MFOS Quad Timbre Bank, Eurorack

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rithma
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MFOS Quad Timbre Bank, Eurorack

Post by rithma » Fri Aug 18, 2017 3:42 pm

I posted this in MFOS section, but I'm feeling boastful.

My summer project is complete!!!



After seeing almost NO videos or documentation out there other than Ray Wilson's original youtube post, I decided to build one of these. It is currently in a radioshack box, but I laid out the panel to fit in my eurorack. 5000hp. :sb:
I call it the PolyMFOS Resonator, after Ray wrote something like "This thing sounds like a polymoog resonator, and I'm pleased as punch about that!"
By far the most difficult build I have ever experienced, especially challenging panel wiring.

There's a couple things you must know if you build one, such as the silk screen has a couple backwards voltage regulators. Call me before you punch the wall.

/Etienne Rithers :goo:

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Post by basicbasic » Fri Aug 18, 2017 9:49 pm

Sounds terrific and great choice of enclosure :tu:

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Re: MFOS Quad Timbre Bank, Eurorack

Post by sixbyseven » Sat Aug 19, 2017 8:11 am

rithma wrote: There's a couple things you must know if you build one, such as the silk screen has a couple backwards voltage regulators. Call me before you punch the wall.
Awesome!! I just finished mine last week and put it down for a bit. I also noticed the Q10 screen was wrong, and caught it when I was testing ground continuity. I reversed the 7909 to what the screen stated. I did not plug in any of the chips yet as I was going to retest the continuity and then power up to double check. I am glad you also corroborated this. Mistakes on Ray's builds are rare, so I always fault myself first when things go sour.

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Post by wiperactive » Sat Aug 19, 2017 9:37 am

Nice to see and hear this beyond Ray's original demos which enticed me into buying a couple of these PCBs on first publication. My pending pile is ridiculously over-bloated at present so having a go at an octuple version is still some time away here.

Having been away from any serious DIY for a while now, I'm not sure if I'd have spotted that voltage regulator error either, so appreciation rithma for your flagging of that.

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Post by Starspawn » Sat Aug 19, 2017 10:54 am

Just to interject here, the part in question is a 79L09, which as a lower rated TO-92 part looks like a smaller transistor and as such has its front to the flat side. So the silkscreen is correct.
Using a 7909 the silkscreen is still giving the correct information as long as you are able to interpret that the flat side designates the front of the part and that the front of 7909 should face that way.

The silkscreen for the 7909 part is usually a flat rectangle with a line on the side where the back is.

So no fault of rays, but yes, although you can use 7909 in 79L09s place with the same pinout, do beware of orientation.

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rithma
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Post by rithma » Sun Aug 20, 2017 4:46 pm

Are the pinouts different between various 79L09 and 7909? All I had were the 7909 in TO220 package. The silkscreen looks to me like the 7809 and 7909 are standing next to each other, facing each other. My timbre bank locked up my whole PSU the first time I plugged it in (and really gave me a bad scare), until I went through with a meter and discovered all the voltage regulators need to be facing the same way. I will include some pictures once i get home.

And... everything I know I know because of Ray Wilson... not trying to fault him!

/E

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Post by indigoid » Sun Aug 20, 2017 6:25 pm

Love it!

I've never attempted a PCB layout for a filter... the time has arrived. Say no to panel wiring!
Zap him again! ZAP THE SONOFABITCH AGAIN!

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rithma
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Post by rithma » Sun Aug 20, 2017 7:25 pm

Say no to panel wiring!
Although I get a twisted joy out of complex wiring projects, keep me posted on this!!! There are connectors sprinkled all over the PCB like buckshot, I am quite curious how you get on.

And I would certainly take one, I accidentally ordered 2 PCBs from synthcube and I'm not about to lace up the second one.

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Post by indigoid » Sun Aug 20, 2017 7:54 pm

rithma wrote:Although I get a twisted joy out of complex wiring projects, keep me posted on this!!! There are connectors sprinkled all over the PCB like buckshot, I am quite curious how you get on.
Yup. As always with Ray's schematics, I need to redraw it in a way that makes sense to me first :-/

I would prefer to build it with a single VCF+VCA cell per PCB. My PCBs are almost always perpendicular to panel (but shallow; I try to keep them within 40mm depth) and 4hp, so an 8-cell version would be 32hp... plus another 4hp at each end for shared input and mixed output, so 40hp in toto

So many projects...
Zap him again! ZAP THE SONOFABITCH AGAIN!

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Post by Starspawn » Sun Aug 20, 2017 11:26 pm

rithma wrote:Are the pinouts different between various 79L09 and 7909? All I had were the 7909 in TO220 package. The silkscreen looks to me like the 7809 and 7909 are standing next to each other, facing each other. My timbre bank locked up my whole PSU the first time I plugged it in (and really gave me a bad scare), until I went through with a meter and discovered all the voltage regulators need to be facing the same way. I will include some pictures once i get home.

And... everything I know I know because of Ray Wilson... not trying to fault him!

/E
It depends, 7809 and 78L09 are reversed, so you were lucky with that one, but 7909 and 79L09 are not. And like I said, the silkscreen is for TO92 and as such correct since the "front" is not the same. There is often a difference in pinout between TO220 and TO92, always check that.

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rithma
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Post by rithma » Wed Aug 30, 2017 2:44 pm

So... Here's what I meant with the voltage regulators -
the silkscreen looks like the positive and negative regulators are standing next to each other, but facing each other:
Image
But your quad timbre bank will not work until the regulators are all facing the same way, like this:
Image

boy does it sound cool. [/img]

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Post by Starspawn » Wed Aug 30, 2017 3:20 pm

Yes, but again, use the following information: The silkscreen is not for that part. Flat side of TO92 is its front. The positive T0220 parts have reversed pinouts from the TO92 parts while the negative have the same in both packages.

It has nothing at all to do with facing the same way other than that that is the incidental result of following those steps to use TO220 parts.
Facing the same way is not a requirement to function, having the correct pins in the correct holes and checking documentation to get there is.

Most builders will use the TO92 parts and just be confused by someone talking about common orientation like that is something to pay attention to.

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rithma
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Post by rithma » Wed Aug 30, 2017 4:21 pm

The positive T0220 parts have reversed pinouts from the TO92 parts while the negative have the same in both packages.
That was my confusion, thanks.

Then I should say: "If you are using the TO92 parts specified in the BOM, please disregard"...

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Re: MFOS Quad Timbre Bank, Eurorack

Post by Midiot » Sat Oct 10, 2020 12:17 am

I'm building this, for my eurorack.
I will turn and mount the too large official MFOS board sideways, and create my own panel/layout. Then it will fit into my eurorack.
http://musicfromouterspace.com/analogsy ... REBANK.php

I understand the use of the "TO-92" type/size regulators.... and the hardest to find part is the 79L09 (negative) -9v regulator..... not impossible, but hard to find. Search the surplus market.
Note that there are "SOT-89" smd sizes currently in production, and the pinout is the same....so can they be cleverly soldered to the board ? (I ordered some, and we'll see).

Next I was wondering, because this is my first MFOS build adapted to eurorack..... are there any differences in gain (?), between his designs and standard eurorack ?

I also noticed on his (Ray's) official boards for this project... there are no larger size power input buffer/smoothing caps on his board.... at the main +/- 12v power inputs. All I see is a 0.1uf on each input's leg.
Since this power input is driving a large amount of op-amps (and who knows how far away the power source is), I would think that at least a 10uf 25v electrolytic should be put at each +/- 12v inputs. I may add those....even if just to cool my mind. (bridge/piggyback C23 and C24 with the 10uf electrolytic caps, oriented correctly + )

And an aside....
Ray's BOM lists eight... 330pf caps as "polystyrene or ceramic".... and I'm curious why these are the only two types are mentioned ?
"We'll be living in all the oceans now."
(type of music I make.... drone atmospheres, deep late-night beats.)

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Re: MFOS Quad Timbre Bank, Eurorack

Post by KSS » Sat Oct 10, 2020 8:55 pm

7805, 78L05 and 7905, 79L05 can be used instead of the hard to find parts.
See the circuit description and schematic on pages 13-15 in this PAIA 4771 manual. It's often a VERY useful thing to know.
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Re: MFOS Quad Timbre Bank, Eurorack

Post by Midiot » Tue Oct 13, 2020 2:52 pm

Thanks KSS, I forgot that most x7805 and x7905 regulators can be made into adjustable regulators with just a few added changes.
But I found some original NOS -9v parts on e bay auction site.
Still,......good to know.
"We'll be living in all the oceans now."
(type of music I make.... drone atmospheres, deep late-night beats.)

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Re: MFOS Quad Timbre Bank, Eurorack

Post by KSS » Tue Oct 13, 2020 10:13 pm

Glad it's useful!
Forgot to add it doesn't have to be as 'complex' as the PAIA note. Each diode between circuit GND and the 78/79XX G pin changes the output by ~.6V. So two resistors or five diodes gets you your 78/7908

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Re: MFOS Quad Timbre Bank, Eurorack

Post by Midiot » Thu Oct 15, 2020 9:33 pm

Forward progress on this build.
Mouser parts order came in today.
It's a solder-fest.

BTW, I am building two of these to get 4 more filter channels so 4 + 4 = 8 adjustable filters. The MFOS page describes how to add the additional channels...aka another board.
Again, I'm wondering about the 330pf caps which Ray mentions could be either polystyrene or ceramic. I opted for polypropylene (PP) WIMA types.
I can't help but love the ultra-low-profile DIPs.
20201015_190629[1].jpg
20201015_190649[1].jpg
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"We'll be living in all the oceans now."
(type of music I make.... drone atmospheres, deep late-night beats.)

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Midiot
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Re: MFOS Quad Timbre Bank, Eurorack

Post by Midiot » Thu Oct 15, 2020 9:56 pm

I do have some 330pf polystryene caps, so on the second board i'll use them. We'll see (hear) if there is a difference.

Wish me luck when I go to solder all those wires to the front panel jacks and potentiometers.. There are nearly 50 wires-to-front panel.... per board.
Since I have opted for two boards.... double that.
What I may do, is just wire the first board, and see if it's working......then add/wire the second board if everything is well.
"We'll be living in all the oceans now."
(type of music I make.... drone atmospheres, deep late-night beats.)

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Re: MFOS Quad Timbre Bank, Eurorack

Post by jonnyjupiter » Wed Oct 28, 2020 6:04 am

I'm about to start my Quad Timbre Bank.
Does anyone know what the power draw is? Ray normally put the power requirements in a box on the build page for each module on his website but I can't seem to find it for this module.

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Re: MFOS Quad Timbre Bank, Eurorack

Post by KSS » Wed Oct 28, 2020 6:29 am

Welcome to MuffWiggler, jonnyjupiter!

Hopefully someone who's made this can take a current draw measurement and share it here!

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Re: MFOS Quad Timbre Bank, Eurorack

Post by jonnyjupiter » Wed Oct 28, 2020 6:40 am

KSS wrote:
Wed Oct 28, 2020 6:29 am
Welcome to MuffWiggler, jonnyjupiter!

Hopefully someone who's made this can take a current draw measurement and share it here!
Thanks! There's a vast amount of collective knowledge here. The musician/electronics hive mind.
I look forward to adding to it when I can.

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Re: MFOS Quad Timbre Bank, Eurorack

Post by Midiot » Thu Oct 29, 2020 8:47 pm

"The module draws 30mA from both the +12V and the -12V supply."

...seen on this page....
http://musicfromouterspace.com/analogsy ... REBANK.php
"We'll be living in all the oceans now."
(type of music I make.... drone atmospheres, deep late-night beats.)

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Re: MFOS Quad Timbre Bank, Eurorack

Post by Midiot » Fri Oct 30, 2020 6:58 pm

RE: 100mA (negative) -9v regulator..... 79L09
(part # U10 on the MFOS board)

Certainly hard-to-find in the package that is supposed to fit the board .....( TO-92-3 )
But..... it is available new as a small SMD part.....( SOT89 )
NJM79L09SU3-TE1
https://www.mouser.com/datasheet/2/294/ ... 346768.pdf

The pin-outs of the SMD package is the same as the TO-92-3, when looking at the parts from the front and the pins point down.

With careful soldering, the SMD part will fit, and can be used.
Here is a pic of my soldered part, onto the board.....
20201030_151836[1].jpg
Tape the small loose part flat to the board, so that the center pin touches center hole....and also, so that the two outer pins are very close to the outer holes.
Solder the center pin to the center hole.
Wait to cool.
Then fill the two side holes with solder and drag the solder onto each side pin, careful not to bridge any of the pins, and let it cool down between each soldering step.
@@@@@@@@@@@
FWIW.... the +9 positive SOT-89 also has the same pin-outs as It's TO-92-3 version.
https://media.digikey.com/pdf/Data%20Sh ... M78L00.pdf

Here are both +9v Positive and -9v Negative regulators, soldered in.
20201030_151836[1].jpg
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"We'll be living in all the oceans now."
(type of music I make.... drone atmospheres, deep late-night beats.)

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Midiot
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Re: MFOS Quad Timbre Bank, Eurorack

Post by Midiot » Fri Oct 30, 2020 8:23 pm

I also noticed this, from the MFOS store.....apparently they sell all 4 regulators needed, for $6 US. ...??
https://shop.musicfromouterspace.com/ca ... 9-6-1uf-ta
Last edited by Midiot on Fri Oct 30, 2020 8:54 pm, edited 2 times in total.
"We'll be living in all the oceans now."
(type of music I make.... drone atmospheres, deep late-night beats.)

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