The quiet sid 2 problem is very likely the transistor. I believe you should be using a 2n2222. Keep in mind 2n2222A transisters are not the same as 2n2222.
The glitch you are describing leads me to believe it is a faulty sid.
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Yeah, sid#2 is bunk, but they're sending me a replacement.
So I decided to go ahead with the rest of the mods while I wait for the sid#2's replacement to get here. I used the "no dead spot" pot mod, added RCA in's and out's, added the feedback circuit, added some switches, and the green led. Everything is working great! All I need to do is pop in the new sid when it gets here and hopefully it's done!
This site was a great help:
http://nealbeardahm.blogspot.com/2012/0 … -mods.html
Next I want to modify my other 64, a breadbin with a 6581, for use specifically with Cynthcart.
A million thanks to TylerBarnes for your help!
Here she is:::
:)
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Milwaukee, WI
Head's up - there are many, many, MANY fake SIDs circulating. I find it a bit odd that someone would be willing to offer a replacement so quickly. This might even be part of the reason the previous SID was jacked.
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Dallas, Texas
Awesome! looking good RJL! I was glad to be some help. Good luck with your SID endeavors!
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how to hook up an LFO::
1) make your LFO circuit, make sure it works on 5V+/Gnd
2) hook your LFO up to the power coming out the joystick ports
-> pin 7 = 5V+
-> pin 8 = GND
connect the output of your LFO into a voltage regulator (just for safety)
connect the output of your voltage regulator into pin 5 or 9 (depending on what you want the LFO for, filter or pulse width
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Awesome, thanks WAX! I juuuuuuust finished my C64 tonight and didn't see this until just now... But I might have to open it again at some point and add the LFO...
This one's strictly for Cynthcart use: audio in, ground switch, feedback circuit, 2 "no dead zone" pots, pot disable switch, & orange led.
Last edited by RJL (Oct 17, 2014 10:39 am)
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So I just happened to have most of the parts to make the LFO on hand, and made a quick trip to Radioshack for some more solder and a voltage regulator.
The LFO has controls for depth, shape (triangle to square), and rate. An orange led flashes with the rate. You can switch between modulating the filter cutoff, or modulating the pulsewidth of the square wave.
I highly recommend the LFO mod, it really adds a new dimension to Cynthcart! Thanks WAX
Last edited by RJL (Oct 20, 2014 3:28 pm)
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Glad you like the LFO idea RJL. I actually don't play C64 in any bands - but I've modded them for one of the members (spiritbunny.bandcamp.com has some tracks), but so far we haven't really used the LFO part.
What LFO circuit did you use?
I used a 555 LFO (see - http://www.mssiah-forum.com/viewtopic.php?id=1372) but I'm not overly fussed by it as a circuit. In another project I recently made this LFO (
) and I like it better, so I'm thinking to get in and add that instead
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I used this one from Casperelectronics... It works so well that I've used it in several other projects too now.
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hmm. me too. perhaps i should have another look. I've used them quite a bit too, but am generally unhappy with them. i don't like the shape/depth playing you have to do to get what you want
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I might as well share it in this topic also, almost finished my C64c mod, still some small problems to fix but 98% working and playable!
Single SID atm. , built in Behringer V-Tone (AMPSIM/DI box) , Internal screen, 555 LFO & Modded MIDI keyboard!
I wanted to do something different in my mod and i think i succeeded 
