I hate to disappoint you, but they probably won't. Decent amps are at a level where the improvements are very subtle and incremental (unless the amp is doing a significant amount of colouring, as tends to be the case with many valve amps).
Hi,
unlike most DIY kits, the nCore should hold their prices quite. This is related to the fact that there is little actual DIY involved... so cost of ownership is not as bad as it first appears.. Combined with that, you get all of the slow start and protection logic for "free"... most DIY are a bit weak in those areas (unless you buy more add-ons).
As to the sound, I can really only compare with my Pass Aleph 5 amp (pretty old but very good). The nCore has more detailed bass and treble. The bass has more punch. Listening exposes harmonies and instruments that I do not recall hearing before. Overall, the listening experience with the nCOres is superior.There is very slightly more hiss from the nCore, but this is only audible within 4 inches of the tweeter. And, don't forget,the nCore does not consume 600 watts of continuous power... so you can use it during the summer too!
Balanced?
I am not sure from the photo, but it seems that you have not connected to the mains earth?
Also, did you have any problems running the mains power cables so close the cables between the nCore and its power supplies... they seem to be right on top of each other.
George
Hi,
I am not sure from the photo, but it seems that you have not connected to the mains earth?
Also, did you have any problems running the mains power cables so close the cables between the nCore and its power supplies... they seem to be right on top of each other.
George
That is of course an electrical safety question that might or might not be an issue for you. Personally I prefer to connect safety earth. More of a sound quality issue is that this seems to be yet another one that goes against Bruno's advice about making sure the output wires start out going towards each other (in order to minimize the loop (that forms an antenna) before the twisting starts.
Yes, I have not connected to the mains earth as Bruno's advice.
I had no hum problems at all.
I don' t think Bruno has ever advised against connecting safety earth. It has nothing to do with hum - it is about electrical safety. Are you certain your design is up to Class II standards?
Yes, it is colpiant with class II regulations.
Of course if you feel better you can connect mains earth.
Fair enough. I would still recommend changing the output leads to go inwards towards each other to minimize the risk of HF noise in the feedback loop.
Please note the text that says "No safety earth connection was depicted. This is entirely acceptable if class II construction is used throughout. Otherwise, connect the safety earth." Again, safety earth has nothing to do with sound quality, and all about electrical safety. Leaving out the safety earth connection does not improve the sound quality, but might kill someone if you haven't taken proper class II precautions. The output lead issue is of course completely unrelated, and might actually affect sound quality.
Help needed
I have been following this thread pretty much from the start and built a pair of smps600/ncore monoblocs in early 2012. I have been driving these from a Antelope Zodiac + dac c/w volume control.
I have just built a balanced Aikido valve preamp (John Broskie) to 'upgrade' the analogue output of the dac but my system is now plagued with a loud hum. I have been following John's advice to locate and eliminate the hum and along the way have discovered a fault with my ncores.
I am measuring half the AC line voltage (approx. 115v) between the chassis and the earth tag on the iec inlet. In line with the recommendations in the ncore manual, these have been built with double insulation. I must admit I would be happier if there was an earth connection. This problem is intermittent - sometimes I read this high voltage and sometimes just a few mV.
When I discovered this problem I initially assumed that there was a fault elsewhere within each enclosure. I have now deconstructed the amplifiers such that only the ncore heatsinks and the metal pcb holes by J1 of the smps' are contacting the enclosures.
Hypex are telling me that this is "perfectly explainable, and that this voltage is connected to ground via capactors and is not harmful". They have not replied to my follow up email as yet.
I am no expert on these matters (hence this post) but surely this can't be right? Without a safety earth connection, presumably this voltage would take the next easiest route to earth (via me)?
I am guessing that this will be the cause of my system hum (via the xlr shielding)?
I would really appreciate some advice and guidance.
Thanks in advance....
I have been following this thread pretty much from the start and built a pair of smps600/ncore monoblocs in early 2012. I have been driving these from a Antelope Zodiac + dac c/w volume control.
I have just built a balanced Aikido valve preamp (John Broskie) to 'upgrade' the analogue output of the dac but my system is now plagued with a loud hum. I have been following John's advice to locate and eliminate the hum and along the way have discovered a fault with my ncores.
I am measuring half the AC line voltage (approx. 115v) between the chassis and the earth tag on the iec inlet. In line with the recommendations in the ncore manual, these have been built with double insulation. I must admit I would be happier if there was an earth connection. This problem is intermittent - sometimes I read this high voltage and sometimes just a few mV.
When I discovered this problem I initially assumed that there was a fault elsewhere within each enclosure. I have now deconstructed the amplifiers such that only the ncore heatsinks and the metal pcb holes by J1 of the smps' are contacting the enclosures.
Hypex are telling me that this is "perfectly explainable, and that this voltage is connected to ground via capactors and is not harmful". They have not replied to my follow up email as yet.
I am no expert on these matters (hence this post) but surely this can't be right? Without a safety earth connection, presumably this voltage would take the next easiest route to earth (via me)?
I am guessing that this will be the cause of my system hum (via the xlr shielding)?
I would really appreciate some advice and guidance.
Thanks in advance....
How have you measured the voltage? If it is with a high-impedance voltmeter, then the Hypex response is perfectly valid, and it is not a fault.
Once again - double insulation is an electrical safety issue, and has nothing to do with sound or sound quality. Double isolation also does not rule out use of safety earth - and the Hypex manual does *not* recommend against safety earth.
Have you tried turning your mains plug around (rotate it by 180 degrees)?
Only if your source connects mains earth to the XLR shielding, and even then it should be a common-mode signal - but the common-mode attenuation is not perfect.
Thanks for the replies so far.
Julf:
I did take the readings with a bench multimeter. I assumed that because I had measured this voltage, that it would then be hazardous. You are saying that this is not the case?
My primary concern is safety. My secondary (perhaps with a hint of reluctance) is sound quality. I will connect a safety earth but will the rest of my system then 'see' this voltage?
My concern about the xlr shielding is because the pin 1's are connected to the various chassis right next to the sockets. Unless I make up a special cable between my preamp and power amps with the Shields disconnected at one end, won't this then cause more of this hum problem?
Thanks, Simon
Julf:
I did take the readings with a bench multimeter. I assumed that because I had measured this voltage, that it would then be hazardous. You are saying that this is not the case?
My primary concern is safety. My secondary (perhaps with a hint of reluctance) is sound quality. I will connect a safety earth but will the rest of my system then 'see' this voltage?
My concern about the xlr shielding is because the pin 1's are connected to the various chassis right next to the sockets. Unless I make up a special cable between my preamp and power amps with the Shields disconnected at one end, won't this then cause more of this hum problem?
Thanks, Simon
What kills you is not voltage, but current - some insect killer devices and air ionifiers run at tens of kilovolts, but have such high internal impedances and low energy storage capabilities that all they cause is a harmless spark. The same goes for ground potential voltages that are caused by leakage through (small) HF capacitors. You might measure impressive voltages when measuring with a high-impedance voltmeter, but as soon as you put any load on it, the voltage drops drastically.
The leakage current that is causing the voltage will safely be dissipated through the earth connection, so the remaining voltage should be minimal (and ignored by the differential input of the nc400).
With the shields connected, the chassis of both the power amps and the preamp will be at the same voltage - but won't be part of the audio circuit due to the balanced/differential connection. The nc400 inputs don't care what voltage earth/ground/shield is at - all they care about is the difference between inverting and non-inverting input. One caveat - in case something is wired wrong, and there is a real low impedance voltage difference between the chassis of the power amps and the pre, the resulting safety earth current through the shielding (and/or through the earth wires of the mains cables) will blow a fuse - alerting you to a potential safety problem.
You need a multimeter with a LoZ measurement mode, electricians depend on them because often they are dealing with ghost voltages, caused from capacitance between live and dead conductors sharing the same conduits. They need to be 100% sure the circuit is dead and not just ghost voltages fooling them.
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Of course you can easily add that mode to your normal multimeter by connecting a 1K resistor in parallel with the meter.
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