Difficulty getting musical feedback from Mark amps

[pastorofmuppets]

I currently have 4 Mark amps (IIB+, III red, III++ green and IV), typically I play through either x2 thiele cabs with EVs, or a halfback with EVs and 100 watt Celestions. I’ve found getting musical feedback is difficult even at deafening volumes (with the halfback at 600 watts that may be only 2 on the master). I also have a 2203 and at same or lower volumes I feedback the second I let go of the strings. With that the Mark’s tend to not need a gate while the 2203 absolutely does, maybe that’s related?

Over the weekend I played both my III red and a Badlander 25 back to back at band volumes and the Badlander has quick onset feedback like the Marshall, the Mark again was almost impossible to feedback.

Does anyone else experience this and if so have any idea what about Mark amps may be more resilient against feedback? For reference I’m playing high gain with the GEQ in a subtle V.

 

[CoG]

take the geq out, take your hands off the strings, face the cab. firmly tap the guitar body with two fingers and see which if any strings start feeding back. mute strings individually with your pick hand to test. start doing barre chord shapes up the neck, don't hit them, same thing, tap the guitar body. you'll start finding your easy feedback spots. now put the geq back in and see if you've lost them. remember that controllable musical feedback is almost always from your wound strings.

you will find it a lot easier to develop feedback with a bigger cab throwing at your guitar, I can't reliably get good feedback off a 1x12 unless I put it at belt buckle level.

I can only speak to the mark III but it definitely takes more practice to get good sustained feedback started than a recto or 800. I think it's that Marks generally don't really put out a lot of bass, which is what gets the strings vibrating. pulling the deep switch will help but that's not great for most high gain situations.

 

[pastorofmuppets]

take the geq out, take your hands off the strings, face the cab. firmly tap the guitar body with two fingers and see which if any strings start feeding back. mute strings individually with your pick hand to test. start doing barre chord shapes up the neck, don't hit them, same thing, tap the guitar body. you'll start finding your easy feedback spots. now put the geq back in and see if you've lost them. remember that controllable musical feedback is almost always from your wound strings.

you will find it a lot easier to develop feedback with a bigger cab throwing at your guitar, I can't reliably get good feedback off a 1x12 unless I put it at belt buckle level.

I can only speak to the mark III but it definitely takes more practice to get good sustained feedback started than a recto or 800. I think it's that Marks generally don't really put out a lot of bass, which is what gets the strings vibrating. pulling the deep switch will help but that's not great for most high gain situations.

I’m often using a 4x12 at permanent hearing damage levels, so that part isn’t an issue. I haven’t tried with the GEQ off so that will he the next test.

 

[danielpasco]

I did a series of extremely bad impressionist covers of the guitar solo from Mother several years ago (playing from memory and wow, string bends can be tricky to nail), and one of the things that I tried to characterize was musical feedback digs around



I used a boost with these and probably a compressor. Volume levels were sane (at home practice with family in the house, probably 90 dB, tops)

 

[bandit2013]

I felt that the RK and the Rectoverb seemed to sound much closer to the actual recording. RK with EL34 in brit or Vintage mode. Awesome comparison.

 

[bandit2013]

A sustain/compressor pedal on the front end may help. I used to use one all the time with the Mark IVB but it was a combo amp. I do not remember having to get onto the floor to get any feedback from the amp. Delay or hall reverb effect will also enhance that characteristic.

Noise gates generally cut low amplitude signals in order to remove the noise floor if used in the FX loop. If you are using one with the Marshall, try it with the Mark and see what happens. I doubt that will enhance the feedback effect.

The Badlander is a little different. It places the Mark Lead Drive circuit where the tone stack would reside and then compresses it into a DC coupled cathode follower tone stack driver. It has a post gain tone stack. A mark has a pre-gain tone stack as well as a post gain tone control or GEQ if so equipped. Try boosting up the 750Hz if you have it all the way down. That was one of the tricks I learned with the JP2C. I also use that with the Mark VII as well. Back in the day with the Mark III, and the Mark IVB, I always dropped it down for a more scooped sound. I no longer have those amps anymore to comment what would make it work better other than what I had used in the past.

Sustain/Compressor pedals will enhance the low signal levels and reduce signals above a specific level, sort of normalizes the volume of signals from soft to hard playing.

Delays or some reverb effects tend to extend the decay rate of the signal depending on how they are used.

You do not need to have a swamped signal, just enough to get the characteristic you desire. They are not necessary though. It should not be that difficult to get feedback without any enhancements.