MN3007 ADA Flanger Clone Questions

[oldschoolanalog]

Test point = 69.6KHz to 2.6MHz
This will give you:
At the BBD = 34.8KHz to 1.3MHz
Hope this clears things up.

[StephenGiles]

Test point = 69.6KHz to 2.6MHz
This will give you:
At the BBD = 34.8KHz to 1.3MHz
Hope this clears things up.

At your next gig, you can say to the audience - " would you mind waiting 20 minutes while I check that my BBD is being clocked at 34.8khz to 1.3mhz before we play this next song"

[neil411]

Thanks OldSchool, that's all I needed to know. You guys were throwing too many different numbers around.

[Tantalum7]

[/quote]

At your next gig, you can say to the audience - " would you mind waiting 20 minutes while I check that my BBD is being clocked at 34.8khz to 1.3mhz before we play this next song"
[/quote]

Don't even bother to tell them.  Just say you'll be performing a 20 minute piece by Webern.  The few who get it will chuckle, and the rest of the people will think you're playing samples of a cat getting strangled.

But thanks to all for the clarification on the clock setting frequencies.

[StephenGiles]

At your next gig, you can say to the audience - " would you mind waiting 20 minutes while I check that my BBD is being clocked at 34.8khz to 1.3mhz before we play this next song"
[/quote]

Don't even bother to tell them.  Just say you'll be performing a 20 minute piece by Webern.  The few who get it will chuckle, and the rest of the people will think you're playing samples of a cat getting strangled.

But thanks to all for the clarification on the clock setting frequencies.
[/quote]

No, I admire the perseverence for getting the settings right! My patience level doesn't reach that far.

[Tantalum7]

I'll give calibration a shot.  I haven't got anything better to do at the moment while I wait for parts for other projects to come in.

[quarara]

Sorry if I bump this thread with some really dumb questions.
In the BOM you can find listed a jack used for external control. Well, I've got two questions about this topic:
- should I use a normal (plastic, preferably) stereo jack or other particular kind of jack?
- which expression pedal is preferred with this application?

Thanks in advance.

[mdh]

Sorry if I bump this thread with some really dumb questions.
In the BOM you can find listed a jack used for external control. Well, I've got two questions about this topic:
- should I use a normal (plastic, preferably) stereo jack or other particular kind of jack?

According to the schematic, it needs to be a stereo jack with at least a switched ring contact.  See Charlie's post at the top of this page here for a part number, but these jacks aren't that uncommon, so you should be able to find others.  They come in both closed frame plastic styles and open frame metal styles.

- which expression pedal is preferred with this application?

It looks like a passive expression pedal with a linear taper pot would be right.

I have my own question, though.  Charlie says:

RE: JK1
Note that the Manual control will not work if you simply do not install a stereo switching type jack, as drawn in the schematic. If you do not want to install a jack, you will need to install a jumper between pad Sw and pad S so that the wiper of the manual pot is connected to R53.

Now, I think I understand this correctly, but I'm confused by the silkscreen legending of the expression pedal jack pads.  If I'm interpreting the schematic and the layout correctly, pad "S" should go to the ring, and pad "Sw" should go to the NC switch contact connected to the ring, while "T" is connected to the tip, and the sleeve of the jack goes to ground.  Yes/no?

[Tantalum7]

I have a couple of questions, and if any of them have been answered in the past, I apologise in advance. 

-What does SW1, the SPDT switch actually do?  It's listed on the schematic as odd/even.  Is that what harmonics the flanger favors?

-Also, has anyone had problems trying to set the clock frequency?  Whenever I try to set the clock frequency, no matter how any of the knobs or trim pots are turned, the frequency oscillates so much that setting it to a specific frequency is impossible.  I have added jumpers to the test points and used clips for the leads of my scope to make certain I had a good connection, but nothing seems to help .  Before I have to put this flanger on the shelf and move on to something simpler, I was wondering if anyone had any suggestions as to what I might be doing wrong.

Thanks.

[oldschoolanalog]

-What does SW1, the SPDT switch actually do?  It's listed on the schematic as odd/even.  Is that what harmonics the flanger favors?

In a word; yes.

-Also, has anyone had problems trying to set the clock frequency?  Whenever I try to set the clock frequency, no matter how any of the knobs or trim pots are turned, the frequency oscillates so much that setting it to a specific frequency is impossible.  I have added jumpers to the test points and used clips for the leads of my scope to make certain I had a good connection, but nothing seems to help .  Before I have to put this flanger on the shelf and move on to something simpler, I was wondering if anyone had any suggestions as to what I might be doing wrong.

Set the range pot all the way CCW. This takes the LFO out of the mix.
Hope this helps.

[Tantalum7]

It definitely gives me a place to start checking.  I've noticed that the range is decreased when turned CCW, but never seems to fade to zero.  I'll go through everything again with a fine toothed comb to see if I have any incorrect valued components or pots.  Many thanks for the suggestion.

s

[Nitefly182]

It definitely gives me a place to start checking.  I've noticed that the range is decreased when turned CCW, but never seems to fade to zero.  I'll go through everything again with a fine toothed comb to see if I have any incorrect valued components or pots.  Many thanks for the suggestion.

s

If you read the other bigger ADA thread there is a simplified tuning process. When you are setting the clock, turn all the knobs CCW and then turn the Manual fully CW so you can set the upper range.

[Tantalum7]

Actually, I never got a chance to post about it, but the majority of the oscillation I was seeing was caused by my not being familiar with the hand held digital scope I borrowed.  I was using it to measure frequency, and it was set to auto scale.  It kept trying to use the highest resolution it could and flip flopping between two scale modes.  As soon as I put it in manual mode and chose one scale, everything stabilized again.  I was never able to get the frequency to vary from 69.6kHz to 2.6MHz with the manual pot, nor was I able to get the range to vary exactly between 34.8 and 1.3 using the range trim pot, so something is still not quite right, but I am making progress.  It is obvious from your sound clips that it's quite possible to get excellent flanging without the use of a scope (I'm assuming that you set only frequency by meter), so I'll keep plugging away at it.

s 

[moosapotamus]

Now, I think I understand this correctly, but I'm confused by the silkscreen legending of the expression pedal jack pads.  If I'm interpreting the schematic and the layout correctly, pad "S" should go to the ring, and pad "Sw" should go to the NC switch contact connected to the ring, while "T" is connected to the tip, and the sleeve of the jack goes to ground.  Yes/no?

Yes.

~ Charlie

[Nitefly182]

Actually, I never got a chance to post about it, but the majority of the oscillation I was seeing was caused by my not being familiar with the hand held digital scope I borrowed.  I was using it to measure frequency, and it was set to auto scale.  It kept trying to use the highest resolution it could and flip flopping between two scale modes.  As soon as I put it in manual mode and chose one scale, everything stabilized again.  I was never able to get the frequency to vary from 69.6kHz to 2.6MHz with the manual pot, nor was I able to get the range to vary exactly between 34.8 and 1.3 using the range trim pot, so something is still not quite right, but I am making progress.  It is obvious from your sound clips that it's quite possible to get excellent flanging without the use of a scope (I'm assuming that you set only frequency by meter), so I'll keep plugging away at it.

s 

It can definitely be done and is really much easier than the SAD1024 version. My second one with the new board really turned out better than expected. Set the clock right and everything else isn't all that hard to tweak.

http://www.youtube.com/watch?v=x2UFfsMi1A0

[grathan]

Can this circuit be calibrated at 12v?

[Nitefly182]

Can this circuit be calibrated at 12v?

Youre better off building an MN3207 version which can run on 9V. The 3007 version could probably function on 12 v but you would lose a good deal of headroom.

[Tantalum7]

It still bothers me that I can't quite get the frequency to vary between 69.6kHz and 2.6MHz at the same time.  Does anyone know if there are some resistor values I might be able to tweak to get the two trim pots to work correctly together.  I realize that some further information may be necessary before someone can make an informed suggestion, but if there is something simple that someone with a better grasp of the interaction of the components in this circuit could suggest, I'd really appreciate it.

s

[Nitefly182]

It still bothers me that I can't quite get the frequency to vary between 69.6kHz and 2.6MHz at the same time.  Does anyone know if there are some resistor values I might be able to tweak to get the two trim pots to work correctly together.  I realize that some further information may be necessary before someone can make an informed suggestion, but if there is something simple that someone with a better grasp of the interaction of the components in this circuit could suggest, I'd really appreciate it.

s

Are you looking for those exact values? Youll have a hard time getting those precise settings if so. I would set the upper range for ~2.6mhz and then check in to see that the lower range is close enough to 69.6. It wont be exact but it will be close enough that you shouldn't notice any difference.

[StephenGiles]

Can this circuit be calibrated at 12v?

Of course it can, just alter the BBD bias.