MN3207

[nedyoung]

Can I use MN3207 for the tonepad small clone project?

I bulit it yesterday,when I fired it up,there's no chorusing sound(sound like bypass)
I use the mn3207 chip for the mn3007,I was wondering that's why I can't
get the chorusing...

anyone help??  thanks a lot   :lol:

[jrc4558]

mn3207 has slightly different pinout.
search google for MN3007 and MN3207 manuals, you will see.

[puretube]

sorry Ned, but you probably fried the BBD-chip:
the 3007 (clocked by 3101) works on minus 15V;
the 3207 (clocked by 3102) works on plus 10V;






//www.puretube.com

[ExpAnonColin]

sorry Ned, but you probably fried the BBD-chip:
the 3007 (clocked by 3101) works on minus 15V;
the 3207 (clocked by 3102) works on plus 10V;






//www.puretube.com

I hate to agree, but there's a good chance if it's just bypassing... if no sonud was coming through it would be a surefire fry.  Eek.

-Colin

[puretube]

hate to disagree: if fried (the BBD), you`d still hear the "other" path,
i.e. the undelayed, which only get mixed with the delayed signal (be it there or not...) to form a chorus...




//www.puretube.com

[Rob Strand]

I don't believe it's possible to determine whether the BBD is blown or not at this stage.

The MN32xx series and MN30xx series BBD chips have a few differences.  One difference is which supply rail you have to connect the "pull-up resistor" to on the BBD the output terminals.  The MN30xx's pulls-up to +V where as the MN32xx's pulls down to 0V.  I have a feeling this is the main cause of  the lack out delay output.

The best thing to do is to get hold of a schematic which uses the MN3207, say an Ibanez schematic, then compare this to a Boss schematic that uses the MN3007.   If you can read data sheets get hold of those too.  You should be able to spot a few connection differences around cht chip. If you re-wire your chips to match the MN3207 circuit there's a good chance you will at least get something out of it.  After you have done this, make sure you adjust the bias trim pot before you jump to any conclusions that something is blown.

The require changes are fairly small and you should be able to work it out.

[nedyoung]

thanks for everyone's reply...

If I switch pin1 and pin5 to get the positive voltage supply,will it work?

[Rob Strand]

switch pin1 and pin5

Hmmm, yeah you *have* to do that.   Actually by running it with the pins 1 and 5 reversed, as you have it now,  it *can* actually blow the chip.  You have to change the output resistor that I mentioned, and change  the pin 4 connection from gnd to +V.   Strictly pin 4 should be at 14/15 times the supply - I'm not sure if the MN3207 works still properly with pin 4 at +V.

I think that covers it.

BTW, that chips is sailing close to the wind with a new battery, and some wall-warts could pop it.  Most effects feed this chip off 5 to 6V - doing that would be a major change for that ckt though, you would have to change heaps of  stuff.