Hello:
Question:
In "general" (no schematic) are these 1uF capacitors interchangeable ?
a) Ceramic (small yellow, not ideal for the "signal path" ?)
b) Electrolytic (polarized, + / -)
c) Electrolytic (non polarized, BP or NP)
d) Film (quite large)
e) other ?
Polarized electro's aren't intended for use in the signal path...being polarized, and facing an alternating current. They are supposed to exhibit distortion, degradation, other 'poor qualities'. I've sure done it, to no ill effect, but NP is best for values you can't find in poly etc. I try not to use electros outside of power supplies at all, but sometimes you do need 1u, 2.2u etc. Film can be hard to find in higher values like that.
Ceramic are said to be 'poo', best kept for filtering high frequencies so their value is small (10-560pF). I only use them in tone stacks or as bypass caps on opamps or whatever.
Film...mylar, poly...all interchangeable. The only ones in your list I'd say no to if in signal path is polarized electros and big values of ceramic. Just based on experience and 'common wisdom' from reading others discuss this.
Ceramic disks can also be microphonic.
In a guitar pedal they are interchangeable, with the caveat that polarized caps might not be suitable for certain positions in circuit. Capacitor distortion is irrelevant in a guitar pedal.
Here is an example, see 1uF at 1 , 7 and 14 for instance..
(https://i.postimg.cc/cgYdykNH/tonepad-rebotedelay25.png) (https://postimg.cc/cgYdykNH)
In general, yes they are interchangeable.
My old rule of thumb was; if it's in the signal path, it can be whatever - polarity irrelevant. But if it goes to ground, polarized electro is a safe bet.
If space is a problem, the traits of ceramic C0G is comparable to film.
Most of the bad mojo about ceramic caps are regarding the old disk type. Nowadays, X7R is prevalent and really not so bad.
Quote from: Phend on April 03, 2024, 01:05:11 PMHere is an example, see 1uF at 1 , 7 and 14 for instance..
(https://i.postimg.cc/cgYdykNH/tonepad-rebotedelay25.png) (https://postimg.cc/cgYdykNH)
In my life, to be honest, anything 1u and up would be polarized electros, because that's what I have on hand and...just because :) I have probably 50 each of 1, 2.2, 4.7, 10, 22, 47 and 100u electros that I bought some time back because they are cheap, and readily available. Not once have I ever had one fry, sizzle, burn or distort that I can tell. Anything < 1u, is a poly film. Because I bought like 5 of those 'cap kits', so I have millions of them, ha ha.
The ones in the Rebot signal path show polarized, so they must not be worried!
Mozz: By "poo", yes, I meant grainy and microphonic.
I have a old Premier tube amplifier, sort of a tweed deluxe, it has all disk capacitors. Didn't have to replace any except the electrolytics. Doesn't sound bad at all. I did have a homemade pedal and one of disk caps was really noisy, when you tapped on the board you couldn't pin point it, it was really bad but the circuit worked.
Quote from: Kevin Mitchell on April 03, 2024, 01:22:58 PMif it's in the signal path, it can be whatever - polarity irrelevant.
::) ::) ::)
Hmmm...
(https://i.imgur.com/178U5zK.png)
I like to face the "+" toward where it's more "+" :icon_cool:
Quote from: antonis on April 03, 2024, 02:29:19 PM::) ::) ::)
Hmmm...
Right in the pride :icon_redface:
Quote from: GibsonGM on April 03, 2024, 02:58:29 PMI like to face the "+" toward where it's more "+" :icon_cool:
I feel like he did that just for me :icon_lol:
Electros can withstand 1V (or so) reverse potential difference, hence C6 above could indeed be placed either way around..
(but better safe than sorry..)
Positive plate facing towards T1 Emitter is one way for C2..
Quote from: Kevin Mitchell on April 03, 2024, 03:31:40 PMI feel like he did that just for me :icon_lol:
Ah, we've all been there! From one New Englander to another, "You walked right into it, bub...." :icon_lol:
Got snow? Time to plow, 6" on the ground here.
Quote from: Phend on April 03, 2024, 01:05:11 PMHere is an example
So has anybody else noticed that those caps don't need to be that big (high in value)?
Probably they wish to have peace of mind.. :icon_wink:
e.g. 1μF output cap could be 50 times smaller for infinite load (-3dB at 80Hz) but marginally OK for 2k load..
For 1uf, where space is an issue, you can sub MLCC or tant for film.
Hi there,
Some 17 years ago I answered in an interview for the Japanese Effector Book why I used Jamicon elkos considered consumer grade rather than the most expensive elkos at the time.
I do use elkos in signal path mainly because of the size of miniature elkos. In may ways the miniature elkos behave like tantals and therefore
They must not be reverse polarized or they can permanently turn into something completely different than a capacitor such as a combined resistor and semiconductor junction, which actually can be really interesting in transistor circuits. Reverse polarization less than a few percent of Voltage rating the mini elkos can recover from while back in the 70s and 80s elkos could be reversed polarized up to 35% of the DC voltage rating for reliable design. It was a consensus that tanks were just better and especially the metal cans.
1uF dip tantals were used in some 70s pedals eg MXR and copies and if we look at the time they were made and units working today they do have an impressive life span. I personally avoid using those because they are mechanically fragile.
Here in repair it is a good idea to check polarization in circuit because in some older electronics such often in commercial music electronics
elkos can by design be reverse polarised part time such as in oscillators where economics department saved on two components. Sometimes this capacitor hs a large voltage rating to ensure stability but not always.
Specifically on 1uF elkos those can be found in signal paths where they are exposed to reverse polarisation ( in many 70s designs) and it can then be a good idea to replace them with a non polarised capacitor.
An example can be budget and even mid priced mixer consoles typically with dual supplies.
Back in the 1980s there was a lot of discussion in electronics magazines about distortion of electrolytic capacitors specifically in mixer consoles and other studio equipment while not really in effects pedals.
When replacing with modern parts it would be advisable to take two elkos twice the value and connect the minus sides together and connect a large resistor such as 1M to most negative supply point to ensure polarisation-the operative being polarization so plus sides can be connected and and resistor to most positive point can be used whatever is convenient. This practice is found in older high end products and then modern miniature elkos can directly replace older elkos because polarisation is guaranteed.
Early sad ceramic capacitors 100nF and higher capacitance where subject to break down and they could randomly turn into low value resistor or a zener junction so they were banned a while from used in critical equipment nd in my personal experience I traced a breakdown in a 200W transistor power amp to an smd capacitor of 470nF decoupling a transistor in the differential stage- it is not the first thing you would expect in a havoced 200W CMOS output power amp.
In my work I have seen minielekos perform in-40C in the Alps and 80% humidity in Florida and at 45C and even recovered from being drenched by water as long as AC voltage does not reverse polarise life expectancy can be similar to tantals.
Older elkos can convert to noise generation and they can be easily spotted in repair with freezer spray as noise stops when the noisy part is freezed.
Yes disc ceramics especially larger values can become microphonic- a plain isolated wire with one end tied to ground can be wrapped around it at shield and mirophonics can be negliable.
Typically I use 500V Hitano ceramic discs and in values less than 1200pF, and they have shown excellent stability through decades but otherwise I avoid ceramic capacitors for low frequency signal chain maybe also because I would be a capacitor snob ;) You know sometimes parts just look cool:)
So for 1uF capacitors in signal path it is advisable to part from building size to look at polarization.Miniature elkos can have some distortion but considerably less than older types and not necessarily in a bad way either.
There are plastic types of 1uF that do not build higher than an IC in a socket but they are hard to find and often listed at minimum quantity 1000 pieces and waiting time two months. But Wima makes a 50V version 1uF that is couple of mm shorter than the 63V type that I can recommend.
But as long as sufficient voltage polaraisation is observed in my humble opinion miniature elkos are just fine and the ever so slight contribution to sound they make in my designs desirable.
.
Have fun
Bjorn Juhl
BJF Electronics
Sweden
Quote from: GibsonGM on April 04, 2024, 04:47:07 AMGot snow? Time to plow, 6" on the ground here.
Never trust a woodchuck
Quote from: Kevin Mitchell on April 04, 2024, 08:31:02 AMNever trust a woodchuck
:icon_lol: :icon_mrgreen: Mmm, just rolled up the yard with the plow truck...good times! Mud season 3 next week.
Snowing hard here in VT, power goes out then on then out / on.
Trees are bent over with heavy snow.
I like to put 1000uF caps right up front so when the power does go out the effect still keeps going,
but the amp doesn't, hum.
We will be able to see some of the eclipse here on Monday, heard you might be able to see stars / planets.
Wonder if we will be able to see the moon too ?
Here in the USA, there are easy stocks of 1uF film caps (Mouser) that have 5mm lead spacing, and are 7mm wide, 5mm thick, and 10mm tall. That is, not much more PCB space than a radial electrolytic. In fact, the availability of 1uF electrolytics has decreased a lot. The film 1uFs are not terribly expensive. Mouser lists 61 1uF caps in stock with lead spacing of 2.54, 5.0, and 5.08 mm lead spacing and 50 or 63 V rating. They're US$0.28 to US$0.40 in 10-unit quantities, down to US$0.18 to US$0.35 in 100's.
I use electros when I just need a big enough capacitance. I use only film when I need to actually specify a frequency rolloff or filter frequency.
I think the moon will be below the horizon at that time, but maybe (I'll have to go open my Adastra program which shows the orbits etc). We're in the totality path, so going to have some fun - wife's a photographer.
Got the cars off the lawn before the thaw - that was a real joy :) Gonna all melt back to mud...
Quote from: Phend on April 04, 2024, 10:45:27 AMWonder if we will be able to see the moon too ?
That would be the eclipse. The moon in front of the sun.
I heard VT is expecting some serious traffic for tourists to catch it. Some places (banks I've been told) are already planning to be closed.
In the last county in the US, a supermarket is changing brands, and planned to be closed for THREE DAYS to swap logos, specials, and POS software. As the population will be about 3X usual, and in a hungry holiday mood, I think this was a mistake.
Kinda alot off capacitors here but,,,
Will the dark side of the moon now be lite up ? So much for PF, lol.
What I want to see is star "light" in front of the moon.
The light that is bent by the gravity of the sun.
Ie the experiment long ago in Russia to prove gravity bends light.
As far as traffic, probably not different than that of a weekend at the ski hills.
Quote from: Phend on April 04, 2024, 10:45:27 AMSnowing hard here in VT, power goes out then on then out / on.
Trees are bent over with heavy snow.
View of the garage out the bedroom window--
(https://i.postimg.cc/cKddHJN2/Snow-4-Apr2024.png) (https://postimg.cc/cKddHJN2)
Snow?? Yikes! It's 80F today here. The ACs are running.
Central Texas is the same latitude as Morocco.
Quote from: R.G. on April 04, 2024, 07:03:45 PMSnow?? Yikes! It's 80F today here. The ACs are running.
Central Texas is the same latitude as Morocco.
Saw a very cool map recently that matched by latitude key European cities to key cities in the US & Canada, a real eye opener.
Quote from: Phend on April 04, 2024, 10:45:27 AMTrees are bent over with heavy snow.
Clear enough at dusk to see a Birch bent in a semi-circle, tip just touching the ground 24 feet over.
(https://i.postimg.cc/K1NJbbhc/vlcsnap-1.jpg) (https://postimg.cc/K1NJbbhc)
AND--- did you know you can carbonate Fireball? BigCliveLive "Fireball vs Sodastream. Will it carbonate?" (https://www.youtube.com/watch?v=6nWHpiTAVhY) Or do you not have Fireball that far west?
I ask about this once.
My rule is to use 1uF film cap. Bipolar electrolytic if is specified in the schematic.
In the 1590A box, if I don't have room enough, low size 1uF, when I had, but the shops I used to order dont' have them so much, now.
Can I use MLCC? Someone told me them are unstable because the temperature.
A few of days ago I read again something about "Temperature Characteristic". I guess, just in case of small boxes, a "X7R type" should be ok, afterall.
https://www.allaboutcircuits.com/technical-articles/x7r-x5r-c0g...-a-concise-guide-to-ceramic-capacitor-types/
Hi there,
Yes for extremely cramped space I have some Multilayer 1uF.There is a 5mm spaced one that is X7R and just 2mm thick.
Bjorn Juhl
BJF Electronics
Winter wonderland with duck trails, Santa did not bring me coal this year.
(https://i.postimg.cc/sMd2GXsw/20240405-065922.jpg) (https://postimg.cc/sMd2GXsw)
Much the same here, Paul...16" of white joy. Huge number of ppl without power. I am at my homestead with the wood stove happily burning, with 6 months of food and no worries, about to put together a FF from a couple of Ge's I managed to sort out 8)
Quote from: GibsonGM on April 05, 2024, 07:26:17 AMabout to put together a FF from a couple of Ge's I managed to sort out 8)
With the use of butane gas soldering iron, I presume.. :icon_wink:
I have a generator. But mainly use that for pumping water and keeping my food cold :icon_cool: So butane is not out of the question! Breadboard for right now.
My fellow New Englanders most certainly just felt that earth quake.
Honestly, I thought it was snow going off the metal roof. Just another 'thing'...I don't keep track anymore, TBH.
Walls were shaking a little bit at work here in Monroe county PA. Most people didn't feel it.
Quote from: Elijah-Baley on April 05, 2024, 02:43:58 AMa "X7R type" should be ok
XR7 is the only dielectric I have "heard". It is different, on MY ear, from all others. Not bad, would not mind on guitar. Does depend a LOT where it is--- if sized for 0.1Hz response it has about no effect on 82Hz, but in a phono preamp where it was sized for a heavy 50Hz (rumble) cutoff it sounded "colored".
XR7 seems to be the magic sauce in some extra-cheap but beloved guitar gear.
Quote from: Kevin Mitchell on April 05, 2024, 10:42:30 AMthat earth quake.
I used to live a few minutes away from that epicenter. What, every 100 years? I may have noted it this morning, but with all the utility trucks on the street it is hard to tell.
Quote from: Kevin Mitchell on April 05, 2024, 10:42:30 AMMy fellow New Englanders most certainly just felt that earth quake.
From friends near-enuff to the epicenter:
Quote from: SharonHoly $hit! Did we ever get an earth quake. I was sitting at the kitchen table, talking to Bill, and Man o Man! 4.7 on the scale.
Windows rattled, pictures came off the wall, pots and pans jingling. It sure was something. Bill says "Rock quarry?" I said "No, that's not the Quarry............ its.... its... an ....Earthquake! Of course the Dogs went nuts.
Quote from: RSWe just had a 4.0 aftershock! I was on the toilet...
(https://i.postimg.cc/S2S0KXSZ/McPhee.png) (https://postimg.cc/S2S0KXSZ)
Getting back to capacitors..
Why aren't Non Polarized aka BP caps used or specified more often in effect circuits?
I think size is a consideration (NP are larger?), and cost. The 'big dogs' trim every penny they can, and NP costs more per unit...I cannot think of any place you can't use a NP in place of polarized (maybe someone else can?).
For the EA Tremolo that calls of four 1uF caps I use BP.
Because I was unsure of which way + goes and film was to big, R.G. gives a good Mouser ref for next time.
Got 20 on Amzon for $8.
They are the same size as polarized. Small(ish).
I'd use 'em, no questions asked. Convenient...and you really aren't supposed to use polarized caps with AC. Y'know - since it's always changing :icon_lol: That hasn't hurt me any - I only think about DC voltages when using them - but still, it's just 'not right'.
Quote from: Phend on April 04, 2024, 05:18:12 PMWhat I want to see is star "light" in front of the moon.
The light that is bent by the gravity of the sun.
Ie the experiment long ago in Russia to prove gravity bends light.
Hi, that would be ace, but gravity lenses don't quite work like that. The light is bent as per a convex lens, so that something that would otherwise be behind the sun/moon would appear further out sideways, not in front. The effect is too small to detect with the naked eye sadly.