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Messages - jkokura

#2671
As far as my research led me, no the order of parts in series does not matter. I you're really worried about it, try it both ways on a breadboard.

Jacob
#2672
Tech Help - Projects Page / Re: PNP zygote LED
May 06, 2012, 02:56:27 AM
An exterior bias control is sometimes handy if you like to play with voltage sag. The more common and appreciated mod here is the Pre gain knob.

Have you got your LED backwards? Easy mistake to make. Also, it's possible you blew the LED when testing with the battery the way you did, though that may not be it.

Jacob
#2673
Build Reports / Re: Roland Bee Baa
May 05, 2012, 09:56:59 PM
That's hot. Nice build lace.

Jacob
#2674
IC 1 looks fine.

IC2 and 3 look strange to me. Particularly, IC2 pin 7 and IC 3 pin 3 should be the same, but they aren't. The wierd voltages on IC2 are also not really important because those 3 pins aren't actually connected to anything.

So yeah. Start looking for wrong values in the resistors in there, and for solder bridges which are more likely because you've done some reworking of the board already.

Jacob
#2675
Voltages would help us a lot.

Jacob
#2676
Open Discussion / Revenge of the Fifth.
May 05, 2012, 05:45:52 AM
Worst day ever?

Jacob
#2677
At this point, it's your closest match so I'd go with it and not worry about it.

Jacob
#2678
1.37 and 1.403 is closer by .004

Jacob
#2679
General Questions / Re: Buffer circuit and PCB?
May 04, 2012, 09:44:28 PM
Check out Coldcraft effects. Austin is a member on this forum, and he is great people.

Jacob
#2680
Open Discussion / May the 4th be with you...
May 04, 2012, 06:40:26 PM
Best day ever.

Jacob
#2681
yeah, really well done! That's pretty clean and doesn't look like it's your first at all.

Jacob
#2682
Pictures may help in this case Bret.

Check your voltage at the 9V input on the daughter board, 9V on the main PCB, and the ground on both. After that, start checking for continuity between your input and output wiring and ground.

Jacob
#2683
The CE-1 was developed for keyboards I believe, and the product got co-opted by guitarists. Jargo's over is awesome, but I think CJ is correct - it's a project that isn't really feasible on a scale most DIYers are interested in.

For the cost and availability factor, the CE-2 circuit is just so much more accessible and user friendly. The CE-1 is quite complicated and large.

Jacob
#2684
Sure, you're confusing +9V with -9V.

Basically, voltage runs on a swing. Consider 0 to be ground in most cases, particularly with pedals. This means that 0 is considered as one end of the swing in some pedals, but can sometimes also be used as the middle of the swing, which only confuses things... sorry

So if 0 is our ground, that means that +Xv is one side of the pendulum swing, and 0v is the other side. So for example, using a typical +9V power supply you'd have a 9V swing from +9V through 4.5 to 0V. However, you could also use a +/-Xv supply you could have a swing from +9V through 0 to -9V which is an 18V swing. Alternatively, you could use +18V through 9V to 0V and achieve the same voltage swing with different numbers involved.

The confusion sets in because some pedals, particularly some using germanium or silicon transistors, use a swing from 0V to -9V instead of +9V to 0V. That's because some of those transistors are built to function that way. They don't necessarily play nice with the standard used by early pedal makers like Roland/Boss and Maxon/Ibanez. They use the same swing though, so you get  a similar performance on them.

With the case of centre ground, that's an entirely mechanical discussion rather than the electrical one above. In this case, we're talking about the plug being used, not the voltage or swing at all. Power plugs generally come in barrel format that have a centre section and a barrel section which connects to a pin and a sleeve respectively. So, when I was talking about ground above, 0V in almost all cases, a centre negative supply or connection assumes that the centre section of the plug, or the pin of the jack, is your electrical ground connection. This leaves the barrel to connect to the sleeve of the jack carrying the +9V.

Some power supplies use a centre negative format, which is what %99 of pedals use, and some use centre positive format, which means the barrel connects to the sleeve for the ground connection.

I hope all of that is correct. I'm still fuzzy on the +/- supplies but I think I have it right.

Jacob
#2685
In theory you could do that, but I wonder about it's effectiveness.

If you build it, try it on a breadboard first. Also, be aware that you need to have at one extreme be the inclusion of only C2 and C5 in the circuit removing C6-8/R7-8, and at the other extreme of the pot be their exclusion while only having C6-8/R7-8.

Jacob