I find it a bit strange that there is recurring mention of “out of spec speaker cables”, while it really is the (older) Naim amps that were using impractical and out of spec implementations that required long or exotic cables.
Any normal / standard speaker cable should just work in an amplifier, and as far as i can tell this is also the case for the Uniti models.
I think you have a point… I also think the stress on the cable and insulation relaxes over time which has an impact. This is why naim possibly shake their cables…and why burndies sound better ‘relaxed’ … but I know something …there is definitely a sonic impact…and a burn in effect…
My post to which you replied gave a listed a non-exclusive list of reasonable possibilities and referenced a previous post showing that some of the proposed mechanisms were extremely unlikely to occur, it said nothing more and nothing less. It said nothing about my beliefs
I, like @Simon-in-Suffolk, am sceptical of the possibility of significant changes in the materials occurring within properly designed and manufactured cables other than within the solder joints. However I do also believe that mechanical relaxation can affect external contacts (e.g through thermal cycling) and possibly the solder joints (directly). However in terms of static charge effects I’m highly sceptical of anything to do with the cables dielectric and very doubtful about the influence of any effect of dust on the jacket.
My observation above (concerning 3y year old cables) illustrates the one effect the existence of which I am certain: I myself, as the listener, change over time.
I have not inspected them personally However, over the past months there were also other members reporting Unitis overheating with more exotic cables, like Kimber etc
Correct. I’ve had my Nova about a month. The dealer sold me Audio Quest Type 5 cables. The Nova over-heated and shut down with a screen warning at the start of the 3rd album. I lifted the Nova and ran a fan on it until new cables (NAC A5) arrived. Big difference in sound and soundstage, plus no more over-heating.
Were they factory assembled Type 5 cables or were they made to length by the dealer, do you know that perhaps? From what i can tell most if not all AQ Type 5 cables are sold in bulk and require the connectors to be assembled separately.
The dealer was simply wrong to recommend a star quad speaker cable for ANY Naim amp…
Many of the Uniti and Integrated amps CAN* drive low inductance cables (e.g. star-quad such as AQ cables or pseudo Litz arrangements such as Kimber) but the combination is never ideal and will always be unpredictable and never get the best out of the amplifier.
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*. Unless when coupled with some types speakers that have significant effective parallel capacitance (e.g. in the tweeter), in this case the combination definitely won’t work. Don’t forget that the load ‘seen’ by the amp is the combination of the cables and the speakers. A high inductance cable ‘protects’ the amp from unwanted low effective load at ultrasonic frequencies (these can cause incipient instability or even oscillation in an amp).
Xanthe - indeed its not so much the level of overall inductance - but absolutely the ratio of capacitance reactive impedance to inductive reactive impedance. If the overall capacitive reactance is relatively too high compared to inductance reactance instability can ensue.
Typically in amplifier design best practice usually determines that best performance in terms of lowest distortion is speaker cable with low inductance and low capacitance
Beyond an extreme scenario, I find it highly unlikely that the speaker cables used are so poor as to literally cause the amp to overheat and shut down. And afaik the Nova has a Zobel network on the output stage so is much less sensitive to speaker cable choice than amps of old.
AFAIK, the Nova has a Zobel network, but no output inductor… Hence is susceptible to low inductance / high capacitance loads (just not as susceptible as most of the ‘classic’ system power amps).
It’s not a case of the AQ5 cable being poor (in design or construction), more a case of it being inappropriate to use it with a Naim amp.
Yes, there have been a few posts from Uniti users here who were having problems which, as the discussion progressed, were found to be caused by badly out-of-spec speaker cables. That includes at least one Atom owner, and probably @airedog too.
(1) I repeat at this level or any level two identical cables Simply Do Not Exist it is basic science!
But maybe you could have 2 Black ones? It is really like Kindy on this forum.
(2) There Are posts on this forum where burn in was claimed to have a Negative effect,
one by my self, you just have to read them! along with other posts that have all ready
made some repeated queries redundant resulting in a shamble of tail chasing going
around in circles trying to present itself as scientific argument.
I find it hard to envisage a cable being ‘out of spec’ in that regard, unless already borderline. The reactive elements of cable are largely determined by its construction and geometry over its length…
Also worth pointing out that reactive impedances of speaker cables can and most likely determined by environment… ie coupling to ground and other cables including mains.
Indeed on my previous 250.2 I could show and hear the effects of coupling of NACA5 to other cables which in my case resulted in increased very low frequency distortion. Remedied by re routing the NACA5.
I have noticed amplifiers with a Boucherot Cell built into the amp output (to form an overall Zobel network with the speaker) have not experienced this.
This may be a coincidence… I can’t be categoric, but relay my relatively limited observation experiences here in my home setup.
I’ve always understood a Boucherot Cell is just another name for a Zobel circuit; a series resistor & capacitor in shunt across the amp output.
As far as I’m aware all power amps have this, including Naim.
Most amps have an additional series inductor coil after the Zobel, whereas Naim & a few others use the speaker cable inductance in place of a the internal inductor coil.