555 vco

[braincell]

Hi Everyone,
I decided to build myself an analogue synth........ And teach myself analogue electronics too.....

Bit of a tall ask I know but I decided on a 555 vco as my first unit after hearing a sound sample.

So I joined this site and messaged a member to get a pcb , but it looks like I missed out on the last run........

So I thought I will learn Eaglecad and draw one up myself...... *facepalm*

just under a week later I managed it

Attached is the schematic :-

here is a link to dirtypcbs if anyone wants to take a chance on a board ....

***removed***

*** ABSOLUTELY NO WARRANTY OR ANY RESPONSIBILITY TAKEN ***

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th555vco schematic + lfo.png
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[braincell]

So after receiveing the boards back from dirtyPCB's i built up the boards and NOTHING.....

No output , Just a lot of heat from the OP-AMPS.......GUTTED!!!!!

Took a break for a couple of days and then looked again with fresh eyes and found EAGLE crossed over some wires because i laid a resistor symbol over the transistors......

Lesson learned , PCB v0.2 went to board house and came back.

As bought in batches of 10 i made 1 up and it looks great , so i populated another 3

Black board at back is MIDI2CV .... waiting on components to finish.

White board at right is TH ADSR , again waiting on components

Have drawn up 7 other boards too , Synth here we come

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[LFLab]

Good work!

I also prefer laying out my own boards, so I am familiar with the layout when I start plugging in components, and the stuff I already have in my parts stash fits.
Which ADSR did you do? The one with or without "light show"?
I have a board ready to go for the version with LED's, and I will be using illuminated sliders, should be good.

[braincell]

hi , Its the fonik 4u version i think..... unsure if its gonna run yet

[braincell]

Hi All,
The 555 vco board works perfectly so im uploading the eagle files incase anyone wants to run some off.........

I recommend "DIRTYPCB'S" protopack 10+/- 1 for $25 dollars

Lee

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[braincell]

Hi All,
CV Ringmod buit and tested here the schematic and Board for EAGLE.

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[braincell]

Heres my scope showing the fm on the 555 vco

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[coaxlix]

[braincell]

Hi,
The VC Ring Mod is foniks i think , i got the schematic online.

I dont think theres anything to tune really as the pots seem to control the modulation.

I built it and it just works......

I used cheap schinese tl074's and 13700 in all theses modules (Ebay) and they seem to work well.

Lee

[braincell]

Hi All,
Heres a scheme and board for a buffered - linked multiple and various LED Drivers on a board.

As you can see from the Scheme there provision to add attenuators to the multiple or bypass them and link both 4's to make 8.

Also a line out from 1 port too

4 standard BI-Colour LED drivers and also a TRI Colour LED driver showing level posted by TH on this site somewhere

UNTESTED yet but im waiting for my boards to arrive

LEE

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[coaxlix]

[braincell]

Hi,
These are Foniks mod i think i found the schematic out there in internet land , cant remember where.

But i have attached a small pic showing how to wire a DPDT switch in to turn this VCO into an LFO with rate LED.

Be sure to use a 2 pin Bi-Color LED (I chose red/blue).

The link is simply just that, as you can see in the schematic it simply supplys the LED buffer OPAMP with a signal. Just bridge the link.

JP 11 = Bi-Color LED signal (after a switch)

JP 13 = other side of the switch to change the timing capacitor from just C4 to C4 PLUS C4B (1uF)

Hope this helps

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[coaxlix]

Ok! Thanks, I wouldn't have figured that out on my own.