Stellar M1200 More Tube Rolling

I had waxed lyrically about the Mazda 12AU7 tubes I tried. It is just the best tube I’ve tried so far, but I’ve only rolled a small number of tubes.

Well I found some Jan 6189W GE tubes for next to nothing (A$20 per tube would be conisdered cheap, surely). These were manufactured in July 1986. Reading about this tube, it would appear these were manufactured with reliability, robustness, and low microphony in mind.

Bung the tubes in. They will need to burn in, I guess.

Initial impressions compared against the Mazdas.
Smooth, but a slight hardness in the upper mid-range.
Sound stage L-R is truncated compared with the Mazdas.
Stage Depth appears to be the same as the Mazdas.
Treble is more muted than the Mazdas.
Bass is slightly bloated.
Deep bass is not as deep as the Mazdas.
Dynamics appear to be lesser.

Overall I would rank the JAN 6189W above the stock Psvane tubes supplied.

I understand these tubes are plentiful. My source in Melbourne has quite a stash. Peter is reliable too. He drove across town to drop the tubes off to me personally, he said he was in the area already!

I am tempted to buy a few more of the 6189W tubes as backup to the three sets of Mazda I already have. But alas Peter does not have any Telefunken 12AU7 tubes, or at least he hadn’t been able to find any yet in what I assume to be a fairly large hoard of tubes.

Message me if you would like Peter’s contact details. I may be slow to respond as I shall be away the front half of December. Sailing to NZ and back is fun!



Just back from a cruise and contracted Covid-19. Bummer.

The JAN GE 6189W has broken in. Sounds good, but not as good the Mazdas.

The Amperex GE tubes I’m using in my preamp sounded mediocre compared to my Mullards. I tried the Ensemble Tubesox which wholly transformed the Amperex to killer status.

Simple I have many pairs of the Tubesox. Slipped them on the 6189W. Another massive transformation. Now might be equal to or better than the Mazdas.

I’m also buying a pair of Sylvania Long Plates labelled as Amperex.

I’ll try these in due course and report back.

Miserable with Covid-19 although quadruple vaxxed but with minor symptoms.

I hope you will feel better soon!

Mazda, Telefunken in M1200, plus Mullards in pre are hard to beat. I like Gold Lion In pre to match with Telefunken in amps too. I doubt you will find another NOS beats these combinations above.

I love the Mullards CV 4024 in line stage of my Doge 8 Clarity. The Amperex 12AT7 made by GE were ho hum until I used the Tubesox. Now they are the equal for a lot less money.

I’ve had mixed results using the Tubesox in my VTL Ultimate Pre-amp and the VTL Deluxe 300 Monoblocks. I now realise it is the tube you use.

Some tubes, maybe especially GE, are great tubes needing the right damping to shine.

Regards from Iso.


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I tried a pair of tube rings in the past. I ended up not using them on either Pre or amp tubes.

The Ensemble Tubesox are designed to slip over the tube like a glove. They certainly improve the SQ of the Amperex 12AT7s in my preamplifier by a quantum leap.

However, the really big improvement is with the JAN GE 6189W in the M1200s. With the Tubesox, I reckon the 6189W is better SQ wise than the Mazdas. Maybe I have to try the Tubesox on the Mazdas?

I also have a pair of Sylvania 6189W longtails to try.

I’ll be tube rolling for a while.

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Sounds like a lot of fun. My tube rolling was all to do with 12au7s since both BHK pre and M1200 use them. But I am ready to try some 6s in the near future.

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So the sock arrangement sounds interesting! My questions are first what about the heat that the tube puts out? If it is totally inclosed will that affect the life of the tube due to all the extra heat being contained?
Secondly, I already use the Herbies ring tube damper. Is the sock sonically an improvement.
And finally, where can I purchase them? I have been to the factory website and it was of no avail.
Thanks and I look forward to hearing from you

The Tubesox is woven kevlar with copper interwoven. My sets date back 20 odd years. I did check with Ensemble who said as long as the kevlar and copper is intact, no problems with their use.

Logic suggests that there is heat retention, but with the low heat generated, obviously, Ensemble do not see any problems?

With the 12AU7 tubes in the M1200 going for 10,000 hrs, even if the Tubesox recuced this by 20%, I would not care.

I’m now 60 with 3 sets of the JAN GE 6189W, 3 sets of the Mazdas, and set 1 of Sylvania 6189W in stock. So I think I’m good for the term of my natural life.

BTW I found this link to the Tubesox. Mine are ugly fugly compared to the stuff they are selling now.

Phrozario, thanks for posting the website. However I have already reviewed it and I have even emailed them a few days ago but no response back. Nowhere on the website does it indicate and US dealers for the product. So sad! Either you are in business or you’re not!
Does anyone know who in the US actually sells the Tubesox?
It would be great to know that information….

I did a search for Ensemble distributor and Audioarts in NYC came up. They had electronics and cable listed, but no TubeSox. Not sure if that helps, but it’s a start …

Thanks guys for pushing this along. It’s all very appreciative, however I must admit that I am somewhat disappointed with ‘Ensemble’ the manufacture of the Tubesox not having a presents herein America. They do sell their main products but not the Tubesox which for me would be a ‘no-brainer’ almost an add-on for the tweakers to get excited about.
I mean we all love to tweak our systems in some way or another, right? I know I do and I find it to be a part of the hobby and fun to hear an improvement that a tweak or modification can make to the sound.

But in this case it also raises a red flag.
If the item does as they claim then why is it not here in the good old US of A?
Which is the largest market.
Something to think about…

Anyway, moving on I have just now received an email from Ensemble and this is what they have said and I quote…

Many kind thanks for your enquiry. **
We have distribution in the US for our main products, however as regards Tubesox it is best to get them direct from us.
A pair is 90 dollars plus 12 dollars postage. Payable via Paypal.
Best regards

Anne Wagner

So how about that???

The question I need to ask is the item in question actually worth 90 bucks?
I would be interested in those who might have used it and what they found out about it. My biggest concerned is about the Tubes getting hot and reducing the life of the tubes?

I look forward to hearing from you…

$90 seems high, but if there is a space limitation it might be the only choice. A good option for a generic recommendation is Herbie’s Audio Lab. Their dampers are good, but do protrude from the tube a bit. I have them on my BHK Pre (lots of space) and a BHK 250 (very tight). I don’t have the M1200, but my understanding is accessing the tubes is difficult so the Herbie’s may not work. Can’t offer anything more than that.

The Herbie’s dampers fit the tubes on the M1200 just fine. I simply put them on and didn’t bother with checking to see if the sound changed. Maybe it is time to take them off and give a listen.


EkW, I agree with you! In fact as soon as I received my BHK Preamp I purchased the exact same tube units that went around the tubes and yes I heard an improvement so I have kept 5hem in place ever since.
But I do want to find out more about the improvement if any to what I have now……

Reverted to the Mazdas. Better than the JAN GE 6189W.

How perceptions change!