MN3007 ADA Flanger Clone Questions

[12Bass]

Hmmm... wouldn't a 256-stage BBD require 1/4 the sampling frequency to obtain the same delay time?  If so, then that would bring the clock down into the audio range (~17 kHz) and lower the bandwidth of the flanger.  Might be a good idea to adjust the low pass filtering to compensate (and avoid aliasing).  Curious to know about the difference in sound when using fewer stages. 

[oldschoolanalog]

Interesting, I'll shove it in then when I get it, did it give a thicker sounding sweep?

Hard to describe. Something you have to hear. It didn't sweep as low, but swept alot higher. IMHO, way too high to hear w/guitar. However, when I had my buddy run his vintage Mini Moog through it the "sizzle" (Harmonics, not noise. Though a white noise input signal was cool too; but not to digress...) at the top of the sweep was amazing. IIRC, the regen trimpot needed a tweak too.
Try it!

Hmmm... wouldn't a 256-stage BBD require 1/4 the sampling frequency to obtain the same delay time?  If so, then that would bring the clock down into the audio range (~17 kHz) and lower the bandwidth of the flanger.  Might be a good idea to adjust the low pass filtering to compensate (and avoid aliasing).  Curious to know about the difference in sound when using fewer stages.

I'll check my notes if you really want but IIRC I clocked it (MEASURED AT THE BBD) ~15KHz to ~500KHz. This is like clocking a 512 stage BBD 30KHz - 1MHz. The only changes to the circuit were trimpot adjustments. The SAD1024 & MN3010 A/DA's have a low clock f of ~ 17.5KHz (At the BBD). I didn't notice any aliasing clocking  the MN3009 at 15KHz.

[12Bass]

I'll check my notes if you really want but IIRC I clocked it (MEASURED AT THE BBD) ~15KHz to ~500KHz. This is like clocking a 512 stage BBD 30KHz - 1MHz. The only changes to the circuit were trimpot adjustments. The SAD1024 & MN3010 A/DA's have a low clock f of ~ 17.5KHz (At the BBD). I didn't notice any aliasing clocking  the MN3009 at 15KHz.

Thanks Dave!

Are you sure about the clock frequencies with the dual 512-stage units?  I thought that their low clock was set for 34.9 kHz, but is effectively doubled because they are using parallel-multiplex mode.  From what I understand, the MN3010/SAD1024A implementations are clocked exactly the same as a single 512-stage BBD would be; however, the dual versions get the benefit of a doubled sampling rate because they multiplex using both halves of the chip.  As to the aliasing matter, it could be that the stock low pass filtering is low enough (8 kHz?) to filter out those frequencies.  FWIW, even my SAD1024A version gets up so high that the very top of the sweep is of questionable usefulness, so I'm not sure a smaller BBD and even shorter delays would be desirable.  Would be interesting to hear though.  Should be building up an MN3007 retrofit board in the next while and will report back.   

[oldschoolanalog]

The 34.9KHz clock f measured at the "test point" (pin 13/4047) for calibration is double the actual clock f at pins 10&11/4047 (what the BBD actually "sees"). This is readily verified w/a f counter. So, when calibrated according to this (pertains to 512 stage units, for MN3007[1024 stage] DOUBLE the f's listed):
http://moosapotamus.net/IDEAS/ADAflanger/ADAcalibration.jpg
...you should have (at the BBD; 512 stage) 17.4KHz-650KHz. For MN3007 double the f's to ~35KHz-1.3MHz (At the BBD).
This test point has long been a source of confusion. If everybody measured the clock f's at the BBD this confusion would cease.
But that would make things too easy.  
As I mentioned, sounds great w/a synth.
According to the SAD1024 datasheet, parallel-multiplex mode doubles the # of samples for the same delay (clock f). The clock rate remains unchanged.
http://www.synthdiy.com/files/2003/SAD512-1024.pdf

[12Bass]

Note: I said that the clock rate is "effectively doubled" in parallel-multiplex, then later clarified that it is the sampling rate which is actually doubled in that mode.  Yeah... there does seem to be a problem with measurement points at issue here.  If we measure at one of the clock inputs of the BBD, aren't we getting 1/2 the actual clock frequency, because the clock signal is divided into two phases, each with half the frequency of the full clock frequency?  Just want to ensure that my understanding is on the right track here....

[12Bass]

Doh!

[mean_dorris]

Hello..

Just looking for a bit of advice..
Got my board a few weeks ago and I've got it all populated and wired up.
I don't have a frequency counter but I'll likely pick up a DMM soon that has one. Until then, I'm trying to do this by ear.

My question is, right now this thing sounds like a weird OD. I've tried a few different techniques I've read about in the instructions and online to calibrate it, but nothing seems to produce a flanging sound. Just how elusive is this sweet spot I'm looking for? Should it still sound somewhat like a flange?

Also, the lt1054 gets really hot. Is this normal?

Any help is appreciated.
Thanks!!

[StephenGiles]

What are the voltages at the MN 3007 clock pins? They should be around half supply voltage.

[gigimarga]

What are the voltages at the MN 3007 clock pins? They should be around half supply voltage.

Because I have a lot of problems trying to debug it, I think that would be very useful to post a set of voltages from a good working one

[oldschoolanalog]

...I think that would be very useful to post a set of voltages from a good working one

I will do this & post them by Monday.
Work is on the front burner for now.
'Till then...
Dave

[Skruffyhound]

That would help me too. Thanks Dave

[StephenGiles]

What are the voltages at the MN 3007 clock pins? They should be around half supply voltage.

Because I have a lot of problems trying to debug it, I think that would be very useful to post a set of voltages from a good working one

Those are probably the most critical voltages - if you ain't got them, it won't work - it's as simple as that. My advice when building the ADA in any format has always been to build one section at a time and test before attempting the next, much easier to troubleshoot. The temptation with a pcb is to stuff the lot - can be bad news!!!

That's why I've always used veroboard.

[solderman]

Hello..

Just looking for a bit of advice..
Got my board a few weeks ago and I've got it all populated and wired up.
I don't have a frequency counter but I'll likely pick up a DMM soon that has one. Until then, I'm trying to do this by ear.

My question is, right now this thing sounds like a weird OD. I've tried a few different techniques I've read about in the instructions and online to calibrate it, but nothing seems to produce a flanging sound. Just how elusive is this sweet spot I'm looking for? Should it still sound somewhat like a flange?

Also, the lt1054 gets really hot. Is this normal?

Any help is appreciated.
Thanks!!

Hi
Sounds like you have at least one error along the build.

The easiest way to find out if you ar OK with the build is inject a guitar signal or a signal generator (use a dist pedal in between if you use a signal generator. Its easier to hear the difference)

Set all trim pots to 50%
Set speed to 75%
Ser Enhance  to 100%
Set range to 0%
Manually turn "Manual" fort and back while playing.

You should definitely have some sort of flanging chorus sound now.

Also, the lt1054 gets really hot. Is this normal?
NO its not. I guess you have some bad ground connection some where.

check out this thread from page 4 and onwards. It's a different PCB and some reference will not check but it's the same circuit.

http://www.diystompboxes.com/smfforum/index.php?topic=83321.msg694204#msg694204

[oldschoolanalog]

Here's some V's to start with. Sorry about the delay. Due to a nasty back injury this is the first time in a while I've been able to sit for more than a few minutes & type w/out pain. "Nuff said. First I'll post the VCO/clock/BBD  V's. CV & audio later. All V's DC relative to GND. All V's rounded to the nearest .1 except where they're not  . Conditions: Threshold full CW (off); Range full CCW (LFO "off"); Regen full CCW (off); Manual (where you see 2 readings), First reading full CCW; second reading full CW. SW1 (harmonics) even. For those "wetting their pants" over clock f's; as Stephen stated in another forum ; Man CCW= ~40KHz, Man CW= ~1.6 MHz. Another note. Where you see (~7.5V), these pins are VCO/clock outputs (f's). Since these are being measured as DC V's you will see they seem to fluctuate down as the clock f goes up. Bottom line: anything from 7.1 - 7.5 should be OK. The reality; when viewed on a 'scope; is these V's are ALL 15V (Supply V), regardless of f. CMOS gives you the rails out. As always, individual performance may vary due to factors too numerous to start discussing. More later...
Oh! Here's the schematic all this info is/will be based on:   http://moosapotamus.net/IDEAS/ADAflanger/ADA_MN3007/FlangerClone_SCH_rev5_MN3007_jan2010.gif

     4007                     4047              3007                 4049 (see note above)
1- NC                 1- 14.9 - 10         1- 15                   Pins 1 & 16-  15
2- NC                 2- .15 - 5             2- ~7.5               Pin 8- 0
3- 0                   3- 7.9 - 8.3          3- 8.4                  Pin 13- NC
4- NC                 4- 15                   4- 1                    ALL other pins-  ~7.5
5- NC                 5- 15                   5- 0
6- 0                   6- 15                   6- ~7.5
7- 0                   7- 0                     7- 7.2 - 5.8
8- NC                 8- 0                     8- 7.2- 5.8
9- NC                 9- 0          
10- 5.9 - 3.1     10- ~7.5                
11- 7.9 - 8.3     11- ~7.5
12- .15 - 5        12- 0
13- NC             13- 14.9 - 10.5
14- 15              14- 15  

[StephenGiles]

You seem to have the correct clock voltages, I'd wager the audio is blocked somewhere. Test output of each opamp in audio path before BBD, then remove BBD (with power off) and test for output on all post BBD opamps.

[oldschoolanalog]

Just a quick note to avoid confusion. The V's I posted are from a properly functioning unit.
I promised to do this for reference purposes several posts ago. I'll post the rest of the (correct) V's later as promised.
Until then, anyone with signal issues should take Stephen's advice in the above post.
Signal source & audio probe anyone?

[gigimarga]

Thank you very much oldschoolanalog!
You're great amd these voltages are a big help for me (and others builders, of course)!

My voltages on BBD are almost like yours, but the mainly problem seems that IC2 from Audio part (http://solderman.fatabur.se/ada/ADA%20Audio.jpg) becomes hot very fast
On 4007 some voltages are off, but I will recheck all tomorrow, with a clean head

[oldschoolanalog]

Here are the rest of the V's. All conditions as per above post.
All the Best!

       IC 1            IC2            IC3                IC4 (LFO; slowest speed setting)
1- 7               1- 4.7           1- 6.9          1- 13.4
2- 7               2- 4.7           2- 7             2- 7.1
3- 6.6            3- 4.7           3- 6.9          3- ~2 - ~12.4
4- 13.9          4- 13.9         4- 15            4- 0
5- 8.3            5- 7             5- 7              5- 6.9
6- 8.4            6- 7             6- 7              6- 6.9
7- 8.4            7- 6.4           7- 7.1          7- ~2.5 - ~11.8
8- 7               8- 7             8- 5.9 - 3.1   8-14.8
9- 7               9- 7             9- 5             
10- 7             10- 7           10- 5
11- 0             11- 0           11- 0
12- 6.9          12- 6.9        12- 3.9         
13- 7             13- 7           13- 3.9
14- 7             14- 7           14- 2.1 - 11.6

PS: Nothing should get hot. Especially the op amps. The 7815's on all my A/DA builds don't even get warm. And this is w/out using heat sinks.

[Skruffyhound]

Thanks for that info Dave, very helpful.

[StephenGiles]

I always have an output test lead with a jack socket on one end and two fly leads with crocodile clips on the other, in order to test the output at various points through the circuit. An additional wire with croc clips on both ends is good for bypassing BBD sockets - because you have removed it for this test haven't you

Also very important - TEST WITH BATTERIES