Mark 2B date help

[24loar]

Serial # 4868.....60W wicker Cane.....Can anyone help date? I bought around 1980 but can't remember exactly.

 

[Boogiebabies]

The final tech date will be written in marker on the bottom of the chassis.

Otherwise, buy it a few drinks and ask her age. 8)

 

[igfraso]

Are you sure it is a Mark II-B?

If the serial number is correct, it sounds like a Mark II-A from March 1980.

Examples:
- 2/22/80: s/n 4806
- 4/16/80: s/n 5059

At that time, they were producing 30 to 35 amps per week. So, a s/n 4868 would put its manufacturing on the first week of March.

 

[24loar]

I looked under the chassis and it is indeed dated March 5, 1980.....thank you! Should have checked. So it is MK 2 A.... Just ordered some vintage tubes ....for 2B....will they work?

 

[Boogiebabies]

You need a bias meter or Mesa tubes.

At 448V to the plates a 6L6 at 75% MPD would be 50ma. Anything at or below 50ma is o.k.
In Boogie's I prefer 35ma.

 

[24loar]

Thanks. I went to TUBE STORE online and indicated my need for tubes for a MarkII B then discovered thanks to you folks that it is a MarkII A. So the tubes will not work? I need to have the bias adjusted? Any recommended techs in NJ area?

 

[dodger916]

They should work fine; just notify the bomb squad and keep a fire extinguisher handy... :wink:

 

[24loar]

Thank you all.