My new project - Page 1
Forum section: electronics / projects

author: white_rabbit007
author_rank: Newbie
timestamp: September 08, 2021, 01:26:09 pm
content: Hello,I am passionate about electronic music and I want to try an experience, that of making my own modules.I have two objectives, after having spent fortunes on manufactured devices, I desire to discover the satisfaction of having done by myself.so here, I have a beginner level in electronics but I am learning little by little. I started from a diagram found on the internet that I tried to understand and modify and I think I succeeded but I need the advice of a much more experienced person to know the functionality of my drawing before moving on to the manufacturing for make one for my system.I thank you in advance for the expertise of your eyes.PS: vco eurorack based on the as/cem 3340power VCC+12v / VEE-12v

author: Doctorandus_P
author_rank: Super Contributor
timestamp: September 09, 2021, 09:21:15 am
content: There are some Euro-rack based projects both here on this forum, github, and probably all over the web.Did you design this all yourself, or cobbled together from different pre-existing parts?I would loose the rectangular boxes around all the sub circuits. They add no information, and make the project harder to maintain and modify.Instead, make the texts for identifying features such as "SYNC", "PWM", "TRIANGLE" in a bigger font (better than all capital yelling).Put all power supply blocks together, preferably from left to right in the direction that the power flows. So: connectors -> Buffer caps -> Voltage regulators -> decoupling caps and IC power connections. You have placed clarifying labels for your signal sections, but not for your power. That is separate blocks spread across the schematic.You have C10 and C11 as buffer caps, and C11 for decoupling. I would also add 100nF decoupling between Vcc+GND and Vee+GND.Is TL074 still used for serious audio? It's a very old design from the early days of IC's in electronics.I'm not sure what I'm looking at around D1 and D3. Q1 & Q2 FET's? If so, then use schematic symbols for (MOS) fet's instead of something resembling a connector.I first thought C9 was backwards. Then saw it has a negative voltage regulator. (And again, in an undescriptive "connector like" schematic symbol. I always do my best have higher voltages in the "north" and lower voltages in the "south" of the schematic, and currents & signals flow from left to right. (You did this last part pretty well)So for negative voltage regulators, I draw them south of the horizontal GND wire.Always be careful with the "L" version of voltage regulators. Often they can handle the current, but they can not handle the dissipation. TO-92 gets hot easily.I am not a big fan of quad opamps. Often PCB's are easier to route with dual opamps.For experimental projects, try to add some pads for modifications on the PCB, or even just a few extra mounting holes, so you can use M3 bolts to fix a piece matrix board. For the same reason I usually use a 2.54mm grid for all THT parts (active, passive, connectors)Always make sure your schematic does not get too crowded. (Your's is OK). Crowded schematics are harder to read and you waste a lot of time by trying to fit it all during modifications. When a schematic starts to get crowded, the first thing to do is to split it over multiple pages. For example use page for all the power supply parts and decoupling capacitors.Some people like simulators, but I like a more hands-on approach more, such as a breadboard. Have you built / tested the individual parts on a schematic or breadboard?Are you planning to make a PCB for this?In my experience designing a PCB needs quite some time. For circuits that are one-off, building a prototype on matrix board is about the same time as making a PCB layout. (and then you still have to solder the parts).With R12 and R16 you have a voltage divider, and then you amplify the signal again with U1.2 This also amplifies the Opamp's input noise.

author: white_rabbit007
author_rank: Newbie
timestamp: September 09, 2021, 12:02:51 pm
content: Thank you for all your answers,I make the changes and I get back to you

author: Renate
author_rank: Super Contributor
timestamp: September 09, 2021, 07:35:35 pm
content: I don't know what you're looking for, but have you ever had time to play on a large modular system?You don't seem to have any sources for low frequency modulation or sweepable filters, noise sources or gates.I don't know if you like that stuff, but it would be a shame to build a limited system.

author: white_rabbit007
author_rank: Newbie
timestamp: September 10, 2021, 01:58:05 pm
content: thank you again for all these tipsI have just made corrections, does this correspond to your recommendations?

author: viperidae
author_rank: Frequent Contributor
timestamp: September 11, 2021, 06:18:02 am
content: The position of those switches leaves the pots in circuit with the amplifier input. They will attenuate each other.

author: Renate
author_rank: Super Contributor
timestamp: September 11, 2021, 10:56:17 am
content: Quote from: viperidae on September 11, 2021, 06:18:02 amHuh? Do you mean R77-R80?That node's a virtual ground. It doesn't care (within reason).I don't like to see RV6 and RV7 so full range. They are trims. Maybe breadboard/simulate this and throw some resistors on the ends so that the range is more useful?