TZF Electric Mistress (sample and layout)

[markusw]

For those of you who are not too distracted with pain when investing a second SAD1024 here's a project file I put together for the TZF board.

http://www.diystompboxes.com/DIYFiles/up/TZF_Mistress_v11_project_file.pdf

Will try to make some sound samples later.

Markus

[Geoff Hunter]

Feel free to shoot me down on this one but.......

Could you make a short serial "delay" out of a

LM311 for comparing the input signal to Vcc/2 and outputting high/low
a CMOS CD4517 128 bit serial shift register clocked by high speed clock (~1Mhz) for clocking the shifter
R-C network to smooth it out? (sure you could get ~5-10ms delay out of this)

This is like a PWM delay?

I saw a website showing exactly this last year, but damnit I can't find it now. 

EDIT- Found it! http://www.elecdesign.com/Articles/Index.cfm?AD=1&ArticleID=8056

[Mark Hammer]

Mark, thanks a lot for this explanation!! Your answer definitely improved my knowledge of clocking BBDs a lot

Re assymetric versus symmetric TZF: personally I prefer to have the TZF points evenly distributed. However, moving the clock pot of the fixed delay to the pannel won't hurt for sure.

How does the SAD1024 compare to let's say BL3207 or BL3208 BBDs regarding clock noise??

Forgot to mention before: coupling caps and the 2-pole active lp filter I added for the fixed delay were designed to keep exactly the same frequency response (up to about 20 kHz) as for the "dry" signal in the Mistress. Don't know whether this is important though. I just wanted to change the frequency response of the Mistress as little as possible when switching to TZF.

Regards,

Markus

Don't thank me.  Thank Mike Irwin.  I can only hope I am doing his vast expertise justice.
The SAD1024 tends to be found in flangers that can sweep pretty high (i.e., to very shot delays) because it was intended for video sampling/processing purposes too, which meant that it came ready to handle very high clock speeds without the fancy interventions needed by the Matsushita chips.  Fundamentally, it is not a "better" chip, merely more readily suited to certain applications.  There are probably spec differences in S/N ratio, etc. but these are always predicated on certain conditions of use so I wouldn't turn to them as the last word on relative noisiness of the chips themselves.

That being said, the ability to use it as two 512-stage sections in parallel (like the MN3010) permits somewhat quieter operation via use of noise-cancelling techniques.  The other thing is that if it was being used for higher clocking, the filtering requirements for keeping clock noise out of the audio path were more relaxed, so people associate it with greater bandwidth and less clock whine too.

[markusw]

Feel free to shoot me down on this one but.......

Could you make a short serial "delay" out of a

LM311 for comparing the input signal to Vcc/2 and outputting high/low
a CMOS CD4517 128 bit serial shift register clocked by high speed clock (~1Mhz) for clocking the shifter
R-C network to smooth it out? (sure you could get ~5-10ms delay out of this)

This is like a PWM delay?

I saw a website showing exactly this last year, but damnit I can't find it now.

EDIT- Found it! http://www.elecdesign.com/Articles/Index.cfm?AD=1&ArticleID=8056

Thanks a lot Geoff!! Unfortunately, I do not have the faintest idea how shift register works. Will require some reading

Don't thank me.  Thank Mike Irwin.  I can only hope I am doing his vast expertise justice.

Thanks to Mike Irwin Still thanks to you Mark also for your clarification on BBD specs!

BTW,

here are the samples. Actually, it's just one plus a short one to give you an idea of the noise (done at exactly the same levels while recording as the real one).

http://www.diystompboxes.com/DIYFiles/up/wind_me_up.mp3

5 ms fixed delay, Rate=0, Range=100%, feedback=0%

http://www.diystompboxes.com/DIYFiles/up/noise.mp3

It's still wired with alligator wires and not boxed.

Markus

[Mark Hammer]

I'm not hearing anything on the noise file but the "Wind Me Up" file is sweet and bang on what the unit ought to do.  Gotta love that through-zero point where just for an instant nothing feels coherent, and then everything seems to come back together.

[markusw]

I'm not hearing anything on the noise file but the "Wind Me Up" file is sweet and bang on what the unit ought to do. Gotta love that through-zero point where just for an instant nothing feels coherent, and then everything seems to come back together.

Ahm, it's just a little noise. Maybe I exaggertated a bit.

Currently, I have the unit connected to my notebook while listening to mp3's. Simply love to hear that TZ point again and again....

[StephenGiles]

Forget the noise, it's nothing. Sounds very good indeed.

[nelson]

If thats the noise with breadboard and alligator clips please box this up in one 1590DD and call it one of the first true through zero flangers that is easy and sounds great.


Would someone trade me an SAD1024, I have lots of parts.......MN3005?

[markusw]

If thats the noise with breadboard and alligator clips please box this up in one 1590DD and call it one of the first true through zero flangers that is easy and sounds great.

It's already two etched boards but the wiring is still with alligators

Would someone trade me an SAD1024, I have lots of parts.......MN3005?

Considering the price of the MN3005 and the SAD1024 I'd order the SAD1024 from Steve

Regards,

Markus

[RaceDriver205]

Oh, great. Now I have to build one of them too. 

[markusw]

Oh, great. Now I have to build one of them too.

Sorry

[RaceDriver205]

Its it an add-on board for the tonepad EM? Or the GGG one? Would it make any difference?
Thanks

[markusw]

Its it an add-on board for the tonepad EM? Or the GGG one? Would it make any difference?
Thanks

It's for the non-deluxe 9V version at tonepad with the layout in http://www.diystompboxes.com/smfforum/index.php?topic=44582.0

Maybe you can use it for the deluxe version at GGG too.

Markus

[RaceDriver205]

Dont suppose you have/could do a sample with a guitar (distorted)?
This thing is 'broken ground' after all.
Cheers RD205

[markusw]

Dont suppose you have/could do a sample with a guitar (distorted)?
This thing is 'broken ground' after all.
Cheers RD205

Sorry, I don't have a guitar. Don't think that with bass the TZF point will be very interesting.

Regards,

Markus

[RaceDriver205]

Really! You have 471 posts at DIYStompboxes.com and you don't have a guitar!
Never mind then, its not a big problem.

So the idea of making a flanger through-zero is simply to apply a pre-delay at the input? Is that all you need to do? (2 new sad1024s is proving hard to justify  )

[markusw]

Really! You have 471 posts at DIYStompboxes.com and you don't have a guitar!
Never mind then, its not a big problem.

So the idea of making a flanger through-zero is simply to apply a pre-delay at the input? Is that all you need to do? (2 new sad1024s is proving hard to justify  )

Yup, I just play bass guitar

It's not really a pre-delay at the input but a  fixed delay of the "dry signal" that gets mixed with the modulated delayed signal. That's it. But basically, as Mark Hammer mentioned several times you could stick in any fixed delay.
Alternatively, you could invert the LFO once and use the inverted LFO to drive the second delay (like with the DimC TZF mod).

[RaceDriver205]

thanks markusw, ill look into that. Should be able to ge a cheaper delay than the sad1024, and apply it to my ultraflanger.

[markusw]

thanks markusw, ill look into that. Should be able to ge a cheaper delay than the sad1024, and apply it to my ultraflanger.

should work the same. to my knowledge it's just important to have the fixed delay line lp-filtered properly to avoid heterodyning. in case of the TZF Mistress I added an additional active 2-pole lp filter. after looking at the Ultra Flanger schem this is basically the same what John Hollis did for the variable delay. also it might be a good idea to have the ps for the fixed delay separated from the main board.

good luck

[bwanasonic]

Really! You have 471 posts at DIYStompboxes.com and you don't have a guitar!

As a guitarist, I'm am prone to this same chauvinism, but it is always wise to keep in mind the "Big Picture" of FX users. I have plenty of old 4-tk tapes of *guitar free* material, using vintage *classic* effects (Thomas Organ Stereo Cry-Baby Fuzz/ Wah, EH Micro-Synth, Ibanez CS-505 chorus) on drum machines, harmonicas, Casio keybords, etc.

Kerry M