Cgs synth

>I just finished the synthacon filter and I get a loud hum at the
>output. The noise can be filtered and resonance can be applied to
>it. Its not really noise, but a low E.
>
>If I attach an audio source to the BP and HP inputs, I can hear the
>audio as well. I dont hear audio when I plug it into the LP. The hum
>may just be drowning it out (but I dont think its there).
>
>Any ideas on what could be causing it?
>
>Thanks
>Scott
>
>
>
>
>
>
>The CGS Modular Synth home page: http://www.cgs.synth.net/
>
>Yahoo! Groups Links
>
>
>
>
>
>
>

--- In cgs_synth@yahoogroups.com, sasami@... wrote:
>
> A poor power supply is the probable cause.
>
> Ken
>
> >I just finished the synthacon filter and I get a loud hum at the
> >output. The noise can be filtered and resonance can be applied
to
> >it. Its not really noise, but a low E.
> >
> >If I attach an audio source to the BP and HP inputs, I can hear
the
> >audio as well. I dont hear audio when I plug it into the LP.
The hum
> >may just be drowning it out (but I dont think its there).
> >
> >Any ideas on what could be causing it?
> >
> >Thanks
> >Scott
> >
> >
> >
> >
> >
> >
> >The CGS Modular Synth home page: http://www.cgs.synth.net/
> >
> >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/>
>

>I dont know what is wrong w/ this now, but smoke just came out of
>the tl071!! It's been working fine for an hour while Ive been
>testing it.. other than the hum.
>
>
>--- In cgs_synth@yahoogroups.com, sasami@... wrote:
>>
>> A poor power supply is the probable cause.
>>
>> Ken
>>
>> >I just finished the synthacon filter and I get a loud hum at the
>> >output. The noise can be filtered and resonance can be applied
>to
>> >it. Its not really noise, but a low E.
>> >
>> >If I attach an audio source to the BP and HP inputs, I can hear
>the
>> >audio as well. I dont hear audio when I plug it into the LP.
>The hum
>> >may just be drowning it out (but I dont think its there).
>> >
>> >Any ideas on what could be causing it?
>> >
>> >Thanks
>> >Scott
>> >
>> >
>> >
>> >
>> >
>> >
>> >The CGS Modular Synth home page: http://www.cgs.synth.net/
>> >
>> >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/>
>>
>
>
>
>
>
>
>
>The CGS Modular Synth home page: http://www.cgs.synth.net/
>
>Yahoo! Groups Links
>
>
>
>
>
>
>

--- In cgs_synth@yahoogroups.com, sasami@... wrote:
>
> See previous answer. You are probably pusing over 30 volts into it
due to a
> failed regulator.
>
> Ken

From: Ryan Williams
To: cgs_synth@yahoogroups.com
Sent: Tuesday, February 07, 2006 10:51 PM
Subject: Re: [cgs_synth] Re: Synthacon filter - hum


c10h14no2i wrote:
> It is possible that while I was messing w/ it on my desk, trying to
> find the source of the hum that it touched a piece of metal and
> shorted something out.

I've done that before, with scraped leads, and meter or scope probes. I
also had a board that worked for about a week and a half, then a short
apeared and fried a few chips. It could be from a small metal burr that
almost was shorted before (probably not on ken's boards), or from some
solder that wasn't quite shorted but is now.

> I checked the voltage. I checked that +, -, and ground are all
> connected properly. I checked for any soldering mistakes, or any
> other scrap of solder or anything I could have shorted something out.
> The IC is still getting hot very quickly

If the IC let out smoke, replace it. I've noticed that sometimes they
will still heat up after that and sometimes not.

blowing the opamp does sound like a power problem.

-ryan


The CGS Modular Synth home page: http://www.cgs.synth.net/




SPONSORED LINKS Sampler Electronic instrument Synthesizer
Music synthesizers Synthesizer music Electronic music


------------------------------------------------------------------------------
YAHOO! GROUPS LINKS

a.. Visit your group "cgs_synth" on the web.

b.. To unsubscribe from this group, send an email to:
cgs_synth-unsubscribe@yahoogroups.com

c.. Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.


------------------------------------------------------------------------------



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

From: Ryan Williams
To: cgs_synth@yahoogroups.com
Sent: Tuesday, February 07, 2006 10:51 PM
Subject: Re: [cgs_synth] Re: Synthacon filter - hum


c10h14no2i wrote:
> It is possible that while I was messing w/ it on my desk, trying to
> find the source of the hum that it touched a piece of metal and
> shorted something out.

I've done that before, with scraped leads, and meter or scope probes. I
also had a board that worked for about a week and a half, then a short
apeared and fried a few chips. It could be from a small metal burr that
almost was shorted before (probably not on ken's boards), or from some
solder that wasn't quite shorted but is now.

> I checked the voltage. I checked that +, -, and ground are all
> connected properly. I checked for any soldering mistakes, or any
> other scrap of solder or anything I could have shorted something out.
> The IC is still getting hot very quickly

If the IC let out smoke, replace it. I've noticed that sometimes they
will still heat up after that and sometimes not.

blowing the opamp does sound like a power problem.

-ryan


The CGS Modular Synth home page: http://www.cgs.synth.net/




SPONSORED LINKS Sampler Electronic instrument Synthesizer
Music synthesizers Synthesizer music Electronic music


------------------------------------------------------------------------------
YAHOO! GROUPS LINKS

a.. Visit your group "cgs_synth" on the web.

b.. To unsubscribe from this group, send an email to:
cgs_synth-unsubscribe@yahoogroups.com

c.. Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.


------------------------------------------------------------------------------



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



The CGS Modular Synth home page: http://www.cgs.synth.net/

Yahoo! Groups Links










what part of sin (w + i sin (w r)) do you not understand?
[reverse engineers]


---------------------------------
Do you Yahoo!?
Yahoo! Music: Check out the gig guide for live music in your area

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

From: Edward r Jones
To: cgs_synth@yahoogroups.com
Sent: Tuesday, February 07, 2006 11:40 PM
Subject: Re: [cgs_synth] Re: Synthacon filter - hum


You're not hardcore about electronics until you have a few burns here and there from chips, or at least from a soldering iron.

re: smoke
Last year our teacher pulled something on all the noobs in our class that always makes me chuckle. He explained how electronics components have smoke in them, and that it's put in at manufacture, and, once the smoke is out, you can't put it back in again, no matter how hard you try. One kid took the bait, and asked what the smoke was made from.

-ed

Haven Sole <haven_sole@...> wrote: yeah, i had the same exact problem when i built my first one. this is why i put a socket in the ic slot, so if i do burn one out, which has happened more than a few times, i can easily replace it. and yes, the ic did still heat up. one time to point it almost gave me a 1rst degree burn on my finger.
----- Original Message -----
From: Ryan Williams
To: cgs_synth@yahoogroups.com
Sent: Tuesday, February 07, 2006 10:51 PM
Subject: Re: [cgs_synth] Re: Synthacon filter - hum


c10h14no2i wrote:
> It is possible that while I was messing w/ it on my desk, trying to
> find the source of the hum that it touched a piece of metal and
> shorted something out.

I've done that before, with scraped leads, and meter or scope probes. I
also had a board that worked for about a week and a half, then a short
apeared and fried a few chips. It could be from a small metal burr that
almost was shorted before (probably not on ken's boards), or from some
solder that wasn't quite shorted but is now.

> I checked the voltage. I checked that +, -, and ground are all
> connected properly. I checked for any soldering mistakes, or any
> other scrap of solder or anything I could have shorted something out.
> The IC is still getting hot very quickly

If the IC let out smoke, replace it. I've noticed that sometimes they
will still heat up after that and sometimes not.

blowing the opamp does sound like a power problem.

-ryan


The CGS Modular Synth home page: http://www.cgs.synth.net/




SPONSORED LINKS Sampler Electronic instrument Synthesizer
Music synthesizers Synthesizer music Electronic music


------------------------------------------------------------------------------
YAHOO! GROUPS LINKS

a.. Visit your group "cgs_synth" on the web.

b.. To unsubscribe from this group, send an email to:
cgs_synth-unsubscribe@yahoogroups.com

c.. Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.


------------------------------------------------------------------------------



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



The CGS Modular Synth home page: http://www.cgs.synth.net/

Yahoo! Groups Links










what part of sin (w + i sin (w r)) do you not understand?
[reverse engineers]


---------------------------------
Do you Yahoo!?
Yahoo! Music: Check out the gig guide for live music in your area

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



The CGS Modular Synth home page: http://www.cgs.synth.net/




SPONSORED LINKS Sampler Electronic instrument Synthesizer
Music synthesizers Synthesizer music Electronic music


------------------------------------------------------------------------------
YAHOO! GROUPS LINKS

a.. Visit your group "cgs_synth" on the web.

b.. To unsubscribe from this group, send an email to:
cgs_synth-unsubscribe@yahoogroups.com

c.. Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.


------------------------------------------------------------------------------



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

--- In cgs_synth@yahoogroups.com, "c10h14no2i" <c10h14no2i@...> wrote:
>
> Ok, I replaced the IC and all is good, except for the hum.
>
> I get absolutely NO input on the LP input. and the hum is definately
> being low pass filtered.
> The other 2 inputs work.. I can hear audio and the hum.
>
> Ive checked all of the connections and components from the LP input
to
> just about everything else, and it all looks ok.
> Could a bad transistor cause the hum, or any other bad component?
>
> I do have a new powersupply on the way, but to me, the clues show
> something else might be wrong. However, I dont know what Im talking
> about :).
>

--- In cgs_synth@yahoogroups.com, "bbluthang" <jumpswine@...> wrote:
>
> at the risk of being redundant, is the electro on the LP input
> alligned correctly?
> also did you use the same transistors specified in the schematic?
> metal cans or TO92s? its worth double checking you haven't got the
> pinouts mixed, there is a lot of variation between different makes.
> check the datasheets for the ones you are using.
> its a common mistake - especially for me
> andrew
>
>
> --- In cgs_synth@yahoogroups.com, "c10h14no2i" <c10h14no2i@> wrote:
> >
> > Ok, I replaced the IC and all is good, except for the hum.
> >
> > I get absolutely NO input on the LP input. and the hum is definately
> > being low pass filtered.
> > The other 2 inputs work.. I can hear audio and the hum.
> >
> > Ive checked all of the connections and components from the LP input
> to
> > just about everything else, and it all looks ok.
> > Could a bad transistor cause the hum, or any other bad component?
> >
> > I do have a new powersupply on the way, but to me, the clues show
> > something else might be wrong. However, I dont know what Im talking
> > about :).
> >
>