Need a +/- 15V PSU - MS20 Filter Clone...

[Milkmansound]

um... what? That was the first schematic I ever drew so please bear with me if its a mess. I have not tried this PSU yet - just doing some homework before the parts arrive next week.

Here is the main filter schem. - it also may have issues - keep in mind, this is the second schematic I have ever drawn, and I am putting together 3 things and using I program I just got and... well, if its not gonna work and someone notices - I would be thrilled to know about it :grin:

that first IC on the far left is a 4558. That is something I added on, I am attempting to have a non-inverting amplifier with a gain of 10, but I am not entirely sure what it is in actuality.

Then, as you can see from the original schematic, I left off some stuff. Like the pitch and CV inputs - they might reappear though, if I intend to add in an LFO or pedal inputs or something... thats way down the line.

So is this going to work at all????

Thanks guys! :thumb:

 

[soundguy]

This is just a thought, but I have been wanting to build one such box for a long time. If I was building it for a line level input, I know that I would use a nice audio transformer on the input even though the intent of the box is mangling.

just something to consider.

dave

 

[Milkmansound]

what ratio would you use? I actually have an extra 1:20 transformer lying around. Seems like overkill - but its closer to my level of understanding than that gain of 10 amplifier. However - it appears that the amp will also work.

Dave you are welcome to use these plans to make your own box! Shred some waveforms.

 

[smallbutfine]

Maybe a bit too late, but i can confim:
the green pre psu i built (V1 psu) was etched, stuffed and ready to rumble with very good result in a one shot hit in 2 1/2 hours without any hurry and a coffee and two beers inbetween.
An excellent easy to built very pro looking and working psu.
:thumb:
Martin

BTW we had such a filter clone MS20 style (SSM inside :grin: ) in that ugly black big box for 140 Euros....
And SOLD it. It sounded good at first, but they used cheap pots (i bet they were radiohm or less quality) that startet to scratch after just 2 months. The big blue LED couldn't wipe away the crappy built... we did not dare to open it really. a shame what hardware quality small manufacturers give to their customers sometimes. Same with a VERY well known berlin manufacturer of synths...very good ideas but high price for a very unsolid hardware and lacking advanced midi implementation...
That both manufacturers were reviewed VERY GOOD/POSITIVELY in the greatest german keyboards magazines just shows, how "individualism" of a box makes it look much better in reviews than synths of the big companies. btw same magazine mentioned that the korg electribes knobs seem to be not so sturdy...well, but they work for years now flawlessly on my performance board with all kinds of abuse i was able to do with them daily... even if they "don't look like" that at first.
I think they use monacor's pots, a good price performance relationship.

 

[alk509]

[quote author="soundguy"]If I was building it for a line level input, I know that I would use a nice audio transformer on the input even though the intent of the box is mangling.[/quote]

I second that! It can't hurt to put one of those 600:10K Edcors on the input - a gain of 10 is probably a little too much anyway. This is precisely the kind of shit that those sweet, sweet Edcors are good for :thumb:.

Peace,
Al.

 

[Milkmansound]

well, I guess I will play around with a few different configs when I get the parts this week.

I do not know why everyone is recomending that I put the green PSU into this - I just want it to be like a little stompbox sized mangler. You guys are so damn good at DIY, that I think that you have envisioned this project to be something amazing like the other things people assemble here - not the case - this is destined to be cheap junk! I am fairly sure a transformer is going to cost more than the entire rest of everything else - and the PRR supply is just cheap/solid enough to make the project under $25.

Renee Schmitz, whose circuit this was originally recomended the gain of 10 - its easy enough to change if its overloading the filter. However, overloading the filter might be just the thing!

 

[smallbutfine]

Yeah, i've seen this filter schem before, very easy to diy and excellent sounding! I've heard it from samples from the internet maybe a year ago, quite interesting...
You're right it might not be worth the effort to deal with audio transformers in this one (if you don't have them laying around useless :grin: ) or even etch a board for psu or filter... maybe you can really skip the regulators (iif you are short of this like me at the moment :grin: ). this is a pure cheap fun thing!
Trying different performance filters can really be fun, thought about a performance dj-like filter board myself with 3 different types of filter (MS20, Mooglike, and a japanese one which i forgot the name, where you can patch the signal in a HP, BP o LP or all filters at once...have to look at this again cause it sounds VERY cool and extraordinary...)
Matching two of your filters for stereo use is an excellent idea and makes it much more usable and flexible.
I wouldn't use this as a stomp box, you probably don't want to bent down the whole time performing with this one :grin: , try a desktop design ... :wink:

Perhaps i mentioned the green psu only because it's a sturdy design and i have 2 of them laying around just for testing purposes... :grin:

Happy DIY with this fun thing, tell us if you're done!

Martin

 

[Milkmansound]

well I left this off of my schematic - but in the original one there are 2 CV inputs that could be used for pedals or LFO's, which could make this into a more conventional stompbox - but, I am just thinking stompbox sized enclosure, sitting on the table.

Most of the opamps I ordered are in quad packages - so it should be fairly easy to make a 2 channel version. Precise matching is not completely necessary - after all, this thing is going to be used for damage.