newer naim amps and sensitivity to naca5 lengths

http://www.the-ear.net/review-...0-dr-power-amplifier

This is a review of 250DR but specifically references cable lengths for newer Naim amplifiers.

The article mentions or implies

Any speaker cable will do

No comment on length and therefore inductance 

Has the SN2 with its DR pre Amp done away with the requirements of super long Naca5  ?

My interaction with Naim service suggests otherwise . They were concerned about high inductance on klotz LY240 Speaker cable i used for some months inbetween.. 

2.5m won’t blow anything up, but longer would sound a bit better. If it sounds ok to you I wouldn’t worry overly. You could always get a 3m pair of Super Lumina...

That Klotz cable has a capacitance of 180pF/m, compared to 16pF for NACA5, which is a pretty huge difference, so I’m not surprised Naim didn’t recommend it. If you can’t deal with longer NACA5, there will be plenty of thinner, more flexible alternatives that are closer to the recommended spec. Exactly how important this is with a Supernait, I couldn’t say. 

I don't know about SN2 but my MK-I Supernait will take anything,  I had it on very uneven left/right lengths of some odd stuff during a furniture change time.  Then as an experiment,  because I had it in my old bits box & before I sold it,   I ran it with 8m per side of Kimber (RA) 8PR,  thats got super-silly capacitance & bugger all inductance,  just what a Naim is supposed to not like,  it sounded quite nice & kept it on for a week or more.   

You say Naim were concerned about high inductance on klotz LY240 Speaker cable.    Klotz LY240 cable does not have high inductance,  so not sure what that was about,  Naim amps are supposed to like high inductance,  NACA5 is 1uH/m.   Klotz LY240 is 0,5uH/m & is more or less typical average for any of the twisted pair type cables on the market.  Its capacitance at 180uH/m is a little higher than average, maybe due to its tight twists, but its not excessive,  

I have a 250DR and use 7m length of NAC-A5. But the article/review above has me wondering about using REL subs. I have two R-328 and was told to connect the high-level output to the speaker terminals instead of at the amp. Has this changed with the 250DR (mine was a 250-2 and upgraded in August). REL now make a cable specifically for Naim amps, but the cost for the two I need is a lot more than I want to spend.

Mike-B posted:

I don't know about SN2 but my MK-I Supernait will take anything,  I had it on very uneven left/right lengths of some odd stuff during a furniture change time.  Then as an experiment,  because I had it in my old bits box & before I sold it,   I ran it with 8m per side of Kimber (RA) 8PR,  thats got super-silly capacitance & bugger all inductance,  just what a Naim is supposed to not like,  it sounded quite nice & kept it on for a week or more.   

You say Naim were concerned about high inductance on klotz LY240 Speaker cable.    Klotz LY240 cable does not have high inductance,  so not sure what that was about,  Naim amps are supposed to like high inductance,  NACA5 is 1uH/m.   Klotz LY240 is 0,5uH/m & is more or less typical average for any of the twisted pair type cables on the market.  Its capacitance at 180uH/m is a little higher than average, maybe due to its tight twists, but its not excessive,  

Hi Mike-B

I stand corrected

regards

mpw

ChrisSU posted:

That Klotz cable has a capacitance of 180pF/m, compared to 16pF for NACA5, which is a pretty huge difference, so I’m not surprised Naim didn’t recommend it. If you can’t deal with longer NACA5, there will be plenty of thinner, more flexible alternatives that are closer to the recommended spec. Exactly how important this is with a Supernait, I couldn’t say. 

letus put it this way

Naim Naca5 capacitance is 16 pF per meter and if Naim recommends minimum 3.5 meters on each side then total capacitance will be 16 x 3.5 = 56 pF for 3.5 meters

If i choose another brand of cable and would like a length of 2.5 meters, then i should be looking for a cable capacitance of 56 divided by 2.5 ie 22.4 pF per meter

Problem is i dont see many cables in the market with this kind of figure..

would the members know of any examples of cables makes and models matching this even somewhat closely ?

is this one ay of looking at alternate cable brands / models ?

hungryhalibut posted:

2.5m won’t blow anything up, but longer would sound a bit better. If it sounds ok to you I wouldn’t worry overly. You could always get a 3m pair of Super Lumina...

Thanks HH..

sometimes its just that itch...

i must also look at funding a small vacation for me with the money saved by not going in for a 6 meter Naca5 !

:-))

Hi MPW,    it’s inductance that is the key factotor with the 3.5 metre recommendation,  its why NACA5 is made the way it is, the spacing gives higher inductance than does a fig-8 or twisted pair.     Don't get confused with capacitance,  although Naim prefer to not have high C,   any & all of the normal parallel & twisted pair types are OK. 

Hi MPW,

if everything else is kept the same, increasing the distance between the conductors will lower the capacitance and increase the inductance. Now if you look at the NACA and Super Lumina, you’ll see a certain similarity in this regard. Some other brands have this spacing as well, DNM, Tellurium Q and Vovox come to my mind. But these are likely to have different capacitance and resistance values from the Naim cables (the “if everything else” part).

High capacitance can be a big problem for Naim amps, and often comes together with low inductance, thus providing a “perfect storm” for the design of Naim’s amps, particularly the classic ones. I once tried some Kimber 8TC (high Cap/low Ind) on my NAP250.2 and it was a short experiment! 

Stick with Naim’s recommendation regarding speaker cable and you’ll have no issues and guaranteed performance.

3.5-4mtr pair of Witchhat Phantom

Not silly Lumina money

More flexible than A5

N2 available too, more affordable, perhaps cost neutral if you flog your A5

Created by former Naim engineer

i think i understand - thank you all..

at the moment, i am inclined to be the frog in the well as long as the well isnt too bad a place to be !

will stick with my 2.5 meter Naca5 

The problem starts when i look out of the well and see all the possibilities outside !

back to music then !

Any thoughts about using Transparent Audio cables? I have a 7m pair of NAC-A5, but it really is a PITA to manage. I need something more managable, and that will be even more true when I change out my Salamander cabinet (under where much of the NAC-A5 is snaked in the suggested arrangement). I believe that my Naim dealer is using some with a 272/200.

Perol posted:

3.5-4mtr pair of Witchhat Phantom

Not silly Lumina money

More flexible than A5

N2 available too, more affordable, perhaps cost neutral if you flog your A5

Created by former Naim engineer

frankly i see no point in the 3.5 meter to 4 meter witchhat phantom - from a length point of view

Ideally - for most homes and apartments - a 2.5 meter pair will be sufficient

so if the newly suggested cables also do 3.5 meters at minimum - then why not remain with 2.5 meter pair Naca5  ?

RaceTripper posted:

Any thoughts about using Transparent Audio cables? I have a 7m pair of NAC-A5, but it really is a PITA to manage. I need something more managable, and that will be even more true when I change out my Salamander cabinet (under where much of the NAC-A5 is snaked in the suggested arrangement). I believe that my Naim dealer is using some with a 272/200.

Perhaps have your dealer cut down to a more sensible length but not below 3.5 metres. For most speakers their capacitive reactance increases at higher frequencies and with open  feedback driver stages, relatively high bandwidth/low slew  with no inbuilt Zobel network which is the majority of Naim amp designs so I believe,  then one needs to use low capacitance cable such as NACA5 as the cable and speaker become more electronically coupled to the amp and becomes more intrinsically part of the amps performance. The appropriate cable should be used at least with the min lengths or you are taking a risk with ultrasonic stability and signal ringing (sharpness on rising edges). The other consideration is to not have the amp in the middle of the cabling such that it forms a dipole... as this will increase the chance of adding low level RFI noise (this doesn’t mean Radio Moscow or hearing voices... but doesn’t exclude it.. it’s more likely additional very lowlevel  hiss/mush that may vary throughout the day / seasons).. best have equipment to one side and coil one side of speaker cable.

With regard to coiling.. there is a little myth about snaking rather than coiling... however as the speaker cables conductors in the cable are in parallel, any effect of creating inductance is cancelled out.. and no discernible heat is created in the speaker cable, so can safely coil either way...

Problem with  Transparent Audio cables is the fancy ends & that "lump" in the middle,  what can you do with them if you cut them down,  not helped by no specifications such as L & C.

Simon,  Naim amps do have a zobel network,  a cap & resistor, typically around 100nF & 10ohm in shunt across the output stage.  What Naim amps traditionally don't have is a series inductor hence the need for the 3.5uH minimum inductance of NACA5.  

mpw posted:

Perol posted:

3.5-4mtr pair of Witchhat Phantom

Not silly Lumina money

More flexible than A5

N2 available too, more affordable, perhaps cost neutral if you flog your A5

Created by former Naim engineer

frankly i see no point in the 3.5 meter to 4 meter witchhat phantom - from a length point of view

Ideally - for most homes and apartments - a 2.5 meter pair will be sufficient

so if the newly suggested cables also do 3.5 meters at minimum - then why not remain with 2.5 meter pair Naca5  ?

 

My experience, the amp sound better with longer lenghts

I would never use a Naim amp with short cables, I understand your space-issue and people have different options and ideas.

Mike-B posted:

Problem with  Transparent Audio cables is the fancy ends & that "lump" in the middle,  what can you do with them if you cut them down,  not helped by no specifications such as L & C.

Hi Racetripper,  I've looked around t'interweb & found that the lump in the middle of Transparent Audio speaker cables contains a series inductor,  (if the info I have is correct) it's a wire coil of around 2.5uH in the positive side & that value will be added to whatever L the speaker cable itself has - & that is a nod of acceptance of the Naim speaker cable method.   Additionally it looks like they are adding another small zobel shunt contained in the lump at the output end of the cable & (if the info I have is correct)  its a 1000pF cap & 31.7ohm resistor.  These values are relatively low & will not effect a significant change the amps internal zobel characteristics.

Simon-in-Suffolk posted:

Perhaps have your dealer cut down to a more sensible length but not below 3.5 metres. For most speakers their capacitive reactance increases at higher frequencies and with open  feedback driver stages, relatively high bandwidth/low slew  with no inbuilt Zobel network which is the majority of Naim amp designs so I believe,  then one needs to use low capacitance cable such as NACA5 as the cable and speaker become more electronically coupled to the amp and becomes more intrinsically part of the amps performance. The appropriate cable should be used at least with the min lengths or you are taking a risk with ultrasonic stability and signal ringing (sharpness on rising edges). The other consideration is to not have the amp in the middle of the cabling such that it forms a dipole... as this will increase the chance of adding low level RFI noise (this doesn’t mean Radio Moscow or hearing voices... but doesn’t exclude it.. it’s more likely additional very lowlevel  hiss/mush that may vary throughout the day / seasons).. best have equipment to one side and coil one side of speaker cable.

With regard to coiling.. there is a little myth about snaking rather than coiling... however as the speaker cables conductors in the cable are in parallel, any effect of creating inductance is cancelled out.. and no discernible heat is created in the speaker cable, so can safely coil either way...

Thanks Simon. I do not want to cut those cables down. They are expensive enough and if I ever change rooms and need the longer lengths again I would regret that. If I change to other cables I could at least sell these in their current length.

My equipment is off to the side as you suggest. I have my collection of records on the wall behind my speakers (which acts very nicely as a diffuser for reflections).