Substituting SAD1024 with MN3007

[opacheco]

Hi,

I have a ROSS Flanger and I would like to know how I can do in order to replace (substituting) the SAD1024 with a MN3007???...I know that will need to add some parts to the actual circuit pedal but I don't care for this, there is sufficent space for some anothers parts inside!!!....Do someone have a Instruction for that??.

By the way I will appreciete so much if someone let me to know where I can find the Data Sheet for both IC!!!

Thanks a lot,
Opacheco.

[Mark Hammer]

The standard way to provide datasheets online is as a PDF document. So, in general, entering the part number and pdf (e.g., "SAD1024 pdf") into a search engine will get you links for the datasheet of your choosing.

The MN3007 can substitute for an SAD1024 functionally in many, but not all, instances. The SAD1024 contains two series of 512 stages. In some applications, they are used in series, in which case an MN3007 can sub, IN other applications, the SAD1024 is run as a pair of 512-stage devices in parallel, for noise minimization purposes. In those instances, you would be better off with a different device, which is unfortunately every bit as unavailable as an SAD1024 itself.

Note that the MN3007 is an 8-pin device that can not be plunked into the socket for an SAD1024. You would need some sort of retrofit board. the Ross flanger is, like many of their products, basically the same as the MXR unit with a couple of minor changes, right? Check over at the diystompbox forum and see if someone has come up with a retrofit board. With over 20,000 members, somebody has to have trodden down that path before.

[opacheco]

Mark,
Thanks a lot for your comments and advise!!!....I will search into the diystompbox for that.


Thanks again,
Opacheco.

The standard way to provide datasheets online is as a PDF document. So, in general, entering the part number and pdf (e.g., "SAD1024 pdf") into a search engine will get you links for the datasheet of your choosing.

The MN3007 can substitute for an SAD1024 functionally in many, but not all, instances. The SAD1024 contains two series of 512 stages. In some applications, they are used in series, in which case an MN3007 can sub, IN other applications, the SAD1024 is run as a pair of 512-stage devices in parallel, for noise minimization purposes. In those instances, you would be better off with a different device, which is unfortunately every bit as unavailable as an SAD1024 itself.

Note that the MN3007 is an 8-pin device that can not be plunked into the socket for an SAD1024. You would need some sort of retrofit board. the Ross flanger is, like many of their products, basically the same as the MXR unit with a couple of minor changes, right? Check over at the diystompbox forum and see if someone has come up with a retrofit board. With over 20,000 members, somebody has to have trodden down that path before.

[doctor]

Mark,
Thanks a lot for your comments and advise!!!....I will search into the diystompbox for that.


Thanks again,
Opacheco.

The datasheets you interested for are attached.

I personally would recommend to you to use special clock oscillator MN3101 intended for MN3007 and not use original ROSS flanger clock.
You only should remember that minimum clock frequency must be not less than twice of the flanger’s antialiasing filters frequency. You can get this info from flanger owner’s manual (see upper frequency of the effect channel) or measure this frequency yourself.

One of the possible options is to use a circuitry with MN3007 from one of the known flangers (see BOSS schematics, etc.).

[Mark Hammer]

I would actually recommend against using the MN3101. True, it was intended as a nice convenient solution for driving the Panasonic line of chips; it drives the BBD directly, keeps the clock lines comfortably short and atakes little space on the board. The problem is that it does not get over the hurdle of input capacitance on the clock input pins of the BBDs very well. I'll explain.

The clock input pins on every single one of the Panasonic BBDs have a certain capacitance. Look at the data sheet and you'll see it is 700pf for the MN3007. For the majority of BBD applications that's not a problem. Where it starts to become a problem is when one attempts to clock the BBD very fast. At clock frequencies higher than those stated in the datasheet, the input capacitance of the BBD CP1 and CP2 pins acts like an ultra-high "treble control", and turns the square pulse from the clock into something much less square (maye even sinusoidal), producing gaps between the shifting of the successive samples, rather than a seamless perfectly synchronized handover.

As noted, if one is trying to squeeze the most delay out of a BBD, then enabling ultra-fast clocking is not anything that needs tackling. When it comes to flangers, though, you need to be able to get VERY short delay times to achieve any sort of dramatic quality in the flange, and ultra-short means ultra-fast clocking. The ultra-fast clock pulse will remain square if it comes in the form of more current than an MN3101/3102 can deliver.

This is why, in any of the commercially-produced flangers that sweep way up high, you will always see some type of "buffering" of the clock, generally via a CMOS chip of some kind. With flangers using an SAD1024, this is often accomplished by using a 4013 to do the clock division and buffering. True, the BOSS BF-2 uses a 3102/3207 combination without need for buffering, but it doesn't really sweep up all that high. One of the things that enabled the legendary A/DA Flanger to sound so dramatic was that it used buffer/drivers to "condition" the clock signal fed to the BBD and permitmuch higher clocking than the MN3101 could.

[opacheco]

doctor and Mark,

Thanks a lot for take time in order to comment for this post!!!....I will check all this info tonight.

Opacheco.

[Mark Hammer]

Look over at the diystompbox forum for threads pertaining to the substitution of an MN3007 for the original SAD1024 in the A/DA Flanger.