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 Post subject: NMAD
PostPosted: Wed Sep 13, 2017 7:49 pm 
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Bottle Rocket

Joined: Tue Sep 12, 2017 3:18 pm
Posts: 12
New Mesa amp day. Decided to by a Mesa JP2C after playing many amps in the Marshall vein and designing and building my own.

I will give my thoughts later.


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 Post subject: Re: NMAD
PostPosted: Wed Sep 20, 2017 6:06 am 
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Dual Recto

Joined: Fri Feb 22, 2013 7:31 am
Posts: 2574
Location: North Carolina
There is a trick to get the amp to sound great for low level playing. Once you drop the master volume below 11 oclock, the bass becomes stronger in the voice. The shred mode will tighten up the bass and bring in more focus on the midrange and it will sound as good as it does when pushing the envelope (shaking the walls). I highly recommend reviewing the manual as there are some statements on how the midrange control interacts with some guitar woods and overall character of the amp. A boost midrange on the Clean channel will case it do drive hard into a crunch type distortion.

Ch2 can be dialed to a Mark 1 tone by taking out the midrange completely on the tone control, treble and bass at noon, use the one of the 5BEQ and drop the 240Hz slider all the way. I am sure there are other tricks or settings that will change the tone or character of the amp. I have yet to discover all of them.

Waiting to hear your comments on the NAD experience.

_________________
Current amps:
TC-50, JP-2C, MK V, Roadster, RA100
Old friends I sometimes miss:
Mk III (blue stripe), Mark IVb-WB


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 Post subject: Re: NMAD
PostPosted: Wed Sep 20, 2017 10:09 pm 
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Bottle Rocket

Joined: Tue Sep 12, 2017 3:18 pm
Posts: 12
Thanks for the suggestions.

Something to think about the Mark series (this was my approach) The Mark Series amps are simply Hot rodded Fender Circuits, that is how Mesa came to be. The first 2 gain stages is a dead on Fender Circuit with the Tone Stack in between and the rest of the gain stages following. This is not done this way in any other high gain amplifier including the Rectifier which is a SLO with some tweaks.

This is why many guitars players get frustrated with Mark Series amps who are used to playing other high gain amps. Most all other High gain amps including the Rectifier series have the Tone stack at the end of the gain stages. So for my little article here, I will call the Mark series the "Fender Style" (Tone stack feeding all gain stages after the first) and the "Marshal" Style (which is after the Gain stages).

With the "Marshal" style, the Tone stack is after the gain stages and only shapes the output of the pre-amp (meaning it doesn't change the distortion character or frequency response in the gain stages) In this application it simply attenuates high, Low and mid frequencies after the pre-amp. It is a passive tone stack it does not boost, only attenuates, same as the Fender style.

In the Marshal Style Topology you typically have 4 types Type 1: ( Guitar=> 3 gain stages =>cathode follower=> Tone Stack), Type 2: ( Guitar=> 4 gain stages=>Cathode Follower => Tone Stack) Type 3 ( Guitar=> 5 gain stages=>Tone Stack), and Type 4: ( Guitar=> 3 gain stages =>cathode follower=> Diode Clipping=> Tone Stack).

In all these examples the pre-amp voicing is shaped by Capacitor/Resistor networks, cathode bypass caps, and voltage divider networks. That is why these type of amps are a modders dream because you can shape the prea-mp in your own custom way.

With these types of amps players usually set the Treble at 1:00, Mid at 2-4, and bass at 3 to 5. This is because the capacitor resistor networks are cutting bass and high -mid frequency response pretty drastically to prevent the amp from being boxy. Power Amp depth controls help allow more bass since it was cut in the preamp

Typical examples of known amps based on the above Topology: Type 1 (Bogner Blue channel, and other mid to high gain amps) Type 2 (Bogner Red channel, SLO, Rectifier,ENGL, Framus and many others, this is very common setup) Type 3 (5150 series), and Type 4 (Friedman, Cameron, Jose Modded amps, in fact they all are almost identical with small changes here and there)

Fender Type (Mark Series): Since the tone stack feeds all other gain stages, it has a huge effect on the pre-amp gain structure. To set it properly you have to set it up differently as it for the most part takes the place of the capacitor/Resistor networks networks. That is why the highs and lows have to be low and or moderate and the mids don't have a big effect. When ever you amplify and keep doing it again through multiple gain stages, the frequencies get amplified exponentially, Bass gets muddy, highs get piecing/harsh.

Here is how the Tone Stack effects the tone and distortion characteristics on the Mark series amps. This tone stack in fact is very similar to the Marshall, but where it is located is where the difference is.

Treble: this is also another gain control, because the treble control is also the signal output on the tone stack, turning the treble up will boost the gain, but all the frequencies above 1K are also being boosted as well, think of increasing the treble control as boosting the gain and boosting the frequencies like boosting the 2.2K and 6K sliders on the graphic EQ, but it is prior to the gain stages, this is where the boxy tone complaint comes from. Try cutting the 2.2 and 6 K on the graphic EQ to remove the harsh boxy tone. Then use the Presence to dial back in the sparkle.

Presence: On the clean channel this is a power amp negative feedback control used for years on Marshall and Fender Style amps, but on the High Gain channels, it is simply a Treble control that effects higher range frequencies. It is a Treble after the Treble or imagine having a 10K slider after the 6K

The Mids when reduced get narrower in band, meaning the "Q" gets very small, thus the lack of a big tonal change, but when the mids get turned up, the "Q" gets bigger so more band width in the mids is cut just not as much.

Bass: This acts more like a High pass filter prior to the gain stages to cut the flub in the pre-amp stages.

The reason Marks have the graphic EQ, is because it is acting in a strange way like the Tone stack in the Marshall Topology amps, but the big difference, the graphic EQ cuts and boosts frequencies where the Marshall style only cuts.

Think of the Tone stack in the Mark series is the capacitor/resistor, cathode bypass cap application to boost/cut gain, and pass filters.

Big tips: for more gain set the treble higher, and cut the 2.2K and 6K to get rid of the associated harshness. Reducing the treble control warms the amp up and opens up the gain structure at the expense of less gain.

Also John Pretucci has a +20 dB pre-amp in all, his guitars so he is already boosting the pre-amp hard.


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 Post subject: Re: NMAD
PostPosted: Fri Oct 13, 2017 6:23 am 
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Mark II

Joined: Sun Feb 02, 2014 11:51 am
Posts: 104
baron58 wrote:
Thanks for the suggestions.

Something to think about the Mark series (this was my approach) The Mark Series amps are simply Hot rodded Fender Circuits, that is how Mesa came to be. The first 2 gain stages is a dead on Fender Circuit with the Tone Stack in between and the rest of the gain stages following. This is not done this way in any other high gain amplifier including the Rectifier which is a SLO with some tweaks.

<snip>

In the Marshal Style Topology you typically have 4 types Type 1: ( Guitar=> 3 gain stages =>cathode follower=> Tone Stack), Type 2: ( Guitar=> 4 gain stages=>Cathode Follower => Tone Stack) Type 3 ( Guitar=> 5 gain stages=>Tone Stack), and Type 4: ( Guitar=> 3 gain stages =>cathode follower=> Diode Clipping=> Tone Stack).

<snip>


Hi,

Do you, or anyone else, know where the TC-50 tone stack fits into the above classifications? Or is it like the hot rodded Fender (tone stack in between the first two gain stages)?

Thanks.


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