Going to attempt first build - need help/info finding components (Sparkle Boost)

[monkmiles]

Hello all,

Newbie here and I'm going to attempt my first build. A Sparkle Boost. First off, does it make for a good first build?

I could use some help identifying and buying components for it from this layout: http://www.aronnelson.com/gallery/main.php/v/MarkMs-Gallery/album15/album76/sparkleboost_458_LAYOUT.gif.html.

The regular resistors and caps aren't a problem. I've found a NTE458 I can order at mouser.

But for the 100k variable resistor, I'm unsure where to find that. Can I just use a 100k trimpot like this http://www.pedalpartsplus.com/mm5/merchant.mvc?Screen=PROD&Store_Code=PPP&Product_Code=7201&Category_Code=Trim?

[GibsonGM]

The Sparkle Boost could be a good 1st build.  The 100k trimmer you suggest is ok; Small Bear Electronics carries all of this stuff, good prices and good service, and has all kinds of trimmers you can look at.  www.smallbearelec.com  Plus other goodies that you will want down the road, ha ha.

If you are 100% without electronics background, you could start with the NPN Beginner Boost instead, which has its own page off the forum's Home page.  But this one is of similar level and probably do-able - good luck, and post questions!  )

[monkmiles]

The Sparkle Boost could be a good 1st build.  The 100k trimmer you suggest is ok; Small Bear Electronics carries all of this stuff, good prices and good service, and has all kinds of trimmers you can look at.  www.smallbearelec.com  Plus other goodies that you will want down the road, ha ha.

If you are 100% without electronics background, you could start with the NPN Beginner Boost instead, which has its own page off the forum's Home page.  But this one is of similar level and probably do-able - good luck, and post questions!  )

Thanks man. Smallbear doesn't seem to have the NTE458, otherwise I'd buy it all from there if they did. Mouser and a couple places I never heard of seem to be the only places I could find so far.

I've done simple pedal mods so far, but this will be my first build.

[CynicalMan]

You'd probably be just as well off making the J201 version (which small bear does carry).

http://aronnelson.com/gallery/main.php/v/MarkMs-Gallery/album15/album76/sparkleboost_201_LAYOUT.gif.html

[monkmiles]

I have a total newbie question.

For both of these Sparkle Boost layouts, there's numbers on the top of the layout that reads:

Gain  Level  Gain
3        3      2 1

Does that correspond to the lug on the gain and level pots? As in... Connect to lug 1 and 2 if the gain pot. Connect to lug 3 of the level pot. Then to lug 3 of the gain pot.

[BoxOfSnoo]

I have a total newbie question.

For both of these Sparkle Boost layouts, there's numbers on the top of the layout that reads:

Gain  Level  Gain
3        3      2 1

Does that correspond to the lug on the gain and level pots? As in... Connect to lug 1 and 2 if the gain pot. Connect to lug 3 of the level pot. Then to lug 3 of the gain pot.

Yes that's exactly right.

[GibsonGM]

Yes, sometimes they're read from the back, and sometimes from the front.  If the knob does opposite of what you want, just reverse those connections, lol.

[BoxOfSnoo]

Yes, sometimes they're read from the back, and sometimes from the front.  If the knob does opposite of what you want, just reverse those connections, lol.

This is how I remember it: 3 is louder than 1, right?  So you turn it UP towards the 3 lug.  Though GibsonGM is right, if you get it backwards it's usually no big deal.

[Renegadrian]

Do you have a breadboard?! You can then try different res. and put in the one it sounds best, else you can have it socketed.

[monkmiles]

Do you have a breadboard?! You can then try different res. and put in the one it sounds best, else you can have it socketed.

I don't. I'm attempting to buy an etched PCB from a fellow member for a Sparkle Drive NTE458 layout. So hopefully I can just populate it, wire it up and it'll work!

[BoxOfSnoo]

Do you have a breadboard?! You can then try different res. and put in the one it sounds best, else you can have it socketed.

I don't. I'm attempting to buy an etched PCB from a fellow member for a Sparkle Drive NTE458 layout. So hopefully I can just populate it, wire it up and it'll work!

As a beginner, I would count on it *not* working the first try - you have about an 80% chance of being right.  If you do, it's a thrill, but if it doesn't, you're not too disappointed. 

Besides, you learn a whole lot more by debugging than by easy builds - if that helps any!   As slacker says, projects that take a lot of debugging have extra mojo.

[smallbearelec]

A few beginner notes:

I deliberately don't carry NTE devices. They are too expensive, and IMO they're not good for FX design  because their parameters vary too much. Someone suggested the J201, and that's a much better way to go.

I just got the basic breadboard strips back in stock. Do get one, even if not from me. You can start to learn to do setups on it from the articles in here:

http://www.smallbearelec.com/HowTos/HowTos.html

Happy, noise-making construction!

SD

[monkmiles]

So, the pcb on its way for me is the layout for the NTE458. Is it possible to use the J201 instead on this very same layout?

This layout here: http://www.aronnelson.com/gallery/main.php/v/MarkMs-Gallery/album15/album76/sparkleboost_458_LAYOUT.gif.html

I know the pins are different, but I don't know if there's a way around that.

[monkmiles]

A few beginner notes:

I deliberately don't carry NTE devices. They are too expensive, and IMO they're not good for FX design  because their parameters vary too much. Someone suggested the J201, and that's a much better way to go.

I just got the basic breadboard strips back in stock. Do get one, even if not from me. You can start to learn to do setups on it from the articles in here:

http://www.smallbearelec.com/HowTos/HowTos.html

Happy, noise-making construction!

SD

Just placed an order from you! I decided to order a j201 to try.

[Renegadrian]

So, the pcb on its way for me is the layout for the NTE458. Is it possible to use the J201 instead on this very same layout?

This layout here: http://www.aronnelson.com/gallery/main.php/v/MarkMs-Gallery/album15/album76/sparkleboost_458_LAYOUT.gif.html

I know the pins are different, but I don't know if there's a way around that.

The good ol' MarkM made two similar layouts, this is the one for J201

[monkmiles]

The good ol' MarkM made two similar layouts, this is the one for J201

Right, I know. But the PCB I bought from a fellow member is already etched and drilled for the NTE458 layout.

That said, I ordered a J201 with the hope that I can bend the pinout legs to adjust for the NTE458 layout (I would wrap wire insulation around the legs so they don't touch).

[potul]

From what I've seen, both layouts use the same pcb. You just need to take care of the transistor orientation.

[monkmiles]

From what I've seen, both layouts use the same pcb. You just need to take care of the transistor orientation.

Not from what I see. The pinouts for the NTE458 are DGS and the J201's pinout is DSG. If you look closely at the two layouts, the difference is where the G and S pinouts connect. I believe,  to make a J201 work in a NTE458 layout, you need the "drain" at the top, the "gate" in the middle, and the "source" on the bottom. Just "flipping it around" would make it GSD ...which I don't believe would work.

But I'm a newbie at this stuff, so I very well could be wrong.

[Renegadrian]

The two layouts are very similar, just some minor changes to accomodate the different pinout - yeah you can put a J201 in the 458 layout, just crossing its legs...but hey you got a dedicated layout, so...

[MikeH]

The two layouts are very similar, just some minor changes to accomodate the different pinout - yeah you can put a J201 in the 458 layout, just crossing its legs...but hey you got a dedicated layout, so...

Yeah, just leave the leads long and strip some wire insulation to put around the legs (so they don't short out when you twist them).  Be very careful doing this; you don't want to man handle JFETs too much (if at all) because static discharge from your hands can kill them.  Insulate the legs and twist them around to the correct formation and it will work.

As far as any NTE stuff goes... my 2 cents is that it is overprice JUNK.  I'd go with the J201.