A/DA Flanger does TZF?

[StephenGiles]

Indeed I do, which I bought from Maplin no less! I used it for the 4047 timing capacitor - if that's what it's called. Vibrato - perhaps you need a VCA on the control voltage so that it comes in gradually??

[markusw]

I don't think you need the extra 68K. You could just use the pad that the jumper goes to. In fact, maybe that would be the spot to put the switch.

The additional 68k would be just for testing whether feedback works in stereo. If this is case, in think the switch -as you mentioned- might be placed instead of the jumper.

I think this might also be the spot to put in a wet/dry (vibrato) control option, replacing the two 68K's with a 150K pot, if desired.

I like the idea of the wet/dry pot!  Including the TZF delay pot this would be 7 in total   

Thanks for the links! Definitely some interesting reads!!

Anyway, it seems that the older ~Rev3 configuration is preferred.

But in Stephens schem the rev4 configuration is used??

Regards,

Markus

[moosapotamus]

Indeed I do, which I bought from Maplin no less! I used it for the 4047 timing capacitor - if that's what it's called. Vibrato - perhaps you need a VCA on the control voltage so that it comes in gradually??

Nice! I'll bet that sounds pretty cool, yes? Do you recall what value you used?

I did a similar thing in a small clone chorus. I used a rotary to switch between 4 different timing caps (from 33p up to 330p) on the 4047. You can hear it in the clips of my wavy gravy. Individual caps on a rotary does give a bit of a 'pop' when you switch them, tho.

Maybe a foot pedal input to control the wet/dry mix would be the next best thing to a VCA for vibrato?

But in Stephens schem the rev4 configuration is used??

Perhaps Stephen just didn't have a chance to go back to revise the scheme?

I think at Mike's suggestion I replaced the diode network on the input with the simpler limiter network on one of the earlier versions.

... additional details in Stephen's build report, repeated a little further down in that same thread.


My remaining questions...

1) Should there be output level control(s) to allow for matching the effect and bypass levels?

2) Should the threshold control and all the related components be left out?

I'm inclined to answer 'yes' to both of the above.

Thanks
~ Charlie

[markusw]

Perhaps Stephen just didn't have a chance to go back to revise the scheme?


Quote from: StephenGiles on October 05, 2004, 07:50:48 PM
I think at Mike's suggestion I replaced the diode network on the input with the simpler limiter network on one of the earlier versions.

Hm, an easy explanation! 

Nice! I'll bet that sounds pretty cool, yes? Do you recall what value you used?

From the same thread:

I also managed to get a 22p - 65p variable capacitor from Maplin Electronics

My remaining questions...

1) Should there be output level control(s) to allow for matching the effect and bypass levels?

2) Should the threshold control and all the related components be left out?

I'm inclined to answer 'yes' to both of the above.

1) Yes

2) No, if there is enough space. If not used it could be turned off anyway. Probably at some rare occasions it might be good to have it, don't know.


Markus

[moosapotamus]

From the same thread:

I also managed to get a 22p - 65p variable capacitor from Maplin Electronics

I just finished reading that! Thanks!

Well, I'm with you as far as the "don't know" part about the threshold control. But, I have not been able to find a single post about the threshold control being useful. In fact, everyone reporting to have already built this seems to indicate that the threshold control is not really needed because the circuit is already very quiet on it's own. I'm just hesitant to include something that may be unnecessary. What about a couple more extra pads in the main layout that would allow it to be built on a small separate piece of perf and easily added as a mod?

~ Charlie

[markusw]

I'm just hesitant to include something that may be unnecessary.

It's just my spleen to build it as close as possible to the original 

Edit: On the other hand..... I browsed through some reviews at HC and it seems you can do some interesting sounds with the threshold pot. So probably for fun factor I would keep it.

Markus

[StephenGiles]

Do think what North Korea has built is near to the original

Better to be in bad taste than to taste bad!!

[StephenGiles]

"Perhaps Stephen just didn't have a chance to go back to revise the scheme?"

At the time there was no need, my build worked well, and I was just waiting for access to an A3 size printer so I could print and frame the drawing!!!

[markusw]

Should there be output level control(s) to allow for matching the effect and bypass levels?

Do you plan an additional control on the enclosure or one (two) trim pots? Trim pots wouldn't even be needed since

I just had to make 2 component changes to my ADA flanger because having found and installed an spdt footswitch, I discovered there was a volume drop on the flanged output. This was easily rectified by soldering a 39k resistor in parallel with each 68k resistor connected to the inverting input of the output mixer, making approx 24K, so probably 27k would do.
Stephen

For the dry/wet pot mod tapering resistors might be added to a 100k pot (just thinking loud  )

Markus

[markusw]

"Perhaps Stephen just didn't have a chance to go back to revise the scheme?"

At the time there was no need, my build worked well, and I was just waiting for access to an A3 size printer so I could print and frame the drawing!!!

Thanks for the confirmation! 
Stupid Q: do you remember the difference in sound between the two diode arrangements??

[markusw]

From the same thread:

There is so much variation of flanging sweeps available on this beast. I am going to have the max clock trim as a panel control because it provides continuous control of which part of the sweep area can be used. So, for instance, if a narrow sweep is set up, the max clock trim can fix whether that sweep is in the high or low end.

Another panel mount pot?? 

[StephenGiles]

"Perhaps Stephen just didn't have a chance to go back to revise the scheme?"

At the time there was no need, my build worked well, and I was just waiting for access to an A3 size printer so I could print and frame the drawing!!!

Thanks for the confirmation! 
Stupid Q: do you remember the difference in sound between the two diode arrangements??

None as far as I can remember.

[moosapotamus]

Do think what North Korea has built is near to the original

Better to be in bad taste than to taste bad!!

LOL I wonder where they got the schematic!?!
They must have had to do their own layout, too.

[moosapotamus]

Stephen & Markus - Thanks for chiming in on all this stuff!

OK. I think I've reached my threshold on the threshold question. Might as well keep it.

And, nix to the level trim(s). Like you point out, Markus, the two 68K resistors can be adjusted as needed for either straight-up level matching or as taper resistors if installing a wet/dry mix pot.

RE: max clock trim... that sounds cool, too. Easy mod to bring that out as a panel mounted control if desired.

RE: enclosure... I'm still thinking the 1590DD will be nice, but I think it might also be nice to orient it vertically so it fits better on a pedalboard. (Am I driving you crazy yet, Markus ). Placing a 1590DD sideways would be like the original, but would take up the space of ~3 normal size pedals. Vertically, it would take up half as much space, width-wise. Just a thought...

Here's my current list of potential mods, so far...

• TZF (second delay line TBD)
• True stereo outputs
• Additional direct/dry output (pseudo stereo with vibrato mod)
• Vibrato (switch to eliminate dry signal, or pot to control wet/dry mix)
• Foot pedal input jack for wet/dry mix
• Ultra slow/fast switch for LFO (dual, extended speed range)
• Bounce & Foldback (envelope controlled?)
  http://home.debitel.net/user/jhaible/jh_storm_tide_flanger.html
  http://img.photobucket.com/albums/v317/StephenGiles/bnce_clock.gif
• Variable cap(s) for 4047 timing capacitor
• Trim pots brought out as panel mounted controls

Also, Stephen - You suggested using a VCA in a couple different places... to bring up the output volume during deep sweeps, and to bring the vibrato (wet/dry mix) in and out. These seem pretty complex to me. Were you thinking of a relatively simple way to do these?

Any other mod ideas that I might have missed?

Thanks again, y'all!
~ Charlie

[StephenGiles]

I could be talking rubbish here, but couldn't the LFO drive an opto in the feedback of an opamp , which is configured for unity gain until the voltage reaches a point near to the high end of the sweep, when the volume reduces, and then provides a gain as required. When the sweep falls back down again, the gain would need to reduce back to unity. I'm assuming that the voltage rises for the top end of the sweep. If it falls, then I reach for the gin bottle!

For the Vibrato, doesn't the Boss Vibrato have a VCA on the controll voltage?

[puretube]

why is everybody talking about a "fixed delay" when it comes to TZF? ... 

[moosapotamus]

why is everybody talking about a "fixed delay" when it comes to TZF? ... 

I think Markus caught that earlier on in this thread....

* For the second delay line one pot for regulating the delay would be cool...

When I was listing the potential mods and wrote "second delay line TBD," I guess I was kind of leaving the configuration of that whole second delay section as an open option.

I could be talking rubbish here, but couldn't the LFO drive an opto in the feedback of an opamp , which is configured for unity gain until the voltage reaches a point near to the high end of the sweep, when the volume reduces, and then provides a gain as required. When the sweep falls back down again, the gain would need to reduce back to unity. I'm assuming that the voltage rises for the top end of the sweep. If it falls, then I reach for the gin bottle!

Sounds really cool, Stephen. But, how would you set the trigger point (voltage) to boost the gain (start lighting the LED) at the desired point in the sweep? Could it be as simple as just a trim pot on the voltage to the LED? And, might it be OK if I reach for tequila instaed of gin?

For the Vibrato, doesn't the Boss Vibrato have a VCA on the controll voltage?

Dunno... gotta check that out.

~ Charlie

[markusw]

why is everybody talking about a "fixed delay" when it comes to TZF? ... 

With a fixed delay that can be adjusted with a pot the TZF point could be set anywhere between symmetric and completely assymetric TZF.
What would be the advantage soundwise of having the second delay line with an LFO too? 

[puretube]

Hoaxy...

[markusw]

Hoaxy...

Will have to check out on my Hoax.....

Vibrato (switch to eliminate dry signal, or pot to control wet/dry mix)

Another Q: in the Hyper Flanger there are "LFO out" and "Delay CV in" jacks. By feeding the LFO out into an expression pedal and then back into "Delay CV in" the amount of vibrato can be adjusted with the pedal. The expression pedal acts as an external LFO depth control. What would be the difference to a dry/wet pedal for vibrato?