A/DA Flanger does TZF?

[StephenGiles]

Even using just one modulated clock and an unmodulated version of it?

[puretube]

...Nevertheless, a building block of a circuit would always be welcome in this area, if only for something new to try, and there may well be ICs available which already contain much of the circuitry required, or maybe just require a few extra components to build say the quadrature LFO...

there are...  

[puretube]

Even using just one modulated clock and an unmodulated version of it?

yes: F1 is the unmodulated (fixed) one in above example...

[Mark Hammer]

I haven't been part of this entire thread, so maybe I'm just adding noise here.  Ton's comments about my suggested dual-BBD/one-clock approach never reaching below the shorter of the two delay times is absolutely spot-on accurate.

That being said, the challenge, as I see it at least, is that some folks want TZF, while others simply want what TZF capability also makes possible, and that is a sweep to near-zero.  While buffering the clock (actually, more like buffering the clock inputs on the BBD) will permit much higher clock speeds from any of the Matsushita chips, and consequently shorter minimum delay times, there ARE still limits to how fast you can clock them.  What I have attempted to suggest is a way of achieving the "near-zero" capabilities of true TZF units without either a) taxing individual BBDs too much, or b) introducing heterodyning risk by means of two individually-clocked BBDs.

The downside, of course, is that while one can tolerate the needed lowpass filtering of the delay path because the dry path is untampered with, inserting a BBD into the "clean/dry" path obligates one to use some lowpass filtering for noise control and that may erode some of the sparkle.  Still, it may be an epxeriment worth trying out.

[StephenGiles]

It would be interesting to know just how long it took to get the Itchycoo Park TZF right on the record back in 67, I might ask Kenny next time I see him.

[puretube]

probably a multiple of 2:52 

[StephenGiles]

Well, it might just be easier to get hold of 2 old reel to reel tape recorders and do it that way

[puretube]

Sure, sir!
but in a live-on-stage-situation you wouldn`t want to let the audience
wait twice the time that the song lasted... 

[StephenGiles]

No.....let the audience wait!!

[Mark Hammer]

Couldn't you just make them run around in circles really quickly while the band stood in one spot and played.  I mean, ANY way you can get your Doppler fix is legit, right?

[StephenGiles]

Ah, try this - wait for a jet to fly over, crouch down and lift yourself up slowly, good exercise and a good doppler effect too!

[puretube]

Couldn't you just make them run around in circles really quickly while the band stood in one spot and played.  I mean, ANY way you can get your Doppler fix is legit, right?

"rotate yourself around the speaker" ? ...

my favorite Through Zero thread...

[StephenGiles]

http://focus.ti.com/docs/prod/folders/print/tle2084.html

This quad opamp chip is listed by TI as an alternative to the MC34074 suggested by Mike Irwin - as a better chip to use for the MC3403. Samples are available.

[moosapotamus]

Thanks, Stephen.

The TLE208x series of JFET-input operational amplifiers more than double the bandwidth and triple the slew rate of the TL07x and TL08x families of BiFET operational amplifiers.

Well, that certainly does sound interesting.

~ Charlie

[StephenGiles]

What news?

[moosapotamus]

Big thanks to oldschoolanalog for proofing my layout...
http://www.diystompboxes.com/smfforum/index.php?topic=51692.msg392549#msg392549

Planning to make final corrections and send in the PCB order tonight.

If anyone else would like to give the doc's a final check...
http://moosapotamus.net/IDEAS/ADAflanger/ADAflanger.html
... please let me know ASAP if you find anything else that could use a tweak.

Thanks!
~ Charlie

[sfr]

Not sure where to ask this, so why not add another post to this huge thread . . .

Populating my board (thanks again, Charlie!) Figuring out what to do w/C24 - C25 - I guess I'm going with two 33uf caps like Rev. 3.    From looking at the various schematics - if I went with one cap, does it need to be non-polarized?  Looking at [ur=http://moosapotamus.net/IDEAS/ADAflanger/ada_MI_1024.jpgl]this[/url] schematic, it appears I can use a polarized cap with the positive facing the range pot and output of IC4b.   

The switch connecting to the speed pot between the two caps confuses me though, because it seems like it would break the connection of the feedback loop on one setting. Someone care to explain what I'm missing? 

Regardless, if I went with the switch, would I *need* NP caps for both of these caps?  Or could I get away with only one NP cap? 

Also - I suppose I can sit down and figure out the current draw, but anyone know off the top of their head if a 78L15 would work or this instead of the 7815?  Just because, well, I have that here in my parts bin.   Looking through the thread, it seems like Analogkid had his working with one, but I may be misreading.

Any recommendations for the FET in this?  2n4393 is the "correct" part, if I understand?

[moosapotamus]

I couldn't find any definitive info about the orientation or size the LFO cap(s) either. I was thinking of just using NP caps, myself, so I wouldn't have to worry about orientation. If you use polarized caps, you might have to orient them opposite to the way they are labled on the PCB.

On the PCB, I set up C24/C25 with pads that will let you use just one cap (Rev4), two caps in series (Rev3) or switch between the two (Rev3 or Rev4) to get a wider range of speed settings.

For one cap, only install C24. Don't install C25. Put a jumper to connect C24's positive lead to the speed pot's lugs 1 & 2.

For two caps, install both C24 & C25. Put a jumper to connect the positive leads of both caps together.

To switch between C24 only and C24/C25 in series, use a SPDT (Single Pole Double Throw) toggle switch. Tie the pole to the positive leg of C24. Tie one throw to the positive leg of C25. Tie the other throw to the speed pot's lugs 1 & 2.

I don't know about the expected current draw. But, I think analog kid settled on a 5485 for the FET in his build.

~ Chalrie

[sfr]

To switch between C24 only and C24/C25 in series, use a SPDT (Single Pole Double Throw) toggle switch. Tie the pole to the positive leg of C24. Tie one throw to the positive leg of C25. Tie the other throw to the speed pot's lugs 1 & 2.

Ah, yeah, that makes more sense and is what I ended up at this morning.   

The "ADAflangerPCBrev01notes" file from the site mentions tying the pole to Speed pot lugs and the throws to the two caps and that didn't make sense to me.  I was fairly tired and under the weather when I posted the other night, and as such realized that was incorrect, but didn't have the sense to just sit down and figure out how to wire that switch correctly.  Sorry for wasting folk's time.  Nyquil and the internet apparently don't mix well. 

So now that circuits are actually making sense to me, I see that these caps are basically adjusting the range of speeds available via the speed knob, correct?  Now I have a better idea what I'm doing.  As people start putting these together, I'd be interested to hear what they go with for various values, but at least now I can move forward.

What is going to change with the various values for the two C29s?  Won't changing the clock rate again result in just a different range of available speeds, or am I missing something? 

I'll just order the LM7815 - I thought I had all the parts I needed for this here, but it turns out the usual trimpots from Smallbear I have in the parts drawer don't really want to fit this board, (now to trawl through the threads and find where Charlie posted a Mouser part # for trimpots . . . ) so I'll need to order some parts before I can finish this anyway. 

Thanks for the assistance.

[moosapotamus]

...it turns out the usual trimpots from Smallbear I have in the parts drawer don't really want to fit this board, (now to trawl through the threads and find where Charlie posted a Mouser part # for trimpots . . . ) so I'll need to order some parts before I can finish this anyway.

These fit great... 858-72PR20KLF

~ Charlie