Mesa amp tips

The Mesa Mark Series

The Mark Series Graphic EQ

One very well known and important feature of the Mark series is the on board graphic EQ. Analysis of a Mesa/Boogie Mark IV schematic revealed the following settings for recreating the famous amp's eq controls:

Frequencies:

• 87.61 Hz
• 371.74 Hz
• 723.43 Hz
• 1575.87 Hz
• 4822.88 Hz

Q:

• 1.414 (ideal for octave equalizer)
• 1.3 (actual, due to component values used)

There's about 18dB of cut and 17dB of boost. This is in the ideal world, so +/- 15dB was probably the design goal. The pot response is logarithmic – i.e. most of the cut/boost is near the end of the pot travel. Also, this is not a constant Q design, so the Q decreases (or bandwidth increases) with less boost or cut. I don't know if Cliff's graphic is constant Q, but the parametric should be constant Q, given you have a Q setting.

One of the most common uses of the on board EQ in the "Classic V" curve:

Shredi Knight had a great post on recreating this using the Parametric EQ after the amp sim...

The supposed real frequencies and Q's can be found [above], but I never liked how they sounded. I just use the actual frequencies as they appear on the front of the Mesa amps (like in the above pic) with the Parametric's default Q's (with a couple of exceptions) and it sounds pretty close to me (I can give you the exact settings I use if you want).

Here's the settings I use for the Parametric EQ on my Mark IV patch. It goes directly after the Amp block:

Parametric EQ:

F1 Freq. 80.8 Hz Q. 0.812 Gain. 8.79 dB Type. Shelving

F2 Freq. 238.8 Hz Q. 0.707 Gain. (minus) -0.47 dB

F3 Freq. 748.2 Hz Q. 0.718 Gain. (minus) -7.46 dB

F4 Freq. 2181 Hz Q. 0.707 Gain. 2.36 dB

F5 Freq. 6618 Hz Q. 0.707 Gain. 0.00 dB Type. Shelving

One very important thing is to use the Amp blocks Depth control. I use this instead of boosting the 238.8 Hz frequency in the Parametric EQ. Experiment with turning it up until you get the desired amount of "Thump". On my Mark IV patch the Depth is at 6.69, and is set to Active on the advanced amp page.

Additional notes from Shredi Knight

Taken from Shredi's post(s) on the Fractal Audio Systems Forum:

As far as the USA Lead sims (Mesa Mark series) go, I tend to approach them like the real things. Here's my list of tips:

- Keep the amp sim's Bass low. Anywhere from 0-4 is typical with Mesa users, with 2 seeming to be the most common. I have the Bass around 2.00 on my patches. Mid anywhere from 5.00 to 8.00, and Treble fairly high (from 6.50 to 8.50). I personally have the Treble on my patches between 6.50 - 7.50, depending on the USA Lead sim. This is how the Mesa Mark series amps are typically set up. I also have the Presence at 2.52 (between 2-3 seems typical on real world settings). I have the Tonestack Type set to Passive and the Presence Type set to Active.

- Keep the power amp Master relatively low so most of the gain is coming from the preamp stage of the amp sim. Mesas are about preamp distortion, not power amp distortion. Typical settings I've seen on the Mark series are between 3-4 (I set the Master at 3.23).

- Mesas are set with a very cold, fixed bias. I've researched this a lot and the consensus seems to be that it is 200-205, so you might experiment with turning the amp sim's Pwr Tube Bias parameter down (I have mine at 0.205).

- This isn't specific to just the Mesas, but to the high gain amp sims in general: Try turning up the Transformer Match parameter. I read where someone on another forum described it as the "Mojo" control, and that's pretty accurate. I can't describe too well what it does to the tone, it just makes it sound better. More lively and 3-D sounding. I set it at 6.38 on the USA Lead 1, and 6.85 on all the other Mesa Mark sims.

- I always use a Drive block before the amp sim (all high gain amp sims, not just the USA Leads) to tighten up the bass and give the tone more punch (Drive at 0.00, Level 10.00). I like to use the Full OD, with the Clip Type changed to HV Tube.

A note from Radley

Taken from Radley's post(s) on the Fractal Audio Systems Forum:

For those who love the Mk 2, 3 & 4 Boogie sounds as much as me, check this out:

I may have found an easy way to get great sounds out of the USA llC+ Amp *without* needing to duplicate the 5-Band graphic post-EQ. All you do is move the Amp's tonestack from pre to post position - I still hear the unique tonality of the Mark series overdrive, but without the overbearing mids that made the 5-Band necessary for most users. FWIW, I do use some pre EQ to cut lows to keep the distortion 'tight'. Worth a try!

The Mesa 2:90

Cliff posted a cool trick to tighten up the low end on high gain patches. Some users have found that implementing this in conjunction with a boost to the transformer match parameter (on the advanced page of the amp block) yields a result similar to the "deep" or "deep extend" mode on the 2:90.

1. Put a filter block before the amp block. Set the type to Highpass.
2. Attach the Envelope controller to the Frequency parameter. Use default settings for the Envelope parameters.
3. Set the Scale to 40%, Offset to around 22%.

Also, as mentioned with the Mark series above, dropping the Pwr Tube Bias parameter down to .200 - .205 helps clean things up a bit too.