Voodoo Main Discussion

[SilverSurfer17]

Thanks for the advice on changing the speaker being brand new that would of been the last thing i checked

[SilverSurfer17]

I tried another 8 ohm speaker turned it on got a 4 second beep left turned on for a minute and only slightly warm so i guess the speaker was bad so one problem solved

[SilverSurfer17]

I found some thats only a 1/2 inch bigger then the 1 inch 8ohm ill do some looking around at old speakers i got and try those with the stock resistor and see what happens with those

[SilverSurfer17]

Im only wanting to use the 8 ohm because of its size the 50 ohm speakers are huge and the 8ohm is waterproof also the 8 ohm is more of a tweeter for higher pitched sounds like beeps the cone was crushed a little when i got it and they are sending another one so ill try changing the resistor and use the new one i dont want to even connect it back to the board again thanks for the help my book should be here by Thursday so i can check all the wave forms and adjust the trimmers

[dfbowers]

[ATTACH]54191[/ATTACH]

Hmm. Haven?t tried just two triggers but the polarity of the main clock is inverted to start with... so I added the 3rd trigger to have an odd number and flip it back. Maybe it doesn?t matter?

[ivconic]

Did you ever figure out what resistor to use on r66 for a 8ohm speaker i think thats why my speaker got hot ?

Speaker is getting hot?
What about 2N3904 transistor?
Is it getting hot too?
If not; than replace the speaker.
If yes; than replace R66 33R with 47R to 100R.
Pick value that cools down the transistor and yet to keep audio volume at acceptable level.
Bare speaker on the table will always sounds weaker than when is mounted in a box.
I got impression that audio is too loud and therefore R66 can be of higher resistance.
Best to fit individual hearing is to mount speaker in "resonant" enclosure, box, and than to adjust R66.
Sometimes it takes 10 omhs more or less to cool it down completely or to burn it totally.
That's why is always better to use higher resistance speakers; 16-64 ohms.

[surfdetector]

Did you ever figure out what resistor to use on r66 for a 8ohm speaker i think thats why my speaker got hot ?

See post #414

[SilverSurfer17]

Did you ever figure out what resistor to use on r66 for a 8ohm speaker i think thats why my speaker got hot ?

[ivconic]

For those who still want to make pcb; this is by now the latest version:

[ivconic]

Fortunate coincidence in my drawing is that i did lot of wire jumpers on the top layer and now it will need not much of a surgery to correct those.
Only one track have to be cut actually, the one which goes from pin 2. to trimmer.
Jumper that goes from pin 6. omitted now and trimmer side soldered to close trace that goes from pin 5.
C26 soldered only with one pin to pcb, other pin in the air and with wire connected to pin 6.
Wire jumper that goes from pin 4. omitted. Pin 5. at 4066 connected to pin 2. at 40106 with short wire.
C25 omitted.
And that's all from the "surgery".

[6666]

[ATTACH]54191[/ATTACH]

Love it

[ivconic]

Ohh, sorry to everyone, you rigth!
I meant: R54 (22K) must be connected to pin 1 of U29 (40106).
About: "-C25 and the third gate of 40106 don't should be needed if modification at post #956 will be made" I meant that if the modification described at post #956 will be made, probably C25 and the third gate of 40106 will no needed anymore: a direct connection between pin 2 of U29 and pin5 U2 will be required instead.

[SilverSurfer17]

I guess by the laugh it must not be the same trying to get the best tuning you can as a Tesla coil ?

[SilverSurfer17]

Thanks yeah i saw that was the first thing inline of the output socket and figured that was the first place to start ill have to hunt down my soldier wick and pull it out and check it thanks

[MartinB]

Yes i was i used what i found in a waterproof speaker and in the ohm range that was listed but that still doesn't explain 12 volts on the positive side of the speaker i assume it fried that speaker also if it is a short or wrong installed part it could of taken out something else i have the 5 volts on both test point 14 and 15 and have a wave form coming out the TX but im as far as i can go until i get some more expendable cash im bust for awhile after having to buy the parts the oscilloscope and new multimeter i need to get Georges book a pole a coil a Arm rest coil cable and some other minor parts plus whatever might of toasted

Check that Q12 is still OK