Einstein Biasing Problem

[Pierre Cross]

Hi!

My Einstein 50W need new tubes; choose GT EL34LS!

When biasing with the multimeter i get some strange current variations. A call after and a drive in to my tech to help me and the confirmation of the problem came. The only way to bias was made with using a bias tool from GT to assure that the current was right and stabilized.

What’s up?

Another thing that is bothering my head to is the fact that one valve is glowing more them the other (very much)… he said that isn’t normal in this kind of amps.
I feel some kind of power loss… tested with other power tubes and the same problem.

Apart from this, Einstein rules!

What can be done to have more top harmonics in this amp? (more plexi feel) ☺

Regards,
Pierre

 

[i.ak]

After the problem arise, did you try a completely different pair of tubes (i.e. the old pair)? Was it the same?

 

[Pierre Cross]

Hi!

Yes, with different tubes.

I will try again with new ones tomorrow and report the measures.

Regards

 

[Pierre Cross]

Hi!

The plate resist is damaged!

The lack of power was noticed after 1 month of use (it has 1 year), it came with TAD EL34 STR and now have GT EL34LS.

What mod's can be done to get more brilliance in the mid's/high's? Like a Plexi feel...



Regards

 

[Peter Diezel]

Please tell me the version number of Your board and
I will tell You to replace a resistor.

 

[Pierre Cross]

Hi!

It’s a pleasure to chat with you.

Main Board
v1.5 pn002003

Small board: pn002004

Serial number: 002/158

Teach me some tips. LOL

By the way, in the future, there will be some changes in the Herbert (harmonically speaking)?
The only negative appreciation that i can take on Herbert is just: a little bit brighter wouldn’t be dreadful…
You made a magnum opus in this field by delivering supreme sound, versatility and reliability!



Sound clips from the Schmidt using 6V6? Please...

Keep the good work!

Regards

p.s. - the car is really yours?

 

[FriedChickenBandit]

What mod's can be done to get more brilliance in the mid's/high's? Like a Plexi feel...

Get the same mod I got..."GET A PLEXI"!

 

[Pierre Cross]

I have one.

Regards

p.s. - i want to see what Peter has to me

 

[Pierre Cross]

Hi!

Peter is on vacation?




Were is my tips?

Regards

 

[Peter Diezel]

Hi!

It’s a pleasure to chat with you.

Main Board
v1.5 pn002003

Small board: pn002004

Serial number: 002/158

Teach me some tips. LOL

By the way, in the future, there will be some changes in the Herbert (harmonically speaking)?
The only negative appreciation that i can take on Herbert is just: a little bit brighter wouldn’t be dreadful…
You made a magnum opus in this field by delivering supreme sound, versatility and reliability!



Sound clips from the Schmidt using 6V6? Please...

Keep the good work!

Regards

p.s. - the car is really yours?

Please replace resistor R38 on the mainboard from 68k to 100k.

Sorry, not my car

 

[Pierre Cross]

Thank you!

Changes gone be made.



Regards

p.s. - were is the Schmidt??????