Four independent LFO with triangle, sine, ramp up, ramp down and square wave output. Output voltage 10Vpp. The sine is inverted against the triangle. Ramp up and ramp down are twice the frequency of the triangle. Specs and features Four independent LFO Triangle, sine, ramp up, ramp down and square w...

This might help as well:

https://www.haraldswerk.de/Utilities/Ba ... _2_35.html

Do you really want 16 step ? The current version has upto 64 steps, if you dont mind only 8 individual notes ;) Otherwise there is another way, but you will need 2 x M185. cheers ryk I am interested in this "other way". It might be worth building a second one. Still waiting for the answer to the "o...

:tu: What brand are yours? -------------- Edit- assume these were short tests? As you said above, Heatsinks are going to be needed for larger current draws over long periods of time. Yes. The measurements lasted about 10 minutes. I have used small heat sinks. But I have used them in my synth for ma...

KSS wrote: ↑

Sun Sep 20, 2020 10:10 am

What brand are yours?

--------------
Edit- assume these were short tests?
As you said above, Heatsinks are going to be needed for larger current draws over long periods of time.

LM337. Fairchild
LM317 ST

This adaptor was tested with a load of 1A each rail. It is tested working properly down to an input voltage of 14,5V with an 1A load on each rail. So it should work fine in every 15V system. With a safety margin of 0.5V. Here are some figures: LM337 With 500mA load the output voltage degrades at 14V...

The typical 317 and 337 regulators have a maximum output of 1.5A. In this -bigger- design, you will probably want to draw less than that amount. I'll leave it to Harald to provide or suggest the actual amount of current draw his multi module design supports. In Harald's smaller single module design...

Just have a small question since i don't know much on the +-15V standard. How much current can handle the 3 points connector ? There is no +/-15V standard. Those three pin connectors I use for the PSU are rated 2.5A/250V. You can get them from many sources and with different pin counts. I use them ...

Looks like a very handy module. I'm interested by the choice of LT1014 here... When building something similar I used OPA4197, which as far as I can tell is is cheaper, has a lower offset voltage, and has a bias current a factor of 2000 less than the LT1014 at modular case temperatures - so I didn'...

I fully expected this response. It works. Reliably. Every. Time. I've. Used. It. That's good enough reason -in my book- to make the post. Doesn't mean there isn't something else equal or better. Does mean :tu: to what Harald presents here. Thanks. That's my experience as well. But Neil has a good p...

I would have thought going from 15V down to 12V where you have a nominal 3V difference it would be better to use LDO regulators? The LM337 needs a minimum of 2.5V and the LM317 needs a minimum of 3V differential, which is rather tight on 15V rails and doesn't leave much room for the regulators to d...

BananaPlug wrote: ↑

Sat Sep 12, 2020 12:26 pm

Yes, please make them available. It gladly upgrade from my functional but nasty perf board thing.

You can download the Gerber files from my website and order yourself from a manufacturer of your choice. That's the cheapest solution.

What is the license? Can I sell the PCB in my store? I would be happy to offer this for sale in my store if you will allow it. Probably $6 for the small one and $10 for the bigger one. I am not sure what to do here. My designs are free for private use in the DIY community and everybody can download...

Thank you for this! :sb: Making one of these on perfboard has been on my to-do list for about 2 years I'm going to order some PCBs- if anyone in US wants 1 or 2 lemme know. Edit: I should mention, for trade (ideally) or a couple bucks for shipping. Thanks. I am happy that my PCB's are helpful.

Thanks for sharing this! Have need for such a module but not gotten one yet. Do you have experience if it will keep its precision with other opamps like e. g. TL074 too? Or is the type of OpAmp critical? I would guess, that precision comes mainly from using buffered inputs and selecting matched res...

whyfarer wrote: ↑

Fri Sep 11, 2020 5:25 pm

awesome! thanks for sharing. how precise have you found it to be in practice? really, I want to know if you've found it good enough to add v/oct without the need for a quantizer after the summing.

Adding 1V to 1V. Good enough?

Grom wrote: ↑

Fri Sep 11, 2020 2:22 am

wow, just what I was looking for in utillity, looks brilliant mate.

I'm learning EASYEDA. Mind If I try to replicate it in smd format?

Feel free to do so. This is what this forum should be fore. DIY.

This is a useful and often needed utility module. The input voltages are precisely added to the outputs.The inputs 1, 3 and 5 are normalized. It can be used in different ways: As three independent adders, as buffered multiple, adding a modulation source simultaneously to all three outputs, adding tw...

Here is the bigger brother from the single adaptor above. The documentation and the Gerber files for download can be found in my website.

Beautifully neat and tidy and carefully documented as always. I am intrigued by the compensation capacitor. At 5.6pF it is absolutely tiny so presumably only has an impact at pretty high frequencies, and the LT1013/4 does not have much bandwidth anyway. Is there a reason for this choice of cap? Tha...

This is a useful and often needed utility module. The input voltage is precisely reproduced on the outputs. It comes in handy when you need to distribute signals which must be decoupled. The input signal is buffered and decoupled with means of individual operational amplifiers. One input drives 6 in...

Ahh yes, but this point is already addressed in the building hints. There is only one resistor value to change.

What does the bias knob do? With the bias you can open the VCA by hand. And it comes in handy when you are doing AM with a CV source which has only AC output. Say an LFO with -5V to +5V. Then you can attenuate the CV 1/2 with the CV pot and open the VCA 1/2 with the bias pot. This gives you the ful...

wackelpeter wrote: ↑

Mon Aug 03, 2020 9:29 am

Question is, are 16 enough?

No. Not when you need 2x4 to move signals around the room (4 channels) one chasing another. Only eight left then.

You can never have enough VCA!