ADA Flanger Trim Settings

Started by rove, November 08, 2007, 11:47:33 AM

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rove

Hi, I waded thru the big ADA thread last night and have read thru all of it at some point, but having trouble digging up suggested methods to set up the trim pots or even a reference to what they all do.  I just got mine put together and I am pretty sure it is working as it should except for some calibration tweaks, it is pretty crazy how interactive most of the trims are.  I am calibrating by ear and so far just comparing some settings from the ADA manual to what I hear and its pretty close.
So for those of us calibrating these beasts by ear does anyone have any tips or links to share?
I thought it may be useful for this subject to have its own thread so that everyone building these doesn't have to sift through 30+ pages.
thanks.

slacker

You should be able to pretty much follow the instructions Charlie posted on page 32 of the big thread, http://www.diystompboxes.com/smfforum/index.php?topic=49929.msg434438#msg434438

The only trims that might be tricky to set by ear are R4 and R5. You can probably do it like this, follow Charlie's instructions until you get to doing R4, then instead of setting the frequency adjust R4 until you can hear a high pitched whine. That means the clock frequency has dropped into the audio range, if you then slowly turn R4 up until the whine stops that will be a good starting point. I'm not sure how to set R5 except to adjust it to with the manual on maximum until you get a nice ringing sound on high notes, that's what mine sounds like anyway.

I don't know if this will work but you might be able to set R4 and R5 using a multimeter. The frequency the 4047 runs at, which controls the sweep, is set by the voltage on pin 10 of the 4007. The range of this voltage is set by the trim pots so in theory if you set pin 10 for certain voltages that should give you the right frequencies.

On mine the voltages on pin 10 of the 4007 are as follows.
Manual on minimum 7.32volts which gives a frequency of ~35Khz at the test point
Manual on maximum 4.81volts which gives a frequency of ~1.3Mhz at the test point

You could try setting yours to those voltages and see what it sounds like.
It would be interesting if someone else could measure their pin 10 voltages to see if they are any where near mine, just to see if this method would work.


rove

Thanks, Slacker, for that info and link.  I had been sifting through the big thread from back to front and from front to back and had yet to zero in on that page!
I am going to give the calibration another shot, feeling more confident now.
Also, for the sake of having all the Trim info in one thread, I should mention that it is necessary to sub a 4.7k resistor for the 10k resistor labeled R13, once I did that I got more usable trim range with TR1/TR2.
I will update the post as I work my way through this, thanks again.

rove

Well I pretty much had to read thru most of the thread again anyways, but having the starting point helped.  I followed Charlie's and Slacker's suggestions, and while a bit frustrating it was ultimately doable and, I believe, will be much easier to do on my rev 02 board having gone through the procedure once.  One thing that was causing me grief was the fact that I forgot to jumper the expression pedal pads, something I only figured out after reading an offhand reference in the big thread as it doesn't seem to be mentioned in the build notes--though it is quite clear on the schematic.
The sound of this thing is great, the only modifications I did was to add the vibrato switch (spst to break the connection at pad C) which is pretty neat sounding, and to run it off of 2 9 volts instead of wall power (don't have an 18 volt supply!), which I believe also affected the calibration procedure a bit as my voltages were all a bit low.
I think I will go back in and add the expression pedal as well, but for now I don't have one.  Great work on the boards, charlie, and thanks to everyone that has contributed to the big thread, I hope I haven't confused matters by starting another thread...

chemosis

are any of the trimpots worth mounting for tweakers that like insane sounds??

chuckd666

Look up the build doc for the Flintlock Flanger. It's an ADA clone and might lead you in the right direction?

slacker

Quote from: chemosis on September 24, 2016, 07:30:51 PM
are any of the trimpots worth mounting for tweakers that like insane sounds??

I don't think so, the normal controls get pretty insane already, what you can do is set some of the trimmers to get more extreme sounds from the normal controls. For example you can set the enhance trim so it will self oscillate when the enhance knob is turned all the way up. You could also set the clock trimmers to give a bigger range than intended so it goes down almost to slapback delays, the range and manual controls will then let you get normal flanging sounds or complete madness.

armdnrdy

What Ian said is true.

The A/DA isn't your regular ho hum flanger. There are a multitude of "musical" sounds available...along with a bucket full of "outside of the box" effects that can be obtained by experimenting with different settings.

Overall...one of the most versatile production flangers.
I just designed a new fuzz circuit! It almost sounds a little different than the last fifty fuzz circuits I designed! ;)

12Bass

Apparently A/DA changed the factory calibration in the new PBF so that it self-oscillates, (essentially like the Paul Gilbert mod).  As mentioned, the A/DA already has a huge range of adjustment.  Other than the enhance trimpot, I'm not sure how much use there would be in adjusting the others.  The bias pot is definitely out.  The delay time adjustment might be worth playing with, perhaps for getting into slapback echo range, but the BBD would be getting rather noisy with those long delays.  Given the default adjustment range, I get the impression that friends who have borrowed my SAD1024 A/DA clone missed out on most of its hidden talents, because the normal sounding flanger "sweet spots" can be a little difficult to find among the more extreme settings....
It is far better to grasp the universe as it really is than to persist in delusion, however satisfying and reassuring. - Carl Sagan