Normal or Abnormal?

Thank you for the reply. I have something else to point out (sorry for not doing so initially). This particular amp uses a motorized (presumably) pot volume control. I assume this because it is moved when the remote control is used. Might it be noise introduced by the motor (because that is in use whether moved manually or via remote) and if yes, would that be considered normal in amp in this price bracket?

First, I thank everyone who has responded and encourage your continued input. I truly appreciate it. In fact, I write the following detailed response as further appreciation to your interest in this topic.

The issue occurs regardless of the source. Meaning, even if I tape a 1000Hz cycle and play it back, the same static - albeit very subtle - occurs when the volume is raised or lowered. There are numerous websites that play spot frequency sources, and I was able to reproduce this via the USB input as well.

Granted, I didn't buy the unit to play frequency tones. However, I bought it as a purported "upgrade" over what I had, and the issue I'm reporting did not occur in that case (Carver MXR130).

I have found some posts on the net that do indicate MF has noise issues with their pots, but the articles were not recent and rather dated.

Upon listening, I can say the unit plays "majestically" and produces the entire audio spectrum effortlessly. And yes, I have listened to a few ultra high end systems including McIntosh and so on (overall components in excess of 50K).

Here is something else I've discovered. And I do intend to call Musical Fidelity. First, I talked to a repair rep at the ONLY New York authorized service center - Technetron. The rep claims what I am experiencing IS abnormal and should not occur. Second, I note that the issue is evident when playing a spot frequency SINE wave and does NOT occur when playing a SQUARE wave. Moreover, if there is no source at all and the amp is simply on, if the ear is close enough to the speaker the same issue (slight static) can be heard as the volume control is raised and the noise floor in general is raised.

To Zd's point, my concern is that if I detect an issue out-of-the-box, what will happen in a year - or ten - dwon the line? My carver is over 30 years old and still packs an audible punch. Can/should I expect the same? I would think/hope so.

Further comments welcome.

Turns out, "normal"!! The following is a reply from the company - and I can believe it, given the response. Here is the official word (personal names omitted, but this is from a high level exec at MF ). In my view this does in fact resolve to my satisfaction this inquiry.
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Firstly, I am sorry that you are less than thrilled with your new purchase. I hope that I can explain, to your satisfaction, the effect you are hearing and why, in normal use, we don’t regard this as a problem.

Technetron is, in this very particular matter, incorrect when they say that the unit is at fault. Many of our current units will exhibit this same issue although, I must add, you are the first person who has noticed it to the extent of regarding it as a problem.

On older device, yes, we have occasionally had issue with noisy pots. This is despite us only using high quality ALPS units sourced directly from the manufacturer and rejecting units that were noisy during testing. However, over time every potentiometer will degrade. Making matters worse, left and right tracks in the pot would degrade at different rates leading to channel imbalance. This led us look for a better solution and, we believe, we found one.

We now use a device from Texas Instruments, under their Burr Brown label, to implement a digital control of the analogue output volume. This allows us to control the volume with perfect repeatability, perfect channel matching and virtually no noise. To this we then add a traditional volume control to give the customer the feel of a traditional system even though there is no direct link between the pot and the signal.

Your testing here has been very thorough and you have in fact come very close to understanding what is happening. You have observed that only sine wave signals are effected and not square wave ones. The problem, quite simply, is that the volume control chip is making adjustments in a step-wise fashion, almost instantaneously. This will mean that if an upward shift in volume occurs during the downwards part of the cycle or a downwards shift during the upwards part of the cycle then a very low magnitude, but very sharp, discontinuity will occur in the waveform. This is the noise you are hearing. It is noticeable on a sine wave because this signal is always varying whereas your square wave voltage remains at one of 2 constant values throughout almost its entire cycle. It is unnoticeable in normal use because of the complex and varying nature of the music signal.

What I can tell you is that, based upon your descriptions, the unit is working correctly.

I can also say that over the coming decades you will not experience a noisy pot impacting upon your listening pleasure with this amplifier.
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More specifically, I believe the unit is made in Taiwan. From what I understand it is "designed" in the UK. Also, given MFs response that at least in the case of the volume control the part is from Texas Instruments, it is likely if the unit were completely dissected the parts would be from throughout the globe. It's conceivable that even McIntosh sources some of their parts from Asia and places outside the US. I suspect in the case of MF the unit is manufactured in Taiwan because of lower cost to so. I knew upon purchasing the unit - 2000 less than a comparable Krell and 3500 less than a comparable McIntosh - that there has to be a "reason" for the lower cost. I can tell you that upon listening in side-by-side comparisons to those units I wasn't able to hear any difference. I was able to hear a difference when I put my Carver into the mix. Thanks to everyone on this thread for their meaningful, supportive and knowledgeable feedback.