Hmmm...
There are likely to be two problem areas-
1) construction
2) interface.
1) you seem think you have this sorted. In fact, it is very unlikely that
any components were damaged at any stage, short of doing something
catastrophic like reversing the power supply. There may however still be
construction errors. For example, if an alternate type of transistor was
used, the collector and emitter connections may be the other way around to
what is shown on the PCB.
2) The SAW output is the main output. If it is excessively quite, either
there is either
2a) a construction problem (see reversed transistors) or
2b) an inadequate signal being fed into the device. This wants a sawtooth
wave that is in the area of 5 to 10 volts in hight, before attenuation (via
the pot). It seems to me that you may be feeding it a signal that is simply
too weak. In that case, see the gain stage of the stomp-box adapter to boost
your signal level. (or another suitable pre-amp)
Ken
Ken Stone sasami@... or sasami@...
Modular Synth PCBs for sale <http://www.blaze.net.au/~sasami/synth/>
Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>
There are likely to be two problem areas-
1) construction
2) interface.
1) you seem think you have this sorted. In fact, it is very unlikely that
any components were damaged at any stage, short of doing something
catastrophic like reversing the power supply. There may however still be
construction errors. For example, if an alternate type of transistor was
used, the collector and emitter connections may be the other way around to
what is shown on the PCB.
2) The SAW output is the main output. If it is excessively quite, either
there is either
2a) a construction problem (see reversed transistors) or
2b) an inadequate signal being fed into the device. This wants a sawtooth
wave that is in the area of 5 to 10 volts in hight, before attenuation (via
the pot). It seems to me that you may be feeding it a signal that is simply
too weak. In that case, see the gain stage of the stomp-box adapter to boost
your signal level. (or another suitable pre-amp)
Ken
>_______________________________________________________________________
>No discernible change.
>
>(Very prompt again, thanks)
>
>Stuadh
>
>--- In cgs_synth@yahoogroups.com, sasami@h... wrote:
>> Something is amiss. First, try putting a 100n capacitor in
>series with the
>> input. This will get rid of any DC offset that may be upsetting it.
>>
>> If that fails, report back :)
>>
>> Ken
>>
>>
>> >
>> >
>> >I've just completed my first GCS module, hurray. I'm not sure
>if it
>> >works, though. It is the simple wavefolder. Thing is, should
>> >there be large parts of the range that are silent. When you
>turn
>> >the Pot to give the lowest resistance to the incoming signal,
>> >there is some output, but for most of the travel, there is
>nothing.
>> >The SAW out is also particularly quiet. Is this normal? I've
>> >replaced the TL072, both transistors, the pot and I've checked
>all
>> >the resistors are correct. Any ideas
>> >
>> >Yours Aye
>> >
>> >Stuadh
>> >
>> >
>> >
>> >
>> >
>> >
>> >See the following URLS for the CGS Modular Synth home
>page:
>> >Main: http://www.cgs.synth.net/
>> >Secondary: http://otherunicorn.0catch.com/synth/
>> >Yahoo! Groups Links
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>>
>__________________________________________________
>_____________________
>> Ken Stone sasami@h... or sasami@c...
>> Modular Synth PCBs for sale
><http://www.blaze.net.au/~sasami/synth/>
>> Australian Miniature Horses & Ponies
><http://www.blaze.net.au/~sasami/>
>
>
>
>
>
>
>See the following URLS for the CGS Modular Synth home page:
>Main: http://www.cgs.synth.net/
>Secondary: http://otherunicorn.0catch.com/synth/
>Yahoo! Groups Links
>
>
>
>
>
>
>
>
Ken Stone sasami@... or sasami@...
Modular Synth PCBs for sale <http://www.blaze.net.au/~sasami/synth/>
Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>