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Hello... i know i'm late to the party but is there anyway I still might be able to order one?   _Diode diodemilliampere.bandcamp.com

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Well it took two late nights but my sammichFM now powers up and shows Ready! I'll be trying to load the firmware today, though I haven't been brave enough to supply power to the FM chips just yet.

Wilba, you did a fantastic job with the kit! It has all the wonderful details that made building it fun and even relaxing. The little things, like having the header pins snap-in (which meant I didn't have to take the header down, tack it, then burn my finger while trying to adjust it so it's vertical) and having snap-in sockets. Very cool, and the LCD looks sexah too!

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WOW... Impressive..

Congratulation for this beautifull little box.

I'll definitely have to order one... maybe next month.

I'm surprised to read in the feature list:

"4 simultaneous instruments of 6 voice polyphony each, plus drum kit. Each voice is a 4 operator waveform."

That makes 24 voices of 4 operators + drum kit ??

That sounds much more than in the opl3 spec:

"6 four operators melody sounds + 3 two operators melody sonds + 5 rythm sound".

Did i miss something ?

Thanks,

Xavier

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  • 3 weeks later...

I think there is an error in the voltage testing picture (the one with the colored dots) for the base PCB. Pin 2 of IC9 (2nd from the top on the left row) is connected to GND and not +5V. I noticed that during the voltage/continuity testing phase and looked it up in the PCB layout PDF.

Regards

trilader

Edited by trilader
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  • 3 weeks later...

That looks like a switched PSU to me (though I'm having Google Translate fail). You'd want a linear regulated PSU as the best option typically. Switchmode will work, but can induce noise (and usually causes a big flame-war here on the forums about half the time it's mentioned :) )

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@m00dawg: Well, the description says "stabilisiert" i.e. "stabilized", which to me indicates that it's a transformer based psu. Do switch-mode PSUs need to be stabilized? Probably not. But I'm not sure about this. The product description is quite poor.

@Hawkeye: The sammichFM draws about 200mA according to the sammichFM building guide. If 1A is provided only in the lower voltage range, I guess at least 200mA should be provided at 9V. But still guessing...

@all: Any recommendations for a transformer based (linear) power supply here in Germany/Europe? :clover:

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Regarding a linear psu, you can also build them yourself (but be careful with the high voltages) for low credits.

http://sound.westhost.com/power-supplies.htm for an overview

Coils are available at Reichelt "Flachtransformatoren" for 5-8€ a piece.

Linear PSUs are difficult to get (or expensive, 80€+), because they are considered special nowadays, switching PSUs normally do the job more efficiently (albeit for a few audio audio people who hear ´em :-)).

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@imp: We sure have, but I'm too lazy to visit one. Why leave the house if the mailman can bring me one ^_^

@Hawkeye: You have a great DIY-attitude :-) But with my experience, I will likely blow the sFM into pieces instead of powering her. Therefore I will stick with my switch-mode PSU first and see if induced noise will occur. If so, I'll try the Pollin PSU and report on the forum.

Edited by kristal=
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Regarding a linear psu, you can also build them yourself (but be careful with the high voltages) for low credits.

http://sound.westhost.com/power-supplies.htm for an overview

Coils are available at Reichelt "Flachtransformatoren" for 5-8€ a piece.

Linear PSUs are difficult to get (or expensive, 80€+), because they are considered special nowadays, switching PSUs normally do the job more efficiently (albeit for a few audio audio people who hear ´em :-)).

That's usually my favorite option, though for the Sammich I didn't want a huge power brick as I can't build my own PSUs smaller than a commercial solution. Plus, there's that epic thread about adding circuit protection stuff and all that so I figured the Sammich might be best served via a $20 regulated power brick someone else built.

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I haz sammichFM too! I just picked it up today from the german "Zoll". Seems everything to be there. Now please...another batch of sammichSIDs...my 8580s are freezing alone in the box... :brr: ;)

Maybe some kaffeSEQ too? :tongue:

Edited by pulsn
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  • 4 weeks later...

The PSU from Pollin turned out as a switch-mode PSU from goobay. But I do not notice any noise. At least when no sound is generated. In contrary to my sammichSID, where I always noticed a slight hum even when no sound was generated. So my question is: how do I have to understand the sentence "They generate far too much noise in the audio." from the building guide? Only noise within the sound generation or a general noise on the audio outputs?

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