Leslie simulations - again

[Nasse]

I have a software leslie simulator on my PC, so I did some quick listening tests what it does. I fed it with basic organ tone that had no vibrato or any modulation or delay or reverb in it, but some harmonic content so I could hear the effect of each parameter adjustment of building blocks. I suppose what makes it tick or sound as it sounds could be done with hardware. However we are talking about very complex design with many building blocks.

My quick guess what could be the building blocks of this software leslie emulator:

- cross-over filter for divide signal to low and hi rotors
- "tube-sound" overdrive/distortion (maybe two channels?)
- separate amplitude and freq modulators for Hi horn
- amplitude modulator for Lo horn
- phase shifter (maybe you could adjust it near like chorus and flanger too)
- LFO s for all those, with pre-set speeds and some of them might need be in sync together, and those start/stop speeding/slowing up sims
- some magig circuit that simulates angle and distance of the mic that is used to pick up the sound
- somewhat complex mixing system to mix this together, and in stereo

"Tube-sound" overdrive/distortion does not need explanation, but not just any distortion works in this situation. Maybe pre- and post eq requirements are different than guitar pedal ones. There is more complex processing in Hi Rotor channel, of course. Amplitude and freq modulation sounded sinusoidal, and if you adjust anything "too much" it does not sound "natural". In its own, any element was not so special, but with right mixing level and adjustment of each parameter it did sound much like rome recordings made with "real thing".


Here is some list about this software sim controls (Steinberg Rotary, made by mda?)

6 rotary pots, value range from 0 to 720, propably adjusts the speed of rotary horns, or are pre-sets for fast/slow settings when controlled with midi? Must check, named like this:

Hi Slow
Hi Rate
Hi Fast
Lo Slow
Lo Rate
Lo Fast


9 slider controls:

Overdrive
Crossover freq
Mic Angle
Mic Distance
Low Rotor Amp. Mod.
Low Rotor Mix Level
Hi Rotor Amp. Mod.
Hi Rotor Freq. Mod.
Phasing

Mix and Gain level

Some presets named this:

147 slow
147 fast
147 stop
slow flanger
analog chorus
dirty les
horn mic

[V!N]

Sounds like you guys are trying to come up with the pedal I have been searching for ever since I had to sell my huge Yamaha amp (combo higher than a half stack and about twice as deep!) with TWO build in rotating speakers ! :cry:

Even if it is kept down to earth as in Marks post (volume- and treble-dip and a touch of doppler-delay) it's there. Surely these three effects can be synchronized ?

I agree with Paul on his point on stereo. But if we can make a tremolo go ping-pong-pan, I believe this can work as well.

I'll be folowing this thread closely, this is THE effect I've been waiting for !

[Mark Hammer]

Some interesting and provocative contributions here, and I'm pleased to see the accumulation of info as the thread progresses.

Rotating speakers are probably the only "natural" post-production effect that exists for guitar.  I'd describe it as "post-production" because it is mapped onto the guitar signal after it has gone through the entire signal chain: the effects, the preamp, power-amp, output transformer, and speakers.  As such, it processes all of the various characteristics accumulated along the way, including the assorted forms of distortion imparted by each of those components.  The typical forms of Leslie simulation are inserted en route, although I imagine that outside of the gigging context, plenty of folks do attempt to mimic "Leslification" of an existing mic'd amp.  What that means is that, for most guitarists in most instances, stompboxes or modelling devices will tend not to live up to their experience of using a true end-of-chain rotating speaker.

As is appropriately noted, the spatial aspect of rotating speakers is an instrinsic aspect of their attraction.  Other than the time the nurses gave me Atavan when my kidney-stone attacks were making me a little too unruly for their liking, I think the closest I have ever come to a true drug experience was playing a gig where I was centred between a Leslie and another separate amp set to a slow tremolo.  In that context I think I would have been unable to remember the lyrics to Speed Racer or that supermarionation nugget "Stingray"!

Still, despite the obvious pleasure of a live 360-degree Leslie experience, listen to "Badge" or any comparable tune through the 3" speaker of the cheesiest $9.95 mono clock-radio and it is clearly different than a flanger, chorus, or any number of other attempts to fake it.  For me, what all of this means is that although there is added value in the spatial aspect (and that deserves its own software solution for emulation purposes) it is superimposed upon some very basic aspects that exist in mono or any non-mono format.  And that is more or less what I'm trying to nail.  The ramp-up transition-time, as noted, is one of the aspects that needs attending to, but so does the modulation of bandwidth and amplitude.  

Think of it this way: if you had 20 mics spread equidistantly around the path of the spinning speaker you wouldn't actually *hear* any cancellations and probably wouldn't get any rotating speaker effect at all.  Ergo, part of the *heard* effect comes from being off-axis as listener, and it is those off-axis aspects that I think are the missing link between flangers, et al, and more authentic rotating speaker emulation.

[javacody]

I don't understand most of what you guys are talking about, but by the time you get it all figured out, I hope to.     I would love to build a pedal like this! Of course, whoever does get it right, could probably go into production with it.

[Ansil]

i am tired now. but i think with enough **GREEN SMOKE** we could get anything spinning..   lol... sleep deprivation

prayer for the sleep deprived

now i drag my weary ass out of bed,
althogh it feels as if i'm dead
doing fine alas its sh*tty,

thought i had a heartattack
but stepped on my titty

[Paul Perry (Frostwave)]

It's easy to 'overmystify' the Leslie experience. Fundamentally, what we have is a number of speaker-t-listner audio paths, that are changing in length periodically. Which path variations are causing phasing & level & frequency fluctuations.

[The Tone God]

Well I have an H&K Tube rotosphere and I think it sounds almost dead on for Leslie.  There are lots of stressfull things to think of with a real one.  Micing that muther ain't fun.  Read an article once where Gilmour said they 7 mics on a Leslie and dialed in the perfect sound on the mixer.  Just get the H&K!  No it is designed to try and sound like a leslie not a univibe or a glorified chorus phaser pedal.

The Rotosphere!?! Keep in mind that this is my opinion but I think that its a horrible sounding simulator. Yeah its not a univibe but mind you most univibe clones aren't not trying to sell themselves off as lesilie simulators anymore but as univibes. It sounds like and is in fact a glorified chrous pedal. I have several other complaints about it but I'll leave it at that.

Once again this is just my opinion. If the thing works for you then more power to ya.

I do think there are some spatial effects that come from a lesile that are nearly impossible to recreate in a flat mono enviroment. I have done some playing around with interesting results but the physical aspect can almost never be duplicated.

If you want to a get a leslie sound you can hang an amp from the ceiling using rope and just spin the thing. I did. hehehe

Andrew

[dubs]

What about the Option 5 Destination Rotation pedal? Many claim this is THE pedal that comes closest to the leslie>>>

http://www.option5-online.com/option5.html

[Peter Snowberg]

I've got a Leslie 22H and as far as my jaded opinion goes.... any pedal simulation is like cheap hamburger comparred to filet mignon.

-Peter

[Bluesgeetar]

Tone God, If you would have read my entire post with comprehension you would have seen that I recommended he try a whole slew of Rotospheres if at all possible.  I did and me and many other pro players around Seattle agree the little pedal has got some magic.  But I did not come by this by just taking the first one they threw in front of me.  Mass produced pedals as I have seen stated here many many times all sound different from pedal to pedal.  I have heard vintage FF anf TB that sounded like crap and others that sounded like a dream even though they looked to be the same circuit and tranny types.  Most importantly, what your ear hears is not what you will get in the recording.  A nice real leslie is great but your only allowed so much room for the leslie in the mix.  So unless your gonna just make recordings of just a leslie being played or are just hearing it for your own personal pleasure I still recommend trying a slew of rotospheres until you find the right one.  Everyone I know with a decent ear likes my sound.  I also am not a shallow guitarist in the fact that I love to tweak knobs.  If you plug a guitar into a real leslie you will get instant gratification.  If you want to do it the the pedal way you will have to do some tweaking and trying out different amps, pickups and preamps and so on.  I don't mind doing it that way but most guitarists can't stand to turn a knob and actually tweak and craft a sound out of equipment, they want instant rock stardom with no work.  So again I recommend go to GC and try as many Tube Rotospheres as possible and then go to another GC and do the same until you find that perfect one.   I'm sure all the famous players that use the H&K TR don't just take the first one.  They do just like Eric and send out a tech to try as many Fuzz Faces or whatever as possible and buy the best sounding one.

[Mark Hammer]

Pete Snowberg said: "I've got a Leslie 22H and as far as my jaded opinion goes.... any pedal simulation is like cheap hamburger comparred to filet mignon."

That's my traditional view as well, but the fact of the matter is that the first step to effective simulation is a more thorough description.  If one follows the history of recorded sound, improvements in sound quality have stemmed largely from people comparing real in-person sound against better and worse approximations and conceptualizing what the gaps were, then translating that into technical parameters that could be explored and manipulated.  People would be startled by the advances, but after a while would come to the conclusion that there was still something "missing", and in identifying more of what was missing move another step, then another, then another.

In the case of rotating speakers, there are a number of different aspects to the "real deal" (some of which are specific to certain categories of models, and others of which are generic to all such devices).  Over the course of pedal history, attempts at simulation have tried to encompass some but not all of them.  And certainly, when you try and stuff it all in a little box and bring it in at a reasonable price-point, more aspects are bound to receive short shrift.  Nasse's posting makes it fairly evident the large number of factors/parameters one might be obliged to play with to mimic a rotating speaker, even his listing (courtesy of Steinberg) may well be insufficient.

I guess what prompted this thread was the desire to move beyond a simple tweaked flanger (which is of course what the overwhelming majority of guitar players would use to inexpensively fake that which they cannot own or lug around) to something that wasn't several orders of magnitude more complex or costly, but a few solid steps closer.

It is worth pointing out that, unlike something "easy" like an amp simulation, such a simulation has to reproduce the characteristics of accelerating motors and physical positioning.  That's a bit more complex than a steady state electronic device, and as such I'm more patient than impatient with respect to what can be done through either hardware emulation of DSP/software approaches.

If I may be so bold as to use a sexist metaphor: it's a bit like the difference between a CG depiction of a "hot-looking" or beautiful woman, and an engaging one.  Mimicking the interactive aspects is a whole lot more difficult to render than simply drawing a more detailed cartoon picture with skin-mapping.  Rotating speakers are more like the latter, and amp sims are more like the former.

[YouAre]

Elabortating on the filet mignon to burgers, let me say this, i'd rather carry a burger to a sleazy club than the salmon, its just easier to carry and keep intact...The option five costs more than some leslies, my friend got one for 150, its a matter of convenience

[MartyB]

My 2 cents: Leslie sim sounds are worth pursuing. I LOVE the fact that guys like Mark Hammer are at the problem.   I can't think of a tastier effect.  It's what got me interested in diy.  Since then, I've done what bluesgeetar did and got a RotosphereII (actually my wife got it for me - no she doesn't have any single sisters).  Now I'm building  all kinds of OD/dist tone toasters instead.  How's this for a slightly OT thread: favorite Leslie song (guitar).  Candidates : Badge, Presence of the Lord, Let It Be ?

[Lonestarjohnny]

I have 2 leslie cabs, I know of some pedals that can give a version of the leslie tone, but non that compare's equally, a Magnatone M-20 with both cab's spread about 12 ft. apart and the amp set on vibrato which is done with varistor's and the Fender style tremelo set at a slow throb can be very breathtaking the first time if you have never heard one, most people do not know that on the M-15 A and the M-20 Stereo they came stock with both, vibrato and tremelo, my M15 A has both.
the Fender Vibra sonic is another style, it has it's own way of making a different sound but simular to a leslie.
I am very excited to read this thread, I have a project I'm working on now that involves a Peavey Mace, VT serie's amp, it's 150 watt 6 X 6L6 power amp with a J-fet preamp, there are 18  8 holed socket's on this thing, 3 or 4 of these have house #'s on them, a few are 4558's, the rest or TL072 dual J-fet's, the part I found very interesting about this Amp beside's being an ungodly Big Mutha, is, it has built in phase that had me thinking about a foot controller for the speed and depth, which, if some good mod's were incorperated into the circuit, maybe you could get a simular type sound that would sub for a leslie in a live situation, i know it would probably fall short of this sound but it is a nice dream at this moment, if you would like to give me some input on this I would be very grateful, the schematic to the preamp can be found at this link.
JD                                    http://members.tripod.com/NatCade/pages/peavey.html

[puretube]

hi there JD: do you happen to know, which is the principle in the Fender Vibrasonic`s modulation? (I do know the Magnatone-thing...)

[Lonestarjohnny]

Puretube, Can you say Optoisalator, LOL ! all the Silver Face amps had this Topoligy, the version that sounds best to my ear's is the tweed vibralux cicuit, probably 1958'ish, this circuit is totally different topoligy, but when adjusted properly can sound very good.
JD

[puretube]

I wondered more if it does pure amplitude modulation, or if there is a phase-variation implied, or a timbre/volume modulation?

[jrc4558]

I think you mean this schem here:
http://www1.korksoft.com/~schem/fenderamps/bandmaster_6g7_schem.pdf

[Lonestarjohnny]

Puretube, I'm no engineer so don't get me to fantasizing, I'd only Fibb to ya, but these are simple, Yes, No and Yes, theory on these subjects though I will leave to Guy's like Peter, Aron, RG., Both Doug's, these are the guy's that can give you answers to engineering, I'm a doer, not a designer, LOL !
JD

[puretube]

if Constantin`s schem is that of a "vibrasonic" (?), it`s all I wanted to know...