View Full Version : Help for the colour blind
Can anyone read off the value of this resistor for me please.
Filterlab
10-06-2021, 18:58
Not the best photo in the world, but from here it looks like 100Kohm +/-1%.
Not the best photo in the world, but from here it looks like 100Kohm +/-1%.
Excellent, that’s what I remembered when I bought them 4 years ago. All paperwork is long gone ��
I have a passive 23 step resistor volume control and this is the shunt resistor. At present, having changed my power amp I am having to wind the volume pot nearly fully up for normal listening. So I will change the shunt resistors, but at about £20 a channel they are a bit too expensive to experiment too much.
Am I right in saying that a reduction from 100kohm to say 47kohm will give a worthwhile increase in volume at any step. I think I am remembering that the PVC had a shunt resistor of 15kohm when I bought it but at the time it was too loud at just one quarter up.
The resistor shown has 5 colour bands. Conventionally resistors have only 4 bands: three denoting the resistance and the fourth the percentage tolerance.
So for a 100K +/-1% resistor the colour coding, starting from the end of the resistor body nearest the lead-out wire, would be:
brown, black, yellow, brown. (10 x 104 Ohms, 1%)
Your resistor replaces the third band with two bands (black and orange), which I presume means 100 x 103 Ohms. It is not a convention I have ever seen before.
If in doubt just measure the resistor with an ohmmeter.
The resistor shown has 5 colour bands. Conventionally resistors have only 4 bands: three denoting the resistance and the fourth the percentage tolerance.
So for a 100K +/-1% resistor the colour coding, starting from the end of the resistor body nearest the lead-out wire, would be:
brown, black, yellow, brown. (10 x 104 Ohms, 1%)
Your resistor replaces the third band with two bands (black and orange), which I presume means 100 x 103 Ohms. It is not a convention I have ever seen before.
If in doubt just measure the resistor with an ohmmeter.
Thanks Barry
Its an Audionote Tantalum 2w non magnetic. They do like to be different!
I tried measuring in circuit, but I know from the past that this can give errors :)
Cheers Chris
Beobloke
11-06-2021, 11:46
Hmmm, from the somewhat small and blurry photo, to me that looks like a standard 5 band resistor with colours that are Brown, Orange, Black, Black and Silver. (Silver being the tolerance band which is always spaced further away from the others)
Which means that one is 130 Ohms +/-10%
If the silver is actually grey then that makes it a 0.05%
yeah i'd say 130 ohms as well
willbewill
11-06-2021, 12:27
yeah i'd say 130 ohms as well
Same here
Filterlab
11-06-2021, 17:54
Ahh, may be. It looks brown to me at the end, but I wasn't quite sure.
OK
I hope this is better
29519
OK
I hope this is better
29519
Wife thought it was brown, black, black, orange, brown
Wife thought it was brown, black, black, orange, brown
It is! :lol:
I didn't know what to make of it, and after years of this; the colours are so bad that it is amongst the worst I have seen. Browns and blacks have been confusable, as have browns and oranges in my past, but that takes the cake.
Filterlab
12-06-2021, 08:24
The browns and blacks are very close indeed. But that's definitely a 100Kohm +/-1%.
https://i.ibb.co/gJSC0kz/A0-AE8-BBA-C513-4-F64-9-C14-08-C6-DFCF146-D.jpg (https://ibb.co/m497nf6)
Usually the colours are far easier to differentiate, on this 13 Ohm +/-5% for example...
https://i.ibb.co/6NhZhGc/1-C4-ED8-F9-E41-D-4-B6-C-AD30-F2-B13-D2-B6-BB7.jpg (https://ibb.co/8X3B3Gn)
depends on which end you start reading tho:eyebrows:
Agree with Filterlab, and his lower examples are fairly typical of those found in Quad stuff.
Pinks and golds were always at the tail end.
Filterlab
12-06-2021, 11:08
depends on which end you start reading tho:eyebrows:
I start from the left. :lol:
On that note, I thought the read was from the end where the band was closest to the end.
I start from the left. :lol:
On that note, I thought the read was from the end where the band was closest to the end.
nope it where the bars are closest together
Filterlab
12-06-2021, 11:32
Ahhh, on the left then. :D
The colour coding of resistors is read starting at the end where the bands are closest to one of the lead out wires. Thus in the example shown above, the bands are: brown, black, orange, gold, so 10 x 103 ohm +/-5%, or 10kOhm +/-5%.
https://eepower.com/uploads/education/what_is_a_resistor.jpg
as you can see the the tolerance band here is closest to the leads but it is last to be read. you can also see the 3 readers are all closer together
In that example the order is obvious as gold is never used as a number. And I agree that usually the resistance band are closer together with the tolerance band laying further away.
I'm sure there are several examples of resistors displaying ambigious colour bands - in those instances I would simply measure the resistance to determine its value.
Even worse I have come across cases where the colour coding was wrong, for example with some Piher resistors.
Filterlab
12-06-2021, 14:00
It's all a bit of a mess isn't it. :lol:
nope it where the bars are closest together
Benidorm?
Beobloke
12-06-2021, 16:28
OK
I hope this is better
29519
In that case, 130 Ohms, 1%
In that case, 130 Ohms, 1%
If you are reading the order of the bands as brown, orange, black, black and brown, then that would be 13 Ohm, 0%. What then would the "fourth" brown band imply?
Beobloke
12-06-2021, 20:57
In the picture I quoted I’m reading it from right to left as brown, orange, black, black and then another brown. There’s an bigger gap between this last brown and the others, so this denotes the tolerance band.
The brown, orange, black, black gives 130 Ohms and the last brown denotes 1% tolerance.
It just goes to show the ambiguity that can occur with resistors where the first band is either brown or red. How would you read a resistor if the first band was pink?
I have, until now, never seen a resistor using four bands to denote the resistance value, so if confronted with such I would simply measure the value.
walpurgis
12-06-2021, 21:39
I would simply measure the value.
I do that anyway.
Filterlab
13-06-2021, 09:52
If you are reading the order of the bands as brown, orange, black, black and brown, then that would be 13 Ohm, 0%. What then would the "fourth" brown band imply?
If read from the end of closest bands, ResistorKit says 130Ohms +/-1%. It has 4/5/6 band reading on it.
:lol:
Definitely measure this one I'd have said.
https://i.ibb.co/vmqzLdS/B3-BFC363-F3-B8-4-F48-93-CE-8-B8-F76-CEE5-E5.jpg (https://ibb.co/P4jC1Wd)
But that supposes you know how to read a five band resistor. With the exception of resistors which have a low temperature coefficient, ALL the resistors I have ever seen use four bands only. It is much easier for me to measure the resistance than to try and find a suitable website to interpret the colour coding.
I have scores of 0.1% tolerance resistors and they have the resistance value written on them.
(BTW why isn't there any marking on the body which denoted the power rating of a resistor? :scratch:)
Filterlab
13-06-2021, 14:02
You know, I have NO idea why they just don't print the resistance and tolerance on each resistor? Why rely on multiple and ambiguous colour stripes that could easily be misinterpreted?
If it was stamped on there'd be no abiguity. It's not like it could be read incorrectly in another language.
On the Mac logic board resistors there are no markings (frankly they're way too small), so one has to rely on testing and the circuit diagrams. No pissing around with coloured stripes.
walpurgis
13-06-2021, 15:07
You know, I have NO idea why they just don't print the resistance and tolerance on each resistor? Why rely on multiple and ambiguous colour stripes that could easily be misinterpreted?
I used to ask my dad that when he was building radios and amps over sixty years ago and he didn't know.
I'd guess because the numbers would wear off or bits of them would wear off and a 7 becomes a 1, 3 becomes 2 and so on.
At least with the bands they can take some wear but still be readable.
You know, I have NO idea why they just don't print the resistance and tolerance on each resistor? Why rely on multiple and ambiguous colour stripes that could easily be misinterpreted?
If it was stamped on there'd be no abiguity. It's not like it could be read incorrectly in another language.
On the Mac logic board resistors there are no markings (frankly they're way too small), so one has to rely on testing and the circuit diagrams. No pissing around with coloured stripes.
I thought surface mount resistors had their values marked as a three digit code. In this system the first two or three digits indicate the numerical resistance value of the resistor and the last digit gives a multiplier. The number of the last digit indicates the power of ten by which to multiply the given resistor value. Thus, for example: "450" = 45Ω x 100 is 45Ω; "104" = 10Ω x 104 is 100KΩ .
Sometimes the multiplier "R" (=1) or "K" (= 103) is used as a decimal point, thus 3R3 = 3.3Ω and 2K7 = 2.7KΩ
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