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prophei
Joined: Jan 27, 2007 Posts: 234 Location: san francisco, ca
Audio files: 4
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Posted: Tue Oct 16, 2007 6:32 am Post subject:
mankato builds? |
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hi everybody!
the board has seemed rather quiet regarding results and opinions concerning the building of the mankato filter from magic smoke. i'd love to hear your opinions, stories, tips..etc.
i just finished my first, though while waiting for my tempco and a few of the polystyrine caps i have had to use lesser replacements temporarily making it harder to use as an osc.
for testing, i wired up 1 input to audio and cv, plus all 4 positive outputs. it is a sweet, sweet, sweet sounding filter! i notice that since it is intended to be used also as an osc and has such a large range, it has a very small range for filter use, making it hard to use this way in a live sense. i have considered figuring out which resistor(s) set this range, then adding a switch between the standard resistor(s) (good for osc) and a new value to set it up better for filtering.
has anybody noticed the same? please do tell!!
once i have this setup a little better for recording, i'll post some samples....
-p |
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numbernone
Joined: Aug 16, 2006 Posts: 477 Location: new york city
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Posted: Tue Oct 16, 2007 7:57 am Post subject:
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Yeh the range for filtering is TINY. I seem to find the "midpoint" with the coarse tuning and then use the fine tune for manual adjustments.
I like the idea about switching, perhaps if this can be worked out I will implement it for my second one. |
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prophei
Joined: Jan 27, 2007 Posts: 234 Location: san francisco, ca
Audio files: 4
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Posted: Tue Oct 16, 2007 8:26 am Post subject:
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numbernone wrote: | Yeh the range for filtering is TINY. I seem to find the "midpoint" with the coarse tuning and then use the fine tune for manual adjustments.
I like the idea about switching, perhaps if this can be worked out I will implement it for my second one. |
i found that the fine tuning gave me way too little a range, and the coarse far too much! i think that with a little noodling around, finding the resistor that governs these ranges may be fairly easy. maybe the way to do it would be to add the switch on the fine tuning pot to give it more range, as it is the closer of the two...
if i figure it out, i'll post my results. |
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loss1234
Joined: Jul 24, 2007 Posts: 1536 Location: nyc
Audio files: 41
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prophei
Joined: Jan 27, 2007 Posts: 234 Location: san francisco, ca
Audio files: 4
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Posted: Tue Oct 16, 2007 9:39 pm Post subject:
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the schematic is restricted to those who purchase the kit from what i remember. if you are interested in doing a mod, you might want to ask them for a copy of it? |
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doctorvague
Joined: Mar 14, 2007 Posts: 281 Location: new mexico
Audio files: 2
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Posted: Wed Oct 17, 2007 6:10 am Post subject:
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If you go to this page:
http://modularsynthesis.com/magicsmoke/mse.htm
and scroll down to 'Filter Design' toward the bottom there is a section that talks about this and references R37 as the resistor you're looking for.
Cheers
Phil |
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prophei
Joined: Jan 27, 2007 Posts: 234 Location: san francisco, ca
Audio files: 4
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Posted: Wed Oct 17, 2007 9:17 am Post subject:
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doctorvague wrote: | If you go to this page:
http://modularsynthesis.com/magicsmoke/mse.htm
and scroll down to 'Filter Design' toward the bottom there is a section that talks about this and references R37 as the resistor you're looking for.
Cheers
Phil |
thank you for pointing that out! i had read his page and somehow missed that down there...
this should be an easy switch to add. |
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Scott Stites
Janitor
Joined: Dec 23, 2005 Posts: 4127 Location: Mount Hope, KS USA
Audio files: 96
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Posted: Wed Oct 17, 2007 10:36 am Post subject:
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This looks like a job for....Super Henry Forum!
Magic Smoke is known to hang out there, so I hope you don't mind if I move it on over there - I'll leave a ghost of the thread here in DIY Synths.
Cheers,
Scott _________________ My Site |
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prophei
Joined: Jan 27, 2007 Posts: 234 Location: san francisco, ca
Audio files: 4
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Posted: Wed Oct 17, 2007 11:20 am Post subject:
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no problem at all =] |
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Tim Servo
Joined: Jul 16, 2006 Posts: 924 Location: Silicon Valley
Audio files: 11
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Posted: Wed Oct 17, 2007 7:30 pm Post subject:
mankato builds Subject description: resistor tweaks |
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prophei wrote: | numbernone wrote: | Yeh the range for filtering is TINY. I seem to find the "midpoint" with the coarse tuning and then use the fine tune for manual adjustments.
I like the idea about switching, perhaps if this can be worked out I will implement it for my second one. |
i found that the fine tuning gave me way too little a range, and the coarse far too much! i think that with a little noodling around, finding the resistor that governs these ranges may be fairly easy. maybe the way to do it would be to add the switch on the fine tuning pot to give it more range, as it is the closer of the two...
if i figure it out, i'll post my results. |
Hi E-M denizens!
Changing the range of the tuning controls is pretty easy:
R37 sets the Coarse tune range. It is currently 150K
R39 sets the Fine tune range. It is currently 3.3M.
I think once you get used to the range of the controls, it's actually nice. I'm totally spoiled by the range when using it as an LFO. Audio use can be a little tricky, but try setting Coarse tune at about 1 o'clock, and set the mod level pots a little lower than you might for other filters. The range is nice and gives me a wider sonic pallette than several other VCFs I've used. Anyway, you can easily modify those Rs to change things. BTW, a larger value = smaller range. As far as the schematic, it is proprietary, but anyone who owns a Mankato PCB has the schemo too.
Tim (also a little tricky) Servo |
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Funky40
Joined: Sep 24, 2005 Posts: 875 Location: Swiss
Audio files: 1
G2 patch files: 5
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Posted: Fri Oct 19, 2007 3:18 am Post subject:
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i think i gonna solder the Mankato this evening.
the too big filterrange is not what i'd like to have when using as a Filter, so i will try the option with switching the resistors.
question:
should this be wired to the switches with shielded cable?
Rock stable tune for VCO use is desired.
So i don't want to make there any compromises. |
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Tim Servo
Joined: Jul 16, 2006 Posts: 924 Location: Silicon Valley
Audio files: 11
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Posted: Fri Oct 19, 2007 11:15 am Post subject:
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Funky40 wrote: | i think i gonna solder the Mankato this evening.
the too big filterrange is not what i'd like to have when using as a Filter, so i will try the option with switching the resistors.
question:
should this be wired to the switches with shielded cable?
Rock stable tune for VCO use is desired.
So i don't want to make there any compromises. |
Hi There,
I'd say the wiring for the CV path (including alternate range resistors) does not need to be shielded. Generally, shielded cable is used just for audio connections.
If you want to see a first-class Mankato build, check out Dave Brown's page at
http://www.modularsynthesis.com/magicsmoke/mse.htm
Dave used top quality pots, a tempco mounted on top of the 2164 chip, and says that the result is VERY stable, even when compared to a MOTM VCO and his crystal-controlled A440 reference.
Finally you can also alter the range of the CV modulation inputs by changing resistors R1a, R1b and R1c. These are currently 100k. If you find that the mod level pots are set very low, a larger resistor might make it easier for you to find the "sweet spot."
And above all, have fun!
Tim (not quite so stable... not crystal controlled either) Servo |
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State Machine
Janitor
Joined: Apr 17, 2006 Posts: 2809 Location: New York
Audio files: 24
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Posted: Sun Oct 21, 2007 12:34 pm Post subject:
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Just wondering if there is a panel wiring diagram available. It looks like a simple build but I like to have all the details anyway.
Would really like a schematic also just in case I have to troubleshoot the board.
Thanks everyone ..........
Bill |
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Tim Servo
Joined: Jul 16, 2006 Posts: 924 Location: Silicon Valley
Audio files: 11
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Posted: Sun Oct 21, 2007 7:36 pm Post subject:
mankato builds? Subject description: documentation |
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State Machine wrote: | Just wondering if there is a panel wiring diagram available. It looks like a simple build but I like to have all the details anyway.
Would really like a schematic also just in case I have to troubleshoot the board.
Thanks everyone ..........
Bill |
Hey Bill,
Just a little late getting the docs out. You'll get a package with connection wiring, parts list and a schemo. Like I say, anyone with a PCB should have (or will get) the doc package.
Tim (must have been on a doc holiday) Servo |
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State Machine
Janitor
Joined: Apr 17, 2006 Posts: 2809 Location: New York
Audio files: 24
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Posted: Mon Oct 22, 2007 11:30 am Post subject:
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Quote: | Just a little late getting the docs out. You'll get a package with connection wiring, parts list and a schemo. Like I say, anyone with a PCB should have (or will get) the doc package. |
Tim thanks man. I am sorry if I had to make you repeat yourself. I have been very involved in many other projects with Klee, sMs Mega-Modulation Generator, Integrated Keyboard Controller and MIDI/TRIGGER ... geez --- being the the largest projets on for now
Thanks a bunch, look forward to building this cool filter/oscillator !
Nice job on that PCB BTW. I LOVE the blue solder mask !!!!!!
I also got the Synthesizer for the 21st century ! The print version !! Very nice
Bill |
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Serenadi
Joined: Jul 03, 2007 Posts: 89 Location: Germany
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Posted: Mon Oct 29, 2007 10:40 am Post subject:
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Tim,
I got the boards I ordered together with a friend two days ago and today got the documents.
Really nice, thank you.
(Have to mention the very fast delivery from USA to Germany !! - Great).
I'd like to hear your meaning about the caps at the inputs of the 2164 (e.g. C3)
Its value is 560pF, like recommended at the datasheet of the IC.
I've built VCAs with the 2164 and as I understand these caps should prevent very high frequency dirt.
So, having no 560pF lying around, I tried 470pF and 680pF.
I wasn't able to hear any difference.
Do you think, 680pF is also OK in the mankato ?
thanks,
Bernd |
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Tim Servo
Joined: Jul 16, 2006 Posts: 924 Location: Silicon Valley
Audio files: 11
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Posted: Mon Oct 29, 2007 1:46 pm Post subject:
mankato builds? Subject description: Cap values |
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Serenadi wrote: | Tim,
I got the boards I ordered together with a friend two days ago and today got the documents.
Really nice, thank you.
(Have to mention the very fast delivery from USA to Germany !! - Great).
I'd like to hear your meaning about the caps at the inputs of the 2164 (e.g. C3)
Its value is 560pF, like recommended at the datasheet of the IC.
I've built VCAs with the 2164 and as I understand these caps should prevent very high frequency dirt.
So, having no 560pF lying around, I tried 470pF and 680pF.
I wasn't able to hear any difference.
Do you think, 680pF is also OK in the mankato ?
thanks,
Bernd |
Hey Bernd,
You're right, the cap in the C3 position forms a simple low-pass filter that keeps high frequency noise out of the 2164. You should be able to get away with a slightly different value there, although you may notice a slight change in the Mankato's frequency response. This change will still likely be well outside the audio range, so you would see the difference only when using the Mankato as a modulation oscillator. I haven't tested this, but with a 680pF cap you may loose a little bit of the extreme low frequency range. The units I've built and tested have a range of about 0.011Hz (one cycle every 90 seconds) to just over 22KHz, so you may not really miss a teeny bit of the low end.
Regarding the delivery service - the US Postal Service has been really extraordinary with our deliveries. I've got to admit that I'm a very happy customer!
Thanks, and have fun with your Mankato!
Tim (missing a bit of his low end too) Servo |
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Tim Servo
Joined: Jul 16, 2006 Posts: 924 Location: Silicon Valley
Audio files: 11
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Posted: Mon Oct 29, 2007 4:20 pm Post subject:
Re: mankato builds? Subject description: Tuning range update |
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prophei wrote: | hi everybody!
for testing, i wired up 1 input to audio and cv, plus all 4 positive outputs. it is a sweet, sweet, sweet sounding filter! i notice that since it is intended to be used also as an osc and has such a large range, it has a very small range for filter use, making it hard to use this way in a live sense. i have considered figuring out which resistor(s) set this range, then adding a switch between the standard resistor(s) (good for osc) and a new value to set it up better for filtering.
has anybody noticed the same? please do tell!!
once i have this setup a little better for recording, i'll post some samples....
-p |
Hey Proph,
I've done a little tweaking and testing myself, and have come up with some new component values. I've found that changing R37 to 220K (was 150K), and R38 to 402K (was 200K), gave me much better range with the Coarse Tune control. The Audio Range is slightly wider (goes from about 11 o'clock to 3 o'clock), and the filter will oscillate (when trimmed properly) at settings down to about 8 o'clock (assuming "0" is at 7 o'clock). Before, I had trouble getting the Mankato to oscillate at settings much lower than about 11 (o'clock, that is). Now, the filter will keep oscillating until the Coarse control is turned down into the first 10% or so of travel. That little bit of extra control may come in handy when tuning and offsetting several control voltages, so I left it at that. The new component values still allow a VERY wide range of settings, the ability to offset CVs with a large positive or negative bias, and gives a nice wide range to the Coarse panel control. By the way, if you don't have a 402K, a 390K will work about the same.
We also have a few optional component changes, and these can be found on the new parts list. We'll update the list on our web site in a few days (the new list is dated 10/28/07), but in the meanwhile I can post it here if anyone is interested. Thanks everyone!!
Tim (could use a few updated parts himself) Servo |
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prophei
Joined: Jan 27, 2007 Posts: 234 Location: san francisco, ca
Audio files: 4
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Posted: Mon Oct 29, 2007 5:32 pm Post subject:
Re: mankato builds? Subject description: Tuning range update |
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Tim Servo wrote: |
Hey Proph,
I've done a little tweaking and testing myself, and have come up with some new component values. I've found that changing R37 to 220K (was 150K), and R38 to 402K (was 200K), gave me much better range with the Coarse Tune control. The Audio Range is slightly wider (goes from about 11 o'clock to 3 o'clock), and the filter will oscillate (when trimmed properly) at settings down to about 8 o'clock (assuming "0" is at 7 o'clock). Before, I had trouble getting the Mankato to oscillate at settings much lower than about 11 (o'clock, that is). Now, the filter will keep oscillating until the Coarse control is turned down into the first 10% or so of travel. That little bit of extra control may come in handy when tuning and offsetting several control voltages, so I left it at that. The new component values still allow a VERY wide range of settings, the ability to offset CVs with a large positive or negative bias, and gives a nice wide range to the Coarse panel control. By the way, if you don't have a 402K, a 390K will work about the same.
We also have a few optional component changes, and these can be found on the new parts list. We'll update the list on our web site in a few days (the new list is dated 10/28/07), but in the meanwhile I can post it here if anyone is interested. Thanks everyone!!
Tim (could use a few updated parts himself) Servo |
thanks tim, i'll check these out! also, if you can post the list, that would be fantastic...
-p |
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Tim Servo
Joined: Jul 16, 2006 Posts: 924 Location: Silicon Valley
Audio files: 11
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Serenadi
Joined: Jul 03, 2007 Posts: 89 Location: Germany
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Posted: Mon Oct 29, 2007 9:41 pm Post subject:
Re: mankato builds? Subject description: Cap values |
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Tim Servo wrote: | Thanks, and have fun with your Mankato!
Tim (missing a bit of his low end too) Servo |
I thank you!
I'll surely have fun with my (2) Mankato(s).
Probably the problem will be, that I'm too busy and hardly get no time to wait for 90 seconds periods.
greets,
busybernd |
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softfin
Joined: Oct 11, 2006 Posts: 271 Location: Far in the north
Audio files: 1
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Posted: Tue Oct 30, 2007 3:40 am Post subject:
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I've got two Mankato boards, one being almost finished, will get to try it probably within a week or so. Anyway, I only have one SSM2164 (free sample from AD, hehe ). Does anyone know where I could get those chips?
Are there any suppliers in Europe who carry them? ...I'll consider ordering from US too if I find a source cheap enough.
Any help would be appreciated. |
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Tim Servo
Joined: Jul 16, 2006 Posts: 924 Location: Silicon Valley
Audio files: 11
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Posted: Tue Oct 30, 2007 10:16 am Post subject:
Mankato Builds Subject description: 2164 Chips |
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softfin wrote: | I've got two Mankato boards, one being almost finished, will get to try it probably within a week or so. Anyway, I only have one SSM2164 (free sample from AD, hehe ). Does anyone know where I could get those chips?
Are there any suppliers in Europe who carry them? ...I'll consider ordering from US too if I find a source cheap enough.
Any help would be appreciated. |
Magic Smoke has some coming. These are the 2164 clone by CoolAudio, which has been tested by several sources and performs very well. The lead time is a bit long, but we hope to have them by mid Nov at about the same price as our tempcos (you'd think the chip would be a lot more expensive, but they're about the same cost), i.e. around $3.50. More info to come!
Tim (chips ahoy!) Servo |
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etaoin
Joined: Jun 30, 2005 Posts: 761 Location: Utrecht, NL
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prophei
Joined: Jan 27, 2007 Posts: 234 Location: san francisco, ca
Audio files: 4
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