Preamp tube change in Diezel VH4

[A-Xul]

Hi guys,

I have a question to the more amp-tech experienced users around here.
I want to change a preamp tube in my VH4. It's the V4 position.
My amp tech said I can just remove the back panel and change the tube if my hand fits. I don't have to remove the chassis from the head shell.
The Diezel manual on the other hand says to not remove the chassis or touch any parts inside the amp as it contains lethal voltages.
I'm not an amp tech, but I did change preamp tubes before in my Mesa Lonestar combo, which was pretty easy to do.
My question is, did you guys change preamp tubes like that in your VH4? From my basic amp knowledge, the lethal voltages are inside the actual chassis not on the metal plate itself guarding it. As you know, the caps and transformers as well as the power tubes are also accessible on the outside of the chassis in the VH4 and I'm kinda afraid to touch them by accident. This was not a problem with my Lonestar.
Of course I would have the amp off and cold when doing that, meaning shut down for a long period of time before doing this.
What do you guys think?

 

[FLUXX]

Yesterday, I tested all the tubes in my VH4.
I removed the chassis from the headshell.
I use an amp cradle, but large hardcover book stacks work great too.

Remove the chassis screws on the bottom of the headshell with a screwdriver/no drill
Slowly, slide the chassis out of the headshell
I lift the chassis a bit from both sides using the power buttons/IEC jack, and Input jack/speaker jack ad slide back a little at a time on each side. Once enough chassis is out the back, pull out the chassis on the sides.
Do not touch anything inside the open chassis/underside. You can touch the outside of the chassis.

Put your chassis on top of the book stacks/cradle.
Now you can effectively pull the V4, and correctly seat the new tube.

 

[A-Xul]

Thanks for the info man! I will try to do it like this. So after you extract the chassis enough, how do you hold it/put it on the books, if I can only touch the upper side? Isn't it too heavy to just hold onto the jacks and IEC outlet?

 

[FLUXX]

You grab the chassis by the sides. You can touch the underpart of the chassis with your fingertips.
Just don't let your fingers go into the amp works/wiring.
It's not hard. I do it all the time. You'll see when you start pulling out the chassis from the headshell.

 

[Pain]

Just did this yesterday like Fluxx stated, TAD7025 (TAD7025b is Diezel installed in mine) preamp tubes are at Tube Depot.

https://www.tubedepot.com/products/tad-7025-e83cc-redbase-highgrade-selection

V1 is always vital to have the best tube you can afford go into that slot.