Powerpak extra audio not working (on famicom) *SUCCESS*

Jeroen · Post by **Jeroen** » Sat Dec 20, 2008 1:04 pm

I'm using a famicom av. I solder a 47k resistor on my adaptor from pin 51 (the audio pins on the famicom side lead there) to pin 54 However for some reason this is not working. Can anybody help me?

edit: video on how to do it http://www.youtube.com/watch?v=WsfUviciKxs

Jeroen · Post by **Jeroen** » Sat Dec 20, 2008 1:14 pm

Bridging it worked altough it totally drowns out everything.

edit: so ya now the problem is.....what resistor should I use. I dont have a pot ready. I suspect the reason it doesnt work with the same value is that supposedly exp sound is louder on the av famicom. Anyone wanna help out?

Jeroen · Post by **Jeroen** » Sun Dec 21, 2008 7:34 am

Jeroen wrote:Bridging it worked altough it totally drowns out everything.

edit: so ya now the problem is.....what resistor should I use. I dont have a pot ready. I suspect the reason it doesnt work with the same value is that supposedly exp sound is louder on the av famicom. Anyone wanna help out?

edit2: bridging doesnt seem to work now either...altough it could've been a cold joint. But maybe something inside the av fami fried. I dont see how that is possible though since I have normal audio and the extra audio is mixed inside the cart :-/ .

Jeroen · Post by **Jeroen** » Sun Dec 21, 2008 8:27 pm

Well turns out I had the wrong pin so the audio in stil works. Problem reallly is I get either the expansion sound or the famicom sound....theres no "in between" Anyone have an idea why?

BMF54123 · Post by **BMF54123** » Sun Dec 21, 2008 9:05 pm

I'm pretty sure mixing the two on a Famicom requires more than just a resistor, though I know virtually nothing about electronics or audio circuitry so I'm in the same boat as you.

Jeroen · Post by **Jeroen** » Sun Dec 21, 2008 9:16 pm

Ok I think I got this figured out......just need values. Cut the bridged pins on your adaptor. Where the audio enters the cart you put a resistor, connect this to the other pin. Now use a resistor to connect pin 54 (or 51) to the point where the audio enters the adaptor. I suspect we stil have to use a 47k resistor for the powerpak output. Now just the one bridging the two pins.

Jeroen · Post by **Jeroen** » Sun Dec 21, 2008 10:01 pm

Heres some irc goodies
<@LordNLptp> you should put for a powerpak to fami adapter:
<@LordNLptp> 15k with 10nf cap in series, the 15k resitor attached to the audio in pin of the cart (where the fami audio comes in)
<@LordNLptp> then connect to that the powerpak pin/exp pin 6 (you MAY need to put the powerpak pin/exp pin 6 through a similar resistor-then-10nf-capactor thing that the audio in pin goes through, see mmc5.3 pin))
<@LordNLptp> finally run both to a 10k resistor, and run the out of that to the audio out pin
<@LordNLptp> you may need to do some value tweaking with the resistors later to make everything play at the appropriate volume
<@loopy_> yeah... I don't know if powerpak's output level matches mmc5
<@LordNLptp> but 15k-10nf for powerpak and 15k-10nf for fami audio, then a 10k between that and the fami aud out pin
<@LordNLptp> replace the 15ks with 20k rotary trimpots and tweak to your hearts desire
<@LordNLptp> the 10k should be correct though
<@LordNLptp> since both the nes and fami circuits need it
<@LordNLptp> it MIGHT not really be needed, but i don't think it will hurt
<@LordNLptp> what you do need are those two capacitors
<@LordNLptp> those are the real key to the whole mixing circuit

however I couldnt get the in and out properly cut so thats a bit of a problem (couldnt get them cut on my adaptor)

BMF54123 · Post by **BMF54123** » Sun Dec 21, 2008 10:24 pm

Bleh...I can't follow that.

I don't suppose a quick visual diagram is too much to ask?

Jeroen · Post by **Jeroen** » Mon Dec 22, 2008 4:22 am

Ok heres what I understood of the instructions

remember you might have to pump the powerpak output to a similair reistor cap setup (and its probably better to use a 20k pot instead of a 15k resistor
)

Jeroen · Post by **Jeroen** » Mon Dec 22, 2008 12:40 pm

Just got a message from lord. Its probably better to put a 10k-15k resistor on the pin leading to pin 45. (optional but probably better)

edit: the caps shouldnt be polarized either but ceramic. Sorry wil update the schematic later on.

kyuusaku · Post by **kyuusaku** » Mon Dec 22, 2008 1:53 pm

Maybe better:

Jeroen · Post by **Jeroen** » Mon Dec 22, 2008 6:11 pm

Talked to Kevin Horton (aka kevtris) He said that it should work with just bridging pin 45 and 46 with a 10k resistor and having a pot/resistor from the powerpak down to pin 46 (the one where the sound goes back into the fami)

Jeroen · Post by **Jeroen** » Wed Dec 24, 2008 6:35 pm

SUCCES! I used a 10k resistor solder over pin 45 and 46 (after cutting their connection) and used a 100k pot between the powerpak audio out pin and pin 46 on the famicom

BMF54123 · Post by **BMF54123** » Thu Dec 25, 2008 2:37 am

Yay! That's nice and simple, and I have the parts!

...aside from the pot, that is. Is it really necessary, or could I just go with a fixed resistor value?

Jeroen · Post by **Jeroen** » Thu Dec 25, 2008 4:43 am

Well it only works if my pot is turned from here to here. Otherwise one of the channels takes over. If my multimeter had batterys I'd measure.

edit: btw I didnt use a 10k resistor but rather a 12k (had that laying round and couldnt find my 10k's) so for future reference in case you use the same resistor value as me.......might be a good idea to use 12k. (so the audio is evenly mixed if you use my values)

edit2: http://www.youtube.com/watch?v=SQ0xF_1_Gq8 Video time

nesdev.org

Powerpak extra audio not working (on famicom) SUCCESS

Powerpak extra audio not working (on famicom) SUCCESS