Sammich SID.. Almost there! **FIXED**

[wallofnoise]

Hey guys,

I've finished soldering on both boards and I don't have too many pieces left over. ;) I've done the continuity tests on the main (bottom) board and everything checks out based on the page in the build guide. Now I'm to the point of giving it power... I went and picked up a 9/10.2/12/13V AC 800mA (set to 12v) power supply from Radio Shack based on a post I saw here on the forums from Wilba. They didn't have a 500mA. I also have a 12V DC 1500mA positive tip power supply that fits it. Which should I use? I'm using the standard lcd that came with the kit and 6582s. Also is the rocker switch turned on when the bottom end is depressed or out?

Thanks a ton!

wallofnoise

[Wilba]

The 12V AC 800mA will be OK, most likely it's unregulated. Leave it set to 12V.

The 12V DC 1500mA might be preferable if it's regulated. If you measure exactly 12V DC out of the tip, then it's regulated. Use shunts in JBP so the 7809 receives exactly 12V, not 12V - 1.4V from the bridge rectifier.

Rocker switch: flicking UP is powering ON.

[wallofnoise]

Thanks a lot for the fast response! :) I've tested the 12V DC and it's unregulated, so I'm going with the 12V AC which seems to be more reliable with a voltage pretty steady around 12-15v. I've connected the 12V AC and turned the bottom board on (flicked up) and I'm getting 0 off the J2 when I have the black probe to the ground and the red to +5v. This is using an old but reliable Fluke multimeter which seems to work fine as far as I can tell. What do you recommend I try from here? I have continuity with all the points and I've double checked all the component placements.

This really is an awesome kit and I've had a lot of fun getting it together.

Thanks again,

wallofnoise

[Wilba]

I'll just blat a whole lot of things to do without a lot of preamble:

- check multimeter is set to DC

- check 7809 and 7805 are in correct position

- check voltage at 9V points and 12V points, report values (see section 5. Voltage Tests, Step 1)

- check diodes between 7809 and 7805 are correctly oriented

- check voltage going into the 7805, between middle pin (ground) and pin connected to D5... should be around ~7.6V

- check middle pins of voltage regulators are connected to ground

[wallofnoise]

Thanks a lot for the help. I went through the steps and got it running (I had missed installing the bridge rectifier). I'm now able to pass the voltage tests on both boards. I've now added all the ICs besides the sid and bank chips to both boards. I also got MIOS studio going and successfully uploaded the newest firmware.

I'm about to install the bank chips and the sids, but I'm not able to pass the buttons test. I went to the sid manual online and tried pressing the buttons to go through the menu, but I can't get past the first screen which reads:

EInt|PInt Ld Chn. 1

1***|Lead Patch

I've tried pressing every button. I also tried pressing the buttons while running MIOS to see if the midi note messages were being sent as the manual said, but I don't see anything in the midi in window. Also I've noticed that the first and last columns of LEDs (6 total) are on all the time. How would you recommend I proceed?

Thanks for any input,

wallofnoise

[Wilba]

- check the 74HC165 and 74HC595 are in the correct positions

- check orientation of the resistor networks

- check for shorts or bad solder joints in the header between the PCBs

First and last column of LEDs being on might suggest a short around IC3/IC4, or even a LED in reverse polarity.

[wallofnoise]

Thanks for the fast response. I checked all the ICs and I did have 2 chips swapped. After confirming all the rest were in the correct positions the control panel and all the LEDs started working correctly. I proceeded to installing the bank chips and watched them format with no errors. I then uploaded the default patches which went fine. I then put in the SIDs (6582a), set the jumper horizontal, installed the 4 22nF caps (positions 1,3,4,6) and turned it on. It worked great and I started going through the presets playing notes off the keyboard in MIOS Studio, after about 5 minutes of lovely SID goodness, the unit just turned off like I had flipped the power switch. I turned the power off and then back on, however nothing happened, no LCD / LED activity.

I had unpulled the power when I installed all the components. I checked the power supply and it was still working correctly. I double-checked all the solder points on both boards, but didn't see any shorts. I then pulled all the ICs and the 4 SID caps off the bottom board and tried the voltage tests again. I'm not getting 5v at any of the points I was before. I am getting 9v off the left 7809 pin, but I'm getting 18v off the right pin where I should be getting 12v. The 0 off the right 7805 pin. This was with the multimeter set to DC. Any suggestions of what to do next?

Thanks again, I really appreciate it,

wallofnoise

[Wilba]

You're getting 18V because there's no load. It should drop to 10.5V-12V under load... but since you're using an 800mA adapter it will be higher.

I would recommend switching to the regulated 12V DC one and putting shunts in JBP until you sort out the other problems, then you should be getting exactly 12V at points marked 12V.

9V off the left 7809 pin is good... that's the output.

What is the voltage going into the 7805? (left pin relative to middle).

How are you setting the LCD backlight? (JBL, JR4, position of brightness pot).

[wallofnoise]

I switched to the other power supply and am getting 15.5v (DC probe setting) on all of the 12v points, which is about what the power supply puts out, so I'm not sure it's regulated. This is with both shunts on JBP. I'm getting about 0.15 off the left pin of the 7805. This is using the middle pin as ground. The right pin marked at 5v is 0.

I'm setting both LCD pots all the way anti-clockwise. JBL is default 5v, JR4 is off (no shunt).

Thanks a lot,

wallofnoise

[Wilba]

well that is the problem then... 0.15V into a 5V regulator isn't going to output 5V.

If you're measuring 9V elsewhere then there's something wrong between the 7809 and the 7805... i.e. through those two fat diodes.

[wallofnoise]

I've checked the 3 other 9v points near the 7809 and they are all less 0.20. Does that help narrow down which component might not be working correctly or perhaps the left pin of the 7809 isn't making good contact with the board?

Thanks again,

wallofnoise

[Wilba]

not really...

You could have a short between the 9V points and ground. What's the resistance between the 9V points and ground?

[wallofnoise]

I'm getting 8k resistance between the grd and 9v pin of the 7809. I'm getting 11M ohm on the gnd and 9v pads near the 7809. I'm getting 10M ohm on both the right end of the 'L' shunt as well as off the upper diode. Also I went back through and did some continuity tests and I'm not getting anything on any of the 5v points. In fact it seems between the 12v / 9v and grd pins on the 7809 are the only ones that pass.

Thanks a lot,

wallofnoise

[Wilba]

OK this is getting strange. I'm not following what you say about the continuity tests, but it suggests something like a pin connected to ground isn't well connected, or some other soldering error.

Do these tests and report back.

Test continuity between "GND" pin on J2 and other ground points (middle pin of 7809 and 7805)

Test continuity between "+9V" pin of J20 and other 9V points (JP, 7809, anode of D4)

Test continuity between "+5V" pin on J2 and other 5V points, just for completeness.

Check D4 and D5 diodes are oriented correctly.

If the 7809 and 7805 middle pins aren't connected to ground properly, that will cause problems. Continuity test (or test resistance) between those pins and a known good unsoldered ground point like J2

IF that passes, then while powered on:

test voltages between J2 GND and the orange dots, check they're all the same voltage, report them.

test voltages between 7809 middle pin and the orange dots, check they're all the same voltage, report them.

test voltages between J2 GND and the four blue dots, check they're all the same voltage, report them.

test voltages between 7809 middle pin and the four blue dots, check they're all the same voltage, report them.

then test voltage at the two other points between the 7809 and the 7805... i.e. cathode end of D4 (where stripe is), cathode end of D5 (where stripe is).

Take a photo of the right side of the PCB (top and bottom)... probably won't do much but you never know... I might see something.

[wallofnoise]

Great news, good call, I wasn't getting continuity between the 7809 ground pin and the ground point right nearby, so I re-soldered the pin. It's a little strange as the pin looked to have ample solder on it, but I made sure it flowed in there and it's working great. I put in all the ICs after the voltage tests passed and I'm good to go. I did change the shunts back to support the 12v 800mA ac supply, as the 12v dc is on loan. I'm seeing about 18v coming into the 7809 and the heat sync is getting hot, but I can still touch it after around 10 mins of use. Does this seem ok for a long term setup? I did notice my 800mA power supply has a 10.5v setting which is putting out a solid 12.25v opposed to the 14.5v on the 12v setting. Might this be a better long term solution? I just don't want to burn something out after using it awhile.

Thanks again for all your help, it's so awesome to have it running! :)

wallofnoise

[Wilba]

Good news!

I recommend the 10.5V setting.

Unregulated power supplies have a max current rating, so that in your case, it will deliver 12V when the current draw is approximately 800mA. When the current draw is less, the voltage will be higher. That's why you're seeing 18V because the total current draw is less than 800mA (probably more like 350mA max).

So in your case, switching it down to a 10.5V supply is a good idea... it might even have a 9V setting that outputs 11V... as long as the 7809 gets 10.5V or so, it can output 9V. The tricky part will be that its hard to measure what that 7809 input voltage is when the CS/LCD is connected, and you're drawing an extra 100mA... maybe just once you can take it out of the case, assemble it without the case bottom, and measure voltages on the bottom while it fully working.

[wallofnoise]

I just checked and I'm getting a solid 12.5v into the 7809 with both boards attached using the 10.5v setting of the power supply. It does have the 9v, but when I tested it, it was about 10.2v at the other side of the power connector which seems like it's cutting it a bit close. Would it harm anything if the 7809 went under 10.5v at times or do you think sticking with 10.5v is best?

Thanks a lot!

wallofnoise

[ilmenator]

I'd say stick with the 10.5V setting, then. To go lower does not harm the 7809 in the sense that it will break, but the input voltage might be too low to get a stable 9V at its output. A too low output voltage will prevent your SID from working properly.

[wallofnoise]

Thanks for the feedback, it makes sense.

I'm having tons of fun messing with this awesome little box and may even get around to painting it sometime. ;)

I have been looking at the 'audio in' on the sammichSID and was wondering how that would work. I've read a bunch of posts here on the forums and in the MIDIbox SID V2 user manual, but I'm not sure how they relate to what's in the stock sammichSID, as they seem to be more towards other projects. Could I give the sammichSID a standard line level input (like off a sound card) and then process it? I know I read about filters that can be used, is there a preset patch that works better for this type of thing?

Thanks for any info!

wallofnoise

[Wilba]

Standard line level input will work. You need to turn on external input in the Filter page, then you can control it via the knob or I suppose NPRN messages, can't tell you more off the top of my head, you'll have to RTFM :D

[wallofnoise]

Awesome, will do. Thanks again! :smile: