Am I being too anal over my resistors?

Started by JohnForeman, July 07, 2015, 03:46:03 PM

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Hatredman

Kirk Hammet invented the Burst Box.

snarblinge

this isn't too anal at all,

I usually stress about colour matching all my resistors, not to mention size and if they are all going in the same direction.

the best is when i can include the caps in this insane quest for the impossible. my all blue echo base want too hard, neither is the all green pedals, of which I have now done a few, but do you know how much it costs for red resistors  ?
b.

snarblinge.tumblr.com

duck_arse

snarl - one word - beyschlag. their metal film resistors are/were red, top quality, back when. and back when, I was working for an OEM, and the production manager taught the girls to put the resistors all pointing one way. it makes it easier for the girls to spot their own mistakes in placement, and for the tech testing later it's easier to read the values.

once you have your components colour matched, redesign the circuit for "E1" values. ask samhay.

also, roederstein (flameproof?) for the greens.
don't make me draw another line.

snarblinge

Thanks duck, you must have tinges of the same disorder :) the beyschlags I already have links too for purchasing, and I have a ton of standard green 1% from before dick smiths got out of them, the others mentioned I will look into..
b.

snarblinge.tumblr.com

induction

Quote from: LightSoundGeometry on July 10, 2015, 08:28:49 AM
I have read and seen on videos old capacitors are not near as good as new ones; and their lifespan is typically 15 years at most. A lot of article out on tube amps that go bad because of old parts wearing out like caps etc.

Electrolytics wear out, high quality or low. If you find a batch of old ones, assume they're no good. If you find an old amp with the original electrolytics, assume they are already or nearly dead and need to be replaced. But the replacements will eventually wear out too, no matter how well-made they are. Other types of caps don't have the same problem, but are difficult, expensive, or impossible to find for higher capacitances.

samhay

Quote from: duck_arse on August 18, 2015, 11:09:56 AM
once you have your components colour matched, redesign the circuit for "E1" values. ask samhay.

I almost always stick with E6 values, quite often manage E3, and have a few E1 designs. This is not a good approach when you have finicky transistors to bias, but is usually fine for IC and digital work. You can by a few values of resistors in lots of 100s and learning the colour codes is a breeze. It does mean that you tend to need a good range of capacitors though, and I struggle to get box caps in all values, which are the same colour.
I'm a refugee of the great dropbox purge of '17.
Project details (schematics, layouts, etc) are slowly being added here: http://samdump.wordpress.com

amptramp

I tend to use whatever I have with the most common being the tan 5% values but I have many carbon comp cylindrical brown ones.  I try to design circuits where resistor values are not particularly critical so tolerance is rarely an issue.  When I need to buy new resistors, I tend to get tan 5% Philips ones.

via Imgflip Meme Maker

duck_arse

cheep is also my favourite colour for parts. [I don't know who that ^ man is: Mr Tayda or Kenny Rogers?]
don't make me draw another line.

amptramp

Johnathan Goldsmith plays "the most interesting man in the world" in the Dos Equis beer commercials.  He has enough captions in this picture to rival Chuck Norris jokes such as:

When in Rome, they do as he does.

duck_arse

kenny rogers is the most interesting man in the world?
don't make me draw another line.

R.G.

Quote from: induction on August 19, 2015, 07:18:42 AM
Quote from: LightSoundGeometry on July 10, 2015, 08:28:49 AM
I have read and seen on videos old capacitors are not near as good as new ones; and their lifespan is typically 15 years at most. A lot of article out on tube amps that go bad because of old parts wearing out like caps etc.

Electrolytics wear out, high quality or low. If you find a batch of old ones, assume they're no good. If you find an old amp with the original electrolytics, assume they are already or nearly dead and need to be replaced. But the replacements will eventually wear out too, no matter how well-made they are.
I have been beating on this for years now. Electrolytics have built-in decay mechanisms. They last longest if used regularly (e.g. unit turned on at least weekly - but only in equipment that doesn't heat the electros up just by being turned on, as heat degrades them too), and only 5-10 years if not turned on at all. The voltage helps self repair, but cannot cover every source of internal chemical degradation.

A really, really bad situation to get into is fixing old amps with lots of electros. If you find and fix only one electro, chances are the next-most-bad one will fail in a short time and you're going to be back in there replacing another electro. This then becomes what we used to call an on-the-job IQ test: if you replace more than one single electro at a time in such a repair chain without figuring out to replace them all, ... well, you get the idea.

QuoteOther types of caps don't have the same problem, but are difficult, expensive, or impossible to find for higher capacitances.
It's getting better. "Higher capacitances" now means "above 2uF"; it used to mean "above 0.47uF". Film 1uF and 2uF caps are available, cheap (about $0.50) and highly recommended over equivalent electros on every count except cost; the electros in 1uF and 2.2uF are about $0.08.
R.G.

In response to the questions in the forum - PCB Layout for Musical Effects is available from The Book Patch. Search "PCB Layout" and it ought to appear.

PRR

> kenny rogers is the most interesting man in the world?

No. Different commercial.

Dos Equis beer hired a an actor to play the fictional "Most Interesting Man In The World", to con you into drinking their brand of boring pee.

GEICO Insurance hired the real Kenny Rogers for a nonsense ad which mentions the insurance then says "... playing cards with Kenny Rogers gets old pretty fast". He hums his The Gambler song constantly.
www   .youtube.com/watch?v=SVlRx2U-xUA  (paste-together the link; I don't wanna embed it)

I'm sure they don't have such stupid commercials where you live.
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davent

Quote from: snarblinge on August 17, 2015, 11:32:34 PM
this isn't too anal at all,

I usually stress about colour matching all my resistors, not to mention size and if they are all going in the same direction.

the best is when i can include the caps in this insane quest for the impossible. my all blue echo base want too hard, neither is the all green pedals, of which I have now done a few, but do you know how much it costs for red resistors  ?

Always liked the look of these reds.

http://www.partsconnexion.com/resistors_prp_quarter_watt.html
"If you always do what you always did- you always get what you always got." - Unknown
https://chrome.google.com/webstore/detail/photobucket-hotlink-fix/kegnjbncdcliihbemealioapbifiaedg

greaser_au

Quote from: PRR on August 19, 2015, 02:43:11 PM
I'm sure they don't have such stupid commercials where you live.

Paul,
You'd be surprised... :)     My good lady's  current favourite: https://www.youtube.com/watch?v=YcHxmzAg9us

Down under we get all sorts, and quite a lot internationally made commercials overdubbed with australian voices.

david

duck_arse

QuoteI'm sure they don't have such stupid commercials where you live.

don't be. I'm fast enough on the draw that I don't ever hear what they say in the ads, which here are mostly pointing, open mouthed, at large things. and looking, always the bloody looking! and without the sound, the real qualities of the ads shine.

sorry, that "shine" is spelt with a 't'. odd how threads veer once the original question has been answered.

also: IRH used to make metal glaze 1/4W resistors with dark brown, moulded bodies. philips had a range of 1/4W carbon resistors for use on mains voltages with light green bodies.
don't make me draw another line.

mremic01

Quote from: PRR on July 07, 2015, 09:38:17 PM
...you can have cracked paint lets the damp in and rots the ohms out, bad contacts between carbon and end-caps, all sorts of things. Do NOT buy "cheap" resistors. Your DIY time is not worth saving a penny.

This worries me a bit. I find quite a few resistors with little holes in the paint in those bags of 200 from Xicon. They're quality resistors, but I never thought defects in the paint would be an issue.

Would it be worth it to fill in the opening in the paint with nail polish?
Nyt brenhin gwir, gwr y mae reit idaw dywedut 'y brenhin wyf i'.

hymenoptera

If you have an ebay account, and plenty of free time, you can scour the sellers on there for new old stock.

I've been at this for years, mostly doing repair work and simple upgrades to rackmount gear, and I've amassed quite a collection of resistors, among other things.

I try to find 50, 100, or 200-packs of medium to high quality parts only, and tend to stick with 1/4w metal film. Brand names like Dale Vishay, Philips, BC (Beyschlag), KOA Speer, Yageo, SEI (Stackpole), Mepco and the like make up most of my collection now. Remember that 1/8w mil-spec is the same as commercial grade 1/4w because they've been further derated.

I only buy what values I need (or if I see a killer deal!), but I always make sure to buy way more than I need. I could probably list my favorite ebay sellers, but I'm sure if you know what I'm talking about then you've already got an idea who they are or at least how to find them. :)

I bought some of Tayda's 47ohm 1/4w metal films just to try out for an upcoming build, and was pretty disappointed in what I found. Thin leads and just blah looking. I love shopping at Tayda for other things, but I think the Xicons you can get as Mouser or the pedal-specific shops would be much better than the cheapie no-name resistors I got from Tayda.

Remember, that enjoying working with electronics is what makes this a fun hobby, and just cheap parts and cheap tools = frustration.  ;)
"Radio Shack has nothing for anyone who's serious about electronics." - Jeri Ellsworth

amptramp

A few years ago I picked up two reels of resistors, one being 23.2K 1% and the other being 43.2K 1% for $2 each at a garage sale.  Now that I have thousands of them, it helps to use these values wherever they can be made to fit in a design.  A lot of thought has been given in recent years by manufacturers about reducing the number of separate line items in a design for inventory purposes.  As a builder of one-off devices, this never really influenced my thinking, but the ability to use as few different values as possible in a design works well for me now that I have a lifetime+ supply of them.