Mark V Variac

[244300]

I understand the amp has a Variac option on the power switch to operate on 90v instead of 120v. Ignoring just how amazingly creative and cool it is to even provide that options...

...I’m curious about two questions.

Who loves this option and why?

If wall voltage is 110-115, then is it still 90v or does it lower wall voltage 25%?

 

[Hefalump]

Well....I found out the hard way that you have to use variac power with el34's.......

 

[244300]

Well....I found out the hard way that you have to use variac power with el34's.......

Oh no!

 

[DRS]

Well....I found out the hard way that you have to use variac power with el34's.......

Doesn't the bias switch on the back of the amp look after the EL 34 swap?

 

[Hefalump]

Doesn't the bias switch on the back of the amp look after the EL 34 swap?

Apparently NOT.....they changed it in user manual AFTER I bought my amp.....Mesa never bothered contacting owners.....ended up exploding a resistor....of course a couple months after my warranty expired.....$480.00 IN SHIPPING AND REPAIR.

I am not impressed at all with the Mark V reliability.......that is a long story and I have to run.

 

[conrad79]

Yea several years after the fact Mesa sort of slipped it into a manual revision that you were supposed to use variac power in addition to the EL34 bias switch.

anywho, I like variac mode and use it often. Just makes the amp a little softer. However, if the wall voltage is below 117 I use full power mode

 

[244300]

Apparently NOT.....they changed it in user manual AFTER I bought my amp.....Mesa never bothered contacting owners.....ended up exploding a resistor....of course a couple months after my warranty expired.....$480.00 IN SHIPPING AND REPAIR.

I am not impressed at all with the Mark V reliability.......that is a long story and I have to run.

If this was recent, consider calling Mesa to see what they say.