Problem with The SIDv2 (TWINSID)

MIDIbox SID
1

Hi 

I am trying to build a SIDv2,  actually a TWINSID from yodabe.

I have build only a main board for now, and the sid worked, when I tried the sid tomorrow there was no sound.

So I have tried the testtone app to find out Is there a problem with the output amp.

I have connected the 8 pin and the 27 pin and there is no sound but when i touch the wire with my hand there is a sound, What? Strange.

Can someone give me an advice what to do, what to replace, what to check?

 

I have put the sid to other socket on the board and it works like a charm.

this is the link of the project:

http://www.midibox.org/dokuwiki/doku.php?id=mb-twinsid

By the way, the left sid on the main board is not working

Thanks,

Kike

 

2

Hi Kike,

For the basic Sid part schematic understanding it’s a good habit to use a MBHP_SID_V3 schematic from the Sid Module section. It can help to understand the audio path part and  the control pin part of the Sid chip. The schematic is the same, I think.

There are a lot of soldered wires - jumpers on the Twinsid main board. If you are used the same layout board you need  to check a presence of every jumper - wire , under the ic’s, too. Visually check all solder places on the pcb, not the shorts between the traces,too. To check a non solderable jumpers too.

Supply voltages tests idea are similar to the sammichSID_build_guide_v1_0.zip from page 18, but there are another components layout of course.

To check: right supply voltages for your sids , the right nominal similar capacitors for the sids oscillators on the sid  pins1/2 and 3/4. 

Regards,

Janis

3

Hi Janis

Thanks for the help. 

I have checked everything. I am using  8580 chips, put a 22nf caps on the  pins1/2 and 3/4. Put a pullup resistor on the lcd

Voltages are fine, 9V and 5V. I bypassed power from the TWINSID board and build power supply that was suggested by Thorsten.

I have tried yesterday the socket that worked the first time and now I hear very high noise on the output, SID works

Noise changes when using midi keyboard in mios studio. It is some kind of flickering noise. 

I am going to etch another board, going mad with this one.

Regards

Kike

4

Hi Kike,

Are the Sid chips audio input pins 26 tied  to ground (with the small jumpers)?

Regards, 

Janis

 

5

No, i didn’t tied them to the ground. 

How did I forget that. 

I will try tonight and see what is going to happen

6

I have grounded the input pins and still nothing. 

Going to etch another board, this is not working. 

But this time I will not go with twinsid.