Range Voltage Calibration/ Crap just crossed ground with +V

[j.dilisio]

Hello,. I just finished my Klee today and all functions seem to work as they should.
The one thing that is giving me trouble is the Range calibration. The values I'm getting with my meter are way off the mark.

1> -.333
2> -.013
3> -3.14
4> -3.32
5> -3.20
6> -.7
7> -.36
8> -.38

I was just wondering if anyone has had a similar problem or has a good guess at what might be the culprit.
I'm stumped at the moment.
Thanks,
J

EDIT: The one other thing I noticed as possibly not being normal was when I was checking the analog board IC ground pins. They weren't passing the continuity check until I soldered in the W1 jumper.
Is that normal?

[EdisonRex]

Reference voltage should be 10.0 at pin 3 of U5. That is a 7810, right?

The pot are simply acting as voltage dividers. There's not much else can be wrong there unless your analog ground isn't really at 0. Which, by the way, you were mentioning about the W1 jumper... Yes, unless you have tied grounds elsewhere, it should be jumpered. I expect that if you tie the analog ground down right, the numbers will drop more into place.

[j.dilisio]

I've got a 78L10 for U5.
Here's the data sheet..
http://www.fairchildsemi.com/ds/KA/KA78L10A.pdf

I'm measuring 15V on pin 3 (input), 0v on pin 2 (common) and 10V on pin 1 (output).

Is that correct?

[j.dilisio]

Ok,. all fixed.
Steps 2-8 of the range switch were wired backwards.
I'm still getting negative voltages at pin1 of U8 but the pitch intervals sound correct.
Thanks.

[EdisonRex]

Have you set the register offset trimmers R42 and R43 yet? You want to get those to zero. If you've been in rewiring and haven't recalibrated you might want to go back and do that again. It doesn't eliminate 100% of offsets but it'll help. Also very good that you're getting scaling, it does just sound like a trim problem. Does the B side have the same problem? R43, U9 pin 1

[j.dilisio]

Sorry,., what I meant to say is that it's functioning correctly ie correct intervals and no audible offset. The voltages are correct as well,. just on the negative side.
-8, -4, -2, -1, -.666 ...
I do get an almost identical set of voltages at pin1 of U6 (MaxV in the schematic), except that they're positive.
It works, I'm happy.
Thanks again.

[j.dilisio]

This is frustrating. I just crossed the ground connection with +15V at the power supply by accident. Now I'm getting some strange behavior.

1- The clock is affecting the pitch of the VCO thats attached.
This also occurs with the power off.
EDIT: This is also true of the random and load inputs.

2- Although the range callibration still measures correctly, the pitch intervals are all considerably less than they should be.

3- When the sliders of steps who's voltages are being combined are too high, the clock stops.


It was working fine before so I'm guessing I've got a blown part or two somewhere.
Any guesses/ advice?

[j.dilisio]

So in this situation would it be best to order replacements for all of the ICs and transistors and switch them out one at a time?

I don't really understand whats going on in most of the circuit to pinpoint the problem.

[j.dilisio]

I tried switching out all of the ICs to no avail.

Edit: I thought I was having a problem with the voltage outs but they measure fine. What does it mean if I'm getting the correct voltage output but the pitch intervals don't correspond?

[j.dilisio]

I just hooked up my scope to ground to do a little probing and the Klee magically resurrected itself so I believe the problem is with my power source.
All better.