the Mox Philter..analog toolbox based

[Rio]

i use AOUT_LC.

What is the name of your psu? Which outputs are there? Are you using voltage regulators with your psu too?

Maybe i'll test that, if i got one.

Greets,

Rio

[moxi]

no name, the psu was inside the keyboard.

it's a standard design based on voltage reg ("78mr05r" and "78/79m12ml" ), and there is one flat cable per voltage (each with a ground line), there is a ceramic blue line-filter capacitor just after the 240v input.

i use AOUT_LC.

hum...I was using Aout_LC module when doing my first test where the filters generated sound themselves, I can test if the same thing still happen now with the normal Aout module, but not before a pair of week, I still have to finish the prog and rewire all the knobs/button..

quote from Ucapps Aout_LC page:

Another typical problem of cheap DACs (not only of this circuit, but also for cheap integrated DACs) is, that there is some "zipper noise" each time a new voltage is selected. The intensity of this noise depends on the bits which are toggled when a new voltage is selected - the leftmost bits (most signifigant bits) will produce the highest zipper noise. Even I can see this noise on my scope, I haven't noticed an audible effect with a discrete Moog- and CEM3378 filter, yet.

that could explain the noise..

[Rio]

Thx for your help, but that sweep and the noise are continuous, when no voltage will be changed. Maybe i'll record it at weekend and upload it here... so you can check it by connecting your AOUT_LC after you've finished your programming stuff.

Thx a lot for your help ;)

Best Regards, Rio.

[Rio]

My device sounds with noises as soon as the filter c.v. is connected to filter.

Please, listen to that example in attachment.

Did you hear the same with AOUT_LC? Has someone notice same behaviour or can someone say where this noises are come from?

Best Regards,

Rio

example-cem3378-noise-wav.zip

example-cem3378-noise-wav.zip

[stryd_one]

Maybe the noise is coming from the cv then... you sure it's OK? all flat when you read it with a scope?

[opkod]

with an aout-ng, it will do the same background noise?

[Rio]

Have you noticed the same noises on your installation?

I've checked my again.

There are 2 noises: the first is net zipper noise. I've solved it mostly by put up new ground lines between the SID+Core+AOUT_LC modules which are in the same case.

The second noise is more difficult. Seems the TL072 swings by itselfs and it sounds like a dogpipe, which changes frequency after a while. If I put my fingers in the near of it then the frequency will also be changed.

Bad bad...

[Rio]

the problem is solved by adding few capacities at TL072. I'll describe the solution in the cem3378 thread after weekend. Now the filter sounds fine.

Greets,

Sebastian

[Rio]

The solution is decribed in following thread:

CEM3378 Schematic

[Phattline]

- EG can be triggered by audio signal, with a Threshold knob (I use an audio to trigg circuit, I still have to adapt the trigger signal to send it into a DIN input...will see if that can work)...

Thats exactly what I want for my 303clone, too duck the bassline via basdrum---more infos about the shematic?

[moxi]

hello,

I update this thread, cause some works have been done since, I've finished the whole CS, and the resp. programming. It have been tested and all seems to work fine on the logic side. So I think it's good to share it.

I won't go on this gear before some months cause I have a lot of things to do, and it will need all of my attention and concentration, what it's not possible now. but rather than keep it under dust...

I attach the app and two little pics, as I've ripped some part for other project and be not able to light it up now, I put a little pic I've take last year with some leds lighting and the LCD...

Lot of inter-modulation have been added, cv and audio mixers have been build , but not tested. Just some tests to directly modulate the cem3378 and to check modulation digital mixing have been done..far to be finished!!!

I've added and do the testing with 2x40 LCD, more comfortable, but get no room on the painfully DIYed control surface, I keep this difficult choice for later, when maybe I will get enough dollarz to make a full new CS...

A bankstick and a preset handling is now present, by some way I'm proud of it : you get access with only one buton act to 4 preset, one time you're in a bank, or with two pressing if you have to select another bank, saving it's quick and easy too (just acts on digital mods, of course, analog pots of cv-mixers and audio won't be saved, maybe the new stm32 core that can support more cv's module will be the trick to solve that..but a lot of rework should be necessary).

The MIDI implementation is not finished, an internal bpm sync is present too, but no way to remember if I have tested it..

You will learn more reading the code, I'm open to possible optimisation, I know I tweak the codes always in a rough way, it's cause mathematic and me are two different thingz..

Another thing : the MBsid already can do all of this, so maybe this crappy app is useless... :frantics:

All my best.

Moxi.

zaoum_16_07.rar