MN3007 ADA Flanger Clone Questions

[Paul Marossy]

I had one of those enclosures when one of the forum guys were selling, but when I went to indent for drilling I must have hit it too hard and the enclosure came apart. Very upsetting. Yours looks killer, thougH!

Oh yeah, I vaguely remember those enclosures. I wanted something that was pretty close to the original ADA enclosure. I decided to make it out of wood because it was the easiest route to go. I was originally going to do a Pete Cornish type of thing with it but then had the  thought  to do  the snakeskin simply because I had it lying around and thought it might look cool.

Anyway, I was messing around with a chorus setting on it this morning. Wow, does that sound nice. 

[Michael Allen]

I built one of these back in 09 with a BL3207. Never could get it to work right since I couldn't figure out the clocking. I didn't have a scope or freq meter then so I was just twiddling knobs. it would sweep up and when it came down there would be a huge pitch bend warble.

Got back to it yesterday and it turns out the clock was waaaay too slow. To begin with, as bajaman noted after I had shelved it, the clock needs to be doubled compared to sad1024. The stock clock didn't have enough range for me so I had to do some parts subbing.

I ended up decreasing the 82k after the range control to a 68k, and the 20k from T4 Max clock to ground I changed to an 8.2k. From here I could get the clock to go from about 66kHz to 2.7MHz. At the bbd with the range full clockwise it only sweeps from about 70k to 1.2MHz. Sounds pretty darn good though. It seems if I increase the T3 sweep range trimmer, the clock will swing down lower but then it freezes and won't sweep back up unless I turn the trimmer back down a smidge.

Hope this helps anyone trying to build with a BL3207!

[TOPLEL]

I've built this with 1N5819 diodes (instead of 1N5817) in the voltage doubling circuit and now it probably causes problems.

I get 9V into the circuit but just around 16.5V-16.9V after the voltage doubler. The regulator would need at least 17V i think.

I get 14.6V after the regulator but that voltage varies with the sweep of the LFO, on he bottom of the sweep the supply voltage is around 14.3V on the top it is around 14.6V.

Is that normal?

(i am asking it since my LFO sounds weird, it is almost like two delayed sinewaves sweeping, definitely not normal but i have not calibrated the clock frequency yet)

[moosapotamus]

I have never noticed the LFO sweep affecting the input voltage. Seems odd.

If you can get your hands on an 18VDC wall wart, try bypassing the whole voltage doubling circuit and feed the 18V directly to the voltage regulator. That should give you a solid 15V out to the whole circuit. Then, if you can calibrate and get everything sounding good, you will have confirmed that the issue is in the voltage doubler.

~ Charlie

[TOPLEL]

I have never noticed the LFO sweep affecting the input voltage. Seems odd.

If you can get your hands on an 18VDC wall wart, try bypassing the whole voltage doubling circuit and feed the 18V directly to the voltage regulator. That should give you a solid 15V out to the whole circuit. Then, if you can calibrate and get everything sounding good, you will have confirmed that the issue is in the voltage doubler.

~ Charlie

i can input (after the ADA's stabilizator) stabilized/filtered 15VDC from a synth power supply

i think i will try that and then see what happens.

[12Bass]

I have never noticed the LFO sweep affecting the input voltage. Seems odd.

If you can get your hands on an 18VDC wall wart, try bypassing the whole voltage doubling circuit and feed the 18V directly to the voltage regulator. That should give you a solid 15V out to the whole circuit. Then, if you can calibrate and get everything sounding good, you will have confirmed that the issue is in the voltage doubler.

My SAD1024A A/DA flanger clone does not use the voltage doubler; it is powered by an 18 V adapter.  However, I have also noticed that the DC voltage before the regulator does fluctuate with the LFO even if the depth is zero and the delay time is not being modulated.  The regulator keeps things constant in the circuit.  FWIW, I've measured a significant increase in current consumption as the clock is increased (for a short delay time).

[TOPLEL]

Is there anyone who actually uses this from a 9V supply? (not 9.5V, not unregulated putting out more than 9V etc.)

I installed the right diodes but nothing changed. So i started to look at the datasheets.

Now i have trouble believing that this could work with the voltage doubler option.
Under this current consumption the LT1054 puts out around 17V and then you lost another ~0.4V on the reverse protection diode on the input of the regulator. Putting something like 16.6V into the 15V regulator should be not enough because the minimum dropout voltage should be around 2V-2.5V according to the datasheets.

I know that at this point i should just forget about the doubler but i invested too much time and brainpower into it. Now i am thinking about putting a jumper instead of that protecting diode or maybe getting a 9.5VDC supply (i think a Boss supply of mine used to put out that)

(i have a related story, once i tried to make a synth supply with 12VAC transformers so the DC voltage into the regulators came out somewhat under 17V (maybe around 16.5V) and i had all sorts of problems with the supply (noise, lower than 15V outptut etc.) and going with higher DC voltage into the regulators solved them)

[LaceSensor]

I've built two of these using lt1054 both work great.

[Scruffie]

Is there anyone who actually uses this from a 9V supply? (not 9.5V, not unregulated putting out more than 9V etc.)

I installed the right diodes but nothing changed. So i started to look at the datasheets.

Now i have trouble believing that this could work with the voltage doubler option.
Under this current consumption the LT1054 puts out around 17V and then you lost another ~0.4V on the reverse protection diode on the input of the regulator. Putting something like 16.6V into the 15V regulator should be not enough because the minimum dropout voltage should be around 2V-2.5V according to the datasheets.

I know that at this point i should just forget about the doubler but i invested too much time and brainpower into it. Now i am thinking about putting a jumper instead of that protecting diode or maybe getting a 9.5VDC supply (i think a Boss supply of mine used to put out that)

(i have a related story, once i tried to make a synth supply with 12VAC transformers so the DC voltage into the regulators came out somewhat under 17V (maybe around 16.5V) and i had all sorts of problems with the supply (noise, lower than 15V outptut etc.) and going with higher DC voltage into the regulators solved them)

So jumper the reverse protection diode pads & wire it in parallel with the supply instead or using a diode with a lower fV drop.

Think I used the diode though and it still works.

[moosapotamus]

...or, also try a LDO (low dropout) regulator. Something like...

Mouser pn 512-KA78R15CTU

~ Charlie

[RonaldB]

I digged up my ada flanger clone once again to get the right clock frequencies.
But I still can't get the freq. right.

Stock with know changes to the circuit i can go from 40 khz to 90khz
After changing the clock cap the range goes up from 200khz to 400khz

The voltages seems to be oke. What can I do here?

ROnaldB

[moosapotamus]

Hmmm... What version do you have, SAD1024 or MN3007?

How are you measuring the low and high frequencies?

~ Charlie

[RonaldB]

Hmmm... What version do you have, SAD1024 or MN3007?

How are you measuring the low and high frequencies?

~ Charlie

Hello,
I have the MN3007 version.
And I am measuring the frequencies with a DMM (fluke).
I have allready changed R64 from 20k to 8.2k since I read here someone had good results with that.
But my manual pot reacts very strange. When it's fully CW it now reads 200khz and when it's CCW it reads 400khz but it goes very fast to the 400khz range say after 10% rotation.
I will check all my resistors and caps form the LFO section and clock section just to make sure that good. Could it be a faulty 4007 or 4047? I read you had that problem to?

Thanks

RonaldB

[Valentinych]

Guys, tuning range frequency VCOs MN3007 clone ADA Flanger (drawn by Charlie Barth) should be 34 kHz - 1.3 MHz. Measurement is to be carried out on 2 or 6 pin MN3007. The handle of a potentiometer "Renge" in the top position of the scheme . Then LFO on the frequency of the VCO not affected by this. Frequency change is the handle of "Manual".

[RonaldB]

I feel like a complete idiot.
I wired the Jack for the CV control wrong and did it right know it works 

Thanks in advance.

RonaldB

[moosapotamus]

Glad you figured it out!

~ Charlie

[TOPLEL]

It seems like i eliminated my power supply problems, but the problem with the weird sweep remained.

Basically the sine like sweep sounds like this at some settings:



It kinda sounds like as if at some parts of the sweep the LFO wave voltage jumps quickly to the top or the bottom then continues it's normal sweep.

At test point H with maximum LFO depth (range was at max.) i measured ~4V at the bottom and ~12V at the top of the sweep and it looked kinda sine/triangle like on the DMM without the abrupt jumps.

I tried it with different MN3007s, interestingly the sweep sounds different on them but still defective.

Maybe the clock speed is calibrated super bad and that is the problem? (i don't have a freq counter)

[TOPLEL]

It seems like i eliminated my power supply problems, but the problem with the weird sweep remained.

Basically the sine like sweep sounds like this at some settings:



It kinda sounds like as if at some parts of the sweep the LFO wave voltage jumps quickly to the top or the bottom then continues it's normal sweep.

At test point H with maximum LFO depth (range was at max.) i measured ~4V at the bottom and ~12V at the top of the sweep and it looked kinda sine/triangle like on the DMM without the abrupt jumps.

I tried it with different MN3007s, interestingly the sweep sounds different on them but still defective.

Maybe the clock speed is calibrated super bad and that is the problem? (i don't have a freq counter)

ok i made an arduino frequency counter, if i can believe it my max clock speed is around 300kHz which is almost 1/10 of what i need. probably this was the source of my problems although i can't trim it above 300k so i need to change some parts i think.

edit: C29 is 47p, R69 is 1M

edit: i measured clockspeed @ TP on the pcb

edit: i changed C29 to 4.7P and now the maximum frequency i can hit is around 660kHz

[Fender3D]

You have issues in you building, 'cause if you divide by 10 your cap, resulting clock should multiply by 10 as well.
What PCB is it?
Did you build it yourself, or you bought it anywhere?
~2MHz easily suffer from tracks issues, component leads or tin leftovers, flux on PCB and so on.
In MadBean words, this is not a "noob" or "cowboy" level building...

You say your max freq. is 300/660KHz, what's your min. freq.?
It should be around 2KHz if CMOS chips and "Range" voltage are working ok...
Otherwise check CV control as RonaldB suggested, or check your 4007

[TOPLEL]

You have issues in you building, 'cause if you divide by 10 your cap, resulting clock should multiply by 10 as well.
What PCB is it?
Did you build it yourself, or you bought it anywhere?
~2MHz easily suffer from tracks issues, component leads or tin leftovers, flux on PCB and so on.
In MadBean words, this is not a "noob" or "cowboy" level building...

You say your max freq. is 300/660KHz, what's your min. freq.?
It should be around 2KHz if CMOS chips and "Range" voltage are working ok...
Otherwise check CV control as RonaldB suggested, or check your 4007

it is a rev05 Moosapotamus PCB.
there are some flux spills around most of my solder joints but i was afraid to poke around the cap's solder joints with a knife (i don't want to cut the connected traces)

i think my next step will be replacing all the logic ic-s.