Rega RP10 and Superline - RCA phono contacts

Hi-Fi Corner
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A few days ago I broke down the main system, gave everything a good clean and tighten, and then rebuilt the Fraim and the system. Everything looked good and playing some digital files from the Uniti Core through the DAC showed that it was all sounding really good, even just after switch on.

Only a couple of issues; first was that the rubber feet on my Meridian 200 had started to go gooey, so I’ve removed it from the system and now removed the gooey feet so I can remedy it with some replacements. With the Core in place, I’m not entirely sure I’ll be putting it back into the system. We’ll see…

The main issue was that vinyl replay seemed to have taken a step back a notch or two. It was good in its way, rhythmically superb still, but something had happened to slightly dull the sound, and the wonderful sense of inner detail was missing. It was good, but no longer special. So yesterday evening I spent time trying to see what might be the issue. I gave the stylus a good clean, checked that the deck was all level and the cables well dressed. I double checked the Superline position and cable dressing. I played the latest reissue of Richard & Linda Thompson’s Shoot Out The Lights. It started off well, if not quite as engaging as I remembered. But by the time I reached A Man in Need, all of a sudden there was a sort of fuzzy distortion that appeared from time to time, and as the song progressed just got worse and worse. Aaargh!

Maybe it was a big fluff ball - a quick check of the stylus and all looked fine. A look at the vinyl under a strong light and no stitching or fill issues. Oh dear, my heart sank, surely not a component failure in the electronics? A quick play of a digital file showed all was still OK. Hmmm… the Superline?? Another LP grabbed from the nearest stack, and the same fuzzy distortion every now and then. Yikes, it must be the Superline :frowning:

So… tentatively I decided to do a quick check of the Superline connections and that’s when I realised that the locking RCA collars on the Rega RB1000 tonearm cable weren’t done up as tightly as I thought. I re-tightened them, this time ensuring they were done up as tightly as possible. I know that the Next Gen RCA sockets can be a bit tricky with non-Next-Gen Plugs, and so a plug with a locking collar should be tightened up as far as possible to avoid a poor contact. I put Shoot Out The Lights back on the platter and cued up. Wow! what a difference! The magic was back! And all because the locking RCA plugs weren’t done up quite tight enough on the Next-Gen sockets.

So, if you’re using a deck with RCA phono sockets together with a Superline, and you think the sound is a bit lacking, go and check how well the plugs are connecting to the contacts the sockets.

5 Likes
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I have had one slightly slack RCA on my Superlumina RCA to DIN cable. The Naim RCA is very thick so it is not easy to make it grip tighter. Whilst the signals are not as small on the output as from the cartridge, suggestions on tightening the fit very welcome.

Thanks

Phil

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Top tip, thanks Richard.

I’d better go and check the dac to NAC52 cable now…

Best regards, BF

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Is it the SL DIN that’s loose, or is it the socket? Maybe worth trying it in some different sockets to make sure.
Naim had a batch of SL speaker cables with bananas that were a loose fit. Mine were loose, and Naim replaced the cables without question.

1 Like
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Thanks for replying. Definitely the RCA as if I reverse them it’s loose on the other socket. It been loose on Rega Auras when I had demoed.

I hadn’t realised it might be a manufacturing problem. Perhaps @Richard.Dane can suggest what I do?

Phil

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Phil, I would get in touch with your dealer.

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The rega phono cables come with phono ends that you turn and they then squeeze the outer barrel. You need to unscrew them to fit and remove and then once fitted screw them tight.
I didn’t realise this was the case with my P8 and couldn’t get them on my superline and so used the the other connections, until i found that they unscrewed and guess what they fitted fine then. O well as they say.

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Richard, they are not under guarantee now. Do you think it is an issue? I can easily pop in to Salisbury for someone to fit a new RCA.

Phil

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Yes, the Rega RCAs are very good, and as Richard has found it is important to have the inputs tight.

Phil

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Not tempted to fit BNC?

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I don’t know Phil. That’s why I suggest having a chat with your dealer.

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Yes, but not so easy with the thick Rega cable. I use BNCs with my Aro and Garrard.

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What’s your go-to stylus cleaning method Richard? TIA

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At637 and/or Discwasher stylus brush and some stylus cleaning fluid of ancient and now forgotten provenance…

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Well, well, well. I have just taken DAVE out of the rack, tightened up the analogue RCA connectors on the AR Sound Lunar cable that feeds the NAC52, re-inserted the dac in the rack and switched on my ears.

Ooh, that’s ridiculous. The magic’s back. Streaming has been sounding perfectly fine but not wow recently. Now, the wow is back!

Brilliant tip Richard, many thanks.

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Thanks Richard. BTW which side carries the signal earth from 552 to the phono?

Phil

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Good question Phil. I’m not sure. Maybe a search will give the answer or Else ask Rega on Monday.

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Richard, I was asking about the SL cable. Might be a silly question.

Phil

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Oh sorry. No idea I’m afraid.

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Extracted from FAQs
strong textRichard.DaneLeader

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Jan 4

A few reasons why we use DIN connections:

Naim use three types of DIN connector:

  • DIN4 (4 pins in a 216 degree arc) - Typically used for pre-amp signal OUT and smaller power amp signal IN. It can carry signal as well as 24V DC when used between a suitable Naim Power amp and pre-amp where the power amp’s power supply also provides power to the pre-amp.
  • DIN5 (5 pins in a 240 degree arc) - Typically used between a power supply and a pre-amp or phono stage where it carries signal as well as 2 x 24v DC.
  • DIN5 (5 pins in a 180 degree arc) - Typically used on source interconnects, inputs and input/outputs.

Naim Preh DINs1|600x288

This picture shows DIN4 (216), DIN5 (240) and DIN5 (180)

So why do Naim prefer to use DIN connectors?

The obvious reason: DIN connections sound better than RCAs…

The phono plug, or RCA connector, as best as anyone can remember, was designed decades ago as a direct current (DC) power connector. Its design properties do not lend themselves to transferring music signals that have very low voltages (less Than 5 volts) of alternating current (AC). This is true - no matter how good the RCA plug is or whether it is made with gold, etc.

The first difficulty with the RCA connector is that it has a high-frequency capacitive impedance of around 200 ohms; unfortunately, the typical cable that connects the two RCA plugs together has an impedance of about 50 ohms. In this situation, the two RCA connectors on either end of the cable act as reflective walls at higher frequencies and bounce information back and forth, trapping the signal and extending the decay time of the signal that is trying to pass from one component to the other. These reflections have an effect on musical information and are especially harmful to low-level signals, particularly quiet harmonics and underlying instruments, where the ringing that is generated by the loudest instruments will smear the smallest signals. The result is that the quiet instruments will blur or fade away when the loud ones come along. The complexities of the music and the tones of individual instruments get lost.

The DIN plug has an impedance that is similar to the cable. It does not reflect like an RCA plug.

Furthermore, the system ground (which should be a stable connection point to which all signals and power supplies are referenced) is absolutely critical to the sonic performance of your hi-fi. A single reference ground point is important so that signal details are not lost in the small, yet significant voltage differences inevitable with separated ground paths.

Many manufacturers point to the great trouble they take to “star ground” everything. Sadly, this is all wasted when you connect your system together with RCA-plugged cables. Why?

When you connect, for instance, a CD player to a preamp with RCA-plugged cable, you automatically have two separate ground wires - the left and right shields going between them. This creates a ground loop, which degrades the musical performance dramatically, and negates any efforts that were taken to ground the internal circuits properly.

If you were to connect these same two components together with DIN-plugged Naim interconnects, you would have only ONE cable with only ONE ground shield surrounding both the left and right signal wires. Hence, only one ground path for each connection and no ground loop.