MiniMoog Filter Clone power supply!

MarcoVella · Joined: Apr 05, 2011 Posts: 11 Location: Australia

Hi guys,
any of you know if i could buy a power supply this to use this minimoog filter in a more portable situation, i almost want to turn it into a synthesizer effect pedal not have it in a mod synth rack.

can anyone help me out here????

Mongo1 · Joined: Aug 11, 2011 Posts: 411 Location: Raleigh NC

Hi Marco -
Yes - that's very possible. If you look at the www.musicfromouterspace.com website, there is a very nice 'wall-wart' power supply that would do the job very well. You just need to build that board and attach a wall transformer to it.

You could also just use 2 9-volt batteries, but the pedal would probably drain those pretty quickly.

If you do want to create a floor effect pedal from the YU LPF, I would also suggest going to smallbearelec.com . They have wah-wah pedal bodies for sale, plus all of the mechanical parts needed. If you controlled the Filter frequency with the wah pedal, I think you'd have a heck of nice pedal.

Good Luck
Gary

MarcoVella · Joined: Apr 05, 2011 Posts: 11 Location: Australia

thanks for the reply gary,

I think i might go with the 9v battery approach just for now as its for a uni assignment and timing is essential. would that mean i would just have to attach my 2 battery clip to the 15 + and 15 - power section of the moog filter, is it as easy as that???
and also, i wish to attach a true by pass switch to the filter, would i simply do this at the output section of the pedal, or would i have to rout it also to the inputs??

thanks again

marco

Mongo1 · Joined: Aug 11, 2011 Posts: 411 Location: Raleigh NC

I think i might go with the 9v battery approach just for now as its for a uni assignment and timing is essential. would that mean i would just have to attach my 2 battery clip to the 15 + and 15 - power section of the moog filter, is it as easy as that???

In theory, yes - take the negative lead of one battery and tie it to the positive lead of the second battery - that will be your ground. Then the remaining positive and negative leads will be the power supplies.

In reality you may have some issues. Remember the circuit was designed to work with 12 or 15 volts, and you'll be feeding 9 into it. There may be some adjustments needed as a result. It shouldn't hurt anything to try it though. Someone else may wish to jump in here and advise you on what would have to change.

If I were planning to build something to keep, I would definitely build the power supply. You'll get better sonic results, and you won't have to change batteries all the time.

i wish to attach a true by pass switch to the filter, would i simply do this at the output section of the pedal, or would i have to rout it also to the inputs??

It's always best to do true bypass at in and out. There is good news about that. Smallbearelec.com makes a really nice little PC board that solders onto the back of a footswitch pushbutton that does all of the work for you. It can even control an LED if my memory is correct. It's a very cheap way to the right thing.

One other thing - if you go with the battery approach be sure and wire in a switch to turn the power off. It's common in pedals to do this with a special audio jack with a built in switch, but since you need to use a bipolar supply I think you'll have to add a DPDT toggle switch to the box.

Gary

MarcoVella · Joined: Apr 05, 2011 Posts: 11 Location: Australia

i think ill build the power supply actually, id rather it work at its optimum then it running less efficiently,
sorry for the lack of knowledge on this as ive only done miner soldering before, on guitars etc, im not, lets say, that qualified lol.

one other thing would the power supply run as the following.

15+/15- connection of the moog into the power supply ( soldered) then a wall wart (18v AC) connected to the power supply, i could then have the power supply in the same unit as the moog? would this make sense to do it like this to keep it as portable as possible? once again sorry if my questions seem a little stupid im trying to gather as much knowledge on this topic as possible

thanks gary for all your help by the way, its greatly appreciated.

Mongo1 · Joined: Aug 11, 2011 Posts: 411 Location: Raleigh NC

one other thing would the power supply run as the following.

15+/15- connection of the moog into the power supply ( soldered) then a wall wart (18v AC) connected to the power supply, i could then have the power supply in the same unit as the moog? would this make sense to do it like this to keep it as portable as possible? once again sorry if my questions seem a little stupid im trying to gather as much knowledge on this topic as possible

thanks gary for all your help by the way, its greatly appreciated.

yes- I'd keep the two of them close together or in the same box if possible. That would definitely cut down on the noise.

BTW - I noticed that Ken over at CGS also has a small wall-wart supply too.

Don't worry about asking questions. That's the only way any us of learn anything...

Oh - one more thing. I know the Supply at MFOS has room for 6 big capacitors. You won't need that many for this project. If you just put 1 in for each of the voltages you should probably be just fine.

Best Wishes
Gary

MarcoVella · Joined: Apr 05, 2011 Posts: 11 Location: Australia

awesome i think ill go with the music from outer space supply, just one more thing, so if i only put one of the large capacitors on it, i wouldnt have to change anything else on the pcb?

Mongo1 · Joined: Aug 11, 2011 Posts: 411 Location: Raleigh NC

Hi Marco - No - the supply is set up so that you can either use 1,2,or 3 of the 3300 uF caps per side as your needs change.

Each of the capacitors acts as a storage tank for voltage. When the input voltage is present, the capacitors charge up. When the input voltage drops back down to zero (60 times a second), the capacitor has to supply power to your project until the power comes back.

If your project uses a lot of power, you'll drain the capacitors quickly, so you need all of the capacitors. If you only use a little power, there's no need for so much storage. Since you are only using one module, there's no reason for you to have more than one of the big caps on each side (C1 & C6 for instance).

Please be sure to also use C4,C5.C9 and C10. Their function is a little different and you need them regardless of the amount of power you use.

Be sure and read the MFOS page carefully. Ray is really good at explaining things. He's a natural teacher...

Best wishes
Gary

Paradigm X · Posted: Thu Aug 25, 2011 2:43 am Post subject:

Thanks, useful information in this thread, im just about to put together a MFOS PSU on perf.

MarcoVella · Joined: Apr 05, 2011 Posts: 11 Location: Australia

Hi guys I'm back again,
due to lack of time to get the psu shipped to me, i think im going to have to go with the battery application.

gary if i purchase a two cell 9v battery component would i stil have to ground the batteries together, they would be grounded no?

and for anyone else that could help, would any components on the board need to be changed does anyone know let me know pleasssse!

marco

Mongo1 · Joined: Aug 11, 2011 Posts: 411 Location: Raleigh NC

Yes, if you are using 2 batteries to make a +/- 9v supply, then you need to take the + lead of one and connect it to the - lead of the other. That will be your ground for the system.

Gary