Q on Infinite Melody/CGS32

e-grad · Joined: Sep 12, 2008 Posts: 142 Location: Berlin

I'm about debugging my Infinite Melody (Rev2) module and need some help.

There are 4 TL072 and 2 LM358 ics. Can I substitute those two LM358 for two more TL072?

edit: Will the circuit run correctly with two T072 instead of two LM358 installed?

Mongo1 · Joined: Aug 11, 2011 Posts: 411 Location: Raleigh NC

Hi,

It looks to me like the Rev 2 board is supposed to use the TL072s exclusively.
The older rev boards did have LM358, but they were eliminated in Rev 2.

If you do have a Rev 2 board, you absolutely should use TL072 everywhere...

Gary

e-grad · Joined: Sep 12, 2008 Posts: 142 Location: Berlin

Thanks!

The module is lying around for so long that I have troubles to recollect what I had in mind when building it.

The circuit apparently does not follow the clock and I'm a bit at loss to figure out why.

I used throughout HCF4xxxx chips which should be fine. Just had a look at the datasheet.

Mongo1 · Joined: Aug 11, 2011 Posts: 411 Location: Raleigh NC

e-grad · Joined: Sep 12, 2008 Posts: 142 Location: Berlin

I'm afraid this is the most detailed description of the prob I'm able to provide:

I've opted for the following panel controll: Mix In pots; skipped the output level pots for fixed 27k (before 100k) resistors; I installed the Bit 4 and Bit 5 switch.

The Mix Out is affected by the pots and the Bit 4 switch only.
The other outs are effected by the Bit 4 and Bit 5 switch.

I should add that I hard wired the board to a Diatonic Converter which does not work at the moment.

edit: Just meassured: the 4024 receives the clk but apparently has no output at pins 5; 6; 9; 11 and 12. (Unless I did something wrong with my scope.)

So the HCF-varieties might not work here Question

andrewF · Posted: Sun Sep 04, 2011 9:19 am Post subject:

HCF series should be fine, so long as your PSU is under 18V
one thing with the 1/f, it needs three inputs to operate.
One is a clock to run the 4024, something on the noise/random input to provide data for the initial 4015 to clock thru and a fast clock to tick over this 4015.
If you miss any of these its unlikely the 1/f will do much.

sorry, none of this explains why your 4024 isn't working Sad

e-grad · Joined: Sep 12, 2008 Posts: 142 Location: Berlin

Thanks! I was not aware that I need to the module three sources.

By now I've swapped the 4024 and it almost works. Switching the module on I had 2 or three "notes" and could provoke one further "note" if I'd fiddle with 'sense adjust' or with the 'sense CV' pot.

Idea

Just have fed a forth signal into sense CV and it works!

Great!

The Infinite Melody is like the Modulo Magic: I've absolutely no idea what is going on yet like the result. Thanks to Mongo1; andrewF and of course to Ken.

e-grad · Joined: Sep 12, 2008 Posts: 142 Location: Berlin

Today's dead again! Even though there are clk signals at the 4024's outs.

edit: Works. The module just seems to be quite sensitive regarding the inputs needed or I patched it up erroneously earlier today.