Unanswered Collosolus question of the Universe..

[Scruffie]

Waiting for your trannie measurements before making judgement 

[blearyeyes]

Measured with regulated PS @9.13v
Width 100% dimed
Manual 0
Regen 3/4
Sweep 0
=============

Q1:
C1 480mv
B2 472 - 480mv
E3 3mv

Q2:
C1 8.7 - 10.7v
B2 2.1v
E3 1.49 - 1.8v

Q3:
C1 1.49 - 1.8v
B2 400mv - .6v
E3 3mv

Q4:
C1 14.76v
B2 6.4 - 8.0v
E3 7.9 - 6.1v

Q5:
E1 14.76
B2 14.21 - 14.71v
C3 8.6 - 10.74v

[Scruffie]

IC5, Pin 8, measure it again.

[blearyeyes]

Will do, looked at datasheet and that should be ground. Hmm.

[Scruffie]

Yup, the 4049 not working due to no ground could certainly cause you to loose flanging above 500KHz as the clock can't get over the 3007s clock capacitance without the help of it.

[blearyeyes]

Well it looks like my mistake as IC5 pin 8 is grounded.
.4mv by my DMM.

How do the Trannie voltages look to you?

[Scruffie]

Well... I think you measured Q2 wrong unless there's something really wrong so do check that again but it looks like just a mistake. Otherwise far as I can see they look okay.

I do wonder why your voltages aren't a bit steadier, but it could just be your meter settling...

Could be a bad joint or poor socket connection somewhere though.

[blearyeyes]

Measured with regulated PS @9.13v
Width 100% dimed
Manual 0
Regen 3/4
Sweep 0
=============
The voltages are fluctuating consistent with the sweep on all of the IC pins noted with two voltages. (going up and down with the sweep)
I'm using an auto ranging DMM so the setting is DC.

The ampere readout from my bench supply is also fluctuating consistent with the sweep from about 50ma to 100ma.  (going up and down with the sweep)

I'll check the Q2 pins again.
don't think it was a mistake but easy enough to check.

[blearyeyes]

I messed up on Q2 as you suspected. I have corrected it in the above numbers.
 

[blearyeyes]

Correct me if I'm wrong but I'm beginning to think this is just the way this circuit behaves.

ARRRRRrrgh!

[blearyeyes]

or if despite the clock buffer and the original BBD being 1024 stages, changes are needed to the VCO to achieve the original sweep due to increase in clock capacitance.

If the above is the case, how would I mod this to compensate?

I listened to Brian's demo from a few years ago and listened to an original MXR and it seems to me Bean's build does the same thing mine does.

http://www.youtube.com/watch?v=T3pJwksh_6A
When Brian at about 1:15 into the demo, sets his unit with slow rate and almost full width, it stops flanging at the top. this is exactly what mine is doing.  Near the bottom there is a clump of flanging.

http://www.youtube.com/watch?v=7JYyF97dZWI
Start about halfway through the video.
Sorry if this breaks some kind of DIY unspoken ethical code. I have always gotten in trouble due to a lack of filtering in that area..

Daniel

[Scruffie]

If it sounds like that then yeah it's fine, there is some flanging going on it's just a very short delay so it can be hard to hear. In the original tape flanging effect (look up how it's achieved) when this point is reached the 'sweep' keeps going to the through zero point where the sound becomes almost lost but in a heady everything's weird way, flanger pedals with a single delay line can't have a delay shorter than the original input signal so never achieve this and can get pretty high up there, but then come back down.

You can hear it used here;

http://youtu.be/JGEgRnvFzLY?t=49s

Put a fuzz up front of the flanger and you'll hear the sweep clearer.

[blearyeyes]

I used flanging in the 60s when you actually had to put your hands on the tape flange... I remember that song when it first came out...8-))  Yea I know old fart....

Is there a Zero Point flanger in the electronics world that you know of? Very interesting that that is what is going on. Thank you for spending the time to help educate me on this stuff! I have learned a lot regarding LFOs and BBDs.

So if you used a dual line of delay chips you could achieve a zero point flange crossing? Or would it be easier to just get a couple of old half track tape recorders?  LOL

daniel

[Scruffie]

There are 2 analog ones in production I know of, the Foxrox Through Zero Flanger & Flanger Hoax, DIY there is a project by DrAlx on DIYstompboxes.

Couple of digital ones about too...

[blearyeyes]

Thanks !