popping through superline

Identify the errant appliances (may require a process of elimination) and ditch them! Or very often suppressor circuitry can be added to the offending item(s), most commonly a capacitor fitted across things like relay contacts (I have to add the warning that this must be done by a service engineer or other competent person). I thought modern appliances had such suppressors as a matter of course, though of course they can fail.

Hi Jim,

I have the same problem. My own Bauer phonostage and a borrowed Superline create pops when some lights are turned on or off. The dishwasher seems to be an offender as well. This despite a seperate spur for the Hi-Fi.

IB, as much as I respect your opinion (which I really do), if the phonostage picks up noise from so many appliances, are they all to fault or is it at least to some extend the phonostage itself?

Innocent Bystander posted:

Identify the errant appliances (may require a process of elimination) and ditch them! Or very often suppressor circuitry can be added to the offending item(s), most commonly a capacitor fitted across things like relay contacts (I have to add the warning that this must be done by a service engineer or other competent person). I thought modern appliances had such suppressors as a matter of course, though of course they can fail.

"Identify the errant appliances and ditch them"

i like that

Thanks all. As seems to be the case for Mulberry, it's just about everything that causes pops, lighting, other components & dishwasher amongst many others. Not sure it is practical to rid myself of all of it. Just keen to identify a solution. 

Is there a further mains wiring solution that could help?

the trouble with moving coil cartridges is their output is so very small that they require considerable amplification, such that any electrical interference picked up at the source end is magnified as well.

Whether your particular complaints are due to the design of the particular head amps, or individual conditions I don't know - maybe others with those models can report whether they have experienced or not.  In the past I have had three different ones myself, used with two different cartridges (a home made head amp, the others being inbuilt input stages in a Musical Fidelity Preamp 2a, and a Tag McLaren PA10) - none of which were susceptible.

If normal to the Superline and Bauer that would suggest a design limitation, but if not normal then it could either be a fault with yours, or something to do with the wiring and  connections, or possibly the cartridges themselves. It would be worth checking/remaking all signal level connections, including on the cartridge, and maybe try a different interconnect. Actually, I suggest the amp powered up and as normal but with nothing connected to the inputs (presumably you're aware of the need to select a different preamp input or power down the power amp before Making/breaking input connections), then play with some affecting switches while powered up. If it stops happening then it would seem not to be the head amp - and vice versa. Then try the interconnect connected to the head amp but disconnected at the turntable. Then then connected all the way to the headshell but disconnected from the cartridge. That might help you identify if it is particular wiring (and/or associated plugs).

As for this interference causing failure of the Superline, that would seem a bit unlikely as its transistors should be able to cope with transients that are relatively much higher than the signal level, more likely I would expect damage to speakers if playing music at high levels - but then I'm no expert on the Superline so this is not a definitive statement. It could be worth asking Naim what the fault was and what might have caused it. 

By the way, my original suggestion would be a possible approach if it was just one or two particular appliances causing the problem: I remember my very first system, using a Sinclair Project 60 preamp module with a very basic unregulated power supply, mounted in a wooden box, with sensitivity only down to moving magnet cartridges was very susceptible to that type of interferenc. But one particular appliance caused the loudest thump, my parents' fridge (I was just a teenager at that time) - so I put a capacitor across the compressor terminals which stopped it (stopped the interference, not the compressor!), and other things were sufficiently infrequent and less prominent so could be ingnored.

Hi IB,

thanks for sharing your thoughts. I was in a little hurry the last time around and wrote down only some of my thoughts. Here comes the long version :

Phono stages, especially the MC type, are obviously the most likely devices to suffer from interference and/or noise. Thats what 60 dB or more gain will get you into.

When it comes to the problems Jim and I seem to share, I'd guess it is actually a combination of several less then optimal things adding up to the final result. The one thing that irritates me most, is the fact that both Jim and I run our systems from a dedicated spur and still suffer from these problems. In my case the spur made no difference in this respect (pretty much everything else got better).

I have tried many different things to rid myself of the problem. These were:

-different cartridges (three, from two different companies)

-different cables between arm and phono stage (two, but pretty similar and from thesame company)

-different cables between phono stage and SuperNait (four, very differ types, both shielded and unshielded)

-different phono stages (two)

-different power cables (three, both shielded and unshielded)

-different grounding arrangements (ground to phono, to SN, both units linked together or not, Naim DAC floating or chassis grounded)

-units on the same or on a different spur

While some configuratition were cleary better sounding than others, they all suffered from the popping noises. When things calm down a little around here (most like next January), I would like to dig further into this again. Two things remain on my to do list. These are adifferent tonearm cable (if can get hold of one) and to change the spur to another phase. Here in Germany you get three phases (live/hot wire) each 120° apart from the others and a single neutral feed to the consumer unit. The most powerful appliances (ovens etc.) use all phases. The rest, including the wall sockets, are split among the phases. If things are bad, the current draw is very unevenly split among the three phases. Maybe this is the case around here and my spur shares the busiest phase with a ton of other thingies, while the other two loiter around.

As neither the Superline nor the Bauer seem to have these issues at most other places (neither Willi Bauer nor my dealer are aware of any), I am open to other suggestions.

Thanks IB and Mulberry for your comprehensive responses. 

This discussion and your thoughts have led me to revisit my approach to the Superline.

Whilst I haven't read of many other people mention this sort of 'popping', a number of on-line reviews have brought up radio breakthrough on the Superline (usually Russian for some reason!)

IB noted the approach of adding capacitors to the errant noise sources and this led me to revisit the capacitance plugs  on the rear of the Superline and, blow me, this seems to make a difference.

When i first bought the Superline I tried a number of combinations of loading with the carts i had at the time (and can't say I really enjoyed the process- just too many possibilities!). As I was running a DVXX-1L I finally settled on a 453ohm resistor with no capacitance, as seemed to be consensus for Dynavector carts.

Adding the lowest capacitance available as standard with the Superline (1nF) seems to damp all this RFI/EMI. The trade-off is a slightly less engaging sound with my set up ....... but the ability to control these pops and any potential future damage due to other appliances.

As I am home alone this evening (read: my children are asleep and not turning appliances on and off!)  I have been removing the capacitance and intend to reinsert once I have completed my listening. I always wondered what the capacitance element actually added to the Superline, perhaps Naim have made a phonostage as 'raw' as they were able to to obtain the maximum performance from it (and it is INCREDIBLE) with the ability to dial this back if the environment is unfriendly to these 'raw' electronics.

Jim    

I used to get the radio breakthrough on mine and tried all sorts of grounding arrangements too including grounding the rack (at the time a steel framed Target lookalike). I even moved the system to the opposite wall and put in a dedicated spur. the earthed rack helped a little an using a cap plug helped a lot. I used to run a 17D3 with 470R, a 1nF plug cut the breakthrough but dulled the sound, a 470pf was a little less efective but I actually prefered the sound with it to nno cap plug. I later tried a 453R and no cap after I'd cured the radio pickup but prefered the 470R 470pF.

The radio pickup stopped when I put the system on a Fraim (Lite at first but the change to full fat was worth the extra). My theory is that the steel frame of the old rack was acting like a secondary aerial element, I can't think what else it could have been so an isoblue or similar may do the trick just as well.