[234537]

Hello everyone,

I just replaced the tubes in my amp Stax SRM-006t and noticed something weird.

After waiting for about an hour and a half since powering up, I adjusted the bias and the multimeter seemed crazy: the values swang fast with a lot of excursion.
 
Have you got any idea of what the problem could be?
 
Here is what happened in detail:
 
To adjust the BIAS I followed the instructions here:

http://www.head-fi.org/forum/thread/415385/tube-change-biasing-a-stax-006t-ii/15

The target values are as close as possible to 0 volts, still remaining below the level of 1 volt.

On my machine I could reach these values by going back and forth the balance and offset adjustments.

The problem is that, when I reach them, I remove the screwdriver from the bolts and the values gradually swing with peaks of about 2 volts and -1.5 volts.
 
I live in the UK and measured the electricity from the wall socket, which is supposed to be 240 volts.
 
I noticed that the value fluctuate rapidly with peaks of 239 and 244 volts.
 
Although the problem with the BIAS might not be related to this, have you got any idea on what to do?

Thanks in advance.
 
Cheers,
 
Lorenzo

 

[spritzer]

You will never reach 0VDC, you only try to come as close to it as it possible.  2V in either direction is nothing compared to the hundreds of volts the amp swings so it isn't something to worry about and normal for any amp. 

 

[234537]

Hi Spritzer,
 
Thanks a lot for your post!
 
It is good to hear everything is normal.
 
Bye.
 
Lorenzo