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AD-900 Delay MN3008 version

Started by armdnrdy, January 18, 2015, 01:57:00 PM

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teknoman2

#20
May 29, 2015, 09:37:12 AM
Quote from: armdnrdy on May 29, 2015, 08:52:00 AM
The 10M across the switch is to keep it from popping when engaged/disengaged.
I could have went with a couple of pull downs on either side of the switch but, I wanted to try this method.
I nicked the idea from the Dunlop 535Q. There is a 1P6T rotary switch which switches in different caps. There is a 10M resistor across each switch position to keep it from popping when switched.

The 10M is almost like JFET switching...the JFET is always in the circuit but the resistance goes high causing the signal not to pass.

Great idea the 10M resistor, I was going to propose the jfet tails mode from Brian's forum.
This one is even easier and even lower parts count.

Also regarding the filtering and you can experiment with different values on the HP filter on the feedback loop on the input and output stage. Another try is to change the caps of the BJT Sallen-Key 3rd order after the signal compression and before the signal expansion. These changes will alter the cutoff frequency so you will have more highs but there is always chance to have clock noise on your signal. You can dial your clock trimmer to 7.2-7.3 kHz instead of 6.5-6.8 kHz to eliminate clock freq but this will shorten the max delay time.

armdnrdy

#21
May 29, 2015, 09:51:29 AM
The docs actually say 7kHz +/- 200Hz so the 7.2 is still in the factory ballpark.

Any suggestions on cap values to bring in a bit more highs?
I just designed a new fuzz circuit! It almost sounds a little different than the last fifty fuzz circuits I designed! ;)

teknoman2

#22
May 29, 2015, 10:01:02 AM
Mine had from factory f(ocs) around 13.6kHz so f(cp) is the half around 6.8kHz.

Measure your clock frequency in one of the mn3101 its gonna be around those values probably.

Now regarding the cap values for bringing more highs check Brian's Aquaboy DLX project and experiment with those values for start.

http://www.madbeanpedals.com/projects/Aquaboy/docs/AquaboyDX.pdf

I was working in a same project with bbd delay that we wanted to add tap tempo feature so this project is very familiar.

Cheers,
Panos.

armdnrdy

#23
May 29, 2015, 10:15:10 AM
Thanks Panos...I'll have a look.  :icon_eek:
I just designed a new fuzz circuit! It almost sounds a little different than the last fifty fuzz circuits I designed! ;)

Ice-9

#24
May 29, 2015, 11:03:58 AM
Great work on this armdnrdy, love it.
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Govmnt_Lacky

#25
May 29, 2015, 02:07:07 PM
Quote from: armdnrdy on May 29, 2015, 09:13:33 AM
Quote from: Govmnt_Lacky on May 29, 2015, 09:01:21 AM
Looking forward to the build...  8)  :o

1/8 watt resistors or 1/4 watt standing on end!  :icon_wink:

I'll probably go with 1/4W standing..  :o
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armdnrdy

#26
May 29, 2015, 02:21:03 PM
Quote from: Govmnt_Lacky on May 29, 2015, 02:07:07 PM
I'll probably go with 1/4W standing..  :o

Just thought I'd warn you!

Some folks would run screaming!  ;D
I just designed a new fuzz circuit! It almost sounds a little different than the last fifty fuzz circuits I designed! ;)

Govmnt_Lacky

#27
May 29, 2015, 04:58:34 PM
Quote from: armdnrdy on May 29, 2015, 02:21:03 PM
Just thought I'd warn you!

Some folks would run screaming!  ;D

A Veteran is someone who, at one point in his or her life, wrote a blank check made payable to The United States of America
for an amount of 'up to and including my life.'

armdnrdy

#28
May 31, 2015, 12:24:44 AM
I just designed a new fuzz circuit! It almost sounds a little different than the last fifty fuzz circuits I designed! ;)

Govmnt_Lacky

#29
August 09, 2015, 08:33:42 PM
And here she is!

Biasing was "fun" to say the least but totally do-able with an oscope and sig gen. The repeats were a bit dark but the added Bright switch makes them just perfect for echoing lead tone or brighter rhythm parts. I do still like the dark for dirty rhythm stuff though. An excellent mod! The tails switch also adds to the usefulness! With Repeats at full CW, I can get almost 12 perfectly clear yet, dwindling repeats. There is the ability to put it into self oscillation but, I was able to trim it to the very edge just before that point.

I totally recommend this build for anyone wanting a crystal clear analog delay. All the warmth of analog and absolutely none of the 'random noise' that is associated with analog BBD pedals.



A Veteran is someone who, at one point in his or her life, wrote a blank check made payable to The United States of America
for an amount of 'up to and including my life.'

Cozybuilder

#30
August 10, 2015, 02:21:00 AM
Glad to see its alive! Great job Greg.
Some people drink from the fountain of knowledge, others just gargle.

armdnrdy

#31
August 10, 2015, 06:36:35 PM
Great looking build Greg!

You always seem to out do me with my own project!  :icon_lol:
I just designed a new fuzz circuit! It almost sounds a little different than the last fifty fuzz circuits I designed! ;)

Govmnt_Lacky

#32
August 10, 2015, 08:06:26 PM
Quote from: armdnrdy on August 10, 2015, 06:36:35 PM
You always seem to out do me with my own project!  :icon_lol:

Sorry but, the REAL art is in the research and the project development itself my friend!  ;)
A Veteran is someone who, at one point in his or her life, wrote a blank check made payable to The United States of America
for an amount of 'up to and including my life.'

bluebunny

#33
August 11, 2015, 02:32:13 AM
That is one very sweet build, Greg.
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joesatch

#34
December 14, 2015, 10:55:04 AM
I'd like to build an AD-900 with MN3005's as they are shipping the new ones in a few weeks. Could you point me in the right direction ? What do you think of this AD-3208? Do you think i could swap the IC's for 3005's? http://www.generalguitargadgets.com/effects-projects/modulationecho/ad-3208/

armdnrdy

#35
December 14, 2015, 02:59:45 PM
Quote from: joesatch on December 14, 2015, 10:55:04 AM
I'd like to build an AD-900 with MN3005's as they are shipping the new ones in a few weeks. Could you point me in the right direction ? What do you think of this AD-3208? Do you think i could swap the IC's for 3005's? http://www.generalguitargadgets.com/effects-projects/modulationecho/ad-3208/

The AD-3208 circuit is designed for the lower voltage BBDs. (MN32XX series)
You can't use the MN30XX series BBDs without major modifications to the circuit.
I just designed a new fuzz circuit! It almost sounds a little different than the last fifty fuzz circuits I designed! ;)

pinkjimiphoton

#36
March 17, 2017, 03:21:58 PM
hey larry,
the project links are down bro...

and i just realized looking thru the junk drawers i got 3007's, not 3008's. figgers, right?  :icon_rolleyes:
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"try whacking the bejesus outta it and see if it works again"....
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armdnrdy

#37
March 17, 2017, 06:03:50 PM
Quote from: pinkjimiphoton on March 17, 2017, 03:21:58 PM
hey larry,
the project links are down bro...

and i just realized looking thru the junk drawers i got 3007's, not 3008's. figgers, right?  :icon_rolleyes:


Yep! I'm having some sort of issue with dropbox...I've read about similar problems on the net.

All of my files are intact...but the links I posted are dead. Makes sense huh?

Here is another link for the AD-900 delay:

https://www.dropbox.com/s/ey96geb4vv911dv/AD-900%20MN3008%20Version%20Build%20Document.pdf?dl=0
I just designed a new fuzz circuit! It almost sounds a little different than the last fifty fuzz circuits I designed! ;)

pinkjimiphoton

#38
March 17, 2017, 09:42:30 PM
i hear ya man, lately everything on the internet seems to get worse and worse. crazy!
thanks for the re-up!
really nice looking circuit... it's been added to my folder of must build. there's only, like, 200 or 300... maybe 450? that i "gotta" have still ;)
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"When the power of love overcomes the love of power the world will know peace."
Slava Ukraini!
"try whacking the bejesus outta it and see if it works again"....
~Jack Darr
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