A/DA Flanger does TZF?

[moosapotamus]

I'm still planning to get these boards fabbed from ExpressPCB. For the most part, this is based on Mike Irwin's adaptation of the ADA circuit for use with the SAD1024. But, it also includes the threshold control and some other things to make adding your own mods much easier. Yeah, I know it's taking me a while. But, I think it's damn near ready.

Regarding part values, when I start building mine I'm planning to start with the values shown on Stephen's drawing instead of those shown in the ADA schemes.

Here's the current state of my layout. Overall dimensions are 5.5" x 3.5". I think it's just about done...

ADA Flanger Layout

TZF mod - I was planning to just put in an insert (send & return), so that any other circuit or pedal could be used for the second delay line. Looking at Jürgen Haible's Storm Tide flanger, he used buffers on both the send and the return. I guess that's cool if you use another pedal, but maybe something to be aware of if you're going to try putting you own circuit together. So anyway, since I'm not 100% positive of the best places for the send and the return, I added extra pads at the outputs of IC1a and IC1b as potential send outputs, and extra pads at the inverting inputs of IC2c (shown as IC3c on Stephen's scheme) and IC2b as potential return inputs. Any other thoughts or ideas?

True stereo outputs mod - markus posted a drawing of a second output buffer that, I think, was a duplication of the existing mono output buffer. I guess I'm not sure I understand how that would give stereo. Seems like it would be more like dual-mono. For a second true stereo output, wouldn't you need to invert the delayed signal (relative to the main output) before you mix it with the clean signal? Or, am I not thinking about this in the right way?

Vibrato mod - Added pads between R41, R42 and the inverting input of IC2b (output buffer). To build it stock, just put in jumpers. To add a vibrato switch, put a jumper from R42 to IC2b (delayed signal) and a SPST switch between R41 and IC2b (clean signal). To add a wet/dry blend pot, tie one pot leg to the pad at R41, the other pot leg to the pad at R42, and the wiper to one of the pads at the inverting input of IC2b.

LFO speed switch - Notice the two electro caps both labled C24 near the speed pot. There are pads that will allow you to switch one of them in/out of parallel with the other. You'll just need to experiment to find the cap values that give you a range of speeds that you like.

4047 timing cap - As Stephen metioned earlier, this is a good spot for a variable cap, if you can get one. As an alternative to the variable cap, between IC5 and IC6 there are two identical caps both marked 39p... same deal as with the LFO speed caps. There are pads to let you switch one in/out of parallel with the other.

Bounce - Also, as Stephen mentioned earlier, and illustrated with a drawing (thank you, Stephen!), the bounce circuit basically replaces R65, between the range pot and the clock range trim.

Please let me know if there are any other ideas, and especially if anyone finds any mistakes in the layout.

Thanks!
~ Charlie

[oldschoolanalog]

Nice work Charlie!!! Thanx for all the efforts.  LFO defeat switch? 

[puretube]

for those who missed it, 2 years ago:
http://www.diystompboxes.com/smfforum/index.php?topic=25681.msg170884

here`s wondering, though, why the need for a variable capacitor,
when the frequency range of a 4047 with one pot and one fixed cap
can span from  <5kHz to >1.6MHz?

the simulated variable pot with the 4007 along with its adjacent limiting resistors
is the place to play with, IMHO... 

[markusw]

Yeah, I know it's taking me a while. But, I think it's damn near ready.

Cool! Thanks a lot again 

True stereo outputs mod - markus posted a drawing of a second output buffer that, I think, was a duplication of the existing mono output buffer. I guess I'm not sure I understand how that would give stereo. Seems like it would be more like dual-mono. For a second true stereo output, wouldn't you need to invert the delayed signal (relative to the main output) before you mix it with the clean signal? Or, am I not thinking about this in the right way?

With the second output buffer it should be stereo, at least if the connection between IC1c  and IC2b is removed. Two separate signals would be send to the two output jacks for in-air mixing. Don't know if regeneration will work though.  If the connection ("optional jumper" in my drawing) is  there, stereo out still might work to some extent but I' not sure on this.  Could be tested with the optional jumper (also if regeneration might work). IMHO at least TZF in mono sounds best w/o regeneration anyway .

TZF mod - I was planning to just put in an insert (send & return), so that any other circuit or pedal could be used for the second delay line. Looking at Jürgen Haible's Storm Tide flanger, he used buffers on both the send and the return. I guess that's cool if you use another pedal, but maybe something to be aware of if you're going to try putting you own circuit together. So anyway, since I'm not 100% positive of the best places for the send and the return, I added extra pads at the outputs of IC1a and IC1b as potential send outputs, and extra pads at the inverting inputs of IC2c (shown as IC3c on Stephen's scheme) and IC2b as potential return inputs. Any other thoughts or ideas?

Had one more look at puretubes "guidelines" on  having two separate delay lines in http://www.diystompboxes.com/smfforum/index.php?topic=25380.msg166584.
Since IC2b acts as a low-pass filter (deemphasis) it probably might be the best to recombine the two delay lines (more or less at the output jack) at the output of IC2b.
The IC2b stage would be duplicated for the second delay line (i.e. the already filtered signals get mixed passively like in the 9V Mistress).

Regarding the best place for tapping off the signal for feeding the second delay line I still think that the output of IC1a would be appropriate.
As far as I understand the IC1a stage does the preemphasis (i.e. it boosts the highs). Low-pass filtering is performed at the 1C1b stage (which would be duplicated for the second delay line). Please correct me if I'm wrong.
Don't know what's the frequency cutoff of the 100p in the IC1b feedback loop though.

Any comments on this?? e.g. from puretube

Re analog kid's LFO issue: if I understood it correctly the integrating cap's polarisation is reversed in every second half of the LFO cycle. Maybe the electrolytic cap you're using doesn't like this (or at least doesn't work properly at higher LFO rates when polarised the "wrong way" in every second half of the LFO cycle). You might try to replace the 22µ cap with two 47µ caps soldered tail-to-tail (negative to negative). Don't know if it will help but it doesn't cost much to try

Please let me know if there are any other ideas, and especially if anyone finds any mistakes in the layout.

Will happily check it BTW, does ExpressPCB show air wires (connections that are not done yet)??



Markus

[oldschoolanalog]

For simple RC filters, f=1/ 2pi RC is your friend. This gives you the point where the f is -3db.

[markusw]

For simple RC filters, f=1/ 2pi RC is your friend. This gives you the point where the f is -3db.

Thanks!
Basically I know this formula but in this case I don't know which resistor to use for the calculation (is it the 47k in the feedback loop?  Argh, newbie alert )

[oldschoolanalog]

Yes to 47k, F'back loop. These values give a Hi freq rolloff of -3db @~34kHz.  The stability thing, I guess.

[puretube]

anyone read the datasheet thoroughly:
MN3010: insertion loss typ:0, min:-4dB;
SAD1024: gain: 1,2 (depending on load resistance).

IMHO, this does make a difference, when comparing values in
an original "ADA 3010"
with those in
the "Irwin/Giles 1024"...

[puretube]

concerning wrong values...

[markusw]

Yes to 47k, F'back loop. These values give a Hi freq rolloff of -3db @~34kHz.  The stability thing, I guess.

Thanks! Learned something today....

anyone read the datasheet thoroughly:
MN3010: insertion loss typ:0, min:-4dB;
SAD1024: gain: 1,2 (depending on load resistance).

read...yes..understand...not always (at least in my case)
however, regarding the insertion loss/gain it's not that hard

[moosapotamus]

LFO defeat switch? 

Isn't this achieved by turinig the range control to minimum (fully CCW)?

the simulated variable pot with the 4007 along with its adjacent limiting resistors
is the place to play with, IMHO... 

So, that would be the 47R/2M2 between the 4007 and the 4047, yes?

With the second output buffer it should be stereo, at least if the connection between IC1c  and IC2b is removed. Two separate signals would be send to the two output jacks for in-air mixing.

OK. I think I got it, now... straight signal to one output, delayed signal to the other output. In the back of my head I guess I was thinking you could do the same thing by adding a seperate direct output and installing a vibrato switch to eliminate the dry signal from the main output.

Since IC2b acts as a low-pass filter (deemphasis) it probably might be the best to recombine the two delay lines (more or less at the output jack) at the output of IC2b.
The IC2b stage would be duplicated for the second delay line (i.e. the already filtered signals get mixed passively like in the 9V Mistress).

Not sure I'm following... wouldn't that bypass the existing buffer for the SAD output, the even/odd switch and the enhance (regen) controls?

Regarding the best place for tapping off the signal for feeding the second delay line I still think that the output of IC1a would be appropriate.
As far as I understand the IC1a stage does the preemphasis (i.e. it boosts the highs). Low-pass filtering is performed at the 1C1b stage (which would be duplicated for the second delay line).

So, the second delay line would not get the low-pass de-emphasis? I'm not sure about that, but that's why I just put pads at the outputs of both IC1a and IC1b. So, it'll be relatively easy to try it either way and go with whichever seems to work best.

BTW, does ExpressPCB show air wires (connections that are not done yet)??

No. If a connection is not done, it will not be shown. But, all the required on-board connections are done in my layout. The only connections that are not shown are for off-board components like pots, jacks, switches, etc...

Thanks y'all!
~ Charlie

[puretube]

yes:
pins 11&12 of the 4007 represent the (variable) resistor being substituted by it,
[which controls the frequency of the 4047by resembling the frequency-controlling resistor between the pins 2&3 of the latter];

in series with it, the "47R" limits F_max
when the 4007 is at its smallest value;

and parallel to it,
the "2M2" limits F_min
when the 4007 is at its largest value.

now I don`t know the minimal value of the 4007,
but I do know, that the resistor between pins 2&3 of the 4047*
varies the frequency from ~10KHz to ~6MHz (on pin13)
when R varies from 1M to 470R...
(with one cap of 50pF).

pins 10&11 of the 4047 put out 5kHz to 3MHz, in above example.

*= measured with equivalent "discrete" inverter based oscillator

[oldschoolanalog]

I was thinking LFO defeat switch a la EM/DEM. This could be added later w/out much of a problem. Nothing to sweat Getting all these component values sorted out seems to be the order of the day now.

[markusw]

Isn't this achieved by turinig the range control to minimum (fully CCW)?

That's what I thought too....

Not sure I'm following... wouldn't that bypass the existing buffer for the SAD output, the even/odd switch and the enhance (regen) controls?

Sure....
Sorry, please forget that crap....  Better think twice before writing.
I'd go with the input of IC2b as return point.

So, the second delay line would not get the low-pass de-emphasis? I'm not sure about that, but that's why I just put pads at the outputs of both IC1a and IC1b. So, it'll be relatively easy to try it either way and go with whichever seems to work best.

The second delay line would also get it's de-emphasis (which is done by stage IC2b). Just the input of the second delay line would get a separate lp filter (a duplicate of the IC1b stage).

Yes to 47k, F'back loop. These values give a Hi freq rolloff of -3db @~34kHz.  The stability thing, I guess.

This is actually quite interesting since in the ADA the BBD is tuned to run in a clock range from 17.4 kHz to 650 kHz.  ?

No. If a connection is not done, it will not be shown. But, all the required on-board connections are done in my layout. The only connections that are not shown are for off-board components like pots, jacks, switches, etc...

That's a pretty cool feature of Eagle CAD. It shows you all open connections as yellow lines. Also you can check whether you did a wrong connection automatically. Takes some time to get used with Eagle though.


Re analog kid's high ouput level.

R43 (at pin 6/7  output amp)   27k instead of 4.7k  ?

IMHO the 4.7k should give you a much higher output than the 27k... Might be a place to check


Markus

[analog kid]

 I  hate to keep jumping in with my tsing when the brainstorming on layout changes has kicked back in ( which btw reminds me I wonder If I should've took all my questions to a thread separate  )  but I hope it all applies!
question:  concerning pin 10/11 from 4047 feeding 5/7 of 4049, I've read over and again these need to be indentical in vltg.  I am just wondering how 'identical' they need be. At least using theDMM I have I am getting  7.43-44 on pin 10 and 7.44-45 on pin11 . Now I know this is very small but Ithought worth asking. It's very repeatable and there's always a difference of .01 between these pins.  Non-critical?

Range CCW defeats LFO. And my setting just between say CCW and 1 is the only place I can get fairly even sweeps even at higher speeds. The ugly detuning and abrupt stagger kicks in as it's increased from here.

R43 (at pin 6/7  output amp)   27k instead of 4.7k  ?

IMHO the 4.7k should give you a much higher output than the 27k... Might be a place to check

Ok This is one particular parts difference I have been looking closely at myself but let me point out what i've got going on here.   My flanged output volume is significantly DECREASED from the bypassed.  And the value I have there is the one in the parts lists , 4.7k , and in the MI/Giles Schem. If 27k is going to cause an even more significant vol drop then it's not an issue. 
I planned to half the values of R41 / 42 at the output mixer  to see how the vol drop is affected BUT I don't want to mask another problem! maybe at the input IC1 (where my enhance intensity issue also probably dwells btw)

[markusw]

Range CCW defeats LFO. And my setting just between say CCW and 1 is the only place I can get fairly even sweeps even at higher speeds. The ugly detuning and abrupt stagger kicks in as it's increased from here.

Did you try to replace the 22µ with two 47µ tail-to-tail?

My flanged output volume is significantly DECREASED from the bypassed.

Ups, sorry. Should have read your posts more carefully...

[analog kid]

apolgies Markus , I have missed what you refer to by the 22uf ? were you meaning two 47uf instead two 33uf?    sorry     I recoginize that same pair a 33 caps betweem Range/Rate I think

[puretube]

it absolutely doesn`t matter "what you get out of the 4047", voltagewise!
it goes into the 4049s,
and almost anything you feed them with,
they will put out whatever is on their RAILS...

With a DMM (digmultmeter), you won`t measure much correctness at these frequencies...

a SCOPE will show what is neccessary to view - otherwise: the ears will have to decide.

[oldschoolanalog]

The LFO defeat switch as referred to on pg. 7/posts 125 & 126 of this thread.

[markusw]

apolgies Markus , I have missed what you refer to by the 22uf ? were you meaning two 47uf instead two 33uf?    sorry     I recoginize that same pair a 33 caps betweem Range/Rate I think

I thought you were using one 33µ as integrating cap (like in Stephens schem). If you're already using two of them replacing them with 47µ caps shouldn't change anything.
Another communication issue 

Markus