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Arum's Back, and building a Seq V3


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Hey All, It's good to see some long time Midiboxers still here..... I haven't been around in some years, went to school, got married, moved....... Now Kind of settled in and really wanting a seq V3. So I have ordered a core and some parts from smash tv. Your boards are looking really nice now By the way.

First some pics of what I have started already. I Had an old Altec Mixer lying around that no longer worked (power supply I think, not needed so not worth my time to fix, may use the channels as another project, each chaannel is a discrete board, which surprised me for this type of mixer). So This mixer chassis will become my new Seq's home.


The Faceplate comes off the top and there is another Aluminum frame under it, which I have begun to cut up for mounting the components. Eventually a nice front panel will be made to put on top just like the original design.

I got some old 911 call center equipment at an auction, which had some nice buttons, the ever popular and oft cloned Schadow type. A little time with a desoldering tool (Den-on SC7000Z , google it, then buy one), and I had about 100 buttons free. I have decided to go with the button duo-led matrix, and got started on the boards.


It looks like one big board, but it is actually two boards that I cut so they would line up with no gap between buttons. I have finished the diodes and jumpers of one board and the buttons are only tacked to place on the other. Haven't started the LED's yet. I have my two LCD's and will wire them up as soon as the core is done, I am waiting on a Crystal right now. I am going with the encoders with built in switches for the 16 GP buttons, the spacing didn't work out so well with the Schadow switches so I will just panel mount the encoders so that they will line up.

To the right of the matrix panels I will mount the additional buttons and transport controls, something like this, all buttons not shown yet:


As you can see, there will be some space left on the front panel, also the interior of the chassis is quite roomy:


I am not entirely sure what to do with the extra space... some things I am strongly considering are: A quad stereo Sid, an MBFM, Analog Drums, Or a control surface, or some combination of the above.

So on to the questions:

1) What is the best way to interface the seq to a quad sid if I build them into the same case? Is there a better way than seq midi out to sid midi in? Can I use I2C to send midi directly?

2) How is the built in mixer feature of the seq v3? would building in an extra control surface be redundant? Can I assign the seq's mixer freely to any midi command?

I thought I had more Q's than that but now I am forgetting them. I will update this thread with new pics as the construction progresses, but it may be slow, I am poor, busy, and married now;)

Thanks in advance, and it is great to be back!

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Thanks Stryd_one. After re-reading the info on mixer maps I am confused again and not so sure it would be redundant to have a dedicated control surface. I will just have to try it once I have my crystal in for the core (should be here tomorrow). I made a little adapter and cable for the 2 displays. I bought the cheap ones from electronics goldmine, about 4 dollars each. soldered up some more of the First button led matrix panel, what a job.....still have the Anodes of all the LEDS to solder and then another whole board.

New question

3. Does there exist the possibility for a dedicated record button? I guess I could just use the F buttons? And how about combining the Play and pause buttons to behave like such: Seq stop>press play, seq start>press again, seq pause>press agin, seq start, etc....? This probably wouldn't be worth the trouble, but is more what I am used to.

Thanks, more updates soon.

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Crystals arrived and soldered to core. Time to test, hooked up my two 2x40 lcds and......nothing :( .

Pulled the 2x20 from my old sid module, mios bootstrap loader ready......

Need to recheck my lcd cabling and pinouts......everything seemed fine though.

Also, the encoders I ordered with switch, are detent less.....I hope they will be useable, but I can certainly see why you would not want this for the seq......So now encoders with detent and no switch, or order more encoders? Well at least the core works, though I never doubted it would.

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1) Did you hook up one LCD at a time? Always test *one* thing at a time.

2) "mios bootstrap loader ready......" Does that mean the 2x20 worked?

3) If the ones with the switches aren't any more expensive I'd get those. You never know - might come in handy (slow/fast mode, instant shift function, ...)

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2) How is the built in mixer feature of the seq v3? would building in an extra control surface be redundant? Can I assign the seq's mixer freely to any midi command?

I'm not sure how you envision the mixmap page. The name is a little confusing IMO.

It's not something I've used a lot in my SEQ, but the way I understand it is as a static CC mixer. What I mean by this is that patterns can have CCs set in the mixmap that are sent out when the pattern is changed. This allows you to reset CC's before a SEQ tracks modifies the values. Also this can be used to automate volume changes etc (if anyone wants to correct me feel free!!)

However, what I was originally hoping for in the mixmap page is a mode where I can use the encoders to send out the assigned CC's as I twiddle live. If this could be used in addition to a loopback channel then the 16 encoders could be used for tweaking tracks (for example assign the encoder to a CC that controls a tracks overall note length). As far as I can tell its doesn't work like this, yet :)

I hope that clarifies it...

Dave mK

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Yeah the 2x20 worked fine. I did try the 2x40's one at a time, but on the cable I had made for two. Last night I made a cable for 1 and tried it but this time all I got was a row of black boxes across the bottom of the screen, and no Back light. Also the contrast pot only seemed to have an effect through the last 10 degrees of its range. The datasheet for the lcds says they are led backlight and does not mention any negative voltage requirement, however I noticed 2 things. 1) the current requirement was 410 mA and 2) The display's box has one model number (which matches the Electronics Goldmine website and the datasheet I downloaded from same website, but the display itself has a slightly different number, so I must see if I can find a datasheet for that model Number. Ok I did and it should still work. the controller is KS0066, do I need to do anything special to make this work, I thought it was on the compatible list.

Anyway My power supply is only 500 mA and so is the core regulator. What are other people doing on their seq's? I didn't notice any warnings on any related pages (does not mean theyr'e not there though..) Should I supply the backlight voltage seperately from the core? or do I need to install a higher current regulator? The 500mA power supply can be replaced, it was just the first one I found lying around.....

About the encoders with switch: I definitely want the switch, I was going to use it for the 16 GP buttons of the seq to conserve panel space. I think I will need to order the detented encoders with switch and keep the non detented encoders with switch for a synth, since the accurate selection of discrete values is neccesary on the seq, and the smooth sweep of a non detented encoder more desireable for say a synth filter.


Yes I reread the section on the mixer map and that was kind of what it sounded like but still not so clear. the way you described it is better. I can see the use for it though, but you are correct it is not what I first thought it was, which is much like what you said in the second half of your post.

Thanks all and I'll Keep you updated. Things are slow for me since I only have internet at work right now....

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Ok, having looked at the photos of TK's Seq, he is not using the core reulator and has a larger power supply, so I think maybe that is the problem. I have a big honking condor supply with something like 10Amps a +5V and 3amps +15V/-15V. was going to use it for a modular synth rack, it would take up a good 3U by itself. but I could use it for test purposes. This weekend was a total wash as far as any projects. Did take a nice trip to Penn State University for their Art Fest (Wife loves art) It was fun and good exercise. Anyway, I think I will make sure my power is good and work out from there.

Can anyone confirm the ratings of the Power Supply that works in thier SEQ?


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OK, LCD problems all sorted out, all wiring problems. the first set had every pair of wires swapped somehow? I guess my IDC headers didn't do what I expected them to do.....And I know I checked them with my multimeter. It was late though.... The second LCd I wired up just to test had two pins swapped. The contrast pot still has no range but no big deal. Now I will load the App. Mios Studio anyone?

BTW, Is there an easy way to switch which display is one and two? It seems I have 1 on the right and 2 on the left. Just swap the enable line? I have already cut it in the ribbon cable, but I did leave enough to resolder in case of mistake. but is it possible to redefine in the software?

Thanks all, I promise, no more bad wiring (Yeah Right ;) )

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App uploaded and LCD's corrected. I just swapped the enable lines. now my pretty ribbon cable is all hacked but but what the hey.

BTW, MIOS STUDIO is totally freakin awesome! Boy things have come a long way since I built my SID V1...

Thanks to all for all the great work going on here.

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