Tomas EM3207 build. Voltages Check

[AS74]

Please can someone check over my voltages.  No flanging heard.  Signal from the 4558 to output is audable at guitar amplifier. Input audable on pin3 of MN3207.  Don't find signal any where else.

IC1 4558                   
1.  5.03
2.  5.02
3.  4.53
4.  0
5.  4.94
6.  4.99
7.  4.93
8.  8.82

IC2 3207
1.  0
2.  0
3.  4.94
4.  8.27
5.  8.82
6.  8.82
7.  3.63
8.  4.0

IC3 LM324
1.  Osc
2.  Osc
3.  Osc
4.  8.78
5.  Osc
6.  Osc
7.  Osc
8.  Osc
9.  Osc
10. Osc
11. 0
12. 4.97
13. 4.98
14. 4.99

IC4 LM311
1.  0
2.  Osc
3.  Osc
4.  0
5.  8.82
6.  8.82
7.  Osc
8.  8.82

IC5 4013
1.  8.82
2.  0
3.  Osc
4.  0
5.  0
6.  0
7.  0
8.  0
9.  0
10.  0
11.  0
12.  0
13.  8.82
14.  8.82

IC6  4049
1.  8.83
2.  0
3.  8.83
4.  8.83
5.  0
6.  0
7.  8.82
8.  0
9.  0
10.  8.83
11.  0
12.  8.83
13.  0
14.  8.83
15.  0
16.  0

Q1 2n3904
e  3.02
b  3.63
c  8.83

Q2 2n4403
e  8.47
b  8.0
c  1.59

Much appreciation and thanks to all.

Adam.

[Fender3D]

0V on MN's pin2 (and all those 0s on IC6) means no clock, then no wet signal

[Slowpoke101]

As Fender3D said - No clock, then no wet signal.

Your 4013 seems to be stuck in one state. It is supposed to run as a divider whose output generates the clocking signals which are then buffered by the 4049.

Have a look and make certain that pin 5 (D input) is not shorted to ground. Both pins 4 and 6 are grounded so a short to one of those pins is quite possible. The other possible problems with the 4013 could be that it is faulty or there is insufficient drive signal on its clock input (pin 3).

[AS74]

Ok,  thanks for the info guys. 

Still can't track down the issue after some hours.  No solder bridges, pin 5 not grounded.

Swapped 4013, 311 and 324 with no change. 

Switching the power on and off is causing the voltages on pins 1 and 2 of the 4013 to swap but still remain stuck.

Obviously there is something I'm missing/not seeing and my lack of knowledge has brought me to a standstill.

Than you for any further advice

Adam

[DrAlx]

Q2 collector reading does not match LM311 pin 3.

[AS74]

Thank you DrAlx

After checking Q2 collector it does in fact match pin 3 of LM311. 

Q2
e  8.48
b  8.01
c  2.19

IC4 LM311
1.  0
2.  3.42
3.  2.19
4.  0
5.  8.82
6.  8.82
7.  1.54
8.  8.82

IC5.  4013
1.  0
2.  8.82
3.  1.54
4.  0
5.  8.82
6.  0
7.  0
8.  0
9.  0
10.  0
11.  0
12.  0
13.  8.82
14.  8.82

4013's pins 1 and 2 swap voltages with power switched on and off

[Slowpoke101]

It would appear that the clock oscillator is not running.
Check around Q2 for any problems - component values, orientation, etc.
If you used a different transistor than a 2N5087, that transistor may have a different pin-out.
I usually use BC559 or BC327 to replace 2N5087 as I don't stock them. If you used a BC series
transistor you do have to rotate them 180 degrees from the 2N5087 orientation.

[AS74]

Checked Q2 and pinout is correct.

I'm going to remove related components and check all/replace.

Thank you.

[DrAlx]

My EM3207 has Q2 2N5087 with
E: 8.53
B: 7.85

So VBE is about 0.7 as expected for silicon.
You have a VBE that is quite a bit lower.

Check values of R31, R32 and D1 as those set VB.

[AS74]

R31, R32 and D1 are good.

With transistor removed I measure 0.74 across B and E.

Collector oscillates with the Mode switched.

[AS74]

After several more hours trying to find anything, no luck.

Replaced Q2's surrounding components except the 20K trimpot.  Replaced Q2 to Slowpoke's recommended BC559.  Replaced 4049.

Regarding Vbe, I can't find any connections, resistances or shorts between components or socket pins etc. or other areas either.  (yet)

Votage drop measured across anode of D1 to base of Q2 (LM311 removed) = 0.54
Vbe (LM311 removed) = 0.52

Votage drop measured across anode of D1 to base of Q2 (LM311 installed) = 0.77
Vbe (LM311 installed) = 0.50

RT3 about 50%

Maybe caused somewhere else?  The mode switch or 324?  Although I see nothing obvious there after checking and triple checking.

Thank you.
Again

Adam

[Slowpoke101]

This may be worth trying.

Replace the resistor R34 (10K) on pin 7 of IC4 with a 1K resistor.
IC4 may be actually oscillating but your 4013s may not be able to work with IC4's normal output waveform.
If you have access to an oscilloscope have a look at IC4's output.
But try the 1K resistor and see if the 4013 starts to work.

[AS74]

Replacing the 10K with 1K has started the 4013 working. 

Still no flanging.

Thank you.  Is the circuit now going to work as is (after alignment) or some changes needed?

[AS74]

Fiddling the trimpots with abandon I get siren whistling sounds.  So something.
Learn how to set up bias etc next.

[AS74]

Get some very faint flanging after some bias attempts.  Nothing lush.
Used 200hz signal to set bias,  set feedback to just before oscillation. Not sure about clock trimmer though.

From Ralf Metzger's alignment page, 'Set the CLOCK trim for approximately 35 kHz (a 28.6 ms period) square wave at pin 1 or 5 of the 4013.'  ??

Getting close

[Fender3D]

The clock trim sets the minimum clock,
hook up your frequency counter or your o-scope to pin 1 or 2 (2 and 5 are connected together), select filter matrix mode with the switch, set "range" control for minimum maximum delay (CCW) and trim until your read 35KHz on freq. counter or 28,6 ms period on your o-scope.

[AS74]

Unfortunately I have neither frequency counter or oscillascope.

Could weak flanging be due to the unbuffered 4049?

[Slowpoke101]

Due to the MN3207's clock input capacitance (which is fairly high - 700pF) you really should use a buffered 4049 IC.
It may work OK with an unbuffered 4049 but I really would not like to try.

Another thing that may be causing your poor flanging effect may be that the LM311 clock may be too fast or not falling within the control range of the LFO. Using the standard oscillator circuit with R34 as 1K results in the clock running nearly twice as fast..hmm. But RT3 still had a very broad range of adjustment.

Dr Alx and PRR's alternative oscillator may be better;

http://www.diystompboxes.com/smfforum/index.php?topic=91981.msg1083753#msg1083753

It also gets rid of RT3. Worth a try.

I did do some comparison tests with various brands of 4013 ICs and only a few worked with R34 as a 10K. All worked with R34 as a 1K.

[AS74]

Thank you Slowpoke, your time and infomation is much appreciated.
Buffered 4049's seem quite hard to get hold of.
I'll look at the alternative oscillator.

I've taken new voltage measurements.  In Filter Matrix mode.   (Taken before oscillator changes)
No real flanging when switched to flange mode., very small, barely audible
The color pot causing the most noticable change in sound. 
I hear no delay as DrAlx described in his method of tuning the clock.

Any further help and advice is appreciated as always.

Thank you

Adam

IC1
1.  5.11
2.  5.11
3.  4.62
4.  0
5.  5.03
6.  5.09
7.  5.01
8.  8.61

IC2
1.  0
2.  3.82
3.  4.97
4.  7.94
5.  8.6
6.  3.96
7.  6.53
8.  6.54

IC3

1.  3.34
2.  0.97
3.  0.97
4.  8.55
5.  Osc
6.  3.83
7.  0.57
8.  Osc
9.  3.84
10.  3.83
11.  0
12.  5.07
13.  5.08
14.  5.08

IC4
1.  0
2.  3.34 - Osc when mode switched
3.  2.78 - Osc
4.  0
5.  8.61
6.  8.61
7.  2.66 - Osc
8.  8.61

IC5
1.  4.2
2.  4.11
3.  2.5 - Osc
4.  0
5.  4.06
6.  0
7.  0
8.  0
9.  0
10.  0
11.  0
12.  0
13.  8.61
14.  8.61

IC6
1.  8.61
2.  3.86
3.  3.95
4.  3.96
5.  4.08
6.  4.1
7.  4.2
8.  o
9.  4.11
10. 3.95
11.  4.11
12.  3.95
13.  0
14.  4.03
15.  3.9
16.  0

Q1
e  5.41
b  6.04
c  8.62

Q2
e  8.14
b  7.8
c  2.84

[AS74]

I've made the oscillator component changes and now get some noticable flanging but crazy clock noise and flanging is pulsing hard.

With Range pot on full and Rate full clock noise disappears.  All other settings are full of clock noise.  4013 is stuck/frozen when in Filter Matrix mode.