Sammich Sid Voltage Problem when Sid fitted

MIDIbox SID
1

Hi Midibox community !

all my best wish for 2011 :slight_smile: !

I have finished to mount sammish sid yesterday evening, check voltage points and continuity and everything is right ! Upload setup into pic and bankstick formating with plenty success ! I’m a happy man ! Last step install the 2 6581 sid and begin to play … but unfortunaly when i power on, no lcd and leds light … nothing ! i try without sid’s, it’s ok i have menu, i check with Wilba 6582, of course i set up the jumpers configuration, and same problem no light on lcd and leds !

I remove control pcb and test voltage, when sid’s are fitted voltage are 7v and 3V instead of 12V and 5V into test points ??? when i remove sids, voltage measures are good !

What’s happen ?

Thanks for your help !

K.

2

Hi kroutshev,

it is very likely that your powersupply is to weak and can´t deliver the load current when the sids are attached.

12V DC regulated PSU with 500mA or more is needed.

3

Hi Phunk,

thanks for your quick reply !

i have tought about this, my power supply is regulated DC 12 V ! i have read into building manuel that for 6581 use, psu must absolutly match 12 V and not more ?

Is it right ?

But i havnt’ checked if i have 500 mA !

i will do it that night !

Thanks

4

Yeah, if it is regulated it should deliver 12V DC ± a few %.

The 500mA is a minimum requirement depending on the lcd used. A standard lcd needs about 125mA but there are so called “high current” lcds which need a lot more. So if you got one of those, you have to assure that your PSU can deliver enough current.

5

<br />Yeah, if it is regulated it should deliver 12V DC ± a few %. <br />The 500mA is a minimum requirement depending on the lcd used. A standard lcd needs about 125mA but there are so called "high current" lcds which need a lot more. So if you got one of those, you have to assure that your PSU can deliver enough current.<br />

<br /><br /><br />

About lcd i don’t know exactly … it was included into wilba kit ! Perhaps i have choosen the bad option about lcd jumpers …

6

No, you should be fine then. If the LCD is working when no SIDs are attached the jumpers are set correct. Dont worry about that.

As I said it is very likely the used PSU. Make sure it can deliver 500mA before looking for other possible failures.

7

don’t know about the Sammich kit but if you are feeding regulated 12v DC to a 12v regulator, you’re gonna end up with more like 10.xxxv

8

don’t know about the Sammich kit but if you are feeding regulated 12v DC to a 12v regulator, you’re gonna end up with more like 10.xxxv

When there’s no sid installed i’ve got 11.99 V into 12V rail with my psu !

9

There is no 12V regulator in sammichSID, which is why you must use regulated 12V DC only when using 6581.

It sounds like your problem is too much current draw when using SIDs. Test this by installing only one SID and see if you get it to boot.

You should tell us what power supply you are using… maybe take a photo of the specs on the “plug” part.

10

I have tested with one sid and same problem, no power on from lcd and leds.

Ok i will check specs of my psu !

11

Ok, you’re right guys, psu was in fault. i have changed for another one, measures are 12,45 V into sid pins. I power on, lcd and leds are ok, i start my sequencer, i listen the sammichSID, output volume is correct but after few seconds volume is very very low …

i thought that i have burned my 6581, i remove them and install 6582 checked before into that sammichSID but same thing output volume is very low ???

Arghhhhhhhhhhhh

What’s the problem ?

12

It sound like my output is not stereo but mono ! some patches doesn’t work at and the others have very low volume … I have checked if i have short between pins of the two 6581 supports but everything is good ! Anyone have an idea where i have to search ? Thanks.

13

i listen the sammichSid, output volume is correct but after few seconds volume is very very low

* please give us the specs of your new psu

* photos taken from the soldered pcb would help us, too

* if you are experiencing “mono” output, exchange the sids and check if the “mono” output comes from the other channel afterwards

14

Ok,

About psu :

voltage output is 12,40 V DC . I have checked into sid pin and i have that voltage.

I have tried with 6582 SID and i have the same problem.

I had a correct volume during 2 or 3 seconds the first time that i have power on with 6581 sids and after that i always have low volume into output !

I have removed 6581 and put 6582 and i have the same problem : low output volume.

I havn’t tried with one 6581 ! always with 2 sid’s. I will try tonight !

Thanks Hawkeye.

15

* please give us the specs of your new psu

The current rating is also relevant, please tell us that as well.

Are you using a cable with a stereo jack?

With all the sid type switching make sure you don’t accidentally forget to correct the jumpers every time you do it, or you’ll end up feeding a 6582 with 12V…

16

About rate if my memory doesn’t fail it’s 1.33 A !

About jumpers, i take care a lot about that, to be sure that i don’t make a mistake !

About 6581 using voltage : 12.46 V is ok for 6581 ? it’s not too high in regard of 12 V reference ?

17

12.46V is well within spec (it’s only 4% off), 1.33A is enough as well.

Are you using a cable with a stereo jack?

18

About cable, yes it’s stereo jack !

19

can you remove the sids and install and run the testtone app (available from the mios8 download page on ucapps.de)?

when you run it, is there still only output on one channel and is there still a drop in volume after a few seconds?

bye,

peter

20

One thing Hawkeye, i had during 3 second normal volume, only one time the first time i have power on it and now i’ve got always low volume. Even if i power off and start again after i’ve got always low volume output and same thing with 6582 sid’s.

I will try testtone app !