Aquaboy MN3005 Double Delay @ +15V with Road Rage Question

[pdub]

Hi there. This is my first post here and first Madbean project. 

I have an Aquaboy PCB and the Double Delay and LFO boards. I plan to use 2 MN3005's / MN3101 and the Madbean Road Rage board to up the supply voltage.

I am assuming I can run this setup at +15V without and problems?

Also I am a little confused as to how this project can work with positive voltages as I thought the MN3005's were positive ground.

Any help is greatly appreciated.

Thanks, Charles.

[gtr2]

Just follow the build docs for the jumpers below the mn3005 spot..  Socket every chip on this build, especially with the mn3005's!  For the add on DD board socket the normal spot on the board for the mn3005.  Then you can calibrate it with one mn3005 first.  Then just use some old resistor or diode leads, solder them to the double delay board and put the leads into the socket.  This was madbeans suggestion and it works great!

My suggestion for the socket type in the mn3005 (big board spot) is DO NOT use the machined kind.



Use the retention type socket, it is much easier to line your pins into from the double delay board.



I cut two of the 8 pin sockets for this area.  Just hack 4 of the pins on them and trim them enough so they fit together.  The rest of the sockets types don't matter. 

As far as running at -15v you should be fine but please confirm this with someone else as well..  You just feed in 15v from the road rage.  The aquaboy board is set up for the polarity switch with the proper jumper placement.

Do you have any mn3005's left??  I've been on the lookout for a while now...

Josh

[pdub]

Hey Josh. Thanks for your reply!

That's great advice on the sockets for the DD board. . I plan to socket all the IC's as well.

All the chips can handle 15V so that should be ok. I still don't see any where there is any inversion of the supply to negative for the MN3101 which then feeds the MN3005.

I ordered the MN3005's and MN3101 from Retroamplis in Spain. http://retroamplis.es I had a few emails with them and while they do not test them they stated they have used the same supplier for 2 years with no issues. They offered me a refund if I am not satisfied. I rolled the dice .... so I'll be out some time and return post to Spain if they are not authentic. They shipped next day and the cost was about $22 each including shipping. I feel good about it. We shall see!
I can let you know how it turns out. Here's the direct link:

https://shop.strato.com/epages/62070367.sf/sec95332916a5/?ObjectPath=/Shops/62070367/Products/IC-MN3005

The DD and LFO boards are coming from Poland so it's truly an international affair.

Thanks! Charles

[gtr2]

The V polarities are different between the v3102 and the mn3101 on pins 1 and 3.  Check out the pin configuration on these data sheets and how they work with the schematic.

http://www.datasheetcatalog.org/datasheet/panasonic/MN3101.pdf

http://www.garrettaudio.com/DATA/V3102_DATASHEET.pdf

Josh

[pdub]

Hey Josh

Cool yeah I see that now. The ground and VDD pins are inverted to the 3101

Thanks for pointing that out.

Charles

[madbean]

You could maybe run the whole thing as positive ground and just kick in -15v to the whole board. You'd have to flip all the electrolytic caps, most likely. Or, if using a +18v supply you could run it through an invertor with a regulator. The LM7915 does this, I think.

Never tried any of this, so I may just be talking out my patootie.

[gtr2]

Wouldn't that provide incorrect polarities to the current circuit/pin layout?

[madbean]

Wouldn't that provide incorrect polarities to the current circuit/pin layout?

Not if you do it as positive ground, I think. You would be grounding the supply pins on the ICs and providing the voltage to the grounding pins. This is how the Deluxe Memory Man works.

But, I would spend a lot of time considering that before attempting it.

[pdub]

But essentially if the MN3001 is happy with +15 and it's power and ground pins reversed then there's no need right? You are gaining the extra headroom from the higher supply rails. Or does -15V give the DMM some of it's voodoo? 

[pdub]

Just to folllow up the MN3005's I got from http://retroamplis.es are legit and worked great!

[gtr2]

Did you run at 15v?

[pdub]

I have been running it at 12V with no problem because for some reason I can't get the Roadrage to work quite right. I'll have some more time to look into it this weekend but basically the regulator is only seeing a little over 16V at it's input and is won't deliver 15V from that. Thanks, Charles.

[madbean]

You can sub in 1N5817 instead of 1N4001 on the RR board to get a little extra voltage out of the charge pump. If you do that, test the output without any load on it (disconnect from the delay board) to see if you are getting a more solid 15v reading.

[pdub]

I going to see if my local electronics shop has those this morning and give it a try! Thanks.