Benutzer:Felicia/Modular-Synth/VCO

This is the VCO module, as per YuSynth VCO Website.

Completed Module

YuSynth VCO Front Panel as Drawing

Construction

• I've etched a PCB with the original PCB provided by Yves
• The board was populated, soldering pad size was very good, so this was done in about two hours
• The panel was made of 2mm wood, hand-marked and drilled holes for the panel elements. The front panel design was made by myself and printed onto Zweckform 3487 white plastic sheets using a CLP-315 color laser printer. It was glued with "spray glue" onto the wooden panel.

It is noteworthy that the etching and soldering the PCB took only about 3 hours, while creating the front panel and wiring the connections took about at least 6 hours. Overall build time was 9-10 hours, planning time was the same amount.

I also thought that I probably want an aluminium front panel, but due to the very good results with the plastic sheets, I probably will stick to them for cost reasons. The 2mm wood panel also seems to be quite solid.

Construction Troubles

There are several issues:

• Much wiring is done at the panel itself. This makes it hard to swap the front panel with a more robust one. When I'm building other YuSynth modules, I'll re-design the PCB first to have one connector for each front panel element, even if it might bring a bit of noise into the system.
  • Because I didn't like wiring behind the front panel, I added a separate PCB where I bring connected front panel elements together.
  • Another thing to add to the PCB would be having the octave switch and sync connectors optional, so one can decide to skip or implement both switches by connecting a jumper and a set of connectors.
• Because I'll re-layout the modules anyways, I have an idea of adding a PSU adaptor to each board, so I can build one board and use several different power connectors.
• The schematic contains resistor names, but they are missing from the boards. So it is very hard to debug because only values, not names, are printed on the PCB.

Issues

• All major issues solved. Works like a charm!
• If the frequency pot is turned to 5 (center), the frequency is already very high. Need to investigate if this is wanted or a "bug".
• Switching from hard sync to soft sync causes a minor frequency. Not sure why, needs investigation. Maybe fixes itself once a CV voltage is applied

Previous Issues

• The sine looked very odd. This wasn't actually a bug - T3 wasn't adjusted. I accidently had the scope set to AC coupling, so I actually didn't touch T3.

Experiments

• Once the heat gun has arrived, test how well the tempco works.

Parts List

Quantity	Part	Remarks	Distributor	Distributor Order Number	Price per Item	Sum
1	79L15		Reichelt	µA 79L15	0.16	0.16
1	78L15		Reichelt	µA 78L15	0.14	0.14
6	TT Potentiometer 16 mm, 25kΩ lin, solder pads		Tube Town	tpo16-25k-lin	0.69	4.14
2	TL074		Reichelt	TL 074 DIL	0.3	0.6
1	TL072		Reichelt	TL 072 DIP	0.28	0.28
1	Styroflex Capacitor, 220pF, 2,5%		Reichelt	STYROFLEX 220P	0.31	0.31
2	22µF 63V		Reichelt	RAD 105 22/63	0.04	0.08
2	5 pin PCB Connector (pin+socket), straight, white, 25cm cable		Reichelt	PS 25/5G WS	0.45	0.9
2	3 pin PCB Connector (pin+socket), straight, white, 25cm cable		Reichelt	PS 25/3G WS	0.29	0.58
5	2 pin PCB Connector (pin+socket), straight, white, 25cm cable		Reichelt	PS 25/2G WS	0.29	1.45
5	100nF MKS-2 5% 63V		Reichelt	MKS-2-5 100N	0.09	0.45
2	49,9kΩ 1% tolerance, ¼Watts, Metal Film		Reichelt	METALL 50,0K	0.04	0.08
1	5,6kΩ 1% tolerance, ¼Watts, Metal Film		Reichelt	METALL 5,60K	0.04	0.04
2	470kΩ 1% tolerance, ¼Watts, Metal Film		Reichelt	METALL 470K	0.04	0.08
1	47kΩ 1% tolerance, ¼Watts, Metal Film		Reichelt	METALL 47,0K	0.04	0.04
1	4,7kΩ 1% tolerance, ¼Watts, Metal Film		Reichelt	METALL 4,70K	0.04	0.04
2	33kΩ 1% tolerance, ¼Watts, Metal Film		Reichelt	METALL 33,0K	0.04	0.08
1	3,3MΩ 1% tolerance, ¼Watts, Metal Film		Reichelt	METALL 3,30M	0.04	0.04
1	270kΩ 1% tolerance, ¼Watts, Metal Film		Reichelt	METALL 270K	0.04	0.04
2	220kΩ 1% tolerance, ¼Watts, Metal Film		Reichelt	METALL 220k	0.04	0.08
2	22kΩ 1% tolerance, ¼Watts, Metal Film		Reichelt	METALL 22,0k	0.04	0.08
1	200kΩ 1% tolerance, ¼Watts, Metal Film		Reichelt	METALL 200K	0.04	0.04
1	180kΩ 1% tolerance, ¼Watts, Metal Film		Reichelt	METALL 180K	0.04	0.04
2	150kΩ 1% tolerance, ¼Watts, Metal Film		Reichelt	METALL 150K	0.04	0.08
1	15kΩ 1% tolerance, ¼Watts, Metal Film		Reichelt	METALL 15,0K	0.04	0.04
2	12kΩ 1% tolerance, ¼Watts, Metal Film		Reichelt	METALL 12,0K	0.04	0.08
14	100kΩ 1% tolerance, ¼Watts, Metal Film		Reichelt	METALL 100K	0.04	0.56
6	10kΩ 1% tolerance, ¼Watts, Metal Film		Reichelt	METALL 10,0K	0.04	0.24
1	10Ω 1% tolerance, ¼Watts, Metal Film		Reichelt	METALL 10,0	0.04	0.04
1	1,5kΩ 1% tolerance, ¼Watts, Metal Film		Reichelt	METALL 1,50K	0.04	0.04
4	1kΩ 1% tolerance, ¼Watts, Metal Film		Reichelt	METALL 1,00K	0.04	0.16
1	LM311N		Reichelt	LM 311 DIP	0.22	0.22
3	Ceramic Disc Capacitor, 500V, 47pf		Reichelt	KERKO-500 47P	0.07	0.21
1	Ceramic Disc Capacitor, 500V, 10pf		Reichelt	KERKO-500 10P	0.07	0.07
1	Ceramic Disc Capacitor, 500V, 100pf		Reichelt	KERKO-500 100P	0.04	0.04
1	J112		Musikding	J112	0.25	0.25
1	IC-Socket, 8 pin, low profile, twisted, gilded		Reichelt	GS 8P	0.19	0.19
2	IC-Socket, 14 pin, low profile, twisted, gilded		Reichelt	GS 14P	0.26	0.52
10	Jack plug, 6.3 mm mono, central fixing, with switch, solder pads		Reichelt	EBMS 63	0.22	2.2
1	Photo-coated board, Bungard 75x100mm, single-sided 35µm, 1,5mm width		Reichelt	BEL 75X100-1	0.96	0.96
2	BC547B Transistor NPN TO-92 45V 0,1A 0,5W		Reichelt	BC 547B	0.04	0.08
1	Precision Potentiometer, 25 Turns, vertical, 50kΩ, Type 64W		Reichelt	64W-50K	0.3	0.3
1	Precision Potentiometer, 25 Turns, vertical, 20kΩ, Type 64W		Reichelt	64W-20K	0.3	0.3
1	Precision Potentiometer, 25 Turns, vertical, 200kΩ, Type 64W		Reichelt	64W-200K	0.3	0.3
1	Precision Potentiometer, 25 Turns, vertical, 10kΩ, Type 64W		Reichelt	64W-10K	0.3	0.3
6	1N4148 Planar Epitaxial Switching Diode, DO35, 100V, 0,15A		Reichelt	1N 4148	0.02	0.12
1	LT300014T261K0J		HBE	1174306	0.32	0.32
3	1MΩ 1% tolerance, ¼Watts, Metal Film		Reichelt	METALL 1,00M	0.04	0.12
6	Potentiometer Knob REAN P670 series		-	-	0.20	1.20
1	Wooden Panel, 2mm thick		-	-	1	1
1	One sheet of Zweckform 3487		-	-	about 0,50	0,50
SUM						20.16

Not included in the list are common things like cables, screws, nuts etc.

All prices in EUR.