I think I was sent the wrong capacitors... will somebody varify this for me?

Started by Jumbosize, November 09, 2013, 11:04:08 AM

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Jumbosize

Hey there, I'm currently building a Tube Screamer clone based off of this tonepad schematic: http://tonepad.com/project.asp?id=1 (click the pdf link for the schematic).

The circuit requires two 1.0 uF Non-Polarized capacitors in the circuit. I bought all of the parts from PedalPartsPlus.com, except they do not sell 1.0uF NP capacitors so I bought some on Amazon instead. They arrived the other day and I'm pretty sure they're not actually 1.0 uF caps (But the listing says they are). The only thing written on them is "1 MFD 100v NON-POLARIZED". I'm assuming that "MFD" either means Megafarads or Millifarads, and based on the size of the capacitor and the "M" being capital, I'm gonna guess it is Mega.

So, I have a few questions:

1. I think I've already answered this but: These aren't really 1 uF caps, are they?

2. I'd really rather not return these and get the right caps if I don't have to so: Does anybody know if these could do the trick in the tube screamer circuit I'm building, or are the 1.0uF caps crucial? I don't know a whole lot about audio circuits (yet) so I could really use some help if anybody has some advice.

3. This goes along with question 2: I also have a set of 1.0 uF polarized capacitors, could those work? And if so, how would I put them in?


Thanks in advance to anybody who has any tips/suggestions. Thanks!

armdnrdy

Microfarad can be designated as MFD or with the symbol µ (from the Greek letter mu) , and since most typewriters did not include the µ symbol, the symbol u was used in it's place.

Bottom line......you have the correct caps.  :icon_wink:
I just designed a new fuzz circuit! It almost sounds a little different than the last fifty fuzz circuits I designed! ;)

Jumbosize

Oh, that's fantastic! I guess I've just become so used to micro being denoted with "u" instead of the mu character.

Thanks so much for your input

PRR

> so used to micro being denoted with "u"

That's new. In the last ~~50 years. Some places, old habits die hard.

> I'm gonna guess it is Mega.

In my father's time, they hazed the new boys by sending them out to get a "One Farad Capacitor". The joke is.... there WAS no 1 Farad capacitor. Big caps were 32, 100, maybe 400 *micro* Farad.

Between him and me we've lived too long. You CAN now buy a One Farad Capacitor. It's the size of a cafeteria soup-can, goes in the trunk of your boom-car so the engine doesn't stall when the bass goes BOOM.

I'm going to predict that _I_ will never see a One Mega Farad Capacitor. But perhaps the next generation will.

> I'm assuming that "MFD"

Even when I was starting popping caps, "MFD" was common for micro-Farad. "mmfd" was still in use for micro-micro-Farad, "pFd" came some years later. "nFd" is utterly new to me. "mFd" meaning milli-Farad I have seen a few times, where I think "10,000uFd" would be clearer than "10mFd".
___________________

> 1.0 uF polarized ....., how would I put them in?

Build the circuit without these caps. Put your voltmeter on the pads where the cap will go. Power-up. Carefully observe what polarity the meter shows. (Be sure of your red and black wires, the jack-holes, and the +/- in the meter display). Also note the voltage.

Put the cap in the way the polarity goes. Note that for some strange reason, diagrams often show the + lead but caps often mark the - lead.

If the voltage is less than a Volt, a good polarized cap will work at first but fade in years or decades.

If you get the cap backward, at best the circuit won't work right, and may smoke.
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duck_arse

QuoteIn my father's time, they hazed the new boys by sending them out to get a "One Farad Capacitor". The joke is.... there WAS no 1 Farad capacitor. Big caps were 32, 100, maybe 400 *micro* Farad.

Paul, do they still send the juniors for skyhooks or spotted paint?
don't make me draw another line.

armdnrdy

In my trade (industrial electrical contractor) we send the apprentices to the truck to get the wire stretcher.

I have a friend in the automotive repair industry that sends his new guys after headlight fluid.  :icon_lol:
I just designed a new fuzz circuit! It almost sounds a little different than the last fifty fuzz circuits I designed! ;)

disabled_shredder

When I was in service we sent the newbies from motor pool to motor pool getting exhaust samples they would rap a trash bag around the tail pipe fill up tie off and repeat. Also grid squares was a popular go find and I was a cook so some of the men (I thought it was wrong) but they sent the women for "meat stretcher". Use ur imagination. And my personal fav that works in any business! Hey FNG private go get a bucket of prop wash for the floors ( prop wash is the term for helecopter blades, the sound made)! I got more and better by I want to hold on to something. And sorry for being ot! Happy vets day to all the vets!
The wild man with a loaded gun and no plan. I'm not held back by rules, just don't know which ones to follow

Ice-9

Well my imagination tells me a "mega" farad cap would be the size of a tower block but if you can find an enclosure to fit it in by all means use it.  :icon_evil: MFD denotes microfarad.

Things apprentices got sent for when I was younger were,

they were asked to get "Sky hooks"
told to go ask the foreman for "A long Stand" which when they asked for it were to told to go wait over there, and they were just left standing till they sussed
when working in kitchens new starters were often told to go and ask the waitress for "a ham shank"

Loads of others, which all passed the time of day at work, albeit at someone else's expense.
www.stanleyfx.co.uk

Sanity: doing the same thing over and over again and expecting the same result. Mick Taylor

Please at least have 1 forum post before sending me a PM demanding something.


marley459

I remember when i worked in a kitchen years ago they would tell the younger new guys to ask the dishwasher for a bucket of steam.

Jdansti

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R.G. Keene: EXPECT there to be errors, and defeat them...

duck_arse

so, this thread has veered somewhat, (sorry about that) what can we send newbies to this site to get?
don't make me draw another line.

Jaicen_solo

Agreed this thread has gone astray, but I wanted to mention that my Uncle once sent his mum, my Grandmother to a local car parts chain (Halfords in the UK) for some sparks for his spark plugs. I believe he once also asked her for a left handed spanner.