Lexicon PCM80 & PCM81 Questions, Tips, Tricks & Solutions

Discussion in 'The Rack Space' started by AnalogKid85, Mar 6, 2016.


  1. jaykay73

    jaykay73 Member

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    There aren't any clean slate presets on the 81, only on the dual fx card. To get a clean slate you need to load up an existing preset based on the algorithm you want to use and turn all the parameters "off" to get to a clean slate.

    @Allthesound can I give you a push in a direction?

    Firstly you need to decide what you want to do. For example the other day I thought to myself "hmm... I think I'd like to make a stereo chorus in the vein of the Rockman chorus with the ability to have a high cut filter after the chorusing and potential to have some stereo echo delays feeding the chorus AND an option to have them in parallel to the chorus as well".

    So I looked through all the algorithms to find which would be the most suitable. The PCM algorithm diagrams can be thought of as a "playground" where you need to decide which of the play equipment you want to spend time on. It's like parkour for the brain.

    I decided any of the 4-voice algorithms would suit my needs. Note above one of my requirements was NOT reverb. You don't have to have verb in every one of your presets. I have other units for verb too.

    I found a preset based on the "Chamber" algorithm and went ahead resetting everything to a "clean slate". Organizing the signal flow thru an algorithm is important to conceptualise. I turned Rvb IN to full, Rvb OUT to off and Ref levels R & L to full with no delays so that audio would flow into the reverb block, bypass the reverb shell but pass thru on the Ref level paths and flow into the Post delays. I then used the Post delays to generate my stereo chorus. Here you need an understanding of how to "make" a chorus by patching the LFO and creating pivot points. Notice how in this algorithm the high cut is placed AFTER the Post delays so I took advantage of that. I also took advantage of the independent Rvb Width parameter and modulated that using SW1 as the source for some extra spatial effect. I then worked on tweaking the "preset" to my liking and set up a few variations using the ADJUST knob. I played with the glide parameters for a few hours as well to train my ears better to hear the differences the glide response parameter makes. I set up some soft knobs to assist in tweaking. I still haven't got around to adding the echo delays. If I want to add those I could use the EkoDelays for delay trails which will have the "chorusing" added to them. Or I could use any of the 4 voice delays for echo delays INDEPENDENT from chorusing.

    The next thing I did was dump the preset to a sysex file and emailed it to a few aficionados who will take a careful look at it, play it for a few days, tweak, critique and give me some feedback so I can improve it further. Maybe after a few weeks I'll call it perfect / done and store it on my machine for later or back it up.

    Then I'll set out on the next quest. Or a buddy might send me one of his presets and I'll spend some time tweaking that for him or modifying it for my tastes.

    Now what I have just described is a "process" which has taken me 4-5 years to arrive at and I'm far from expert at it. There are some serious experts here to help you around here. 1 year ago I couldn't imagine half the stuff I do now. The trick is reading that manual, especially the algorithm diagrams. They ARE the machine. You almost want to pretend you are a little pacman character running around that diagram like in a maze, but of course only in the direction of signal flow. Sometimes I daydream I am lost in the algorithm and need to find my way out. You want to have that manual with you everywhere you go and study it all the time. On an ipad or equivalent is handy. Then a perfect time to pull it out is after xmas lunch when everyone is so tired from eating too much. Study those diagrams man.

    But even going back one step you need to know what makes a "chorus" a chorus or a "flanger" a flanger. You should know how to stereoise effects, especially as the PCM was built for stereo. If you're using it in mono it's like watching movies in black & white.

    Any questions you have about any of these things you can post on this thread or maybe even if they are more generic questions, post them in their own thread.

    I would love to encourage you to dip your toe in the PCM water. You'll end up in deep very quickly as this machine is very complex but very rewarding. And you might create something very unique that you can share with the PCM-addicts.

    JK
     
    Last edited: Dec 12, 2017
  2. Baba Louie

    Baba Louie Member

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    I sucked at Pacman.
    Just like I suck at PCM.
    That machine though, in 100 years, will go down as one of the best inventions of mankind.
    Almost as good as the Ronco Pocket Fisherman.
    I don't play around with my 81 nearly as much as I should...but when I do...man, it's amazing. It blows me away every time.
    The quality of the sounds is unbelievable.
    The depth of that machine...it's like as deep as Mariana Trench. Way too deep for me. Thank God it has presets, and I just work from there, and make adjustments. If I had to start from a "clean slate"...I would be lost.
    I probably couldn't even make it sound like a fart.
    The thing about that machine, is, it's a TEACHING tool. If you learn it, it teaches you how time and pitch based Effects work.
    I drown in it, every time I turn the Select knob.
    I've only had mine for like 6 months.
    But, I wouldn't sell that thing ever. I will have it forever.
    Even if I do only use it for reverb.
     
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  3. italo de angelis

    italo de angelis Member

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    And you ended up with nothing like you had in mind in the first place!
    Forgot to notice the DIFFUSION and SIZE always need to be nulled or extra delay and feedback are "picked" up by anything you are doing in the "reverb shell".
    The Glide>Hall does a much better work at that, with the proper levels... but there's no post hicut. Obviously the DualFX card is the solution to this... but won't exactly sound as a Rockman modulation in the first place anyway.
    But all of these are very, very advanced ways to look at the PCM possibilities AND limitations for the moment.

    Now... would I start from something like that as an example for a PCM80 novice? Quite convoluted and looking for a fly in the tank.
    But yes, the idea of looking around at how a structure allows for a result or not.... is somehow the idea... once and AFTER you got quite a lot of other work done.

    I see you also have a PCM70 there. Hopefully you have had it for some time and have done some programming with it.
    If you have a grasp of the 70, the 80 offers those delays (effects) structures and those reverbs...BOTH in the same algorithm.
    The structures are also developed to include some extra parameters and details.
    And you have some new things, like the GLIDE>Hall algorithm and the glide function in a lot of algorithms.
    Add to the picture a strong realtime parmeters modulation section with 10 patches per preset.
    That's a very general description of the 80 to somebody who knows the 70. If you don't know the 70 as hoped... well you are in from a whole fresh start.

    The manual is a must, obviosuly and the algorithms drawings are important to understand what goes on inside a structure and what you can do.
    But before you look into the big picture to find out any tiny details for this and that... you may want to get a hold of the single algorithms.
    The 6 voice ones are very similar to the PCM70. 6 delays you can use for chorusing OR filtered delays or resonators. These are based on multitaps delays, 2 of them, with 3 voices each.
    A multitap delay is a delay with different audio outputs and delay settings for them. Even though each one has its own feedback, ANY of their feedback signal goes back to all of them.
    So this makes things very interactive. You create a chorus sweeping a couple of delay lines for stereo and if you add delays, using another voice or two, they will pickup the chorusing of the other voices from the common feedbacks. That's something you may want to tweak and understand very well as many users don't have it clear, even after years of use... and get confused all the time.
    Keep in mind this interactivity in the 6 or 4 voice structures as it is the main feature for the typical PCM sounds.
    The verbs.. they are actually more complex as some of their parameters do a lot of things internally, controlling hidden parameters. The manual helps but one needs to follow it AND change the parameters to hear what it's talking about. You won't find any discussion about how the verbs work here and elsewhere... because most people don't realize how they work yet.
    The crossover/mid RT and Low multiplier are critical in the way lexicon verbs work. Most other parameters will influence the texture of the reverb and/or tweak its envelope and reveal/"hide" internal reflections. No need for complex information at this time. Just get a more general knowledge of the two blocks, effect (6 or 4 voice) - reverb - reverb shell= an extra 2 or 4 delays added for early/late reflections or special fx.
    If you are interested in creating your own sounds... start from very simple and focused steps. A chorus within the CHORUS algorithm, a filtered delay within the MULTIBAND algorithm, etc.
    Glide is a more advanced concept, involving more knowledge of the unit about patching parameters to realtime modulator(s)... so you may look into that after some explorations and starting from a factory preset... learning from it.
    The presets ARE your teaching base. There is so much in there, no matter the fact you may like their sounds or not. A preset that has some decent tones is where you want to start... and make it better for you.
    But this comes after you have understood the HIGHLY interactive character of the 6 (or 4) voice structures, owed to their common feedback routes... THAT'S what the fundamental PCM concept is... if you want to use effects. If all you want are reverbs, the perspective changes but the reverb structures will need the same kind of attention in getting to know how they work. You can get very nice reverbs from the 80.
    When you put both blocks to work, you get to sacrifice some details, mostly balance and levels of them, but you still have very good results after a while. You also learn NOT to use the PCM80 to try to do something it just can't do or can't make it well. What's even the point in trying if you own another machine that can be better at that?

    For me, when I owned the PCM70, the start was messing with the chorus algorithm.
    Building a simple stereo chorus, using two voices. Realize what the DIFFUSION does.
    Turning those two chorus lines into flangers. Then adding a delay to the chorus or flanger. Realize what happens when feedback is engaged in the chorus/flanger only or in the delay only.
    The kind of thing that discloses how the structure works.
    Now... I take for granted you know how to use a delay line to make a chorus or flanger, echo. Hopefully you are already there.
    Or... we need to wind all this stuff back... and get to start from the fx alphabet.
     
  4. jaykay73

    jaykay73 Member

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    Well actually Italo I ended up with something *I* am very happy with. In a few days I'll know if the guys I shared it with like it too.

    I was telling the story to give @Allthesound a starting point for how someone might think about creating a preset. I just gave an example of what I did. I was not trying to make a Rockman Chorus - just used that concept as a starting platform. A swept delay time from 20-24ms was the only basis.

    Yes I turned off DIFFUSION and SIZE - I wrote I turned everything off to a clean slate.

    I deliberately chose not to use Glide>Hall because I wanted to experiment with the Glide Response parameter. Glide>Hall would be a good way to have the modulation feeding the echo delays.

    I'm happy to share the sysex so you can critique it after you have played through it.

    I'm not going to take for granted @Allthesound or any one else who visits here knows how to work delay lines into effects. We should all welcome questions and be willing to give helpful answers to promote the knowledge and grow the community. As you always do Italo ;)

    JK
     
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  5. italo de angelis

    italo de angelis Member

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    Not a problem JK...
    only thing is that you started waaaay past of what any PCm80 new user really needs,
    like how to get a hold of the basics of the unit.... rather than looking in the hidden far corners of it for some "specialized" task.
    What did it take for you to get there? A few years?
    Long before creating any preset, one needs to get a grip of how the effects work, then the verbs... then put both together... then maybe moving to more in depth parameters modulation.
    The structure of the machine. That's where you start.

    So, exactly, *helpful* answers! I'm not embarking on how to do "morphing" on the PCM80... for the same reason why I would not start with Glide if I didn't assume one knows about the basics of digital delay and effects.
     
    Last edited: Dec 12, 2017
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  6. Allthesound

    Allthesound Member

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    Thanks thats pretty helpful perhaps i was lookin at this in the wrong way. i have alot of studying to do no doubt!
     
  7. Allthesound

    Allthesound Member

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    I wish i could say i have experience with the 70 but t i got it less than a month ago and haven't had much time to do more than try out the presets and load some v2.0 stuff via sysex. The only other Lexicon i have owned was a MX200 a few years back but i did no programming on that either. I spent a while last night going back through this thread and found some really useful info posted by you and others. Thanks for this thread really! initially i was mainly interested in the PCM for just reverbs , but after trying out some of the other pitch/ delay effects i'm excited to dig much deeper and wrap my mind around programming this beast to see what i can come up with..

    I'd really like to make a usable simmer reverb effect but that may be biting off more than i should to start. Would i be better off focusing on the pcm 70 to start or just go full on into the 81?
     
  8. italo de angelis

    italo de angelis Member

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    The 70 would feel like a smaller PCM80, running a 6 voice chorus delay or a reverb. In this regard it is a simplified version but what goes on within the single structures is very similar or exactly the same. I'm not sure it would be an easier path anyway, nor I see any reason to be intimidated. You just have to start listening to the presets and getting the clear picture about how things work.
    People approach these units with many different reasons or even nor reason at all but their "quality".
    Do you have experience with the digital delay... how to make a chorus/flanger/ADT/etc. with it?
    What are you expectation from the PCM80... in realistic terms... that is what do you want to make it sound like?
    Whatever your reasons to have a 70 and an 80 may be, the scenario about learning them doesn't really change.
    You may start investigating the 80 for effects and the 70 for reverb, separately and anything you learn from either unit will also be useful on the other one... pretty much.
    But until you press that EDIT button, navigate the parameters, listen to them and follow along with the manual... wasting your time on a forum... you won't get the real thing.
    Do the above and get questions down if your work and the manuals don't answer them. That's where the forum is about.
    You don't take medicines before getting sick... nor should you look for any specific ones as you don't know what you will face.
    Just get your pants wet on EDIT and come back. We'll have treatments for you.

    Get the bloody bull by its horns and rule it, man!
     
    Last edited: Dec 12, 2017
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  9. Allthesound

    Allthesound Member

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    It wasn't my intention to get both units to be honest i wasn't sure which one to get and i shot a bunch of offers out and ended up getting both for what i was willing to pay for just the PCM81. I was lucky in that both work great with no issues other than the 70 needed a new battery which was simple to install since Lexicon had the good sense to make the underside of the mainboard easily accessible . Really the only experience i have in creating patches is on the many synthesizers i have owned over the years , so things like LFo's, filters ADSR envelopes ect are familiar to me but not much on the effects side other than applying what was already available on board.

    I think my interest with the 81 will be geared more towards the ethereal - other worldly type effects. the wild stuff. I'm going to start simple though. Is there a clean slate sysex available or can the PCM initialize one in a empty register??
     
  10. italo de angelis

    italo de angelis Member

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    So you ended up with two Lexicons! Not too bad. You can always use the extra one, be it a smaller rig or your recording setup. These are good machines.
    The experience in programming synths may be a good help when you will start using the parameters modulation section, because you fill find some familiar stuff in there.
    For the sounds prgramming... it may not be as important.
    Plenty of power and interesting ways to access the etherdoom on both units!

    About clean slates...
    there are several algorithms on board so a clean slate patch would ONLY be based on one fo them. There is no clean slate without an algorithm.
    You can't reinit anything to a clean slate. You must create it... and you need to do that for each single algorithm if that's the way you want to proceed.
    You can also start from the factory presets and learn thru them, before you build a clean slate and work off that.

    To create a clean slate it will take some work as you'd first need to kill all realtime patches between modulators and parameters. The UI works as a matrix of rows and lines.
    The realtime mod patches are in the last row. Use the manual for that. Just remove any parameter that you may find there and any modulation source.
    Start from simple presets, those having no or very few patches. those can help in building the clean slates.
    You then need to null every parameter and store the preset.
    Not the quickest path to editing.... but you get familiar with the way the unit works and its UI by creating your clean slate patches.
     
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  11. Allthesound

    Allthesound Member

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    Thanks for all your help Italo! I'm going to grab that bull by its horns right after dinner , might be a late night :)
     
  12. Allthesound

    Allthesound Member

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    I know its a old post but thanks for sharing this , it really was helpful not to mention it sounds great. more more! Heaven help me i think i'm addicted to PCM's
     
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  13. Allthesound

    Allthesound Member

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    Over the holidays I was searching for the dual fx card and could only find one bundled with a Pcm81 so I bought it and at the same time saw a smokin deal on a PCM91 so I figured why not? And grabbed that too.
    I have both of the PCM81’s in my guitar rack one goes into my Focusrite 18i20 so I can use it as a movable insert in my DAW the other is using both aux sends on a Mackie 1202 VLZ and return into two of the mono channels hard panned L & R. Seems to be working out well.

    Problem is I have the PCM91 & PCM70 on my synth rack and have a Mackie 1402 VLZ with only 2 aux sends both are going into the 91 and return into two mono channels. I’m not sure how I can feed the 70 which is only mono input , can I just run a Y splitter off one of the aux sends or is there some other way? The back of the mixer has Alt 3/4 outputs and control room outs can one of those be used as a send?



    a couple shots of the racks

    [​IMG]
    [​IMG]
     
  14. italo de angelis

    italo de angelis Member

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    Study this...
    Line Mixers
     
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  15. Allthesound

    Allthesound Member

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    Thanks that sorted me out , ended up using one of the tape outs , wouldn't have thought of that.
     
  16. italo de angelis

    italo de angelis Member

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    Mixers... heaven ass savers!
     
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  17. italo de angelis

    italo de angelis Member

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    Some data people might like to know...

    First production PCM80 uses:
    -Cirrus Logic CS5389 A/D 18 bits Delta Sigma converter, 64x oversampling
    -Analog Devices AD1865 D/A 18 bits converter

    First production MPX-1 uses:
    -Cirrus Logic CS4329 A/D 20 bits Delta Sigma converter, 128x oversampling
    -Philips SAA7360 D/A 18 bits bitstream Delta Sigma converter, 128x oversampling
    "Units with serial number 0798-XXXX (0798, 07 = July, 98 = 1998) or higher have the 24-bit converters."

    and PCM81 uses:
    -Asahi Kasei Microsystems AK5391 A/D 24 bits Delta Sigma converter, 128x oversampling
    -Cirrus Logic CS4390 D/A 24 bits Delta Sigma converter, 128x oversampling



    CS4390 FAQs

    1)What is the difference between the CS4329 and the CS4390?
    A: Although the analog performance of the CS4329 and CS4390 is essentially the same, the CS4390 supports 24-bit conversion.
    2)What would happen if you input 24-bit data into a 20-bit converter D/A converter like the CS4329?
    A: A 20-bit D/A converter will provide poor distortion performance when presented 24-bit data. The 24-bit CS4390 however will be able to provide true high performance 24-bit conversion without any degradation in
    the distortion performance.
     
    Last edited: Jan 3, 2018
  18. Allthesound

    Allthesound Member

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    I read early in this thread you mentioned some of the earlier PCM81's were 20 bit, is there a way to tell without popping the lids which ones i have?
     
  19. italo de angelis

    italo de angelis Member

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    Nope.
    Open... locate the converters... use Google.
    CS5390 is the 20 bits converter:
    http://studiorepair.com/gallery/Lex...80_ADC__STUDIOREPAIR_10101801_1206040543.html

    Converters are close to the display area. The A/D is right beyond it, left side of the battery, and the D/A a bit further away.
     
    Last edited: Jan 3, 2018
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  20. Allthesound

    Allthesound Member

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    Thanks next time i pull them from the rack i'll have a peek , not that it really matters they both sound superb!
     

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