Mesa boogie king snake and the mid/boost control

[oj]

Have anyone seen how is connected ?
Also the SWITCHABLE PRESENCE CIRCUIT would be interesting to see how is done

Go easy on me am from Sweden

[M Fowler]

http://www.mesaboogie.com/amplifiers/el ... index.html

This write-up discusses each feature. The mid boost is patent applied for of course so one could research the patents and see what he submitted.

The presence appears to have the pot plus a switch to engage different resistor values I imagine.

Mark

[oj]

http://www.mesaboogie.com/amplifiers/el ... index.html

This write-up discusses each feature. The mid boost is patent applied for of course so one could research the patents and see what he submitted.

The presence appears to have the pot plus a switch to engage different resistor values I imagine.

Mark

Hi Mark!

Do you know fore Shure The mid boost is patent applied ?

The mid boost is a interesting control, so like to know it is done .

[M Fowler]

Hi Mark!

Do you know fore Shure The mid boost is patent applied ?

Did you read the link I posted?

This simple but incredibly powerful (and patent applied for) MID/BOOST feature allows you to dial-in additional gain into either Input’s signal path ranging from subtle enhancement to substantial overdrive.

[oj]

Hi Mark!

Do you know fore Shure The mid boost is patent applied ?

Did you read the link I posted?

This simple but incredibly powerful (and patent applied for) MID/BOOST feature allows you to dial-in additional gain into either Input’s signal path ranging from subtle enhancement to substantial overdrive.

Well I have seen that link before, but had miss (and patent applied for)

[M Fowler]

No problem easy to overlook.

I don't know anything about how this amp works but reading the page it appears to have a input jack #1 for 1/2 triode gain stage in front of the normal input jack #2.

You have both volume pots available when in high gain input #1 so you can dial in a nice grit or distortion.

That mid-boost could be something simple as a slope pot or what some people also call a mid-shift pot.

Mark

[John_P_WI]

I would guess that it would be a pot at the bottom of the tone stack, between the 5k6 resistor (on Marks scheme) and ground.... Regardless, it is Mesa... yawn (in reference to Randall Smith's appetite to PAF everything under the sun that has ALREADY been done).

[oj]

No problem easy to overlook.

I don't know anything about how this amp works but reading the page it appears to have a input jack #1 for 1/2 triode gain stage in front of the normal input jack #2.

You have both volume pots available when in high gain input #1 so you can dial in a nice grit or distortion.

That mid-boost could be something simple as a slope pot or what some people also call a mid-shift pot.

Mark

The amp is this one, but whit some new tweks

http://tubefreak.com/mk1.gif

Personally I think they are using a special pot that split after 50%

[brewdude]

Is it a separate mid pot and boost pot?

Or, a single mid/boost pot?

Could it simply be a high resistance (250k) mid pot--like a Dumble style tone stack?

[John_P_WI]

Yep, again my guess is a pot right under the mid pot where the gain switch is shown.

[oj]

Yep, again my guess is a pot right under the mid pot where the gain switch is shown.

But It's just one nob .
So it have to be a special pot.
It works like a normal mid up to 5, after that It starts to be a boost.

[John_P_WI]

Hmmm, look at the schematic that Mark posted with the fixed 5k6 to ground.

What happens if this fixed resistor becomes adjustable?? We now have a mid pot tone control.

What happens IF this fixed resistance value is increased? We have a boost.

What happens IF we add a fixed resistance and a pot together? We have a mid tone control and a boost.

So a pot and a resistor overlap the mid-control, any additional resistance on the pot is now a boost. Nothing special, 1 "knob". There may be an additional cap in play connected to one of the pot lugs?? Just speculation on these points, but have done similar things more than 20 years ago.

Nothing Mesa does, is, or will be magic ever... Certainly not worth patents. Yawn.

[M Fowler]

That Mark 1 is just a PAB (preamp boost) or tone stack bypass whatever you want to call it.

[John_P_WI]

That Mark 1 is just a PAB (preamp boost) or tone stack bypass whatever you want to call it.

Yes, you are correct Mark.

Now make it variable with a pot overlapping the mid tone control range....

[d95err]

http://www.mesaboogie.com/amplifiers/el ... index.html

Kind of funny how they first claim the amp to be an "exact replica" of Santana's old amp and then go on to describe all the changes made from the original...

I'd be willing to bet that the mid/boost function is just a logarithmic pot with 5x - 10x the value of the regular mid pot. At half rotation, it would be approximately like a regular mid pot at max. From there on, it would act like a tone stack lift. Still, just a regular tone stack with an unusually large mid pot value.

The feature is "Patent applied for" so I assume it has not been grated. I assume the patent application will be denied, since AFAIK you cannot patent specific circuit values.