Mutron Flanger dissection.

[Fender3D]

Do I still retain the original 4011 for the clock signals?

Is the pull up resistor R8 on your schematic? Can I use a trimmer like R80 on the Mutron, but to positive?

1)Yes
2)Yes
3)Yes, but be prepared to add a tranny (my Q1) if level is not high enough...

So is this circuit working from 0 to +15V with a +7.5V reference?

Or... Is it working from +7.5V to -7.5V with 0V as reference?

Well, to be picky, it is working from +7.5V to -7.5V with 0V as reference.

Actually, you have 15V total, period.
If then anyone divides this voltage by 2 ....  

We can say our beloved pedals work @ 4.5V+4.5V...
Vbias may be GND, if GND is -V ! (better do not try this if you have just 2 resistors as voltage divider....)

[Mark Hammer]

Keep in mind, Dino, that 800khz, with the SAD1024 run in dual-parallel mode, is equivalent to an MN3007 run at 1.6mhz.  Nothing to sneeze at.

[digi2t]

OK guys. clarification...



Sorry for the confusion. I'm learning too.

@Fender3D - thanks for the prompt reply. I'm going away soon for the weekend, but when I get back, I'll rework the drawing to reflect the MN3007 set up. Unless you've got some time to spare Greg.

@Mark - You'll have to educate me (again!) on that one. Is that a good or a bad thing? Moosapotamus states that the MN3007 ADA Flanger is maxing at 2.6MHz. Ouff!! My noob a$$ is taking a shit-kickin' here.

[Fender3D]

Is that a good or a bad thing?

It might be a bad thing, since higher frequency also means shorter tracks, good soldering and shorter parts pins to avoid issues...
It is of no concern here, 'cause SAD runs in series mode; then SAD's clock = MN3007's clock

[Gus]

Bonus question) Why don't I have +/-15vdc in this circuit, like the schematic implies? The whole thing is running at +/-7.5vdc. Bad caps?

'cause designer made a mistake  
you have just one 15V regulator, then you have 15V from positive to negative
Z11b will provide half supply (GND).

BTW
you did invert labels @ power supply...  

@Gus

Z6a simply set LFO reference, not circuit GND.

The Z2B and Q1 and Z2A based circuit fragments look to be some kind of noise gate.  Z2B is a full wave rectifier to a R10, C8 attack, C8, R11 decay Q1 fet switch.  Z2A is a lowpass filter.

ADA docet...

@12Bass

I wouldn't matter so much for BBD signal dimming...
Every analog flanger ever built suffers (well, TCE aside   ) from this...
We're used to, aren't we?

Read my post again I did not post  Z6A is the ground ref it is ref voltage for the offset for the LFO  
note I did post about Z11b

Do people every read my posts I mean read?  Don't add to what I did not post.
I also posted about splitting the 15VDC with the opamp buffer after using a resistor divider before the buffer Z11B

[Fender3D]

...The buffered voltage divider output of Z6A is not set at 1/2 +7.5VDC and -7.5VDC but more to +7.5VDC

Now the tricky thing is what is ground in the schematic?

Is ground the same set by the output of Z11B or is it a mix of grounding?

Sorry Gus,
I misunderstood...
I thought it was part of the following ground question...

[12Bass]

Keep in mind, Dino, that 800khz, with the SAD1024 run in dual-parallel mode, is equivalent to an MN3007 run at 1.6mhz.  Nothing to sneeze at.

The schematic appears to show the two BBD sections wired in series.  So, shouldn't that make it basically equivalent to an MN3007 at the same clock rate?

[Gus]

I should have written a nicer last post

Looking at the schematic I see there is no protection for the input differential pair in IC Z11B.  I would have expected a series input resistor to pin 5 but maybe the 22Ks(R73,R74) is all that is needed.

digi2t
What voltages do you measure? 
What do we know about the schematic is a Mutron one or is one that someone drew?

[digi2t]

Those are the voltages that I recorded on my unit. It's just that I screwed the pooch on putting together how the bipolar voltages were created. I had never seen that set up before. The x-fo puts out 18vdc, which is then regulated down to 15vdc. The op amp then creates the +/- voltage with a virtual (?) ground in the middle.

The schematic is one that was posted on the other forum, in a Mutron Flanger thread. It's origin is from ARP, titled "SCHEMATIC, FLANGER", drawing number 77208. You can download it from over there.

Since it's hi-rez, I could blow it up to 11 x 17, and then trace the unit to it. There were some minor corrections, and some of the writing needed to be clarified, but in the end I decided that it would be easier to just Paint Shop all the writing, and just keep/correct the diagram. That's me being lazy

[Mark Hammer]

Keep in mind, Dino, that 800khz, with the SAD1024 run in dual-parallel mode, is equivalent to an MN3007 run at 1.6mhz.  Nothing to sneeze at.

The schematic appears to show the two BBD sections wired in series.  So, shouldn't that make it basically equivalent to an MN3007 at the same clock rate?

Yes.  I think I was looking at the wrong schem when I suggested that.  I stand corrected.

[digi2t]

I've had more time to look at the circuit, and I've realized that the schematic is very confusing insofar as the voltages are concerned. Specifically the arrow up/down convention. Some of the arrows up may mean either 15vdc, or 7.5vdc, while the arrow down may mean -15vdc, -7.5vdc, or 0vdc. The only symbol that seems to hold true is the ground symbol, which is the virtual ground created by the op amp. A good example of the confusion regarding the down arrow is the LED's. The negative side shows a down arrow, which the original legend shows as -15vdc. Again, since we don't have -15vdc anywhere, one could assume that it's -7.5vdc. In reality, it's 0vdc (x-fo center tap, pin 2 of the regulator). There's just too much chaos here, and it needs to be sorted out.

Also, the voltage regulator numbering is wrong. The output pin is 3, while the ground pin is 2. It's backwards on the schematic.

I'm going to go over it again this weekend, and redo the legend to clear up what power is going where. Disregard the schematic I've posted. I'll post an update soon.

[Ronan]

No Dino, its all fine. Just connect the +15VDC arrow to the +7.5VDC arrow of the +/-7.5VDC circuit and call all points from there on +7.5VDC. Connect the 0VDC to the -7.5VDC of the +/-7.5VDC circuit and call all points from there on -7.5VDC. The 15V and 0V points from there on are irrelevant because they have been converted to +7.5VDC, ground, and -7.5VDC (which equals a total of 15VDC).

Some will argue that the regulator pinout is correct since the pins are not numbered in a straight line, as I discovered recently. I would have lost money if a bet was made So just pin it out whichever way works for you.

Edit: If the 15V arrow was marked +7.5VDC, and the 0V arrow was marked -7.5VDC, the confusion would have been avoided. Hope that makes sense...

[armdnrdy]

I would mark the regulator IN, GND, and OUT. That way you don't have to worry about it's orientation.

[digi2t]

I would mark the regulator IN, GND, and OUT. That way you don't have to worry about it's orientation.

Excellent idea. Duly noted for the update.

[digi2t]

All right folks, I've got it sorted out. The second half of Z11 is only there to produce a virtual ground. The unit is running on 15vdc / 0vdc. There is no -15vdc, or +/-7.5vdc requirement. I've updated the schematic, and this is the final version;



Now... could someone design a PCB. With a MN3007 retrofit. That fits into a Morley enclosure. Anyone?  

Don't ask for much, do I.  

Here is the drawing of the LDR's - LED arrangement too. For some reason, I accidentally deleted it from Photobucket.

[armdnrdy]

The second half of Z11 is only there to produce a virtual ground. The unit is running on 15vdc / 0vdc. There is no -15vdc, or +/-7.5vdc requirement.

See Reply #39

[Govmnt_Lacky]

@Dino,

The schematic could be easily updated for an MN3007 retrofit BUT....

I think that the actual PCB will need to be re-designed for a Morley-style enclosure 

There is not a lot of "vertical" room in those and I doubt you will be able to stack a mod board on top of an original OR a cloned board for that matter.

The only solution I see is to either do a vero -OR- a new PCB with he 3007 retrofit already incorporated. I absolutely SUCK at PCB design or I would do it but, if someone were to take this on and work out a plug-n-play PCB for the Morley shells..... you will definitely see the prices of those old Morleys go through the roof on eBay 

I would be MORE THAN HAPPY to provide measurements of a Morley shell or anything else to support the effort though 

[digi2t]

The second half of Z11 is only there to produce a virtual ground. The unit is running on 15vdc / 0vdc. There is no -15vdc, or +/-7.5vdc requirement.

See Reply #39

You were absolutely right Larry. I'm simply confirming what is in the box. I hate loose ends, especially when they're in my head. 

@G_L - I PM'd Ronan about it. He did the Talking Pedal drop-in PCB for Morley enclosures, and he says that he could use that as a template. We just need someone to replace the SAD1024 with a MN3007, and test it to be sure it works. If it does, we could send the modified schematic to him, and see what he can do with it.

Unfortunately, I'm swamped right now, and I won't be able to breadboard something this big for a while.

[armdnrdy]

I just wanted so desperately to be right for once!  

It almost looks like Musitronics used a template to draw their schematics. The +/- voltage symbols and placement look very much like the Bi Phase schematic.

[digi2t]

OK, I hacked in the MN3007 chip. Does this look right? (You're not the only one who's desperate Larry. )



The transistor Q4 might not be needed, but until someone tests this, I stuck it in there. The original R79 trimmer is 10K, but I put in the 100K from the other drawing. This too will have to be tested.

Aw hell.... this whole thing needs to be tested.