Build Report: Voodoo Lab Sparkle Drive

rocker-D82 · April 02, 2006, 08:45:03 PM

I find the schematic of this pedal in this forum. So, I start to work on layout. I trace layout with PCB (an open source program) under Linux OS. I post some picture. Any idea is accepted!

jrc4558 · April 03, 2006, 01:56:54 AM

I "think" the layout can be shrunk a little. Care to share for common effort to make it smaller?

rocker-D82 · April 03, 2006, 05:22:34 AM

Which format you prefer? PCB format file? Gerbv? PS? EPS? PDF?

jrc4558 · April 03, 2006, 07:06:07 PM

PDF. necrasov at gmail dot com

Thanks! Looking forward to it.

JimRayden · April 03, 2006, 07:28:02 PM

I checked your page and I really love your PCB's. Clean job etching and drilling. Looks like you do a decent job taming those wires too. Anyway, two thumbs up for the sparkle drive.

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Jimbo

b_rogers · April 03, 2006, 08:27:46 PM

i love the sparkle drive. the clean blend is a great addition to the TS type circuit. had one years ago and sold it for a RM octavia. need to build one!

jrc4558 · April 04, 2006, 12:17:45 AM

Got it, rocker-D82!
Next week, once I'm done with exams, I'll try to modify it.

markm · April 04, 2006, 10:20:25 AM

any chance I could get a copy of this layout from one of you kind gentlemen when it is completed??
thank you
MM

MR COFFEE · April 04, 2006, 12:45:01 PM

Nice job!

Glad to hear you're doing a shrink of the pcb, Constantin. I may finally get around to building one

rocker-D82 · April 04, 2006, 04:59:35 PM

Quote from: markm on April 04, 2006, 10:20:25 AM
any chance I could get a copy of this layout from one of you kind gentlemen when it is completed??
thank you
MM

My idea is to improve the layout than post it on my site. Stay tune!

I'm for free distribution!!

MR COFFEE · April 04, 2006, 07:11:34 PM

Right on!

jrc4558 · April 05, 2006, 10:05:38 AM

I may, however, use a quad IC for it, if you kind gentlement are not too atached to JRC4558. Objections?

spudulike · April 05, 2006, 10:41:46 AM

Is there a link for the schematic ? Cant find one ...

rocker-D82 · April 05, 2006, 10:43:30 AM

Quote from: spudulike on April 05, 2006, 10:41:46 AM
Is there a link for the schematic ? Cant find one ...

Here: http://www.diystompboxes.com/smfforum/index.php?topic=38964.0

Quote from: Constantin Necrasov on April 05, 2006, 10:05:38 AM
I may, however, use a quad IC for it, if you kind gentlement are not too atached to JRC4558. Objections?

No, it's ok for me. We can use a TL074!

markm · April 05, 2006, 11:46:19 AM

I prefer the 4558 however, beggers can't be choosers!
I'll take what ya got!!
Thank you,
MM

MR COFFEE · April 05, 2006, 12:00:44 PM

Constantin,

It's you're baby, but I would suggest sticking with partitioning the circuit onto two dual op amp packages because of the possibility of op amps in such close proximity (i.e., on the same tiny piece of silicon), and sharing common bias circuitry, to bleed through from one op amp to another in distortion circuits. Since the distortion stage has feedback diodes to clip IIRC, it might be OK, because the distortion stage wouldn't depend on driving the op amp itself into clipping, but there's still a risk you might hear some unwanted grit coupled in places it wasn't intended. Of course, it IS a circuit to make distortion. It'd probably work OK.

You want to use a quad to save PCB real estate?

Glad you're doing a layout in any case!

I might build one just to hear what it sounds like - I've never heard one.

jrc4558 · April 05, 2006, 02:02:43 PM

Quote from: MR COFFEE on April 05, 2006, 12:00:44 PM
because of the possibility of op amps in such close proximity (i.e., on the same tiny piece of silicon), and sharing common bias circuitry, to bleed through from one op amp to another in distortion circuits. Since the distortion stage has feedback diodes to clip IIRC, it might be OK, because the distortion stage wouldn't depend on driving the op amp itself into clipping, but there's still a risk you might hear some unwanted grit coupled in places it wasn't intended. Of course, it IS a circuit to make distortion. It'd probably work OK.

[quote/]

Hey! That might be exactly the reason why my XXL lite is so noisy... Thanks for the tip!
Ok, I'll try both ways.

Guitar Toad · April 05, 2006, 02:10:38 PM

The Sparkle Drive is definitely on my build list. It's great to see pics of how you did it. Thank you.

MR COFFEE · April 06, 2006, 12:56:33 PM

Constantin,

QuoteHey! That might be exactly the reason why my XXL lite is so noisy... Thanks for the tip!
Ok, I'll try both ways.

Odds are very good that is the source of your excess noise with that XXL circuit because it overdrives the op amp to generate distortion.

Looking forward to seeing your layout !

Great thread guys !

jrc4558 · April 11, 2006, 12:44:39 AM

rocker-D82, check your mail. I sent you a preliminary version.
Anyone willing to review my PCB is welcome to. Just send me your e-mail to the address some few posts above.

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Build Report: Voodoo Lab Sparkle Drive