EHX Mig 50 bias range/value

[alex73013]

I have the EHX Mig 50 amp. It has an external bias. When I got it it read 80 ma. I was wondering if anyone has this amp and where they set their's. The EHX support said the recommended range is 62-65 ma.

[JMP/HBE]

Re: EHX Mig 50 bias range/value

You need a bias meter that measure plate voltage.

[devastone]

Re: EHX Mig 50 bias range/value

Yes, bias meters are nice, but you have the manufacturer's recommendation and apparently it has external bias points to measure the bias, so I would think that would be a good place to start.

[JMP/HBE]

Re: EHX Mig 50 bias range/value

Bias is Calculated in relation to Plate voltage & not a random number.

{tube wattage} Divided by {PV} = [X] Multiplied by .7 or 70% dissipation.

Anything else is a roll of the dice.

[devastone]

Re: EHX Mig 50 bias range/value

I'm guessing EHX has already done that since they manufacture the amp so their numbers should definitely be in the ballpark.

[JMP/HBE]

Re: EHX Mig 50 bias range/value

I'm guessing EHX has already done that since they manufacture the amp so their numbers should definitely be in the ballpark.

Sounds like EH is coping MESA> My Dual Rec came with 6L6's but were only biased @ around 40%. It was only after i swapped EL-34's i had stashed where i could get the bias around 70%.

And i would never had known any of that without my Compu Bias Bias meter.

But people have to figure this stuff on their own. I have no Dog in this fight.

Sometimes i wonder why i even bother.

[devastone]

Re: EHX Mig 50 bias range/value

FWIW, the Mig 50 was originally a Sovtek design when they tried to get into the amp market in the late 80s/early 90s.

And yes, I still agree, a bias meter is great to have but not everyone has the desire or means to own one. Besides, his seems off on the bias judging by his reading vs EHX's recommendation.