help with 2nd Moosapotamus mn3007 ADA Flanger clone!

[njkmonty]

Ive already built a Mn3007 ADA flanger clone and just finished populating the 2nd

Ive got sound coming through but appears to be only through dry signal.

here are my voltages
1st is my working one and 2nd is the one im having probs with.


ic's 1,2 &3 ( all LM324 / TL074 ) have the exact same voltages
Ic 4 (Tl072)  has the same voltages in both,
Both V+ are puting out 14.9v coming of regulator
and both VB are 7.4v

I used an audio probe and traced sound at point  " C & D" get sound but nothing on the other side of resistor R42 (27K ) & Pin * of IC1c
here are the ic's with discrepencies...

ic5) 4007

1) 0    /  0
2) 0    /  0
3) 0    /  0
4) 2.4 /  0
5) 0.7 / 0
6) 0    /0
7) 0    /0
200mv - 1.2v /100mv
9) 100mv / 50mv
10) 5-5.5v / 9.3v
11) 7.8 / 7.7
12) 300mv -1.2v / 100-200mv
13) 14.9 /14.9
14) 14.9 /14.9

ic6) 4047

1) 13.6-14.7     / 100mv
2) 200mv-1.2v   /  250mv
3) 7.8   /  7.8
4) 14.9 / 14.9
5) 14.9 / 14.9
6) 14.9 / 14.9
7) 0    /0
0    /0
9) 0    /0
10) 7.4v / 0
11) 7.4 / 14.9
12) 0  / 0
13) 14.9 /14.9
14) 14.9 /14.9

ic9) 4049

1) 14.9 / 14.9
2) 7.4  / 14.9
3) 7.4 / 0
4) 7.4 / 0
5) 7.4 / 14.9
6) 7.4 / 14.9
7) 7.4    /0
0    /0
9) 7.4   /14.9
10) 7.4v / 0
11) 7.4 / 14.9
12) 7.4 / 0
13) 0 /0
14) 7.4 /0
15) 7.4 / 14.9
16) 14.9 /14.9


ic10) 3007

1) 14.6-14.8     / 14.5
2) 7.4   /  14.9
3) 6.8   /  7.4
4) 0.9 / 0
5) 0/0
6) 7.2-7.4 / 0
7) 3.9-4.3 /9.7
3.9-4.3    /9.7


http://www.moosapotamus.net/images/FlangerClone_SCH_rev5_MN3007_jan2010.gif




http://www.moosapotamus.net/images/FlangerClone_OVR_rev5_MN3007_jan2010.gif

[njkmonty]

anyone?

[StephenGiles]

Remove BBD and 4049 (carefully!!) and all ICs in the audio path, then measure voltages at pins 10 & 11 of 4047 - they must each be around 1/2 supply voltage. If they are not, suspect 4047 and associated components initially. If OK, replace 4049, then same voltages should appear at its pins 10/12 and 2/15.

However, you should also check the LFO for a rising and falling voltage, best done on an analog multimeter, because a problem with this caused more than one I breadboarded to not work.

I'd wager your problem is something to do with that hideous noise gate, which I always ignored. If something is going to mute your audio when you want it, sod's law that it will mute when you don't want it!!

[Fender3D]

You can't have

the exact same voltages

at IC3 when IC5's pin 10 is 9V.
You have no signal @ R42 because VCO (IC6) does not oscillate...

You may lift IC5, eventually place a 10K>100K resistor on pins 11 and 12 and see if IC6 works (you'll have signal @ R42)

[StephenGiles]

You can't have

the exact same voltages

at IC3 when IC5's pin 10 is 9V.
You have no signal @ R42 because VCO (IC6) does not oscillate...

You may lift IC5, eventually place a 10K>100K resistor on pins 11 and 12 and see if IC6 works (you'll have signal @ R42)

Yes - he's right you know, I was forgetting about the 4007 acting as a VC variable resistor. The 4047 will oscillate on its own with suggested fixed resistor between pins 1 & 2.

But have you checked for any solder bridges - also a likely suspect here!

My advice for building any circuit of this magnitude is always to split it up into separate blocks, build one - make sure it works, then move on to the next block in the sequence etc.

[njkmonty]

Just wish to say thankyou!!!
turned out the mn3007   was a fake , it did delay, but about 1/4 of what the real one did,
secondly i replaced the 4047, and got the correct voltages on all those pins.
then...
i could hear the delay sound any everything but couldnt hear the lfo,,,,
after trying different chips etc , i realised in my first build i had ommited c24 (cant remember why!), but had connected
the negative side of  of c25 to  pin 7  of IC4B!,I forgot to do the same  and now works all well.  the online youtube calibration videos are great too!

where I was referring to on the schematic section " E",  is leaving 1 electrloytic cap out ok? ive just got 1 x 33uf (c25), should i have the other 33uf cap in??

this is the section where negative sides of both caps are connected together

also..StephenGiles ,  did you implement the bounce mod on your builds? any good

can anyone point to me a schematic they have done for this build for the add on tzf  mod?
basically now i have 2 flangers, i would like to try all the usuable mods on one of them,

stereo
c29 cap switching
tzf

some wizdomatic input from any wise persons would be received with appreciation,
wow a case of sesquipidelian!!

[DrAlx]

  is leaving 1 electrloytic cap out ok? ive just got 1 x 33uf (c25), should i have the other 33uf cap in??

If you have a non-polarised electrolytic then you need just one. I don't think you have that though.
You are most probably using a regular electrolytic and so you will need that second electrolytic in series with it and with opposite direction.
As it stands you are damaging the existing electrolytic.

[njkmonty]

just found this...




also..StephenGiles ,  did you implement the bounce mod on your builds? any good

can anyone point to me a schematic they have done for this build for the add on tzf  mod?
basically now i have 2 flangers, i would like to try all the usuable mods on one of them,

stereo
c29 cap switching
tzf

some wizdomatic input from any wise persons would be received with appreciation,
wow a case of sesquipidelian!!

[StephenGiles]

"also..StephenGiles ,  did you implement the bounce mod on your builds? any good"

Yes I did try it on the ADA Flanger (my TDA 1022 version) many years ago when it was on my breadboard. It did work but for some reason I could never get it to work when I build the ADA Flanger on Veroboard. I think it was just before a trip to Argentina when my wife was packing (!!!!!) and never bothered with it again.

[armdnrdy]

turned out the mn3007   was a fake , it did delay, but about 1/4 of what the real one did,

Can you post a picture of the "fake" BBD?

Also, where did you source it from? If eBay, which seller?

Good to know this info so one can stay clear. 

[njkmonty]

 this is the fake one, bought a couple of years ago on ebay, from polatia or something, cant remember sellers name, but had a red background on everything pictured


this is the good one below


anyone done successfully stereo of tzf mods?!!

[armdnrdy]

Thanks for that.
I always look for the 0s that are shaped a certain way. I have seen the logos copied pretty well but...not a lot of attention is paid to the lettering.
The 0s are a dead giveaway to me.

If I recall correctly...I purchased two bad MN3205s from him some years back.
Seems as if you can't even trust the more common BBD ICs from that seller.