I am really feeling like throwing my faders in the bin right now. I have spent an entire week (even skipping college to work on this) tweaking these things, and still I have unsatisfactory results.
If anyone at all is happy with these faders, then please speak up as otherwise more people will be dissappointed like me, if they keep buying them.
My faders refuse to work properly at each end of their travel, they stop at the wrong positions, and sometimes don’t even move at all. I can’t do a mix using this thing, as I’m afraid it will stuff up my mixes.
can someone tell me how good the alps faders are?
apparently LO’s panasonics work ok, but he is using an old '877 firmware (lower resolution, I think)
BTW, I tried offsetting the dc offset as I mentioned on the other thread, but no joy.
Once you are happy with your project, it would be nice if you hang around for a while to help others who are having troubles, even if it is only occasional. (Thanks to all those who do help, though)
I searched through old posts, and could my problems be similar to these old posts? TK?
quote…
"Hello Thorsten,
Ok, the Midi Overrun problem is solved . Thank You.
I’ve wired up all the eight faders with cables less than 30cm. But i still have the problem of midi data intermittenly being sent by faders only moved by the motors.
That is, if fader1 is assigned B0 00, and the motor is moving fader 1, it will sent out just a single value
for example B0 00 02 or some other value at another time during automation playback. This happens also to all other faders only if they are moving. It happens intermittenly.
If the automation playback is stopped, the midi output is stable with no jitter or false data being sent.
I’m using Panasonic Faders, could this be in conflict with the delay settings you use in the Feedback elimination routines?
Peace
Frank"
and…
"Hi Frank,
I changed the timeout algorithm (slightly): up to now, the current fader value is copied into the “target” register during the timeout state after a fader has been moved. This should fix the problem (?)
OK, for the benifit of those who have bought panasonics…
the best setup so far…
-6.5 volt motorfader voltage
-0d  motorfader speed up/down
-chunky cap (2200uF) across the 5v rails on adc input
-another cap across supply for MF, after regulator
-7 for adc deadband
-3 for mf deadband
-shorten all wires as much as possible
now, there are no major errors anymore, when faders update, only small ones… say 0.4 db and once I had a midi value change from 100 to 95, but this size error is very occasional.
<<<<<<update… bugger now they are bigger… just ignore this post!!!>>>>>>>
the faders hit pretty hard on their stops though, and there are still problems at the ends of travel… but this is only really a problem at the bottom… how often do you see volume faders at the top of their travel?? (except for panning hard right, or if you ‘flip’ to control other parameters with the Motorfaders)
OK good luck, those using Panasonics, and if you discover improvements, please let us know!!
BTW, if anyone is too scared to customise the settings to make a sysex file using MPLab and perl, I can help out. (for the first few times anyway)
the MF deadband value must be greater or equal the AIN deadband value, otherwise the motorfader driver tries to move the motors with a higher precision than the AIN driver can deliver the conversion values (=fader position), as an result you will notice those stuttering moves.
I guess that all the caps between the AIN inputs and ground are not really required, especially high capacitance values can cause more problems than they should solve.
More important is a good ground connection between the fader chasis, the Vss pin of the fader and the Vss pin of the core module.
And (this is a new awareness) one 100nF cap across +5V and ground very near by the faders. I just have measured the signal quality of my MBLC with a scope and noticed some noise at the +5V input of the fader rail. Such noise is very common on a digital circuit and it can be eliminated by using small caps near by the drains. One cap should already be enough to fix this problem.
I just did all those things, I removed the big cap, installed 100n, put a big thick ground wire to the ground of faders, deadband mf…8 adc…7, earthed my fader chassis,(previously I insulated them, wierd, but it got much less jitter… my electrical engineer friend said maybe it was a problem of Al panel, Steel faderdodies=mini battery) checked the panel earth, and now it is worse than it ever was
So, I think I’ll pay an electrical engineer friend to fix it!! (I really wanna start to use this baby)
Look, all my 'boxes seem to have jitter problems. This jitter seems to come and go. It must be something to do with my local environment, as why dosen’t anyone else have such problems… maybe it’s something unexpected, like the brand of solder I’m using or maybe some of the components are not up to scratch. LO’s panasonics work ok… and I’ve set mine to 7 bit resolution too, yet still no joy.
SORRY TO DISCOURAGE ANYONE…
Sorry I’ve been posting over and over again… the same crap everytime… I’m too impatient… anyway I’m going to lie low for a bit… let yourselves be encouraged by those who have had some success!
BTW… I changed both the adc and mf deadbands to 5, and it was improved.
I’m a little reluctant to try the pic 16f877, as I don’t think it runs the LC emu, but I would give it a go if someone can email me a logic environment just to test it out? (not ready to get into that environment just yet!)
still havin probs… but it is usable…maybe I’m a bit too fussy.
I get errors… approxiamately 2-3 over 50 faderbank switching cycles e.g. 22 midi volume becomes 23, and audio volume -47db may fluctuate between -50, and -43dB… Can someone with a bit of mixing experience on the LC tell me if this is worth worrying about??
please answer me, so I can get some sleep at nights instead of thinking for solutions…he he!
I’ll try to get someone with a cro to look at it soon.
…Steve
edit… I’ll try putting some ferrite suppressor beads on the ain input leads, and the power lead tomorrow, when I go to Jaycar. (Handy, it is across the road from college! I sneak over there when the teacher is not looking sometimes!!! ;D)
does anyone know how to put a small delay in the program, to make the midi handler wait a little bit between sending a pitchbend (volume) message and the point in time where the fader has reached its last moved position?
(my faders are sending midi before they have reached their last movement position)
… or is the motordriver moving them after they have finalised their correct position???
this delay is already available: the MF driver doesn’t trigger events for about 50 ms after the fader has been moved. The only case where events are sent is, when the fader didn’t reach the target position.
Ok, I will think about some new analysis applications which will help to narrow down the root cause. For example a “jitter monitor” which visualize the signal noise. Please hold the line
Best Regards, Thorsten.
P.S.: programming the flash more than 1000 times is no issue, I assume that most PICs can be burned more than 100k times without problems
I’ve just programmed the “jitter monitor” which allows to measure the signal noise. It would be an important input for me how much noise influence the AIN results of your MIDIbox. Could you please check this?
The application can be found under Concepts->MIOS->Download
thanks for the reply! I have since increased my power supply capacity, and noticed slight improvemens in jitter factor. My 'box is now good enough to use without worrying about my mixes getting messed up! Though I look forward to such features ahead in the future!
BTW, even though it goes against logical thought, I still feel my 'box goes better when I set MF deadband lower than AIN value, I do AB tests, to check which value works better, before settling on a value. But I’ll be trying Alps faders soon, if Rowan in NZ can hook me up with a good deal!! (LO will probably remind me of how well his panasonics go again now!)
bye, from Steve ;D
P.S. Hey TK, I am so happy now that I have a great system jto work with, instead of the mouse!! I’ll post you a pic soon. (gotta borrow a proper camera, my digital keyring camera is bad!)
I switch fader sets, the faders move to their new positon, however, they move to within about 3-4 mm of where they should stop. (total range of about 6-8 mm) then, shortly after, (usually within a second) the value changes on the computer screen by even up to 6 midi values sometimes!. This really sounds like a jitter problem, but I can’t see how, as the deadband is 5 for both motor and ain (I changed it back to what you suggest) Judging by your jitter monitor, I am not getting enough jitter for this to happen… ???
oh well… I still think this controller is cool though! ;)
The results given by the monitor are showing that you’ve no jitter on the AIN lines, this is very good! This means also that you can decrease the AIN deadband to 1, and the MF deadband to 3 or higher (but I think that you’ve already tried this). But it makes sense to use these settings and to vary only the motorfader voltage AND the calibration value (motor speed) for upward and downward movements.
Maybe I should integrate the calibration feature also into  the LC application so that you are able to start some experiments with the settings without reburning the PIC.
Best Regards, Thorsten.
P.S.: the described effect (fader stops ca. 4 mm beside of the target position) means that the faders are too fast, so that they never reach the exact position. A timeout will happen after 5 retries, thereafter the MF driver will send the “real” position. You can slow down the fader with a lower MF module voltage and with the Up/Down calibration value.
instead of thinking for solutions…he he!