shopping list (n00b question)

[fokfokfok]

hey guys

I wan't to built a 1xSID synth with the simple control unit :D

I know I have to get:

1 a sid chip (going to buy a 6581R4)

1 core kit (with pic)

1 sid kit

1 DIN kit (or I could make a DINx1 on a protoboard)

1 rotary encoder

6 buttons

1 20x2 LCD

1 15V 500mA psu

1 enclosure

2 audio sockets

But is that all?  What about cables? Don't I need some ribon cables and connectors?

Does the psu have to be regulated or can I just buy an el cheapo ac adaptor?  I guess I need to buy a socket for the adaptor plug as well?

Also, I've noticed that smashTV sells a rotary encoder with a switch.  What is that used for?

[stryd_one]

hey guys

Hi welcome aboard :)

But is that all?  What about cables? Don't I need some ribon cables and connectors?

Heheh I almost forgot them the last time :-[ Yeh you'll need other stuff like cables and connectors and all the CS stuff like enclosure, front panel, knobs, and possibly button caps and LED(s) etc

Does the psu have to be regulated or can I just buy an el cheapo ac adaptor?  I guess I need to buy a socket for the adaptor plug as well?

Easiest PSU is to use the one from the c64, and use the optimised PSU design.

Also, I've noticed that smashTV sells a rotary encoder with a switch.  What is that used for?

Up to your imagination ;)

[carsten_the_dane]

The once with switches doesnt cost that much extra. I have bought them even though i have no idea what to use them for at the moment. But it might come in handy one day.

/carsten

[stryd_one]

Heads up though - they're a different shaft length.

[fokfokfok]

I don't have the original psu, so that's not an option. I cannot figure out if there's a problem, using a standard ac adaptor? If it just gets a little hot and introduces some background noise, then it isn't really a problem I think.  But I don't want to damage anything...of course.

As for the cables/connectors.  How do I know what I need?

[HL-SDK]

I strongly urge you to get a C64 PSU, otherwise, you can power the whole thing from 15VAC or dc... Either way, you can just power the sid and core from the same adapter, as long as it can spit out more than 500mA, or .5A (same thing)

[fokfokfok]

as long as it can spit out more than 500mA, or .5A (same thing)

So 500mA isn't enough?  15V 500mA adaptors are pretty common where I come from (Denmark), but I cannot find any regulated adaptors which are over 15V. I guess I could get an unregulated adaptor but that would only make the problem worse right?

Why is everybody so keen on that old c64 ps?.  It's obvious that it's the best solution from a electrical point of view, but from a practical point of view it sucks.  It's not easily available/replaceable, it's big and most importantly (for me at least) it's ugly and maybe even smelly.  I want a machine that sounds dirty, not look dirty.  From searching the forums and uCApps, it seems like the only problem using a standard 15V wallwart is that 7805 get's very hot.  Why can't I just put a heatsink on it?  I haven't found a post yet where someone fried something because of the psu.  And even if you still think that it would get too hot, why couldn't I just add another voltage regulator like a 7809 and do the conversion in to steps.  Then it definetly wouldn't be a problem.

[seppoman]

Hi,

whether 500mA is enough depends on your implementation. With only one SID, a 2x20 LCD and not the full control surface, 500mA is plenty. One of the most power consuming parts is often the LCD backlight. I´ve got a 2x40 LCD whose backlight takes up to 400mA if you adjust it to max. I used a 15V wall wart with 800mA capability and adjusted the backlight to around half power. My box runs with this cirquit:

http://www.ucapps.de/mbhp/mbhp_core_power_fix.pdf

With the additional 7809, the dissipated heat is split to two regulators. The core regulator got a normal heatsink, while the 7809 is mounted to the (metal) case. I find the temperature of the regulators quite acceptable.

Why are people recommending the C64 PSU all the time? There are two reasons:

1. Using it keeps the heat out of the box as regulation of the 5V power is already done in the PSU.

2. Supposedly, the noise floor is better using the ...optimized design. I tried both, and couldn´t really hear a significant difference. At first I had a problem with ground loops (hum), but avoiding these and taking care for clean wiring in the box got me a comparable noise floor. Probably there´s some measurable difference, but background hiss is really a smaller problem compared to all the dirt coming from the 6581. Anyway, aren´t these imperfections part of what we all love about this old bastard?

Seppoman

[AndrewMartens]

The powersupply current does vary a great deal depending on the size of your implementation, as seppoman pointed out.

For a smaller (control surface A) design - like it appears you are planning to use - a 500mA supply will probably be fine.  I have something similar (CS A with 16x2 backlit LCD, one SID), and it tends to draw about 210 mA at 13.8V from my supply.  Again, this could vary a lot with your LCD.