BassBalls layout question

[svstee]

I built a BassBalls using this layout
http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=36798&g2_serialNumber=1
and it is not working. Normally I would just check the layout against the schematic, but the one listed seems to have disappeared. Does anyone have a copy of the schematic this was drawn from, or a schematic similar enough to check the layout against, or the knowledge that this layout works and is verified?

Thanks!

[Mark Hammer]

You can find it all here:  http://topopiccione.atspace.com/PJ08EHBassBalls.html

[svstee]

Thanks Mark, I also read your comments on this circuit and will try implementing some once I get it working.

The layout looks good to me, no errors that I can find, but I would feel more certain if someone has built/verified it. I just don't trust myself much.... I will return with voltages!

[Mark Hammer]

I was reboxing one the other day, and decided to exchange a "split" function (high filter to output A and low to output B) with a Q function.  The Q function simply involves using a 1M feedback resistor in the high filter, instead of the stock 470k unit, and a SPST toggle to switch in a second 1M resistor in parallel.  You could also use a pair of 470k in series and a toggle to shunt/bypass one of them.  Same deal.  The effect is to a) drop the range of the high filter a bit, and b) make it more emphatic and "vocal"-sounding.  A very simple mod that takes little room or parts and expands the tonal palette.

[fuzzo]

  you must be courageous to do this huge veroboard.

[svstee]

I've done an Echo Base and a Klon on vero, this is small potatoes compared to those.

I have voltages!

IC1
1 1.9
2 1.9
3 1.2
4 0.0
5 0.0
6 1.9
7 2.2
8 9.3

IC2
1 7.7
2 6.3
3 1.5
4 0.0
5 1.5
6 3.6
7 2.3
8 9.3

Q1
C 9.3
B 1.8
E 1.2

Q2 and Q3 (both read exactly the same)
C 0.0
B 0.5
E 0.0

Thanks!

[svstee]

Anyone? I've looked around for correct voltages to compare mine to with no luck.

[svstee]

I've been messing around with this some more, I audio probed it but lost the signal at lug 3 of IC1. Still haven't found any correct voltages to compare mine to either. This is making me crazy...

[svstee]

Well, still no luck,and since this has morphed into a debug thread...

The BassBalls works bypassed, but no sound at all when effect is engaged. Switch checked with DMM, no problems.
Layout I used http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=36798&g2_serialNumber=1 is NOT verified, but I check against the schematic http://topopiccione.atspace.com/PJ08EHBassBalls.html and found no problems.
I audio probed it but lost the signal at lug 3 of IC1

Voltages

IC1
1 1.9
2 1.9
3 1.2
4 0.0
5 0.0
6 1.9
7 2.2
8 9.3

IC2
1 7.7
2 6.3
3 1.5
4 0.0
5 1.5
6 3.6
7 2.3
8 9.3

Q1
C 9.3
B 1.8
E 1.2

Q2 and Q3 (both read exactly the same)
C 0.0
B 0.5
E 0.0

I really want to get this one working, thanks!

[templatezero]

Hi svstee,

I've just built the BassBalls using the same stripboard layout from http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=36798&g2_serialNumber=1 and it is working without any problems. Thus I think the layout is correct.  I'm using LM1458N and AN4558 for IC1 and IC2 respectively.

You mentioned that there is no signal at lug 3 of IC1. From the layout, lug 3 is the non-inverting input of IC1a in the schematic from topopiccione. This might suggest a fault anywhere between the input jack to IC1 lug 3. You may want to check for cold solder joints around R2. Also try swapping a new 1458 for IC1 just to confirm the opamp is not at fault too.

From the voltages you provided, the bias voltage on IC1 lug 3 seems too low. It should typically be around half the supply voltage (in this case about 4.5 Volts). Though I've not measure any voltage on my unit, the voltages provided by B Tremblay http://www.diystompboxes.com/smfforum/index.php?topic=70368.0 confirmed my observation. Maybe you will like to check R21, R22, C14 and C15.

Hope this helps.

Cheers!

[svstee]

Switched out the 1458, no luck, still no signal. I'll double check for continuity up to IC1 lug 3, and the parts you mentioned.

Thanks for the help!