what happened to the bias-tutorial on the diezel website?

[DvE]

Hi all,

I changed some powertubes at the beginning of the year and used the tutorial on the website.
http://diezel.typo3.inpublica.de/tech-corner.3.0.html
Am I blind or is it gone now?

For the second case, please tell me what steps to do. I have a Herbert with external bias pots.
Wasnt that hard last time, but then I had this step-by-step tutorial.

After pull the old tubes and put the new ones in, how have I to continue switching power and run on/off, connect the amp to a box, at which point set the bias, etc?

Thanks for your help =)

 

[duesentrieb]

Herbert values in brackets

1) Remove the backpanel. You'll see three (four) jacks above the fuses.

2) Set your multimeter to 200 mA DC and plug your black probe into the black jack and the red to one of the red jacks.

3) Remove the jack-corresponding fuse from the fuse holder which is located on the backplate, turn volume controls to 0 and make shure a load or speaker is connected to the amp.

4) Now switch it on and read the bias current from your multimeter. Adjust it to the proper value by turning the bias pot which is accessible with a little flathead screwdriver through the hole in front of the red jack.

5) When finished, turn off the amp, install the fuse and repeat the same
steps for the other pair(s) by using the other red jack(s) and removing the other fuse(s).

 

[DvE]

Thanks olaf!

 

[Nico]

Cool that was instructive, does the same apply to the Einstein 50W? Only simpler because there is only a single pair of tubes....

 

[duesentrieb]

yes.

 

[DvE]

I have changed the tubes yesterday and everything worked as it should.

Now I am rocking with 4 x EL34 and 2 x SED "C" 6550s - perfect crushing tone

 

[duesentrieb]

 

[Pirre81]

I have changed the tubes yesterday and everything worked as it should.

Now I am rocking with 4 x EL34 and 2 x SED "C" 6550s - perfect crushing tone

I have the same setup I had some problems to read any mA value of the 6550 pair? I have installed 6550's in 1/6 slot.

 

[DvE]

Thats strange. I had no problem with the whole procedure at all.
Heaviest "problem" was to get the Herbert out of the rack