STELLAR M1200 Snake Oil Upgrades

New to the forums as I’ve only taken possession of a pair of the M1200s.

Have not rolled tubes as I do not have any 12AU7s. But I will order a variety soon.

But I do have noise blockers. Like so below.

I am using the RCA inputs into the amps.

But the XLR noise blockers are are a revelation.

The harshness in the midrange is gone. Without any loss elsewhere. These actually work. Noise blockers gave been around for yonks and the argument in support has always beento do with proper grounding.

Thoughts and prayers?

Melbourne, Australia

Hey Paul
Yep, caps on the holes makes a difference. It’s a conceit first shared with me decades ago by a recording engineer who said it’s common practice to have something plugged into every socket as it lessens the impact of RFI/EMI. Graham Slee said something like if you’ve got holes in your casework, they’re easy paths into your electronics. So I thought I’d give it a whirl and I like the results. I think it’s more effective on RCA than XLR or BNC, but worth it to me.
I’ve got everything covered. I suppose I should take it all out and listen again, to make sure I’m not deluding myself…
I’m in Bendigo if you want a catch up. M700 driving Kanta 2 here. Welcome to the community!
PS - it all matters. There’s precious little real snake oil around. A sift through this forum will give you a lot to think about.

Welcome to the forum! When I had a pair of M1200’s I used XLR connectors. The snake oil that worked for me was the Gold Lion 12AU7 tubes and the Herbie’s RX-9 dampening rings for me the sound was much better than the stock Psvane tubes. Good luck!


Happy M1200s owner here. Gold Lion really shine in them but most of all XLR UPOCC cables from Iconoclast. Wonderful natural sound. As suggested by dchang05 soon I will try NOS telefunken 12AU7 Mazda branded, can’t wait.

Noise stopper AQ for unused RCA made no audible difference in my experience.


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It depends what preamp you’re running as to whether XLR or RCA is better into the M1200. Chord TT2 definitely sounds better RCA into the M700 I have. Nothing to do with the amps, but whether or not the preamp is balanced or single ended. This is only one example, of course, but shows it’s worth experimenting.
Also, do the AudioQuest ones have Teflon insulation? It’s an important element.

You can find my complete system on my member profile, in particular I use the BHK Pre that is IMO a perfect mate for the M1200s and preferably connecting them via XLR.

A P20 feeding all components (M1200s included) ensures a remarkable improvement in sound quality in my experience.

As for noise stopper here more info (no mention about teflon):


I am using all XLR cables in my system. I have tried both RCA and XLR caps on the non-used connections, but I could not detect any sound change in my system also.

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Sorry to say, after extended listening to the noise blockers, I removed them.

Although the mid-range was improved, everything else was hammered.

  • High frequencies were diminished.
  • Stage width significantly narrowed.
  • Stage depth truncated.
  • Imagery became less precise.

This is in context of my specific system, though.
Source is Esteric K-03XD. Preamplifier is the Doge 8 Clarity (yes, an excellent piece of Chi-Fi which sounds sublime). Loudspeakers are the Aurum Cantus New Grand Supreme (more Chi-Fi with ribbons).

I had the same effect using RCA noise blockers on the Esoteric and the unused outputs of the Doge.

Next stop tube rolling.

Regards and thanks for all your warm responses!



That is interesting. I actually have the caps on as dust covers. I am going to remove them to see if I will hear any difference.

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Paul, among XLR, RCA, and digital connectors I have 25 caps on all spared inputs and outputs for my system. I upgraded to all PSA gear about two years ago, and I spent quite a bit of time with these caps on and off but did not hear any difference, so I thought. I kept them on as dust covers for the last two years.

After reading your post I removed all of them tonight. Within a few minutes I heard an obvious improvement in soundstage width and depth, and the sound is more organic! After two years, I know my system much better compared to two years ago.

So, for all of you using these caps you should try to listen to your system without them.

Thank you for posting your findings. I have always thought the soundstage was not as good as my previous system, not anymore!


I sometimes think some of these teaks work well on built-to-a-low-price electronics but not so much on higher cost equipment. Why? I wonder if higher end gear is engineered/voiced (consciously or not) to compensate for the effect EMI/RFI has on sound. Possible?

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No tell me it isn’t true. Since a few months I put XLR RCA and digital caps on all unused input/outputs. Never heard an audible difference.

Now on your advice I need to move them away from the beginning, I’m too lazy but curiosity killed the cat!

I have to stay away from this forum for a while!


And what is the result? I’ve only recently gone fully capped and I like how calm and quiet the system sounds. I’ll give it another week before I pull them all out again.

The RF and EMI environment has changed dramatically in the last 15 years with all of the frequencies bands reserved for Military purposes transitioned for cell and wifi purposes. I doubt many companies in audio understand what and how it affects audio. After i started addressing RF, EMI, and EMF my music sounds like music again. It’s hard to realize since changes were gradual we got acclimated to crappy sounding reproduced music.

I truly get the return of vinyl. Start with cleaning up power is my new matra.


It is strange how much improvement I heard this time. You should keep them on for a while to get used to the sound before removing them😂

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Nah, here is Monday morning 07 AM, time to wake up and work… this evening I’m quite sure I’ll have “caps for dinner”… to be continued…

Have a nice day!


With so many improvements including yours lately. maybe I could just hear my system better now.

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I found this interesting. Check out the demo video half way through this Benchmark Application note selling the virtues of Star Quad cables

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Here I am…

Just removed all the noise stopper caps from both the M1200s and the BHK Pre.

You are right, some differences are audible. Not night and day but clearly audible. Maybe I’m victim of a sort of placebo effect, who can say?

The soundstage is a little bit wider and deeper.

This is the biggest difference I can hear. Music sounds more analog, vivid, voices in particular are more realistic. So in the mid area guitars are more present in a way that let them emerge compared to what I used to hear before.

Not so a big difference, anyhow a little layer seems to be unveiled now. Engagement has increased if this kind of sound matches your tastes. Especially in high frequencies I can hear a more sparkle feeling. Not harsh or edged but definitely more refined.

It seems that also for what concern this quality a little bit of more impact is reaching the chest now in a pleasant way. I hear basses produce less echoes or resonances. Simply more tighten without exaggeration that sometimes may appear like distortion.

Am I really hearing all these things just taking away 20 little pieces of metal from unused inputs and outputs? For sure! Be aware, you need to know your system very well, there aren’t improvements or differences so evident to be heard by all. If I probably ask to my wife she would say I’m crazy. As she usually says when I cry for a miracle changing cables, regenerators or cartridges, and she is probably right. So what?

Have I spent money for nothing? I don’t know. I will keep all the caps away for a while before deciding what I like or not even if a dust protection is a factor I want to consider too. As for merely sound consideration I probably prefer my system without the caps, for the moment.

Thank you dchang05 and phrozario, a trial was necessary to play with these tweaks indeed. More accurate listenings will tell.

Once more: what a wonderful hobby!


I had these caps on for two years, and after removing them I heard all the improvements you have described easily.

They could have some uses for some systems. But our systems are very resolving so minor changes make a difference. In this case it is a negative one.

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