I’m hoping for some guidance from the experts here, because I’m clearly missing something obvious with my phono setup.
My system:
NAC 252
SuperCap (for the 252)
NAP 250DR
Stageline N (MM)
Rega P3 (MM cartridge)
The Stageline came with one SNAIC (it’s a SNAIC 5).
What I’ve tried
Stageline powered from NAC 252 AUX2 (in & pwr)
I connected the Stageline via the SNAIC to AUX2 (in & pwr) on the 252.
Result: I get a 50 Hz hum which increases with volume. Music is there but the hum is very noticeable.
Trying to power the Stageline from the SuperCap
I then tried feeding the Stageline from socket 2 (power & in) on the SuperCap using the SNAIC.
Here’s where I’m stuck: I do not know how to get the Stageline’s signal from the SuperCap back into the 252.
On the back of the Stageline, I have an additional 4‑pin DIN output that is currently unused.
On the 252, all the source inputs (CD, Tuner, Tape, AV, AUX1, AUX2) are 5‑pin DIN only.
My questions
What is the correct way to power and connect a Stageline N MM in a NAC 252 + SuperCap + 250DR system?
Should the Stageline be powered from the 252 AUX2 at all, or is that only for specific Naim sources and not for Stageline?
If powering from the SuperCap is possible in this configuration, how exactly should the cables be run (which socket on the SuperCap to which input on the 252, and using which type of DIN/SNAIC cable)?
Is the 50 Hz hum I’m hearing a symptom of the Stageline being incorrectly powered / earthed with the 252 AUX2, rather than a faulty unit?
Any clear “plug A into B, plug C into D” explanation specific to 252 + SuperCap + Stageline N would be hugely appreciated. I’ve checked the manuals but I’m still not confident I’ve understood how Naim intend this to be wired.
Okay, understood. All I can suggest is that the locking RCA phono plugs on the end of the Planar 8’s tonearm lead may not be tight enough on the sockets.
The plugs are in two parts, and, for each channel, the knurled brass ring should be turned against the silver coloured sleeve, to lock it finger-tight onto the Stageline socket.
Stagline power by AUX2 via SNAIC5. Make sure the banded end of the SNAIC5 goes closest to the Stageline.
The Stageline can be very sensitive to induced hum fields so be sure to position it well away from any transformers. Similarly the Rega Power supplies should be well away from the Stageline. As Chris says, the locking RCA Phonos need to be tightened a much as possible onto the RCA Phono sockets of the Stageline.
taken on your recommendations. the hum is still hearable but at higher volumes only (far beyond normal listening volume pot stetting (12h)) . At normal listening volume, (9h) it (almost) gone/ nor hearable at listening position. Not as prominent as last night when I was playing after full re-set of all cables. May be warming up also helped?
The hum is still there, although a bit softer.
I also experimented with cable dressing (Rega PSU cable away from the RCA leads), but it didn’t change anything. Checked underneath the Rega and I can’t find any earth cable, which I understand is normal for Rega.
Any other ideas on what could cause the hum, or what I should try next?
I have done it twice couple of days back, but got mixed results so i have to do it again, hence i was hesitant in answering. I want to make sure i have consistent results;
once it seem when removing the earth (black) the humm was gone
another time i did the same, the humm was still there
Removing both RCA remove the hum altogether (makes sence)
Just tested — removing either RCA cable doesn’t eliminate the hum. Worth noting: I now need to push the volume to 12 o’clock to hear it at all (~51 dB at 10 cm from the speaker). A massive improvement over before. The Rega P8 is a sensitive beast — but that sensitivity comes with its perks.
