[sdiy] Power supply

[Scott Gravenhorst]

"Christopher Mullin" <stuadh at hotmail.com> wrote:
>Steve,
>
>  I wired it up as you suggested.  Ground from the synth to the '-" peg 
>(which as you guessed rightly also attached to the socket sleeves), and +12V 
>to the '+' peg.  No more fuses blowing, but the module effect is that of an 
>attenuator.  I can't detect any amplification.  I've replaced the 741 IC but 
>with no effect.  Given the schematic at
>
>http://velleman.be/Downloads/0/Manual_K1803.pdf

This circuit should show a voltage gain of 100 when the output control is set
to maximum.  Have you tried to measure the signal levels?

>
>can anyone suggest what's going on.
>
>Cheers,
>
>Christopher
>
>>From: Steve Ridley <spr at spridley.freeserve.co.uk>
>>Reply-To: spr at spridley.freeserve.co.uk
>>To: Christopher Mullin <stuadh at hotmail.com>
>>Subject: Re: [sdiy] Power supply
>>Date: Wed, 29 Sep 2004 14:05:50 +0200 (CEST)
>>
>>
>>
>>Christopher
>>
>> > The two power inputs are labelled + and -. It specifies 10-30V, so 
>I
>> > wired the -12V from the synth to the - peg, and the Ground from 
>the synth to
>> > the + peg, giving a potential of 12V overall.
>> >
>> > Can anyone suggest the correct wiring for this as I've run out of 
>fuzes.
>>
>>Without the schematic of the preamp, it's going to be
>>an educated guess, but I'd suggest the preamp "+" to
>>+12v and the preamp "-" to 0v.
>>
>>I expect the signal screens also go to the "-" on the preamp,
>>so by connecting it to -12v, you may have been shorting
>>the -12v to ground, hence the blown fuses.
>>
>>A scan of the preamp schematic would confirm this.
>>
>>
>>Steve
>>
>>
>>--
>>
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>>
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