Stopped Before I Could Even Start!

Started by MrShake, April 22, 2010, 11:36:46 AM

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MrShake

Hi everyone!  I'm on my second build in 2 weeks and it's safe to say I'm hooked, even if I'm not really very well-informed. 

The first one was a BYOC 250+, which was simple, easy, went great.  My big fears were in knowing what to put where, and my untested soldering skills.  BYOCs instructions took care of the first part, I did alright on the second.  Job DONE.

So now I've stepped it up to a GGG FY-2 Shin-Ei Companion clone, with far less idiot-proof directions.  So my first step was to go through the inventory and label every single part, and then just "paint by numbers", so to speak... I think I can handle it, as long as I pay attention to the parts whose orientation matters.

In my own personal inventory, everything adds up except for one of my resistors.  R15.  The inventory indicates that it's supposed to be a 390.0 ohm resistor with an orange-white-black-black layout.  Now, what I have for that position is an orange-white-black-orange, which, based on what I could scramble off the net, would ALSO be a 390 ohm resistor, but with a different tolerance?

I'm so sorry for the complete ineptness of my terminology, but it's been a long day.  Basically, is this an equivalent resistor to use, or was I sent the wrong part?  And if this is in the wrong place, mods, can you relocate it for me?
"It's not the band I hate, it's their fans."

Paul Marossy

Quote from: MrShake on April 22, 2010, 11:36:46 AM
In my own personal inventory, everything adds up except for one of my resistors.  R15.  The inventory indicates that it's supposed to be a 390.0 ohm resistor with an orange-white-black-black layout.  Now, what I have for that position is an orange-white-black-orange, which, based on what I could scramble off the net, would ALSO be a 390 ohm resistor, but with a different tolerance?

Are you referring to a 5-band color coded type of resistor? None of that makes sense for a 4-band color coded resistor, there's generally only silver or gold tolerance bands on those.

petemoore

  The resistances of any component [including R's] can be measured with the DMM, set for next-up-appropriate R range, the next index above the R in question.
 [my cheep DMM'd get set to 2000ohm =2k] to measure a 380, because it's bigger than 200ohm the DMM won't register at that setting.
 For unknown value, I may start with 2 meg [highest R my DMM alone can measure], to find where the decimal point falls [telling me about what range the DMM should be set for] and then index to lower settings to get a more accurate reading.
 The debugging thread, read/follow instructions there.
 One approach is to focus on 1 node at a time:
 Count the # of connections of a node on the schematic, then, note any polarized components and their + or - markings. Use the DMM to determine if your populated board reads exactly what the schematic shows, every connection, every R rating. Also verify that every polarized component is correctly oriented. Move to the next node, repeat all node-check steps.
 From collector through collector resistor and most anything else except a capacitor [which blocks DC], a resistance reading between two 'distant points' [ie goes through numerous connections, say from collector [and __,__] to battery clip +] can test many connections and a resistor value with 1 step.
 
Convention creates following, following creates convention.

MrShake

#3
With my lack of vocabulary, maybe a picture is worth a thousand words...



The bill of materials (http://www.generalguitargadgets.com/pdf/ggg_secf_bom.pdf) says this should be a 390 ohm resistor (at the bottom of page 1), but I'm not putting this badboy in until I have confirmation!

Also.... Here is my almost populated board:
"It's not the band I hate, it's their fans."

Paul Marossy

That is a 390K, 2% tolerance. Looks like they included a wrong value resistor with your kit.

Boogdish

You should get a cheap digital multimeter.  When you have moments of doubt/dyslexia/colorblindness it's nice to have something that will tell you the actual value of a resistor on hand.

Kinetic

..especially because you sometimes get slight colour variations on the bands which can confuse!  I was using some resistors yesterday with yellow coloured bands on them which looks very orange to me.

robertreynisson

Don't loose faith! I spent about 3 weeks breadbording a 250 type distortion... I was on the verge of insanity when I realized that one of my resistors was 100K ohms (100.000) when it should have been only 100 ohms....  I've purchased TWO dmm since than  ;), it's definitely worth having one.

MrShake

Thanks, everyone... sorry for my premature panic yesterday.  Everyone's answers were incredibly helpful - I know enough to understand that even the things that don't make any sense to me are fundamentals, so any info is appreciated.  Ultimately, I figured it might be an incorrect resistor, and contacted GGG.  They're sending me a replacement today, and have been wonderfully helpful at every turn.  I have most of my wiring done, leaving space and slack to plop that resistor in, and hopefully, I'll be creating the unholy racket it's DESIGNED to do by the end of the week.  The transistors included were the old-fashioned "metal can" type, with the tab.  I've oriented them in Q1 and Q2 with the tab pointed northwest, according to the pic of my board below... since I'm typing, if anyone feels like confirming or denying that that's correct, I'd appreciate it, but I'm pretty confident I've got that right.

A multimeter is now a must.  I think I dove in a LITTLE bit over my head with this one, as I'm (obviously) electronically braindead.  However, I can now recognize the different parts and have SOME idea of what they do, so that's good.  I didn't think one of those magnifying lamps would be necessary, but I'd be helpless without it.  I think whatever my third and fourth builds are should go just fine after these first two.  I'm hoping to build a handful of Dist+ kits and use them as groomsmen gifts in about 6 months.  Totally within my reach!  After that, well, my pedalboard's about to get a lot less spacious.

Oh, and I realize that I may have started this thread in the wrong place and gave it a TERRIBLY uninformative name in my panicked haste.  OffsetGuitars.com was right, diystompboxes.com is fantastic, thanks for being cool with all that.  Thanks everyone!
"It's not the band I hate, it's their fans."

diydave

A breadboard is also very handy. It took me 2 years to realize that. But now I cannot imagine me tinkering circuits without it.  :icon_rolleyes:

Paul Marossy

Cool, glad you got it figured out. As pointed out, a DMM is an absolute must. Especially when you have some resistors where the red looks orange-ish, etc. It's nice to be able to just measure it. Makes life much easier.  :icon_wink:

Dingus

And hey let us know if you get that GGG FY-2 working. I've tried to build that thing like 3 times and I have no idea what I'm doing wrong but it doesnt work.

I've built much more complicated circuits but something just isnt working here, I'm tempted to just built it from veroboard instead of the GGG PCB.

BoxOfSnoo

+1 on getting a decent DMM.  They are absurdly cheap for the value they give you.  If you can get one with a capacitance meter and a transistor tester, those might also come in handy.

I got this one for $25 on sale: http://www.canadiantire.ca/AST/browse/3/HouseHome/2/Electrical/ElectricalTesters/PRDOVR~0520052P/Autoranging%252BDigital%252BMultimeter.jsp?locale=en
My Dropbox referral link - bonus 250MB of space for both of us if you use it

Paul Marossy

Quote from: BoxOfSnoo on April 23, 2010, 12:17:38 PM
+1 on getting a decent DMM.  They are absurdly cheap for the value they give you.  If you can get one with a capacitance meter and a transistor tester, those might also come in handy.

I actually have three. One of them has a continuity checker, a transistor checker, everything except for capacitance and inductance. Cost me $20.

I also bought an LCR meter for I think $25. Now I can measure capacitance up to 200uF and inductance up to 20 Henries.

Very small investments that can save you a lot of grief.