A modification recommended in the Notes is to add a 100 ohm resistor
between pin 1 of TL074d and pin 3 of 4052. This was suggested if you
use a larger capacitor for CX. I used 100nf caps and did add the 100R.
Note: These are special 100nf caps, WIMA mixed film type, Mouser #
MKP2-.1/250/5
I also added 100nf bypass caps on the two power pins of the TL071 that
buffers the clock input. That should help protect against the clock
feeding back into the power supply.
Richard Brewster
http://www.pugix.com
Louis van Dompselaar wrote:
between pin 1 of TL074d and pin 3 of 4052. This was suggested if you
use a larger capacitor for CX. I used 100nf caps and did add the 100R.
Note: These are special 100nf caps, WIMA mixed film type, Mouser #
MKP2-.1/250/5
I also added 100nf bypass caps on the two power pins of the TL071 that
buffers the clock input. That should help protect against the clock
feeding back into the power supply.
Richard Brewster
http://www.pugix.com
Louis van Dompselaar wrote:
> Hi list,
>
> I'm running into some small problems with my ASR. It is working as it
> should, apart from two things:
>
> First, the LF356 are running warm, which usually only troubles me if the
> circuit doesn't work either. Should they get warm if it works fine?
>
> Second, the outputs step up and down by around 10mV in sync with pin 12 of the 4024.
> With no input, it steps between 90mV and 100mV.
>
> This stops if I pull out the clock, so it's not coming in through the
> power rails. This pcb trace is pretty small and I can't see anything
> wrong along it. Anyone ever seen this before? How can this signal
> get into the outputs?
>
> When the clock is off, the outputs are rock solid. No drooping whatsover,
> it can hold the input seemingly forever. I got some big bright yellow
> polypropylene capacitors off eBay that work great. It turned out to
> be quite hard to get decent sized 47nF polypropylene over here...
>
> Louis
>
>
>
> The CGS Modular Synth home page: http://www.cgs.synth.net/
>
> Yahoo! Groups Links
>
>
>
>
>