Cgs synth

> I just finished wiring my Sequential switch and everything looks fine. The
>LEDs cycle according to the clock input and the Reset and direction switches
>work. The problem is that nothing comes out the Output. When I patch the
>output of the switch into the CV input of a VCO it just pitches the VCO a
>few octaves up but there are no steps. It just stays on one note and
>tweaking the pots does nothing. Any ideas what is wrong? Have I overlooked
>something?
>
>Thanks
>pete
>
>--
>http://www.myspace.com/23isgood
>
>
>[Non-text portions of this message have been removed]
>
>
>
>The CGS Modular Synth home page: http://www.cgs.synth.net/
>
>Yahoo! Groups Links
>
>
>
>

On 2/8/07, sasami@... <sasami@...> wrote:
>
> Yes, you've probably made an error or two in construction. If everything
> seems right, solder a 47pf capacitor between pins 1 and 2 of the TL072,
> and
> another between pins 6 and 7.
>
> Ken
>
> > I just finished wiring my Sequential switch and everything looks fine.
> The
> >LEDs cycle according to the clock input and the Reset and direction
> switches
> >work. The problem is that nothing comes out the Output. When I patch the
> >output of the switch into the CV input of a VCO it just pitches the VCO a
> >few octaves up but there are no steps. It just stays on one note and
> >tweaking the pots does nothing. Any ideas what is wrong? Have I
> overlooked
> >something?
> >
> >Thanks
> >pete
> >
> >--
> >http://www.myspace.com/23isgood
> >
> >
> >[Non-text portions of this message have been removed]
> >
> >
> >
> >The CGS Modular Synth home page: http://www.cgs.synth.net/
> >
> >Yahoo! Groups Links
> >
> >
> >
> >
> _______________________________________________________________________
> Ken Stone sasami@...
> Modular Synth PCBs for sale <http://www.blaze.net.au/~sasami/synth/>
> Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>
>
>
>
> The CGS Modular Synth home page: http://www.cgs.synth.net/
>
> Yahoo! Groups Links
>
>
>
>


--
http://www.myspace.com/23isgood


[Non-text portions of this message have been removed]

> Well I tried the capacitors but it didn't do anything. What are the
>capacitors for? Is there a certain part of the circuit I should look at for
>errors? Also the VCO pitches up quite a few octaves when I use my XR VCO's.
>When I try my Oakley and MOTM VCO's I cant even hear them since they go so
>far up.
>
>thanks
>pete
>
>On 2/8/07, sasami@... <sasami@...> wrote:
>>
>> Yes, you've probably made an error or two in construction. If everything
>> seems right, solder a 47pf capacitor between pins 1 and 2 of the TL072,
>> and
>> another between pins 6 and 7.
>>
>> Ken
>>
>> > I just finished wiring my Sequential switch and everything looks fine.
>> The
>> >LEDs cycle according to the clock input and the Reset and direction
>> switches
>> >work. The problem is that nothing comes out the Output. When I patch the
>> >output of the switch into the CV input of a VCO it just pitches the VCO a
>> >few octaves up but there are no steps. It just stays on one note and
>> >tweaking the pots does nothing. Any ideas what is wrong? Have I
>> overlooked
>> >something?
>> >
>> >Thanks
>> >pete
>> >
>> >--
>> >http://www.myspace.com/23isgood
>> >
>> >
>> >[Non-text portions of this message have been removed]
>> >
>> >
>> >
>> >The CGS Modular Synth home page: http://www.cgs.synth.net/
>> >
>> >Yahoo! Groups Links
>> >
>> >
>> >
>> >
>> _______________________________________________________________________
>> Ken Stone sasami@...
>> Modular Synth PCBs for sale <http://www.blaze.net.au/~sasami/synth/>
>> Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>
>>
>>
>>
>> The CGS Modular Synth home page: http://www.cgs.synth.net/
>>
>> Yahoo! Groups Links
>>
>>
>>
>>
>
>
>--
>http://www.myspace.com/23isgood
>
>
>[Non-text portions of this message have been removed]
>
>
>
>The CGS Modular Synth home page: http://www.cgs.synth.net/
>
>Yahoo! Groups Links
>
>
>
>

On 2/9/07, sasami@... <sasami@...> wrote:
>
> The caps were to stop the op-amps oscillating, should that have been the
> case. It apparently wasn't.
>
> Pull out the 4051 if it is in a socket. The output should drop to zero. if
> it doesn't, the problem is with the output buffer and the circuitry around
> that - such as the mix input being fed a high voltage or a short
> somewhere.
>
> If it does make a difference, the problem is either the 4051 itself, or an
> error around it.
>
> Ken
>
>
>


[Non-text portions of this message have been removed]

> Ok So I pulled the 4051 out and the output stoped. So its not the output
>buffer. I changed the 4051 for another one and the problem is back. I
>checked the orientation of all the diodes and transistors and they all look
>good. Im stumped.
>
>On 2/9/07, sasami@... <sasami@...> wrote:
>>
>> The caps were to stop the op-amps oscillating, should that have been the
>> case. It apparently wasn't.
>>
>> Pull out the 4051 if it is in a socket. The output should drop to zero. if
>> it doesn't, the problem is with the output buffer and the circuitry around
>> that - such as the mix input being fed a high voltage or a short
>> somewhere.
>>
>> If it does make a difference, the problem is either the 4051 itself, or an
>> error around it.
>>
>> Ken
>>
>>
>>
>
>
>[Non-text portions of this message have been removed]
>
>
>
>The CGS Modular Synth home page: http://www.cgs.synth.net/
>
>Yahoo! Groups Links
>
>
>
>

On 2/9/07, sasami@... <sasami@...> wrote:
>
> Check the voltages around the 4051. Make sure it has it's ground and -Ve
> voltages.
>
> Ken
>
>
>


[Non-text portions of this message have been removed]

>Ok so here are the voltages,
>
>pin 7,8: 2.12v (this should read -.6v?)
>
>pin 16: 14.31v
>
>pin 3: 1.59v (should this read 0v?)
>
>I also checked the voltages at the 2.2k resistors located by the power plug
>and they are reading, 2.12v and this should be at -.6v correct? How do I get
>it to be -.6v? It seems that this is the problem? At the other end of the
>resistors it reads -15v. I checked the voltages at the power supply
>connection and they are correct.
>
>thanks for your help Ken
>pete
>
>On 2/9/07, sasami@... <sasami@...> wrote:
>>
>> Check the voltages around the 4051. Make sure it has it's ground and -Ve
>> voltages.
>>
>> Ken
>>
>>
>>
>
>
>[Non-text portions of this message have been removed]
>
>
>
>The CGS Modular Synth home page: http://www.cgs.synth.net/
>
>Yahoo! Groups Links
>
>
>
>

On 2/9/07, sasami@... <sasami@...> wrote:
>
> Have you used any 74HCxxxx chips? Something is drawing way too much
> current.
>
> Ken
>
>
> >Ok so here are the voltages,
> >
> >pin 7,8: 2.12v (this should read -.6v?)
> >
> >pin 16: 14.31v
> >
> >pin 3: 1.59v (should this read 0v?)
> >
> >I also checked the voltages at the 2.2k resistors located by the power
> plug
> >and they are reading, 2.12v and this should be at -.6v correct? How do I
> get
> >it to be -.6v? It seems that this is the problem? At the other end of the
> >resistors it reads -15v. I checked the voltages at the power supply
> >connection and they are correct.
> >
> >thanks for your help Ken
> >pete
> >
>
>


[Non-text portions of this message have been removed]

> Yes! Im using one for the other 4051. It says on it, CD74HC4051E. Is this
>the problem?
>
>On 2/9/07, sasami@... <sasami@...> wrote:
>>
>> Have you used any 74HCxxxx chips? Something is drawing way too much
>> current.
>>
>> Ken
>>
>>
>> >Ok so here are the voltages,
>> >
>> >pin 7,8: 2.12v (this should read -.6v?)
>> >
>> >pin 16: 14.31v
>> >
>> >pin 3: 1.59v (should this read 0v?)
>> >
>> >I also checked the voltages at the 2.2k resistors located by the power
>> plug
>> >and they are reading, 2.12v and this should be at -.6v correct? How do I
>> get
>> >it to be -.6v? It seems that this is the problem? At the other end of the
>> >resistors it reads -15v. I checked the voltages at the power supply
>> >connection and they are correct.
>> >
>> >thanks for your help Ken
>> >pete
>> >
>>
>>
>
>
>[Non-text portions of this message have been removed]
>
>
>
>The CGS Modular Synth home page: http://www.cgs.synth.net/
>
>Yahoo! Groups Links
>
>
>
>

On 2/10/07, sasami@... <sasami@...> wrote:
>
> Yes, it is MOST DEFINITELY the problem. The 74HC series are 5 volt chips.
> If
> you connect them to 15 volts they either immediately blow up, or if the
> current is limited as it is in this case, they draw what current they can
> to
> the detrement of whatever is going on around them. Make sure you get a
> genuine 4000 series chip.
> These are MC14051 if made by Motorola or most likely CD4051 if made by
> someone else. There will probably be B or something like that after the
> code.
> Never use a 74HC4xxx in any of my designs, unless I specifically give the
> full code number. So far the CGS46 is the only board to use one - a
> 74HC4046.
>
> Ken
>
>


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