hypex ncore

[ChrisPa]

Extremely low output impedance

[barrows]

Input stages often have more influence on the "sound" of an amplifier than the output (current) driver. The input stage of the nCore is quite different (discrete instrumentaion amplifier circuit with discrete regulators as standard) than that employed by the ucD modules, perhaps the input stage accounts for a lot of the difference?

[back]

Originally Posted by ChrisPa

Extremely low output impedance

no way i have heard this from 3-4 amplifiers but can`t find what was in

common.

crown ce2000 PA amp, earthquake 2150 car amp and earhquake 2075 car amp.

[back]

Originally Posted by barrows

Input stages often have more influence on the "sound" of an amplifier than the output (current) driver. The input stage of the nCore is quite different (discrete instrumentaion amplifier circuit with discrete regulators as standard) than that employed by the ucD modules, perhaps the input stage accounts for a lot of the difference?

maybe.

[Juhleren]

Originally Posted by back

no way i have heard this from 3-4 amplifiers but can`t find what was in

common.

crown ce2000 PA amp, earthquake 2150 car amp and earhquake 2075 car amp.

I think low o/p impedance is another way of saying "feedback loop" in these cases.

Maybe all these amps have feedback loops that works well for bass.

Low intermodulation distortion is probably key to get authoritative bass reproduction.

That said my vote usually goes to upstream components and the buffer stage with integrated PS regulation on the ncore probably has a lot to say too.

[back]

Originally Posted by Juhleren

I think low o/p impedance is another way of saying "feedback loop" in these cases.

Maybe all these amps have feedback loops that works well for bass.

Low intermodulation distortion is probably key to get authoritative bass reproduction.

That said my vote usually goes to upstream components and the buffer stage with integrated PS regulation on the ncore probably has a lot to say too.

well the ucd2k have remote sensors that include even the cables in the feedback loop.

i am not talking about authority.

all the amps control the woofer without any booming.

i am talking about speed.

it`s like the woofers are moving faster especially at the mid bass.

maybe 80-200hz

[Juhleren]

Originally Posted by back

well the ucd2k have remote sensors that include even the cables in the feedback loop.

i am not talking about authority.

all the amps control the woofer without any booming.

i am talking about speed.

it`s like the woofers are moving faster especially at the mid bass.

maybe 80-200hz

I don´t like the notion of "speed" in bass, thats why I used another term. I do think we mean the same, though

Well the perception of "speed" -especially in the bass seldom has anything to do with "speed" in the physical sense as in "velocity" which generally is used to refer to the high frequency extension of a driver.

From my experience (and I am not alone) perceived speed in bass is typically related to the 80-150Hz area which you also as say in this case, + the roll off downwards (which is very, if not the most important). Getting this right you can have "fast" or "speedy" bass from physically slow woofers. This is a great part of why old school woofers with small magnets and high Qt can generate "fast" bass in closed boxes.

The role of amps is in theory to produce low o/p impedance to keep Qes of the driver low so that the speaker will have its intended low end roll off.
That said, where nfb loops are used, they are the main reason for the low o/p impedance, but they are also largely responsible for controlling/producing distortion.

When we are talking damping factors of 500+ my guess is that these distortion characteristics are the dominant reason for the perceived experience of the bass. DF 500+ is definitely beyond what cause "booming".

Ncore has magnitudes lower distortion than any of the UCDs and I believe this has much greater importance (also in the bass) than the power specs unless you really do use peak currents that exceed the specs.

The UCD2000 might have features to include remote sensors, and although I don´t really get that approach, I assume that they still must rely on the topology of the internal nfb loop which in the case of UCD now is from the dawn of times in terms of class D. The nfb loop on Ncore is quite an advancement on this, to say the least...

[back]

we definitely say the same thing.

the reason i added the 80-200hz is to make it clear.

i understand the part of distortion but not the roll off part.

the speaker is same unless you mean the frequency response of

the ncore is rolled off downwards.

[Russell Dawkins]

I imagine this can only be related to damping factor associated with the ultra low output impedance.
I, for one, think "speed"can be an appropriate term to describe bass quality - especially associated with settling behaviour of the entire system as a function of damping factor, motor and cone power to weight ratio, and resonant environment of driver, box and room.

Most systems make square waves barely recognizable.

[Juhleren]

Originally Posted by back

we definitely say the same thing.

the reason i added the 80-200hz is to make it clear.

i understand the part of distortion but not the roll off part.

the speaker is same unless you mean the frequency response of

the ncore is rolled off downwards.

The roll off part was meant as a general statement and is probably not especially evident for this concrete case as DF >500 should indicate other parts of the chain to be the main contributors of impedance between the theoretical o/p of the amp and the driving force in the speaker motors (Cables and especially coils adds far more DCR).

What I did mean with the roll off part is the effect of the systems energy distribution across the frequency domain. Too much low down somewhat perceptually "slows" the sound of the system. This is typically perceived as a dynamic property, but is in fact often a voicing or frequency balance property of the system.

- We are of course talking in room performance here -

Amps generally don´t have much frequency variation compared to speakers, so if the ncore sounds different in the bass, it is most likely not because it rolls off or alters the frequency response. However, many amps do sound very different though their frequency responses are very alike. This implies that the perceived voicing of electronics like amps relates to other attributes such as their distortion behavior. Due to that Ncore reduce distortion compared to most amps, it is likely to assume that this is part of why it perceptually sounds different and maybe even sounds like it has tighter bottom end (normally associated with having tighter roll off/better damping). Voicing and perception of tonal balance seems to relate not only to measured frequency balance, but also heavily on distortion behavior. More distortion low down is probably perceived as having more output low down.