.
My N Core have been on all day and there is no issue with SMPS or Ncore generating heat. The amp cases are relatively cool, slightly cooler than my UcD400/SMPS400.
Both my Ucd and Ncore case designs are identical and I did ensure adequate ventilation for the case to operate vertically behind my speakers with very short cables or in conventional horizontal mode on a rack or shelf.
Perhaps some of those giving feedback of a heat issue may have fallen short on allowing adequate airflow through the case?
I have commented before that I thought the Hypex data sheets would benefit from a simple schematic showing all the interconnects and options - to me a drawing speaks a thousand words.
My N Core have been on all day and there is no issue with SMPS or Ncore generating heat. The amp cases are relatively cool, slightly cooler than my UcD400/SMPS400.
Both my Ucd and Ncore case designs are identical and I did ensure adequate ventilation for the case to operate vertically behind my speakers with very short cables or in conventional horizontal mode on a rack or shelf.
Perhaps some of those giving feedback of a heat issue may have fallen short on allowing adequate airflow through the case?
I don't understand the confusing, the SMPS600 is unregulated. The fact we have written expliciet for the aux. voltage that these are unregulated doesn't means that the high power rails are regulated.
The SMPS600 has one transformer, all voltages are generated from one transformer and are all proportional to the input voltage.
There is not a single regulator on the SMPS600. Its main benefit, as I have stated several times in this thread, lies in the synchronously rectified secondary side. The UcD and NC amps have symmetrical PSRR. Since the synchronous rectifiers force the ripple to be symmetrical, it cancels in the amp. As a result, the benefit of regulation (reduced AC mains components in the output signal) is obtained without the trouble of regulation.
@Pieter T., Z.
@Pieter T., Z.
Thanks, this makes good sense.
Clever way to do it
A rather different question if I may:
For the NCORE, besides the extra power potential of the smps600 and its driver supply, what should be the reason for choosing the smps600 over the smps400?
Are these designs essentially similar and should deliver the same sound quality on the Ncore´s if used within their respective power spec´s?
Or, is tweaking/specific ncore tuning playing in on the performance?
best,
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