Electro-Mechanical Changer

Instruments, mechanical issues, copedents, techniques, etc.

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Joe Stoddard
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Electro-Mechanical Changer

Post by Joe Stoddard »

Howdy all - I did a search and didn't find anything on this topic. I'm sure I'm going to get dissed by some purists for even bringing this up - but time is marching on and nothing much has changed in the world of PSG in decades. But 6-string guitars are changing... and live sound gear is definitely going digital - so please hear me out and keep an open mind before just dismissing what I'm going to offer. (I'm probably nuts to post this on a public board but let's be real- I'm probably not the first guy to think about this and probably won't be the guy who applies for new patents... So here goes...

Does anyone know of a prototype (or otherwise) attempt to 'modernize' the pedal steel changer mechanism with more of an electro-magnetic hybrid. What I'm envisioning would be some kind of magnetic/relay or a servo-motor driving the changer.... and instead of mechanical pedals and rods - the pedals could be anything from a simple momentary floor switch to a bank of pedals that look and work exactly like an all-mechanical guitar works now. The pedals could trigger the servos or magnetic changers either via a standard CAT5 ethernet cable, or even wirelessly using BlueTooth or some other near-field wiresless radio between the pedal "board" and the guitar.

The actual mechanism could be a fast-acting servo motor or multi-position relay on each string. The hardware already exists in other form factors and is proven reliable.

Along the same line - you could also put a servo-driven tuning system on a PSG much like the 2015 Gibson Les Paul line. That system is amazing - you can program all kinds of alternate tunings, and also 'touch up' standard tuning in seconds without making any noise. Any guitarist who disses it is nuts - it's such an improvement over a plug-in tuner and manually cranking tuning keys. I was one of those big-mouthed critic of the new-fangled tuning system too... until I actually tried it. Now I wouldn't purchase a new guitar without it, and I'm in-process of adding to as many of my guitars as I can (without mods). Being in-tune aside, the greatest thing about the Gibson Min-E-Tune system I've discovered is if you need to drop to Eb or D or even C# to accommodate an aging rocker's voice - it's absolutely no problem and you don't need to lug around a second guitar for that one song We're all aging and having problems with the high notes.

Now envision this - if you were to combine the electro-mechanical changer with electro-mechanical tuning... and then control everything with a small "black box" (no different than any Midi-switching fx pedal or inexpensive keyboard)- now the player could do amazing things like change his/her entire co-ped on-the-fly. Or go into/back out of an alternate tuning DURING a song - Play one gig or one recording session with one type of tuning/tempering.. and the next one (with the fussy piano player) with another tuning tweak - and have it perfect for both sessions.

And just so I totally blow up your brain - imagine taking it one more step - combined the electro-mechanical changer with a CPU-driven "Min-E-Tune" type of controller... with a 10-string piezo/midi pickup (like the Roland Guitar Synth pickup). The magnetic pickup PSG could be digitally doubled an octave up and/or down... (or a fifth for power chords) ... the piezo/midi pickup could trigger a true Dobro or Fiddle or Clawhammer banjo sample.. by itself or in tandem with the PSG magnetic pickup (Like the Roland system works on the Roland Stratocaster) You could trigger keyboard synth modules (Pedal Steel one minute -convincing dobro or clawhamer banjo the next... - or a very realistic B3/Leslie or Mellotron or 80's Arp Omni pad the next - (yes I know about the EHX B3/C3 stomp-boxes - but once the novelty is gone, those all sound the same IMO - like one of those 'glass organs" where they rub the rims of wine glasses... nice sound, but not a B3) true digital samples of real instruments are in a different league altogether) You could even use the Piezo to sound like the nuances of an Emmons one minute - A vintage Sho-bud the next...

Finally - by de-coupling the pedals from the guitar body - you could set up the instrument to play standing up.. or as part of a keyboard stack... or develop a guitar that looks/plays exactly like a Dobro - except with a full complement of true pitch-changing pedals on the floor. The possibilities really are endless. The same technology could be adapted to any 6-string and would be a lot more reliable and less hassle than the current "B-Bender" types of rigs that depend on tugging on your strap - and it could control all 6 strings instead of just one or two.

And - once you did all that, to keep the costs of on-board displays and etc. to a minimum, develop a SmartPhone/Tablet app - exactly like all the digital mixing consoles now use. You could save hundreds of pre-sets of combinations of copedant/tuning/piezo-digital, organized into banks like any of the digital 6-string multi-effects units or keyboard synths. This could all be continuously backed-up to the 'cloud' (Dropbox for example) so there would be no chance of losing your programming in case of a crash or power outage, etc.

My initial research is that he electro-magnetic changer and basic de-coupled pedal mechanism would be a wash cost-wise to the machine-shop version, or at most would add a couple hundred $$ at cost. The Min-E-Tune system retails for $300 on a 6-string (cost is around 50% -$150-ish), so assuming you could license that for a 10-string neck - it would also add a couple hundred $$. The Roland 6-string controller and MIDI pickup retails for around $200 - the pickup is no big deal, the controller electronics are the issue - good pickup + bad controller = latency, stutter, etc. - no good. But bottom line - I think you could build some working prototypes for about the same cost as building an all-mechanical PSG. And I'm guessing something like the "plays like a Dobro - but with full pedal steel capability" will probably generate more interest than trying to replace the current sit-down PSG. The key to something like this making it in the marketplace so you could take advantage of economy of scale on the required components. A total demand of a few hundred instruments per year would not be enough - it has to find a new/different market - 6 string or Dobro players who want full pedal capability and more.

Ok - that's it. Sorry for the very long post but this was a bit of a brain dump. Start shooting holes in it. ;-)
Peter Harris
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Post by Peter Harris »

Hi Joe,

FWIW, the Roland (synth) pickup is NOT a midi pickup..it consists of six individual (very small) humbuckers which each take the signal of ONE string and feed it to an individual pre-amp circuit. There are other (guitar-synth) manufacturers (such as Godin) who fit piezo saddles to the bridge which also send in turn individual string signals out via a set of pre-amps. Graphtech and others manufacture such systems. When these piezo systems are used with Roland synth units, extra filtering is often necessary to get things sounding ok and string cross-talk is also a potential problem.

Differing models of Roland (and now also Boss) 'guitar-synth' units cope with these systems to greater and lesser degrees.... and string damping can also cause mis-triggering.

The signals sent 'down the wire' are then recognised and processed by the synth unit to generate the sounds that are heard...(most of) the synth units certainly understand MIDI and operate in that manner - some being also able to send and receive MIDI commands and work in close-coupling with both hard & soft synths, but it IS not quite as simplistic as you assert.

I have been working in this area for some years and am quite willing to discuss things with you if you wish to take your ideas further at some future point.

By all means PM me at any time..

Regards,
Peter :)
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Lane Gray
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Post by Lane Gray »

Georg, I can't help but think that a stepper motor system would do it.
Pedal A has, for example, a pot with a range of voltage at the other end. And one "tunes" it so that it moves string 5 X pulses along its entire range, and string 10 Y pulses (and perhaps sharps 6 a titch). So halfway along the pedal travel, it will have gone halfway.
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b0b
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Post by b0b »

Here's an overly complex idea I had some years ago.

Image
Read about it: Pedal-Steel-Changer-Controller.pdf
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Scott Duckworth
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Post by Scott Duckworth »

b0b, I LIKE it! :D

Now, when are they going to be available?

You know, I only pretend to know a little about computers, but with the creation of the Raspberry Pi and Arduino, this should get easier to implement.
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Scott Duckworth
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Post by Scott Duckworth »

Did a little poking around on Google, and came up with these two links for the same guitar with servos.

https://www.youtube.com/watch?v=fSQ9Dg65EFo

http://imgur.com/a/a0ZlW

The servos seem to be highly accurate as to the pulls and returns, and the "pedal steel" sound can be heard.

My thought as to limitations of doing the servo pedal steel would be the ones addressed in the links about, the accuracy of notes, and the timing of the "bend" so it retains that "foot on pedal" or "knee pushing lever" sound on the pedal steel that is so unique.
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Henry Matthews
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Post by Henry Matthews »

I think in the very near future, there will be options to purchase a steel guitar that works with servers instead of mechanical links. It's just progress. There are already guitars so why not steels.
Now if they could only re-invent the windshield wiper, 8)
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Tom Gorr
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Post by Tom Gorr »

Ive seen this topic come up about five times in the 15 years I've been a member.....

While it would be an interesting machine to test programmable copedents on. ..once a copedant is settled I can't help but believe mechanical linkages are actually the superior technology.

Sometimes the best solution is the simplest one. .. not the most complex.

Being a farmer these days....the last 20 years has seen a shift to computerized and servo everything. The consensus is that in general this is NOT PROGRESS. Just headache and cost.
Last edited by Tom Gorr on 11 May 2015 8:15 am, edited 1 time in total.
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Earnest Bovine
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Post by Earnest Bovine »

Steel players have been looking for programmable pitch changers for years but the only devices I've read about here on b0b's Forum have been too slow & too noisy.

Gibson Min-E-Tune, Tronical, and similar systems will not work for steel because they get their info from the frequency of the vibrating string.

The AxCent system would work well because it reads & changes string tension. When you put on a string, you calibrate it, and it remembers tension vs pitch. Apparently it operates quietly enough but I would be very surprised if the motors are powerful enough for the quick movements that steel players require. The 6 string systems are in in $4K range so it is plausible for steel, altho steel players would also need controllers (continuous, not on/off), no longer limited to pedals & knees. Writing the software would be the fun part.
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DG Whitley
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Post by DG Whitley »

I'm going to quote Scotty from Star Trek on this one: The more you overhaul the plumbing, the easier it is to stop up the drain.

I just simply do not see the necessity of doing all this. The all-pull system in use does everything that is needed for playing a PSG. Why the needless complexity of circuit boards and/or hydraulics when the human knee and foot does it all?

So is your stepper motor going to be able to precisely match the human foot/knee ability to slowly slide into an AB pedal or an AF pedal/knee? Did it ever occur to anybody that the slight imperfections we humans introduce in our playing is what makes it enjoyable. Producing such perfection in my opinion injects sterility.

I think this all for naught, and a waste of time trying to build something much more complex than you have now. You could use all that time to be woodshedding and getting better at your craft.

My 2 cents, YMMV.
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Lane Gray
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Post by Lane Gray »

Dg, while it may well not lead somewhere useful or economically viable, it's still interesting.
And, for folk like John McClung, you could have infinite compensators (for that matter, the programming could have compensators that only moved a string if, for example, the A pedal AND F lever moved at the same time.
It's probably a gilded lily, but who knows?
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DG Whitley
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Post by DG Whitley »

Lane, one point of my "rant" was the fact that more often than not it's the imperfection of things that attracts a music listener. Vibrato in a singers voice is actually a type of distortion, but one generally loved/appreciated by music lovers. The same could be said for the effects we introduce on our instrument.

My question is what are you going to do with all that "perfection" when you get it? As you noted, is the cost worth it? IMHO, the PSG isn't broken enough to be fixed. A good set of ears takes it close enough.

Again, my 2 cents, YMMV.
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Dan Robinson
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Post by Dan Robinson »

The PSG has a certain "feel" when a pedal or knee lever is pressed.  The sound of a change depends on how fast a pedal is pressed and released. So there should be some tactile feedback from the system. It's got to be more than just ON/OFF. A simple button press (mouse click) won't do it.

At minimum there must be some graduated (spring) tension for the duration of the pedal travel. Changer activation should track the amount a pedal is pressed.

Any system without this would be
"sterile" and lack playing dynamics.
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Scott Duckworth
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Post by Scott Duckworth »

As for the pedal or knee "feel", if you will look at the second link I posted above, and scroll down to the pedals, you'll find that guy already has a good handle on it.
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Mike Vallandigham
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Post by Mike Vallandigham »

One of the things I really like about Pedal Steels is the mechanical aspect of them, and how accurate they can be, while using centuries old technology.

:)
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Henry Matthews
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Post by Henry Matthews »

DG Whitley wrote:I'm going to quote Scotty from Star Trek on this one: The more you overhaul the plumbing, the easier it is to stop up the drain.

I just simply do not see the necessity of doing all this. The all-pull system in use does everything that is needed for playing a PSG. Why the needless complexity of circuit boards and/or hydraulics when the human knee and foot does it all?

So is your stepper motor going to be able to precisely match the human foot/knee ability to slowly slide into an AB pedal or an AF pedal/knee? Did it ever occur to anybody that the slight imperfections we humans introduce in our playing is what makes it enjoyable. Producing such perfection in my opinion injects sterility.

I think this all for naught, and a waste of time trying to build something much more complex than you have now. You could use all that time to be woodshedding and getting better at your craft.

My 2 cents, YMMV.
I agree with part of your post and that is the modern guitar we have today does everything that's needed but being broad minded, this is the 21st Century. No telling whats in store for steel guitar as well as other instruments. They have already printed a fiddle that actually works and sounds good. I remember when cell phones came out. They said that they will never work good and nobody will by them cause they are to big, blah , blah on and on. Someone will figure out a way for an electronic steel, and I'd bet my britches on it. That is if steel guitars survive, period. Maybe not in our lifetime but it will happen!! My 2 cents
Henry Matthews

D-10 Magnum, 8 &5, dark rose color
D-10 1974 Emmons cut tail, fat back,rosewood, 8&5
Nashville 112 amp, Fishman Loudbox Performer amp, Hilton pedal, Goodrich pedal,BJS bar, Kyser picks, Live steel Strings. No effects, doodads or stomp boxes.
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David Griffin
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Post by David Griffin »

IMO: A hybrid approach would be awesome. In another words: servos (w/ pitch detection) to keep the beast in tune w/ the modern all-pull mechanical changer mechanism. :)
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Post by Donny Hinson »

As the saying goes..."If it ain't broke, don't fix it". Adding needless technology would only harm the instrument, IMHO. Then we'd probably wind up with a "Steel Guitar Forum", and a "Servo Steel Forum", and most of the time would be spent arguing which was best. (You know, like the tube and solid-state guys argue now. :lol: )

I hate to be a hard-ass on this, but people simply need to learn to tune it, and they need to learn to play it. You don't need gizmos or technology to do that, you just need time in the seat. :mrgreen:
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Glenn Demichele
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Post by Glenn Demichele »

An exciting topic - I've thought about it as well, and even suggested the approach as an option for a player with a physical handicap. I built a single-string version using a solenoid to get a feel for the issues, and the first thing I noticed was that you needed a lot of current to get the tension. A stepper driving a lead-screw gives you lots of force, but might take too long to make the change. I imagine taking your steel out of the case with the strings all floppy, and they snap to pitch when you turn it on (no tuners). There are so many cool things one could do with such a system. However: aside from the beautiful feel of the mechanical body-to-string linkage (ok, you can simulate the haptics with servos in the pedals), I suspect that with 1hp worth of (heavy) motors within 3 feet of your pickup, you'll be able to clearly hear your PSG whining away. At least your system could know what key you are playing in so that the whine would follow your bar around...
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