Phoenix, MOBO & SMR MKII assembly help needed


#1

Hello synthlovers,

My name is Ronny and i like to make electronic music and i needed some nice warm bass. After listening to a lot of bass synths i stumbled upon the Shruthi (Phoenix, Tubeohm). What a sound!

What a project!
I have never soldered before. i am very messy, but i thought this project would learn me patience, accuracy and it couldn’t hurt to get a little handy with a soldering iron.

Soo, i started with the MOBO ( Motherboard) and i made a lot of mistakes. I had to pull a few things out and resolver etc. Messy.
I haven’t been able to test the board but here is the result:
I wonder if anyone can see if there are any mistakes i made.
had to remove picture because of forum rules. I will upload this one after i get permission*

After finishing this part of the assembly i started on the SMR MKII filter board. I was more cautious this time and i thought i did everything correct. BUT after i hooked up a power supply (Moog 9V as in picture), and got the multi meter (as seen on picture), but i’m getting strange readings. It’s supposed to be 5V or -5V but i get 1.2, 2,5. Very low and i guess not any minuses.
Here two pictures with my board, adapter and multimeter. Can anyone see something is wrong?


! had to remove picture because of forum rules. I will upload this one after i get permission*

I appreciate the help.

Ronny


#2

You forgot the jumper wire next to the power inlet. Also, If you want to get any voltage on the -5V, you will need to insert the LT1054 in its socket.

Edit: Maybe move this topic to the “discontinued products” section?


#3

It might be better with the LT1054 in place in the IC socket but it’d have been easier to insert it before soldering the electrolytic caps… :wink:
As a general rule, you always start from the lower parts (diodes, resistors) and finish with the highest (regulators, electrolytic caps).


#4

Yeah…Didn’t see that one. :sleeping:


#5

Hello!

And thank you for helping.

So, i just bridge a wire on the sw22 like this?


#6

Very nice that you guys are helping out a noob⛷


#7

Yes, that’s how you should solder the bridge.


#8


It should read +5 v


#9

This should be -5V
Am I measuring correctly?


#10

This is my multi meter


#11

What are you powering the board with?


#12


#13

on wich mode should i set my multimeter?


#14

On 20 in V DC mode.
Did you put the LT1054 ?
Could you measure the AC adapter alone ?
It is rated 9V 400 mA but it will tell us if it is regulated or not.


#15

You have your multimeter set to the hFE (transistor test) mode. That is wrong. You want to measure a voltage.
Why don’t you set it to the DC (not AC!) voltage mode? Set to to 20V-, that should do the trick :wink:

I suggest you watch a youtube video on multimeter basics. (Knowing how to measure stuff is crutial to finding an error)

And don’t put the LT1054 in backwards, it blows very easily. :slight_smile:


#16

TheSlowGrowth got the last piece of the puzzle, I think. The multi-meter isn’t in the correct mode in your last set of pictures. After that, you should be in good shape. Also, a general tip on building your first synth - TAKE YOUR TIME! I know it seems obvious, but using care to get it right the first time will pay off in the long run. I rushed through building my Anushri a few years back, and didn’t have the skills/ experience / patience to get it functioning for a couple years. The build instructions are really well made, so follow them closely and you’ll be done before you know it. Have fun, Shruthi-1 is a fantastic little box. That reminds me, I should bust mine out and jam on it soon…


#17

Is this correct?
It should be 5V. So, it’s wrongly measured or the board is messed up.

I looked up an Lt1504 and it looks like an metal lasso. It’s not included in the kit. Why do I need it. Was it for the bridging of the SW22? I used a piece of wire for that.


#18

How do I measure voltage on the adapter? Like this?


#19

Haha. I take my time and Take breaks. Go on YouTube and try to educate myself. There is nothing else on my mind than this assembly.

But now I’m really stuck. So I hope for some help.
I will later post pictures of the motherboard. Man, that is a real mess💩


#20

Sorry, typo…
You want a 8 pin IC with LT1054 on it.
Should look like that:
s-l225