Basic functionality of the Voicings on the MP-1 & MP-2

[INRI]

I was wondering: what is the magic of these units for them to have different voicings? How can it go from sounding like a fender clean to cranked marshall? Chat GPT was brainstorming and going all about the DSP being able to change tube bias on the fly etc. But that sounds extreme. Do any of you guys have any idea how this works?


As you may have noticed Im all out fascinated by these units even though Ive never been nearer than 500 miles to one.

[Harley Hexxe]

Hey INRI,

   I can't tell you anything about magic, but I can tell you that the MP-1 does things like this when you manipulate the tube gain levels, and combine that with the way you set your EQ, and maybe add some of the chorus effect in creative ways, you get what some would call a "magic" tone.

  By selecting the voice you want to create from, i.e. S.S. Clean Tube, or Dist Tube, there's a lot of ranges in those voices. It's all about selecting the right voice and tweaking it the way you want to hear it, and that's the key. Use your ears.

   The MP-2 on the other hand does not do the S.S. voices that the MP-1 does since it has no S.S. voice at all. Everything there is all tube voicing. It does every tube voice from crystal clean to gnarly dual rectifier tones and all points in between.

   If I had to sum it up, I would do it like this: These ADA preamps are not modelers, and they don't have DSPs. Instead think of them as extremely versatile amplifier preamps that do what no single amplifier can do.

   That's why they're legends.

[rnolan]

Hey INRI, totally agree with Harley . Simple answer is yes, we've got some idea how it works.
So  technicalities later. Let me say, I did a comparison to a MP-1 (that I'd just bought) with my '73 Marshall 50 (which I'd loved and used for many years). The MP-1 made the Marshall sound like a toy amp (no easy feat?).  While it's not as easy as pressing one button, you can make these preamps sound however you want them.  I think they were chasing a circuit that let you make any amp sound you wanted.

So given most of the tone is initially generated in your fingers, and PUs make a big difference BTW, from an amp perspective, the pre-amp does most of the tone, and tubes do a good job.  While not exclusive, most guitar tube input stages are based around 2 x 12AX7 tubes.  So 4 stages of gain (each is a twin triode).  So what ADA did was take that structure and make it customisable.  So each (most) popular amps have a similar 2 x 12AX7 circuit (i.e. add gain to input), but implemented it different ways.  So what if you could mimic that (by varying the circuit around the tubes) which is what ADA did (and what made the other amps different).  Something to remember for context, amps at the time had only just got master volume and at best had 2 channels which only some let you switch between.  So ADA used digital control circuits to control the analogue tube circuit so you could change and configure what you want.  The best version of that approach is the MP-2 where they created 10 tube "voices" to cover all situations and make new sounds.

So in the tube circuit, ADA made a bunch of things controllable, eq and gain between the 4 triode stages of the tubes (i.e. the voice), other tube control parameters (bias?), all these settings and variables could be changed "on the fly" as they are stored with each (128) program.
Along with volume , master volume, chorus etc.  They also made it stereo (sort of), when the signal hits the chorus (either in or out) the signal is split A & B with B 180deg out of phase (i.e. pseudo stereo). This is also very much part of the magic (for me). 
So more Magic? Well not really, I think they tried (and largely succeeded) in emulating (with real tube circuits) all the other amps of the time. What I loved was I could develop my own tones .