5 band EQ - Nowt Out!

[kaycee]

5 band EQ with gain, Harald Sabro's vero from here:

http://www.sabrotone.com/wp-content/uploads/2010/05/5-band-EQ-w.-Gain.gif

Based on the general guitar gadgets 6 band eq schematic here:

http://www.generalguitargadgets.com/pdf/ggg_eq6b_sc.pdf?phpMyAdmin=78482479fd7e7fc3768044a841b3e85a





Has the required number of trace cuts and jumpers, and seem to be in the right places, no solder bridges - not getting anything out of it at all.

Have DMM, signal tester and can post voltages if folks let me know which pins.

thanks for any help

[PRR]

Power rail voltages A C B.

On each chip: one pin at voltage A, one at voltage B, all others at voltage C.

The linked schematic has an error.

Ah...

The linked vero-layout is _not_ identical to the schematic.

"A" is layout Ground, "B" is layout +9V, and "C" is strip b7-b23.

[runmikeyrun]

your pic is pretty blurry... but your soldering looks pretty good.  When I build on vero I build under very strong light and use a magnifying glass to verify my trace cuts are indeed cut.  Occasionally one is not completely cut but is so thin that I can't see it with the naked eye.  It's immediately apparent when I use the magnifying glass.  It may be a bit tedious,  but it's something you should do.  I also run an exacto blade in between all of the rows when I'm done building to assure I don't have a hair-thin solder bridge.  It's good to use the magnifying glass to inspect those too.  75% of the time a vero build doesn't work for me it's because of one of those two above problems.

Good luck.

[kaycee]

Hi PRR,

thanks for the reply, not sure I'm following you though? Need readings for all pins both IC's in reference to power rail, ground rail and line B7-B23?

Re: Solder bridges - I always run a junior hacksaw blade between the tracks, brush with a little wire cleaning brush and then check with jewllers eye-glass, I'm sure that I'm clean there.

Thanks.

[PRR]

> Need readings for all pins both IC's

_I_ don't need "all" the readings.

One pin will be one number, one pin will be another number, and "all others" should read the SAME number. See if one of them is not like the others. Report odd readings with pin numbers. Meanwhile look closer at what is connected (or hair-bridged) at that pin.

[kaycee]

Took the readings, could see the idea but didn't help me much. Built a second board and thats the same, I've tried following through the scematic, but I'm not that hot with IC's so didn't get me anywhere either. This is posted as verified but I wonder if anyone other than Hararld himself has got one going? Might take a punt at the GGG layout on perf.