ANAMORPH HELP NEEDED. (Solved)

[blearyeyes]

Cabintech Xvive MN3005 doc says pin #1 is GROUND
Anamorph docs says 15v should show on Pin #1
I'm confused.

I traced test tone all the way to the input to the MN3005 and then get motor boating on TP1 (output) and directly on the chips output. Tried both chips same result.

[blearyeyes]

Solder side, cleaned off flux but alcohol messed with solder mask...

[blearyeyes]

Pin one is ground? I'm goin crazy 😜

[blearyeyes]

Docs show 15v on pin one

[madbean]

Yes, both are correct. The MN3005 was originally designed for positive ground DC circuitry. It works fine as negative ground, you just have to flip the ground and DC supplies (as well as change the output pulldowns to pullup and alter the VGG supply). Pin1 is 15v on the Anamorph. You see the same thing with many other negative ground BBD circuits like the DM-2, neg. ground DMM, etc.

[blearyeyes]

Thanks Brian, Now I just need to figure out why the BBDs are motorboating. Audio gets there and then putt putt, putt...out of the chips. Voltages were looking good but my VOM finally gave up for no reason other than age.. Tomorrow's a new day...

[blearyeyes]

Anamorph Test PS @ 9.40V

IC1  TLO74

1. 7.51
2. 7.51
3. 7.45
4. 15.00
5. 7.51
6. 7.51
7. 7..51
8. 7.52
9. 7.51
10. 7.51
11. 0
12. 7.51
13. 7.51
14. 7.52

IC2 V571D

1.  1.04
2.  1.86
3.  1.86
4.  0
5. 1.86
6. 1.86
7.  4.70
8. 1.86
9. 1.86
10. 5.19
11. 5.19
12. 1.86
13. 15.00
14. 1.86
15. 1.86
16. 1.11

IC3 MN3005

1.  14.98
2. 7.49
3. 7.15
4. 7.15
5. .0
6. 7.49
7. 7.94
8. 1.03

IC4 MN3005

1. 14.96
2. 7.49
3. 8.75
4. 8.75
5. 0
6. 7.49
7. 9.23
8. 1.01

IC5 4558

1. variable
2. 7.84
3. variable
4. 0
5. 7.84
6. 7.78
7. 7.84
8. 15.00

IC6 CD4047

1. 7.39
2. 7.5
3. 7.51
4. 14.99
5. 14.99
6. 14.99
7. 0
8. 0
9. 0
10. 7.49
11. 7.49
12. 0
13. 7.44
14. 14.99

IC7 LT1054
1. 1.39
2. 4.95
3. 0
4. 0
5. 0
6. 2.59
7. 1.45
8. 9.04

Q1
1. C 15.04
2. B. 6.13
3. E  5.75

Q2
1. C  15.03
2. B  4.67
3. E  3.71

Q3
1. C 14.97
2. B  8.75
3. E  8.11

Q4
1. C  15.04
2. B  4.96
3. E  4.36

Q5
1. C  15.04
2. B  4.32
3. E  3.72

REG1 78L15
1. I   16.62
2. G  0
3. O  15.05

REG 2 78L15
1. I  16.64
2. G  0
3. O  15.01

[blearyeyes]

Thanks Brian, Now I just need to figure out why the BBDs are motorboating. Audio gets there and then putt putt, putt...out of the chips. Voltages were looking good but my VOM finally gave up for no reason other than age.. Tomorrow's a new day...

After going back to the beginning of the calibration process, the 4047 is outputting 10hz square wave and when the delay pot is turned it goes to about 150hz.  At first I must have misread the 10Hz as 10khz....now to figure out what controls the clock freq. 

[madbean]

No, it should be around 10kHz+ at the longest delay. You may have the wrong value cap at C45. That would explain the motorboating.

[jimilee]

Yep, looks like he has a 220n instead of a 240pf.


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[blearyeyes]

That was it. 

"Captain, there Be Whales!"

[blearyeyes]

Yep, looks like he has a 220n instead of a 240pf.
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Hey Jimilee, you know I can hear you… hehe

P.S. nobody caught the missing transistor..

Thanks for the help you guys, fresh eyes and all that…