BrianC7927
Active Member
Hi All,
First post and kinda new to tube audio so forgive any ignorance.
I purchased about 6 months ago an original Dynaco St-70 amp, not the new ones but an early 60s model.
Been enjoying it and it's all be working great, i have a Scott Type 130 pre-amp that it is plugged into.
Just moved a few months ago, and as I was resetting it up, i had the cage off, and had a screwdriver in my hand. I was out of it, and saw the two screws on the top of unit (the Bias Potentiometers), and was like, i'll tighten those screws so they don't fall out, not knowing what they were. So I turned them both fully to the right, and have played about 10+ albums or so like that.
Well, as may be expected the amp didn't sound right, and in a few weeks one of my EL 34 tubes went bad, so I figured I just had a bad tube. I replaced, and the replaced tube is much louder than the other side now (right louder than left channel).
As I finally read and understood the manual, i realized I turned both potentiometers to full voltage and burned the tube out, and not sure what else damage I did.
I got a volt meter, and following the manual instructions, i set the potentiometers to the 1.56 v recommended in the manual. But, I know I burned a tube out already, I am concerned about what other potential damage i have done to the system or it's components.
Can anyone tell me what potential damage I did to the amp and it's components with setting potentiometers to full for 10 albums? Maybe 8-10 hours of listening. Will I need to replace all the tubes? It burned out one EL 34 which was new so not sure what else I did.
Appreciate any guidance or input for a noob tube guy.
Thanks and appreciate it
Brian
First post and kinda new to tube audio so forgive any ignorance.
I purchased about 6 months ago an original Dynaco St-70 amp, not the new ones but an early 60s model.
Been enjoying it and it's all be working great, i have a Scott Type 130 pre-amp that it is plugged into.
Just moved a few months ago, and as I was resetting it up, i had the cage off, and had a screwdriver in my hand. I was out of it, and saw the two screws on the top of unit (the Bias Potentiometers), and was like, i'll tighten those screws so they don't fall out, not knowing what they were. So I turned them both fully to the right, and have played about 10+ albums or so like that.
Well, as may be expected the amp didn't sound right, and in a few weeks one of my EL 34 tubes went bad, so I figured I just had a bad tube. I replaced, and the replaced tube is much louder than the other side now (right louder than left channel).
As I finally read and understood the manual, i realized I turned both potentiometers to full voltage and burned the tube out, and not sure what else damage I did.
I got a volt meter, and following the manual instructions, i set the potentiometers to the 1.56 v recommended in the manual. But, I know I burned a tube out already, I am concerned about what other potential damage i have done to the system or it's components.
Can anyone tell me what potential damage I did to the amp and it's components with setting potentiometers to full for 10 albums? Maybe 8-10 hours of listening. Will I need to replace all the tubes? It burned out one EL 34 which was new so not sure what else I did.
Appreciate any guidance or input for a noob tube guy.
Thanks and appreciate it
Brian