Mesa Bias Mod?

[Ruction11]

Why does the bias mod seem to be so popular for 5150's but not rectifiers, mark series, etc.? Don't they all have fixed bias that is generally pretty cold?

[Sixtonoize]

Mesa bias isn't nearly as cold as Peavey bias.

I think most of the time people don't think that the improvement is worth the hassle.

[PaoloJM]

Mesa's bias isn't really that cold, most wouldn't notice a huge tonal difference. The 5150 is so cold as to be fizzy and harsh sounding and there's a definite benefit from warming it up a touch.

I've always thought a better version of the bias mod is to simple alter the resistor value to provide a higher idle current level.

[Slaymoar]

Because mesa wants to sell their tubes as the only viable replacement. So you are stuck looking for "warm" or "hot" tested tubes according to your amp's bias circuitry/plate voltage.

 

Really, it doesnt matter. Mesas are meant to be on the cool side.

 

-D

[sled]

My DR 3Ch biases EL34s considerably hotter than 6L6s

[pine]

I bought the Mesa bias mod from Mansfield Guitars in NJ, installed it on my Lone Star Classic, it made a huge difference in tone for the better

[Sixtonoize]

How exactly did you buy a bias mod?

 

It's not like there are more than $5 worth of components that go into it.

[pine]

I looked up Mansfield Guitars on the internet and bought it

[Sixtonoize]

I can't seem to respond without sounding like a dick, so I'll just say that I'm glad that your amp sounds better.

[pine]

OK fine, I bought a bias mod KIT from Mansfield Guitars and installed it on my amp and then biased the power tubes at a more normal value (70% of the maximum plate dissipation for that particular type of power tube) which to my ears sounded way better than the cold-biased setting the amp came with from the factory.

[greg apocalypse]

I can't seem to respond without sounding like a dick, so I'll just say that I'm glad that your amp sounds better.

 

This is why your name highlights in "mod blue" and mine doesn't. :lol::lol:

[Slaymoar]

This is why your name highlights in "mod blue" and mine doesn't. :lol: :lol:

 

[boxcarmonument]

Do it yourself bias mod for Rectifier>>>> http://www.forum.grailtone.com/viewtopic.php?f=24&t=35849

[tech21man]

Jerry from FJA mods says the bias mod in the 5150 is {censored} and does it if the client asks for it but he doesn't really thinks the amp "needs" it or "benefits" from it. Something like mud was the word he used.

 

Anyway, mesa's do it for promoting their own tubes but then again you can actually use other sellers sets for mesa's. Plus they sound fine...what else needs to be said?