Tube rolling on EAT E-glo petite phono stage? Glued heat sinks

[Exophile]

Just got an EAT E-glo petite phono stage, an upgrade from a Vincent PHO701 with upgraded Telefunken ribbed plate 12AU7. The new one has a couple of 12AX7 tubes, and I was looking forward to experimenting with different tubes. I tried to find out what the stock tubes are, but my retailer did not know, and EAT has not replied yet (only a couple of days).

After opening it up, I notice that the tubes have heat sinks glued to them, they are cylindrical metal profiles with protruding lamellae. I cannot see any markings on the tubes, so have no idea what they might be. Additionally, I wonder how important those heat sinks are, and how to remove them safely without destroying the original tube.

It sounds quite a bit better right out of the box, more detailed, more defined soundstage. I got it with an upgraded power supply (Sbooster), so don't know how much that affects sound compared to standard wall wart. Adjustments of resistance and gain are easy and quick. I use it with a Soundsmith Zephyr MIMC* on a VPI Super Prime Scout and it sounds best so far with 65 db gain and 600 or 1200 Ohm. Looking forward to burning in the tubes a bit more. So far so very good. Just curious about the tube rolling aspect.

[Firebottle]

Valves don't need heatsinks, they run perfectly well without. Have you any picture of the valve and internals of the stage?

Just fit alternative 12AX7/ECC83 without heatsinks.

[ovlov854]

Don't the EAT have some overly priced tube dampers fitted to their stuff?

[Exophile]

Thanks for the quick replies. First image is the opened chassis, one tube in place, the other removed.

29166

These two pictures show the top and side view of the 12AX7 tube with the metal sleeve-y-thingy. In the top view, you can see the peach colored tacky stuff that holds the sleeve to the tube.
2916729168

Could well be that this is a dampener to eliminate any microphonics. As it is made of metal and has all those fins, I thought it might be a heat sink. I agree, I have never heard of heat sinks with tubes, but I am certainly not a tube expert, so ask here. I thought that tube dampeners were more of a plastic thingy that easily slides on/off the tube.

Any idea how to safely remove the dampener from the tube so that I can see what tube is used in the stock configuration?

[Marra]

Read about them here.

https://www.europeanaudioteam.com/en/e.a.t.-cool-damper-wp000039.html

[Exophile]

Thanks for the link. No mention of glue in that document. Looks a bit on the snakier side of accessories. Still wonder what the stock tubes are, and I a bit worried of breaking the tube while trying to remove the dampener/cooler-thingy. Hopefully EAT will reply to my direct emails.

[jahsavage]

I have the all tube E-Glow Phono which is probably due a tube replacement. I assumed it was easy to remove the heat sinks? I ordered a set of four heatsinks a few weeks back for another amplifier, they are due to arrive any day soon. I'll let you know how to fit them and how easy it is to remove them as soon as I discover.

[jahsavage]

I just read the HiFi + document in the link above and does mention some teflon strips that sit between the tube and the heatsink.

[Exophile]

If you look at the pictures, there is some chewing-gum-like material between the heat sink and the tube. That peach colored thing is certainly not a teflon strip. Still no word from EAT ...

[jahsavage]

Hi Exophile

My EAT tube coolers arrived today, here are the pictures but note the fixings appears different.

https://i.ibb.co/ZMWLKH0/In-Shot-20210210-123948796.png

https://i.ibb.co/kmJD5xP/20210210-124121.png

[Chakeet]

@exophile I have the Petit and have rolled 3 different tube pairs into it. But first, about the stock tubes: They are Slovakian unbranded JJ 12AX7s (at least mine are). The tube coolers come off quite easily. They are secured to the Petit with a red dampening glue/putty (not sure exactly). I simply heated mine up with a hairdryer, and they slid right off. Make sure you slide them off towards the pins. You might just consider leaving them on though because once they are off, they don’t fit snugly back on because the glue/putty gets smeared.

I have rolled Gold Lions, Tung Sols, and NOS RCA short grey plates. All sounded good, but the Gold Lions stood out. In particular, female vocals really stood out and sound incredible, like a curtain was lifted. All three sounded better than the stock tubes. The stock tubes are nice and quiet, and I’m certain EAT screens them for noise because the Petit is VERY sensitive to tube noise. If you decide to roll, make certain you are getting phono-rated noise tested tubes. If you buy from Upscale, that would be Platinum grade or “Kevin’s Stash”. Also, be very careful rolling as the sockets are PCB mounted and plastic.