Thank you Stephen. I’m sure it will be figured out one way or another. What a GORGEOUS system at night with all of the green…
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Hi EBWhite,
I compared your pictures to our wiring copy today & the DIN sockets are wired to factory spec as far as I can see. Unfortunately the copy unit PCB is not populated & I couldn’t find an NBL spec PCB to compare, but it certainly doesn’t “appear” to have been modified outside of the factory.
Have you tried swapping the two Hicaps around when configured in full active mode, to see if that makes any difference?
Also try linking the two Hicaps together using socket 1 on both (instead of 3 as per your wiring diagram). I’m concerned that white corrosion substance on the DIN sockets might be causing a problem.
Regards
Neil.
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Hi @NeilS,
Super awesome of you to compare my internal SNAXO photos of the ones on file. Very helpful to my cause.
• I have tried swapping the Hi-Caps around as you suggested, but when I do this, there is a loud buzzing at idle that comes through both speakers (also present during low volume periods of the song). The other Hi-Cap does not produce this buzzing sound. So one of the Hi-Caps clearly needs some professional tech review/adjustment.
• I tried what you wrote about the other day, to systematically go through each of the six outputs. I had done this previously, but your method was more exacting. By doing this, the layout is factory original correct, following the SNAXO to 3 x Amps diagram I posted in my original posting here.
That testing confirmed that one amp is dedicated to Left + Right speaker highs, the next amp is dedicated to mid and bass for the left speaker, and the final amp is dedicated to mid and bass for the right speaker.
• Lastly to try, I connected the Hi-Caps to one another using socket 1 to 1, versus socket 3 to 3. Unfortunately no change. Issues persist.
• Something additional to note that I thought was my imagination and has been happening since I’ve been testing this system from the start. THEN it happened twice last night and once right in front of my eyes!
Intermittently, the preamp will switch from the Aux input (and probably the CD input too) to the Phono (apparently default) input.
The first time this happened I thought I blew a fuse, checked with my multimeter, but all amp fuses were good. I cannot nail down any specific action, like raising or lowering volume, that is causing it. And sometimes it doesn’t happen for a length of time/not at all.
It appears one/both of the Hi-Caps are experiencing a power issue that is causing the pre to power down and power up quickly, bringing it back to the default Phono input.
So as a next step, I am having a professional shop I’ve worked with in the past many times go over each Hi-Cap in-depth, as well as the SNAXO. I do not believe either Hi-Cap has ever received any service, they appear original/untouched inside from factory, and from what I’ve read over time they can require service. These are over 20 years old I believe. Pics of each Hi-Cap internal to follow in this thread.
I will be sure to update this thread once I hear more from our professional technician.
Thank you so very much for your assistance.
-EBWhite
Hi EBWhite,
In your original post, I assumed the buzz you mentioned was transformer hum. As it is through the speakers, I am more convinced that your issue is being caused by high resistance short circuits between the DIN socket pins due to the corrosion present.
I have seen a few examples of this with odd fault symptoms as a result. It is an environmental issue which I’ve always assumed is due to the units being situated near the coast in humid, salty conditions.
Hopefully your technician will replace all the DIN sockets & the issue will be gone!
Regards
Neil.
Hi @NeilS - Most interesting! You called it on environment. This system lived at a second home right off the coast in humid, salty conditions.
Question - what would a high resistance short circuit look like from the DIN socket pins? Would I see significantly less voltage than the roughly 24-25v I received of each HiCap VE+ pin?
Neil
I have a few components where the ‘plastic’ components of the DIN sockets seem to have a white/grey powdery appearance - I’d assumed it was some kind of deterioration of the ‘plastic’ possibly due to humidity but I’m certainly not near the sea. Is this common?
It’s more of an issue with the voltage rails & ground pins shorting to the signal pins. The voltage rails would be largely unaffected, but you don’t want the influence of 24VDC bleeding into your signal lines.
With the Hicap disconnected from everything, measure between the signal pins & all the other pins on the 5 pin socket using a DMM - they should be completely open circuit.
Regards
Neil.
Hi Alley Cat,
I’m not sure exactly what the substance is, but I think it’s on the surface of the plastic rather than the material breaking down.
Certainly not common, only seen a few examples.
Regards
Neil.
Thanks, unusual, I may have to take another look, assumed it was just affecting the plastic not the DIN connections. I seem to recall trying to clean the plastic ages ago with isopropyl alcohol but the discolourtion remains on some.
Thanks for your reply @NeilS. Seems like no issues on that test.
I should know more this week on where things stand with the two HI-CAPS and SNAXO units. I’ll be sure to update this thread with findings.
Related - is there an official source online where I can source SNAIC cables, preamp shorting pins/caps, etc?
Any Naim dealer can supply the correct (and genuine) Naim SNAICs and link plugs here. Some also have online shops for these small accessories as well.