Simon Hickie wrote: ↑Sun Sep 17, 2017 10:26 am
Most modern properly designed amplifiers should not have a problem."
Which raises the question as to what he thinks is a "properly" designed amplifier?
The kind of unconditional stability he appears to value comes at a cost in terms of additional components and filtering. Depending on where, and how, an amplifier is to be used such stability may not be necessary, particularly in a domestic environment where connections will be made only once. If you want an NVA amplifier you have to accept the manufacturers requirements and use low capacitance cables. I am not sure that makes the design improper though.
Indeed Geoff, and that's the key point. My understanding of electronics is very limited, especially with respect to amplifiers. However, I believe that the output stage of a typical mass market amplifier incorporates a network including resistor(s), capacitor(s) and inductor(s) in order to deal with the capacitative reactance of a speaker cable in order to minimise the risk of oscillation which in turn causes bad things to happen to the amp. These additional components degrade sound quality, but when the extra output components are excluded, the risk of oscillation is minimised with the use of low capacitance speaker cable.
So quite simply it's a choice: Amplifier with the additional sound degrading gubbins but use any speaker cable, versus amplifier without the extra bits but insist on low capacitance cable.
Olive Naim amps had a zobel network to ground and a series resistor on the output. Speaker cable had to have a certain inductance to keep things stable. That is why they recommended their own naca cable. Unwieldy stuff with the two cores separated at a certain distance. So any claims about improper design must surely apply to Naim.
Avondale audio and many others put a small coil with a resistor running through the middle of it (in parallel i think) on the output as well as the zobel. Any cable can then be used.
I think it is a load of bollocks. If a design sounds better for not having zobel, resistor and inductor coil on the output and needs certain cable to be used then so be it. Surely we are all intelligent enough to understand and follow manufacturers instructions and guidance ?
A lot of manufacturers want to have a product that is fool proof, which isn't a bad thing in itself but does imply a degree of compromise on sound quality. In many cases the loss can be accepted, PA and stage systems for example, because the need for frequent set-up and break down overrides other considerations. Where domestic Hi-Fi is concerned portability and abuse resistance shouldn't be considerations, at home it is about quality. The same can be said of any controlled environment. Where the equipment is installed in a fixed manner it doesn't need to be protected against unexpected loads, in theory an active speaker would be such an environment (leaving aside arguments against active speakers).
Unfortunately many buyers want to simply slot their new purchase into their system without reference to the manufacturers instructions and, for a whole range of reasons, many manufacturers accommodate them by designing amplifiers that can take the abuse.
I can't think of two words in the English language that are separated by a further distance than NVA and compromise! (ok I know NVA isn't a word).
Audio Grail "Sable" Garrard 401 with Cumbrian Green Slate plinth / Audiomods 6 / Benz Micro Gullwing SLR, Phono 2, NVA INT400sa. (Oh and a Copland CDA823 CD Player, for when I fancy a bit of the devil's spawn!)
Here's another analogy from the world of photography, an area I must confess to knowing more about than hifi. A friend and fellow music / hifi enthusiast is also a very keen photographer and uses Fuji cameras and lenses. However, because the camera sensor is not the standard type found in Nikon, Canon etc, to get the best results when converting RAW files you need to use a dedicated converter such as Iridient which works better with Fuji files before then doing your usual stuff in Lightroom or Photoshop. Another friend (a dedicated Canon, Naim, Linn, Audi enthusiast) borrowed the Fuji but converted his files using an old version of Photoshop (which did not deal with the in-camera corrections properly) and then complained that the corners weren't sharp and were too dark. He didn't want to be 'forced' into using another bit of software even though it gave better results and so plans to carry on using his Canon gear even though the results are poorer than possible with Fuji.
My Fuji owning friend and I have concluded that there is something in the mindset of some people (especially the Canon, Naim brigade) which makes them incapable of accepting an alternative even when it can be demonstrated to be better. It's as though these people have such an emotional attachment to their previous buying decisions that they are incapable of looking elsewhere because it somehow invalidates all their previous decisions rather than seeing it as a learning process. And they carry on making the same sub-optimal decisions because to change implies previous errors rather than an openness to new ideas and an acceptance that something else might be better. I think a psychologist would call it a hefty dose of cognitive dissonance. It also probably explains why some people (no names but you can guess) behave as they do towards others who are prepared to think outside the box.