tonepad Small Clone:can I use MN3207 instead of MN3007?

[ISC]

To answer FP's question and confirm Mark's thoughts I have made a Small Clone using  MN3207. I couldnt get a 3007 in OZ so I checked out the datasheets for both and decided to give it a try.
I modified the power and gnd tracks for the chip on Tonepad's Pcb layout to take the MN3207 then etched my board. To my ears it sounds exactly like the sound samples of the real thing. Go for it if you can spare the time and effort to modify the PCB  .

Regards
Trevor

[Steben]

Hey, what about revealing  your PCB modifications then to the world? 
How did you do the mods? Did you scan a print out or what?

[Steben]

Thanks for the link! 

Interested parties should check this one out:  http://www.diyitalia.com/index/schematic/Guitar%20FX/Luix%20Chorus.gif

Hey! That is just brilliant! Well, it's not a lot different, is it?

[PenPen]

Thanks for the confirmation. I am also very interested in what changes to the stock build it took. Even just a revised schem would be fine with me, I don't mind sweating through making a layout myself.

The Small Clone just jumped a few notches in my build list, now that I can source the parts relatively cheaply. I had put it off until I had more experience, because that 3007 chip is too expensive for a newbie like me to fool around with. But if I can use the 3207, I'll be putting one of these together soon!

Also, big thanks to hippo for that Italian site, and Mark for finding the chorus schem. That is exactly what I was looking for, something using the 3207 and CD4047 that I can follow. Thanks again!

[Steben]

BL3207 + CD4047 = 4â,¬ (4.8$ ?)
MN3007 + CD4047 = 10â,¬ (11.8$ ?)

Well you can mess it up about two times
Of what I know and read here I guess there is no difference between the two in sound when using it for chorus. For flanging you can easier results with 3207 for it is designed for higher clock rating. Yet Mark explains with some well-thought ciruitry you can "overclock" the 3007 too.

[A.S.P.]

10â,¬=11.8$

[Steben]

Thx, edited.

You have to admit one thing: BBD's are fun. It's pure analog electronic designing.
Digital modulation (usually one-chip-adventures) doesn't need electronic skill, but programming skill, doesn't it!
yuck...

[luix]

Honored to be linked in this great forum...

I build the luix chorus because I can find MN3207 in big quantity and at good price, as you can see is a collage of various ideas found on the net...

The very first sample is disponible here , this was taken on the prototype with a tamaki guitar (horrible) and a Rogers 30W amp, were the sound is distorted is due to the bad guitar condition.

The PCB is the definitive (i think)...

[Steben]

Honored to be linked in this great forum...

I build the luix chorus because I can find MN3207 in big quantity and at good price, as you can see is a collage of various ideas found on the net...

The very first sample is disponible here , this was taken on the prototype with a tamaki guitar (horrible) and a Rogers 30W amp, were the sound is distorted is due to the bad guitar condition.

The PCB is the definitive (i think)...

I can't see the parts placement (pcb TOP) in the zip file...

[luix]

Is in the zip file named luix chorus top.jpg!?!?!

Anyway here it is:

[Steben]

Grazie!

Couldn't read the file: it was blank.
(only file I couldn't read by the way)

[luix]

Di niente...

It's strange... I will ask around to see if someone else can't wiev it...

[analogmike]

I stand by CD's post about the chip spec differences. Hand waving arguments aside, all things being equal, a 3007 based circuit must sound better than a 3207 circuit. If you are investing hundreds of dollars in your own time to build a pedal, you might as well spend a few more bucks for the real Japanese made  MN3007, Small Bear has thousands of them in stock. They will easily last 25 years, we don't know how long the Chinese chips will last yet. Have fun!

[Mark Hammer]

Meet you back here in 25 years and we'll see if it makes a difference!

[Steben]

I guess there are so many Chinese that ... sorry Chinese chips , that you can swap them quickly.
After all I don't think that a Japanese tech advantage is still reliable as advice 30 years later. I mean: the Chinese will know how to make by now, won't they. They have men in space, the Japanese don't.

[Fp-www.Tonepad.com]

Interesting.

[analogmike]

Meet you back here in 25 years and we'll see if it makes a difference!

Will do!

By then, forums will be just like meeting in person, face to face, but not in real time. Will be able post sound clips that appear to you in hifi any time. Will be able to see pedals and designs in 3D, in detail. Maybe even smell them? "My TS-8000000008 fried, does this smell like a diode or transistor to you?".

[Fp-www.Tonepad.com]

A/B'ing two otherwise identical builds except one uses MN3207 and the other MN3007 now that we have that italian schematic shouldn't be too hard at all.

[A.S.P.]

time to re-name that gadget to: MINI-CLONE

or: " Pico - Copicolono "

[Mark Hammer]

I stand by CD's post about the chip spec differences. Hand waving arguments aside, all things being equal, a 3007 based circuit must (emphasis added - MH) sound better than a 3207 circuit. If you are investing hundreds of dollars in your own time to build a pedal, you might as well spend a few more bucks for the real Japanese made  MN3007, Small Bear has thousands of them in stock. They will easily last 25 years, we don't know how long the Chinese chips will last yet. Have fun!

Again, I have to question what "must" requires in order to be valid.

*** IF I was running a pedal from a regulated 15v supply (instead of an unregulated 9v battery), and
*** IF I did tight-spec'd bias-voltage setting for the pedal (instead of tweaking a trimpot until it sounded okay), and
*** IF I took care to keep the input signal level sensible (instead of plugging myhigh output fuzz directly into the BBD-based pedal), and
*** IF the rest of the circuitry holds up its end in the way of noise-elimination/attenuation (instead of cutting corners to keep costs/size
       down)

THEN...

*** I can pretty much guarantee the S/N ratio will be optimized to the limits of what the chip can do,
*** I can pretty much guarantee the overload-based distortion can be kept to a minimum
*** I can pretty much guarantee the samples are as high quality as the technology permits.

I have no quarrel with any of that.  Once somebody makes themselves a Zombie Chorus, or something similaly lean in design that has no supply regulation, provides a supply voltage much less than an MN3007 can take, does all set-up by ear, and inserts abusive signals into it, whatever advantage is provided by one chip over another in the ideal world simply disappears.  As an example, if one looks at the datasheets for the 3007/3207/3307, it is fairly clear that deviations of a half volt in bias-voltage can have significant implications for THD levels.

I'd like to think one could depend on chip specs to make decisions, but all too often we ask chips to do things that are impossible unless we provide them with the support they need.

As for the relative quality of Chinese vs Japanese chips, I am curious as to what it is that Beiling makes.  Those with more industrial process knowledge are likely better-placed to say what happens.  My limited understanding of the matter is that Matsushita decided to be completely "done" with these devices, so I am assuming they sold the dies and license to Beiling and Beiling simply carries on the making of the same chip in the same manner, only in a new place with new people.  I doubt whether there are any design changes to the internal workings of the chips, though I could be naive in that regard.  Certainly, if I were Beiling, it makes more business sense to simply buy the rights to making a product which I didn't have to sink R&D money into and keep making it for as long as there are clients, and as long as I don't have to sink money into making any changes to the product.  Now, is it possible that there are differences in production quality control that result in a different number of device failures per million units shipped?  Sure.  But assuming the device "works", I can't see how there would be differences in sonic quality.

Forums in "smell-o-vision"?  Ummm, I dunno.  There are days when I decide to surf when I should be showering.   I can't imagine I'm the only one.  Cripes, if you thought there were too few women here NOW......      As for the capacity to have sound samples easily, I'm not too sure about that either.  When was the last time you visited a music store on a Saturday?  On the other hand, if radio keeps going the way it does, you may well HAVE to come to places like this to even hear any guitar!