Badlander mods?

[Snicksound]

Well to my ears it sure sounds like alot of Mark DNA is embedded in this one.


Yea with you on that. Depending on the desired tone I find either an OD or a GEQ in the loop easily provides enough "tone shaping" to get there.


The secret weapon Depth/Resonance. I added that to my Stiletto... simple and so effective. I never understood why Mesa didn't add this to their amps.

The only thing that is a bit disappointing to me is how the Crush mode isn't that different from Crunch, wish there was a bigger difference. Having a Dual Rec like Modern mode (sans NFB) would have been nice, pretty much impossible to implement though, or at least very difficult.

I'm curious about attempting Depth though, although that requires drilling the chassis for the extra pot.

As to why Mesa never does that, well Peavey patented it back in the 90s I think (which is why the EVH 5150 did not have it until the patent ran out). Maybe that's why they did the no-NFB thing on the Dual Rec, get the full resonance Boost in a way that does not challenge the patent? And then, well Depth doesn't work when there's no NFB...

As for the Mark, being able to get massive low end but without the flubbiness using the graphic EQ differentiated it from most other amps.

The Badlander would benefit from it though.

 

[bandit2013]

If you ever looked at the schematics of the Dual Rectifier circuits, the Modern mode makes use of an adjustable NFB circuit. Rectos have two NFB circuits. For all the modes except for Modern, it is a fixed NFB that cannot be adjusted. The presence controls are not connected to the NFB circuit, they are used as high pass filters. In Modern mode, that fixed NFB gets disconnected and switched over to an adjustable NFB, at the same time the Presence control also gets rewired for the NFB adjustment. What Mesa said was true but they did not tell the whole truth in what is really taking place between the modes. They kept it simple for most to understand. If the NFB was completely taken out, the amp would sound like Sh!t. The NFB cuts the odd-order and higher order harmonic frequencies. Without it, the amp would be an ice pick and the distortion would not be very pleasing. Even the Mark V90 Extreme mode retains the NFB, it just reconnects the feed for that circuit from the 8ohm tap to the 4 ohm tap as well as alter the capacitance in the circuit. Makes it sound huge. Still has NFB in the circuit. If you understand schematics, the truth of what occurs is on paper or in electronic form of PDF. I doubt they added it to the schematic and not implemented it in reality. It is patented or was.

I understand the deception of the name on the front of the amp. It is not a Rectifier, it is not a Mark, it is a hybrid of the two in some ways. First thing I did when I got the first BAD, compare it to the MWDR. Followed by the Roadster. Totally different amps. Out of the box, it can run the 7 string without the swamp. I had assumed it retained a cold clipper circuit like the other two Rectifiers. Nope. No such circuit. It was not until after poking around the amp to see what plate and cathode resistors were used in the gain stages is when I realized it is the hybrid amp. Converting the one gain stage to a cold clipper would be interesting or it may flop. I would agree, if they could have managed to do something different with the amp. Since it has two channels, use on in the hybrid mode and the other in Rectifier mode using the cold clipper. Not sure if the 2nd gain stage could be modified for that purpose or would it be better to mod the 4th gain stage? There is potential in this design if Mesa chose to improve on it. Badlander is much closer to the Mark VII than it is to the MWDR or Roadster or any other Rectifier amp and housed in the same shell as that of the TC series, just different appointments of appearance.

 

[rarebitusa]

I understand the deception of the name on the front of the amp. It is not a Rectifier, it is not a Mark, it is a hybrid of the two in some ways.

it's just a BAD Mesa

 

[bandit2013]

The only thing that is a bit disappointing to me is how the Crush mode isn't that different from Crunch, wish there was a bigger difference. Having a Dual Rec like Modern mode (sans NFB) would have been nice, pretty much impossible to implement though, or at least very difficult.

As for the Mark, being able to get massive low end but without the flubbiness using the graphic EQ differentiated it from most other amps.

The Badlander would benefit from it though.

I get that, crunch and crush are similar and so is the clean mode when you push the gain all the way up. After exploring the Mark VII for a bit, all of the gain modes sound basically the same to me. Nothing really sets them apart but a slight shift in character (not sure if it is the tone stack changing position from pre gain to post gain in the crunch and VII modes. The exception is the IIB mode which seems out of place for CH3. The two gain channels on the JP2C are also similar as they are the same basic circuit just with a shift in gain control. Bummer the Mark VII does not have a variac power mode like the Mark V. Come to think of it, the JP2C does not have that either.

Variac power on the Badlander, that does bring out some interesting character with the amp. Crunch sort of gets closer to the Modern MWDR sound, just not as much sub-harmonics though. Thank the cold clipper circuit for that.

The difference between crunch and crush will become more apparent if you are using the amp with another. Crunch will be 180° out of phase with the clean and crush modes. Probably why I like to pair it up with the Mark VII as crunch and IIB will have the same phase shift. Clean and crush will be in phase with the MWDR or Roadster if running those amps in parallel. TC100/TC50 and the RA100 has a similar phase shift on the lo gain mode vs clean and hi gain. Not sure about the Electra Dyne or other Mesa amps. As for the Mark V, mine died and I do not feel like fixing it. So, the crunch mode of that will be out of reach to compare to the BAD. I believe it has the same phase shift as I did run it with the Mark VII and did not notice any cancellation when running them in tandem.

The only dislike I have for the Roadster and the MWDR: raw and vintage modes are so weak compared to the Modern. I barely ever use those modes. Wonder if I am missing out?

I believe the Badlander was directed to the 7-string addicts. It sounds really good with a 7-string. I cannot say the same for the MWDR. The Roadster is much in the same boat but can be fixed with some preamp tubes (1990 Mesa Chinese square foil getter [6N4-J Beijing] tubes). Drop the power tube bias to reds in the STR440 tube and the Chinese tubes loaded in the preamp and the Roadster is more of a beast with the 7 string. Sounds great with the 6 string too. The sub-harmonic content is still present but does not get soupy or turn into a mud fest. It was like getting a new amp.

 

[Snicksound]

it's just a BAD Mesa

More like BADASS Mesa!

I really like this amp. Heck, I've been building amps for 15 years cause I could never find something "off the shelf" that I liked. I love the Bad!

 

[dtrax]

If you ever looked at the schematics of the Dual Rectifier circuits, the Modern mode makes use of an adjustable NFB circuit. Rectos have two NFB circuits. For all the modes except for Modern, it is a fixed NFB that cannot be adjusted. The presence controls are not connected to the NFB circuit, they are used as high pass filters. In Modern mode, that fixed NFB gets disconnected and switched over to an adjustable NFB, at the same time the Presence control also gets rewired for the NFB adjustment.

Not to derail this thread, but the above is incorrect.

NFB is 100% disconnected in Modern mode for Rectos. The presence pot is rewired to a passive HF shelving filter connected to the treble wiper. This is confirmed in the schematics.

Otherwise, Raw/Vintage mode operate in the traditional fashion (w/ NFB, Pres pot in NFB circuit).

 

[Snicksound]

Not to derail this thread, but the above is incorrect.

NFB is 100% disconnected in Modern mode for Rectos. The presence pot is rewired to a passive HF shelving filter connected to the treble wiper. This is confirmed in the schematics.

Otherwise, Raw/Vintage mode operate in the traditional fashion (w/ NFB, Pres pot in NFB circuit).

Yeah that's correct, I've spent enough time looking at those schems and experimenting with it in my builds to know.

No NFB does not sound bad, else an AC30 or a Tweed Deluxe would sound bad. It just sounds very different, and lets a lot more tube personality through (EDIT: and also why modellers struggle so much to replicate the Dual Rec properly, same as AC30 and Tweed Deluxe)

And because NFB affects power amp gain, Vintage and Raw will sound "weak" when switching, you have to bump up the volume to compensate. Vintage is closest to a Soldano SLO.

 

[rarebitusa]

FWIW another BAD 100 vid with Mr Scary. Actually not bad as comparison vids go, it outlines the differences well.

Mr Scary

I do have to admit some admiration for the logo, it's kinda cool

 

[kmanick]

I love the concept of the Mr Scary mod, I wish I could fit one into my Mark IV, I'd love to hear R2 with anther gain stage (lead channel as well)
If I ever do pick up a Roadster (been eyeing one for years) I will definitely get one and throw it in there

 

[Snicksound]

I love the concept of the Mr Scary mod, I wish I could fit one into my Mark IV, I'd love to hear R2 with anther gain stage (lead channel as well)
If I ever do pick up a Roadster (been eyeing one for years) I will definitely get one and throw it in there

Mark series doesn't use a cathode follower stage for the tone stack so this doesn't work. Cathode follower puts full DC voltage on pin 6 which is how this manages to run 2 tubes in the place of one.

For me that's too much gain though, just like how I ended up never using the Red channel on a 5150. Just got me lost in the mix on stage. But it's cool that options exist.

 

[bandit2013]

Not to derail this thread, but the above is incorrect.

NFB is 100% disconnected in Modern mode for Rectos. The presence pot is rewired to a passive HF shelving filter connected to the treble wiper. This is confirmed in the schematics.

Otherwise, Raw/Vintage mode operate in the traditional fashion (w/ NFB, Pres pot in NFB circuit).

I take it you never looked at the schematics of these amps. I will post the schematics parts this weekend showing the details on Modern mode wiring of the presence pot and NFB. I can use what ever schematic I see for the Dual Rectifier. May use the Roadster as the key as I have the complete schematic for it.

 

[Snicksound]

I take it you never looked at the schematics of these amps. I will post the schematics parts this weekend showing the details on Modern mode wiring of the presence pot and NFB. I can use what ever schematic I see for the Dual Rectifier. May use the Roadster as the key as I have the complete schematic for it.

Let's take this schematic of an old 2 channel Duel Rec:
https://el34world.com/charts/Schematics/files/Mesa_boogie/Boogie_dualrectifier.pdf

You can clearly see that LDR19 completely disconnects NFB when off. On the last page it confirms LDR19 is off for Orange Modern and Red Modern.

It does have LDR20 that increases NFB by paralleling another resistor, and it's used only for Orange Clean mode.

 

[Snicksound]

And here's a schem for a more recent 3 channel version:
https://el34world.com/charts/Schematics/files/Mesa_boogie/Boogie_3ch_dual_rectifier.pdf

No more variable NFB in Clean mode, but on last page you can see that Relay 7b again interrupts NFB completely for Modern mode

It can be confusing, cause there's both FB and FB' on the schematic.
- FB goes from the speaker to the .1 cap and 47k resistor that make up the NFB circuit, which is interrupted by RY7b in Modern mode.
- FB' feeds the Presence circuit AFTER the relay (you can see where it says "To Presence relay CH2 CH3", because switching between Marshall style and high shelving Mesa style Presence happens at the tone stack (since the same pot does dual duty). But the NFB does get disconnected always in Modern mode. THAT is the sound of Modern mode. THAT is what gives the massive loose low end.

 

[Snicksound]

Couldn't find the Roadster schem, but here's the Road King II: https://el34world.com/charts/Schematics/files/Mesa_boogie/Roadkingii.pdf

Here, you have RYFB used to interrupt NFB entirely, the NC (normally connected) position has the NFB connected. In the switching matrix we see that this relay is energized when either Ch3 or 4 is in Modern mode. Energizing it interrupts NFB.

 

[incertracing]

Just did the Mr Scary mod in the Badlander and its rather great. Did a quick vid when I got it, no real super dialing in, just left my eq the same and moved gain. Did 12 O' Clock on crush and crunch pre and post mod, as well as full gain crunch and crush pre and post mod, although full gain with the mod is rather overkill lol, but. its still clear even tho the gain is so high. I set mr scary to 1 O' Clock and fat switch on. You can vibes it. here:

 

[bandit2013]

Couldn't find the Roadster schem, but here's the Road King II: https://el34world.com/charts/Schematics/files/Mesa_boogie/Roadkingii.pdf

Here, you have RYFB used to interrupt NFB entirely, the NC (normally connected) position has the NFB connected. In the switching matrix we see that this relay is energized when either Ch3 or 4 is in Modern mode. Energizing it interrupts NFB.

Yeah, I was looking at the early model schematics at work. You are right, it is disconnected.

Something is missing in the Road king schematic. If you look at the presence control, it has the FB net listed. But at the phase inverter, the connection states RLY8/RYL9. I can be wrong, my bad. Thanks for pointing it out. The same for the Roadster schematic. Not much different than the Road King II. What threw me off here was the reference to FB on the tone stack connection where the presence control is located for CH3 and CH4. RYL8 and RYL9. I took that as a literal or physical connection and not just text indicating what it does or where it goes. This part of the schematic is incorrect as it has FB stated, which in its context is the connection at the output marked as FB. It is evident that the other net on the phase inverter is intended to be connected to the presence control and not the FB node. I have to take into consideration that the text on the diagrams are not the actual nodes or net names. Often times I see similar things for the JFETS. Same name on the node but actually different connections. Probably a way to miss-lead those that take a literal sense to the design and not assume it is not the actual net itself. The way it looks now, NFB is disconnected. The presence control never connects to the NFB circuit connected to the output section. Raw and Vintage, it is just a high pass filter. In modern mode it is a HF cut on the phase inverter and not associated with the output feedback. You win. I have been defeated. This is not the first time I made an a$$ of myself by taking the Mesa schematics literally. Sorry for the trouble this put you through to show me you were right and I was wrong. After looking at the older models with the LDRs I had realized I was in error. What was I smoking when I thought it was wired that way?

 

[bandit2013]

It is no wonder that the schematics can be miss-leading. I doubt that Mesa used any form of CAD to create the PCB designs. Considering the Roadster, it is evident it is tape on film so the schematic is just for reference. At least they managed to upgrade how they create the schematic. They used to be hand drawn. I should take a closer look at the Badlander boards to see if they were made by CAD or hand-taped on film.

It is hard to tell with the Bad board. It almost looks CAD but there are some signs in the copper pour (large copper areas- typically ground plane) that it may not be CAD. Traces are not rounded like the older designs, instead it uses 45° angles to make bends. (Most CAD programs will use this method, they do have arcs too but not splines, at least not the CAD programs I am familiar with.) What indicates it may be something different are the fine rounded corners on the copper pour, some of the corners are rounded off and some are not. If it was a CAD and if they know how to use it, you can set the minimum distance from nets based on the applied trace voltages. For traces that would have the full plate voltages, in relation to the traces that would be based on the 12V circuits for the relays and such would have a different spacing. So this layout does look like it was CAD driven, not sure if it was though. CAD designs are done in a 1 to 1 scale. Tape on velum or film is done at a much larger scale compared to actual size. Besides, the legend is more readable as it was not hand drawn on a large velum before it got reduced to the proper size by photo reduction onto a film.

Here is a closer look at the MWDR board. I can tell that this was not CAD generated based on the radial curves. They are more or less a spline than what you would get with the arc mode on a CAD. I did not have a good picture of the Roadster to use. The MWDR came out after the Roadster so it is fair game. When taking a closer look at some the layouts, it almost appears as if they are not quite aware of IPC standards. Usually based on the annular rings on the vias or pads on the components. Sorry for the technical stuff here. IPC is an organization that set standards of practice for printed circuit boards, called the Institue of Printed Circuits. A via is an electrical connection that joins different layers, in this case it is top to bottom. Pad was used in poor reference as that is usually associated with surface mount components and patterns. I should have used the word "land" which means the same thing but with through hole parts. Annular ring is the copper area surrounding a via or land to ensure proper solder wetting and sufficient copper to prevent issue with hole offset during the drilling process.

So when it comes to looking at the schematics, I look at them based on what I am familiar with, a net name is one physical connection to a trace or set of traces that connect to component leads or lands. I have been creating layouts for designs for over 30 years. I barely ever came across tape on velum but once or twice and that was for military projects. When the schematic is not tied into the actual layout using a CAD system, things may not be what they seem. FB to me indicated a common net connection and not just a reference where it may go too. I am flawed in character, so I make mistakes like everyone else. I learned form this. I appreciate those who can point that out or explain where I went wrong with my understanding when it comes to the Mesa designs.

 

[bandit2013]

I take it you never looked at the schematics of these amps. I will post the schematics parts this weekend showing the details on Modern mode wiring of the presence pot and NFB. I can use what ever schematic I see for the Dual Rectifier. May use the Roadster as the key as I have the complete schematic for it.

The bad thing is I did look at the schematics on many occasions only to be fooled by the schematics to believe what I thought was how things were but only to discover later on I was wrong. It would not be the first time I have made a mistake in this. Yeah, the NFB is disconnected. I admit I was wrong in my thinking and what I saw makes sense if you do not take the labels as nets or nodes. The older Rectos that make use of the LDR's show the truth which I probably have not looked at in any detail. Trem-o-Verb is different but yet similar. Yes, the presence pot does get rewired but it never changes its roll or function as a high pass filter. Raw and Vintage it is a filter following the tone stack, in Modern mode it is a filter on the phase inverter in place of the NFB circuit. Interesting. When you think you understand something you may not understand it. Not the first blunder as I did the same thing when I was looking at the PCB assembly of the Badlander and did not see the decimal point on the LCD of the meter and thought , Oh, they are using a 15k in the cold clipper. Well, had I looked again at that 2nd gain stage and notice it has two cathode bypass capacitors, on is fixed and the other I believe is switched by a relay, that would not be in a cold clipper as there is nothing to gain in doing that. The fact it had Rectifier on its faceplate may have biased my judgement on what was inside.

 

[domct203]

This is the beauty of the civilized human being, to be able to adapt and learn.

I’ve learned most of what I know about electronics on my own, especially tube amps, over the past 20-something years. A dozen fuses and a few sets of power tubes later and here I am today, able to follow signal flow on the schematic, and can identify simple parts of the circuit quickly. I started with modding and building pedals (including etching my own pc boards). I’ve swapped transformers, screen grid resistors, coupling caps, slope resistors and changed a few of my amps to adjustable fixed bias following schematics and tracing circuits.

I look forward to the next 20-ish years as I continue to learn, and this board is a great resource of info from a great community of like-minded gear nuts .

Dom

 

[domct203]

Just did the Mr Scary mod in the Badlander and its rather great. Did a quick vid when I got it, no real super dialing in, just left my eq the same and moved gain. Did 12 O' Clock on crush and crunch pre and post mod, as well as full gain crunch and crush pre and post mod, although full gain with the mod is rather overkill lol, but. its still clear even tho the gain is so high. I set mr scary to 1 O' Clock and fat switch on. You can vibes it. here:

Thanks for feeding my G.A.S. LOL.

I just ordered the Mr. Scary Mod to try in my Roadster, David at Legendary Tones said the reverb tank has to come out to make room for it. I don’t use the onboard reverb anyway, and once the chassis is out it’s easy-peasy to pull the tank.

I’ll start a new thread when I get it installed.

Dom