[sdiy] 4 bands, no succes

[Brown David]

Schmatic looks fine except:
1. 22k resistor omitted from between 1M pot and TL072
2. the 'straight through' pot, capacitor and resistor are omitted
3. some 2uF caps are now 4u7 (is this intentional?)
4. caps labled 57n should be 47n presumably

Try tracing the input signal through the circuit.  It may help to remove the
TL074 from its socket first and check that TL072 is working as both an input
and output amplifier.

-----Original Message-----
From: Dave Krooshof [mailto:krooshof at xs4all.nl]
Sent: 26 September 2001 16:15
To: synth-diy at dropmix.xs4all.nl
Subject: [sdiy] 4 bands, no succes


Hi,

I made a 4 band filter, or at least I tried.
I based it on >>>Marjan<<<'s Dual Filter.  <- credits!

Both are posted here: http://www.xs4all.nl/~krooshof/4band
as I didn't find Marjan's original link. mine's in schematic-layout hybrid

The problem is: It only hums wildly, it doesn't filter, so it seems.
no volume changes either. My question to you: Is my re-design bogus?
(or did I made soldering mistakes?)

thanks,

Dave

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