Commodore 64 - ferarri edition

[djjonnyjams]

I'm still modding commodores to raise funds for my midibox projects.

Finished this one last weekend:

Now on Ebay:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MESELX:IT&item=200341152795

[Smithy]

http://www.youtube.com/watch?v=X0VtRN46zqo

Love the feedback mod demonstration.

Man i cant wait to mess with feedback when i get my sid finished in like 300 years.

[joewhat]

haha,,, ooohhhh shit,, ! crazy..

[Wilba]

You should ship worldwide - there are probably more SID fanatics outside the U.S. than inside.

[djjonnyjams]

I DO ship worldwide.....

Maybe I should state that in the listing.

Yeah, feedback is great on the 8580's, and probably just as good on 6582, but it's a worthless mod for 6581. I can't wait to get my new 6582's, I'm definitely dropping one in a commodore. 

[lief138]

I just got done watching the video posted. Just one question. Is the gaint ashtray and also the weed pipe included?

[Goblinz]

I just got done watching the video posted. Just one question. Is the gaint ashtray and also the weed pipe included?

Don't be silly.... that's a crack pipe!

[djjonnyjams]

Sure, I'll throw in the ashtray, but the pipe is strictly for tobacco...

[/tilted/]

Sure, I'll throw in the ashtray, but the pipe is strictly for tobacco...

All the holmies are doing it...

[img width=350]http://zatetic.files.wordpress.com/2008/01/sherlockholmes_wrong.jpg

[Smithy]

All the holmies are doing it...

LOL

[Smithy]

LOL

Hehehe, yo wilba? whats up with the phantom edit on my post?  ;)

BTW, Mr. Jams, would be so kind as to tell me where you got that 500k potentiometer with button?

Cant seem to find one on ebay since potentiometer button doesnt reveal anything!

Cheers

[Smithy]

I think i found a few:

http://shop.ebay.ie/items/_W0QQ_dmptZUKQ5fGuitarQ5fAccessories?_nkw=potentiometer+push&_sacat=0&_trksid=p3286.m270.l1313&_odkw=potentiometer+switch&_osacat=0

Try getting them in dual gang, and getting them to fit in an mb-6582 though!

[Wilba]

With my suggested wiring of feedback pots for MB-6582, you don't need a switch, unless you want to add audio in jacks.

[Smithy]

With my suggested wiring of feedback pots for MB-6582, you don't need a switch, unless you want to add audio in jacks.

Ill be wanting audio in alright, i might as well use that jack plug shown in the alphamod for when i wont be using the audio in. Cheers.  :)

[djjonnyjams]

Hehehe, yo wilba? whats up with the phantom edit on my post?  ;)

BTW, Mr. Jams, would be so kind as to tell me where you got that 500k potentiometer with button?

Cant seem to find one on ebay since potentiometer button doesnt reveal anything!

Cheers

Yes, they can be purchased at Radioshack in the United States, if you can't find a local supplier, you can order through their website. Sorry it took so long to reply, I haven't been following my old posts.

Do a search for 500k pot with push button toggle. "Toggle" is the key word here.

[djjonnyjams]

Ill be wanting audio in alright, i might as well use that jack plug shown in the alphamod for when i wont be using the audio in. Cheers.  :)

Ok, I read your suggested wiring for feedback pots:

"Ground goes to left pin (facing towards pot shaft, pins pointing down). Output goes to right pin (facing towards pot shaft, pins pointing down)."

This would be fine with a 500k pot, and really, I feel foolish for not hooking it up that way in the first place, but now I'm using 100k pots to get a more gradual taper from dry to feedback, my guess is that hooking them up your way will make my output quieter since 100k is not enough to kill the input completely. In this case I'm just using a 100k stereo pot, and 1 dpdt mini toggle switch.  That is my reccomendation for your commodore.

[Wilba]

This would be fine with a 500k pot, and really, I feel foolish for not hooking it up that way in the first place, but now I'm using 100k pots to get a more gradual taper from dry to feedback, my guess is that hooking them up your way will make my output quieter since 100k is not enough to kill the input completely. In this case I'm just using a 100k stereo pot, and 1 dpdt mini toggle switch.  That is my reccomendation for your commodore.

It doesn't matter if it's 100k or 500k, they both should have the same effect, taper, whatever... since my wiring is as a voltage divider, not as a variable resistor inserted in series with the audio output.

[djjonnyjams]

Yes, you are absolutely correct. I hooked up my 100k stereo feedback pot as you suggested last night, and it works beautifully. I wish I could find a quad-pot so I could set it up to lower the final output volume as feedback is being applied. Any ideas on a simple circuit that would limit the output so I don't have to turn my mixer down while applying feedback?

[Wilba]

You could use one dual-gang pot per SID... one pot for feedback, one for volume. The volume pot would then go between the SID output and the audio jack.

i.e. if the feedback pot is wired A=SID output, B=SID input, C=ground, you want the volume pot wired A=ground, B=audio out jack, C=SID output.

That way, if the feedback pot is fully turned to ground (no feedback), the volume pot would be at max volume.

You can then insert a resistor in between pin A and ground, to adjust the minimum volume level when at full feedback. If you wanted half volume at max feedback, you'd use a resistor of the same value as the pot. BTW this is using linear pots so it might not be the right amount of volume at each feedback setting.

[djjonnyjams]

I have thought about that as well. I wasn't completely sure about the wiring. I'll give it a shot on one of my commodores with a single SID. My goal is to drill less holes in my beloved commodores, so I'll still be searching for quad pots, but your wiring instructions were very helpful. Thanks!