Cgs synth

> 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
>
>
>
>
>

> > Did you use beads
> > or 10R resistors as power rail isolation?
>
> Ferrite beads, but the ones where the wire goes through the bead
> multiple times. I have some plain ones lying around that I could use.
>
> > It sounds like the LF356 are are drawing too much power for some
> > reason. Not a bad batch per chance?
>
> I've ordered some new ones just to make sure.
>
> Louis
>

--- In cgs_synth@yahoogroups.com, Louis van Dompselaar <louis@...> 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,
> 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. How can this signal
> get into the outputs?
>
>
> Louis
>

>I'm having the EXACT same problem as described in the post below.
>Louis, did you fix the problem? I tried the suggestions in the
>follow-ups but they didn't help with this problem. I'm using LF356H
>made by National with these markings: H24XX.
>
> I'm putting it on the breadboard to see if I can work this out, but
>if you (or someone) already has a fix...I'd love to here it! Also,
>more suggestions and/or guesses would be helpful, too.
>
>Note: I swapped the 4052 with another brand and got no change. The
>LF356 are soldered in place so I haven't swapped them out yet. I only
>have one make of the 4024 so I can't swap that yet.
>
>
>Thanks,
>p.
>
>
>--- In cgs_synth@yahoogroups.com, Louis van Dompselaar <louis@...> 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,
>> 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. How can this signal
>> get into the outputs?
>>
>>
>> Louis
>>
>
>
>
>
>The CGS Modular Synth home page: http://www.cgs.synth.net/
>
>Yahoo! Groups Links
>
>
>
>

>At 09:10 PM 6/3/2007, sasami@... wrote:
>
>>It may not be coming in through the power rails from outside, but rather
>>being introduced onto the power rails by the 4024 itself. The first thing to
>>do is to solder a 10uf to 100uf electro directly across the power pins of
>>the 4024. ...
>
>uF or nF?
>--
>john
>
>
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>
>
>
>
>The CGS Modular Synth home page: http://www.cgs.synth.net/
>
>Yahoo! Groups Links
>
>
>
>