Please help identify a guitar circuit componant

Denny Turner · From: Oahu, Hawaii USA

I need help identifying a guitar's circuit componant. Racking my distant-past electronics memory I just can't remember what this is. It vaguely seems that it might be a ceramic resistor, but I can't see resistor color codes in it's color code. Any help appreciated. It's the square ceramic componant between the switch group and potentiometers ...above the orange wire, in front of the yellow wire, ...color code bottom to top red yellow black red (ceramic natural color on top) ...leads coming out of it's top corners, ...with toothpick pointing at it in this picture

Thank You,
Aloha,
Denny T~

[This message was edited by Denny Turner on 30 August 2006 at 03:19 PM.]

Gareth Carthew · From: West Sussex, UK

It's definatly a capacitor.

What it's value is right now I'm not sure.
It's late here (0025) and I'm just off to bed. Let me check out some old text tomorrow to find old capacitor colour codes and I'll see if I can help you out further.

Gareth

Bob Lawrence · From: Beaver Bank, Nova Scotia, Canada

From what I see it's a Cap. You can use the link below to input the colors and generate the value.

URL Updated

http://www.ee.unb.ca/thesis98/ee4000aj/

[This message was edited by Bob Lawrence on 09 September 2006 at 03:46 AM.]

Michael Brebes · From: Northridge CA

The first three colors (I'm pretty sure) represent the value in nanofarads. The first two (red and yellow) represent the two digit number, 24. The third (black) represents how many zeros come after the number, which is zero. So the value should be 24 nanofarads, or .024 microfarads. The fourth represents value tolerance. My guess is that it's a 20% tolerance.

Gareth Carthew · From: West Sussex, UK

So I didn't go to bed and had a quick check.

It's been a long time since I've worked with polystyrene capacitors but they do use the same colour code as resistors.

It's actually two red bands then yellow giving 2-2-4
220000pF or 220nF or 0.22uF

[This message was edited by Gareth Carthew on 30 August 2006 at 05:06 PM.]

Blake Hawkins · From: Florida

I agree with Gareth.
My "code" chart lists that as a
.22uf, 20% tolerance, 250 volt, polyester cap.

Jim Sliff · From: Lawndale California, USA

Yep.

I don't see many of those. What's it out of?

Michael Brebes · From: Northridge CA

Yep, you are correct about the value. The 0.22uF is a fairly standard value for tone control capacitor when using humbucker pickups.

Denny Turner · From: Oahu, Hawaii USA

THANK YOU, Gentlemen.

First, please pardon any typos, errors, brain-farts, etc; It's late ... long days ... and I'm quite fatigued but wanted to reply to your kind answers.

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The color code online engine is GREAT. Thanks Bob. It helps mitigate the aroma of my old brain farts

.

Here's what it reports for my cap in question:

.....ALTHOUGH notice that the resulting value is in a whole number uF ...not .24 or .024 as I would expect. Maybe that's what's meant by the engine's disclaimer "under construction ... don't rely on uF values".

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My previously not recognizing that there were two adjoining red bands on the cap is one of the things that threw me such a curve in trying to make sense of it's color code (Thanks for that clue Gareth) ...besides not having remembered at all that some caps color codes had a temp coefficient first band ...nor even being able to determine if it was a cap or odd resistor (*flies buzzing around my skull*). (Uncle Sam rapes our young soldiers but Violet......... nah, that don't work!).

So here's what I gather from the engine and your answers:

The color codes results from the online engine are in mf standard. So, digit 1 is the temp ce (-880x40C* ... more flies) .... and (Digits 2&3 ReYe = 24)x(digit 4 Bl = 0) = 24 mf ; ....digit 5 Re = 2% tolerance. I suppose that should be noted .24uF? (.024uF?).

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Assuming we've determined that the cap value is .24uF (.024?) :

Although I've finished the refurbishing and repairs of the guitar this cap is in, and am packing it for shipment to it's new owner, ...I am still perlexed about just how it's circuits work and won't be able to "rest" until "I" figure it out. As I do for some customers / jobs, ...I made webpages to keep the customer and advising techs apprised of progress.

Here is where the real brain-strain (for me) entered the picture:

Looking at the schematic I made we can determine that (1) the switching is not a simple pickups on/off switching logic, but is quite involved with routing pickups selected on/off with (2) pickup volume pots that are acting as balance controls turning up one side of each pot's pickup "hot-side" circuit(s) while turning down the other side of the pot's pickup "ground-side" circuits (and vs/vs) while switching / ganging multiple pickups in series and balancing the "hot-side" circuit of one ganged pickup with the adjoining "upstream" pickups' "ground-side" circuit). This guitar's circuits drove me crazy for awhile because at first I thought that since the "tone" knob / pot acted like a volume control it must indicate a short to ground on what would normally be the filter side of a tone pot circuit; BUT, after studying the schematic for a LONG time (refusing to unsolder original wiring on a vintage instrument for testing componants unless neccessary) I came to the conlusion that the "tone" knob/pot is not a tone control at all but is a Master Volume control for the 3 pickups and their switches and pots acting like a 3 band EQ for tone control. Once I came to that conclusion the switching and circuits started making some sense.

Even the Master Volume has a 2 sided balancing scheme feeding "ground-side" into the output jack's "hot-side". At any switching and/or volume settings, changes in the Master Volume setting keeps the "mix" of tone equal and balanced at all pickup switch and pot settings throughout the Master Volumes full range. Quite a feat of passive circuitry for a guitar and my old cloudy electronics theory memory (army elec tech 39 years ago)

.

I still haven't got a good mental picture of what the circuit does in all it's abstract of switching and CIRCUIT BALANCING going on in each pickup's volume (circuit balance) control circuits. I am assuming that the balancing scheme between any 2 pickups' ganged circuits are the same with switching putting the balancing circuit of each pickup in or out of the circuit; BUT then the obvious "humbucking" feature of the reverse magnet orientation in the neck pickup comes into question for seeking out the polyester capacitor's influence on the total switching / balancing scheme (Neck PU magnet is "S" up, Bridge and Middle "N" up).

I've also not quite got it in my mind what the cap in line with the Bridge pickup's "hot-side" is for. At .0015uF I would guess that it's part of a tone filter rolloff bypass scheme.

My next step is to draw simple schematics of the different switching, ...without the solder-point routing drawn in, ...and with the componants that are switched off eliminated from the schematic, ....and see what my old brain can see in a simpler schematic without the brain-load and distraction of tracing opportune solder-points and switched off circuits.

Michael's mention of .22 uF common in humbucking circuits might be a good clue to what this capacitor might be doing when the humbucking feature is switched into the guitar's circuits.

THANK YOU,
Aloha,
Denny T~

[This message was edited by Denny Turner on 01 September 2006 at 02:24 AM.]

Blake Hawkins · From: Florida

Denny, I have doubts about the Online engine.
Checking all my charts and references, I can't find any color coded caps with the temperature coef. in the first band.
In the picture, the cap is upside down,
so, reading from the top towards the leads,
we have: Red= 2 pf
Red= 2 pf
Yellow, multiplier= 10000
Black, tolerance= =/- 20%
Red, Voltage= 250 volts

So you have 220000 pf. Move the decimal
point 6 places to the left and you have
.22 uf.
Which, as Michael said, is a normal value for a cap in such service.
Another indication that the engine is wrong, is that the value is given "24 mfd."
Caps in that range are generally electrolytic or tantalum much larger physically than your cap.
Also 24 mfd would be way too much capacity to work in a guitar tone circuit.
In standard color code, red,yellow, black would be 24 pf, not mfd (uf).
Another problem is "2% tolerance."
We're talking lab grade, expensive caps here.
So, I don't know where the author of that engine got his info, but it is not for consumer grade caps.
Blake

[This message was edited by Blake Hawkins on 01 September 2006 at 06:15 AM.]

[This message was edited by Blake Hawkins on 01 September 2006 at 06:16 AM.]

Gareth Carthew · From: West Sussex, UK

Agreed. I've not seen caps with coefficent first either.

Another thing to be wary of especialy when scouring the net for information...

I've seen many times on a whole whost of different amateur websites people incorrectly abreviating Microfarads to mF.
Which would actually mean millifarads.

It obviously comes from misunderstanding the alternative abbreviation mfd. Which is why generally you'll see uf.

Just be aware there is alot of misinformation out there.

[This message was edited by Gareth Carthew on 01 September 2006 at 07:32 AM.]

Denny Turner · From: Oahu, Hawaii USA

THANK YOU again, Gentlemen.

The importance to me, of figuring out this guitar's circuit is that after long searches I cannot find any archive providing any relative info on this guitar's circuit; And it's darn sure not like any other Danelectro nor other guitar I've ever encountered ...unless I'm seeing it much more complicated than it actually is. In any event I think it important to archive.

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The info below is gleened from what I could find about color banded-or-dotted capacitors. Searching online brings up quite a bit of scewed / conflicting / erroneous / etc. data, so I had to comb and assemble data online and info in this discussion as correctly as I could suppose from old memory and what made the most sense. Please correct any errors herein:

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Resistor / Capacitor color-number code:
Black 0, Brown 1, Red 2, Orange 3, Yellow 4, Green 5, Blue 6, Violet 7, Gray 8, White 9.
(bad boys ravish our young girls but violet glows willingly) (in words suitable for all viewing).

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Here is what seems to me to be the 2 most congruent methods of color code applied to capacitors:

METHOD 1:

(Source: Integrated Publishing; Publishers of technical courses geared for military contractors).

(Color bands said below can also be color dots common on the rectangular molded caps, in several different schemes):

Capacitor color codes commonly have 2 value-number bands followed by a multiplier band follwed by a tolerance band. HOWEVER, it's not uncommon to have up to 3 temperature performance info bands (depending upon which of 3 systems is used) preceeding the numerical value bands (or shown after the tolerance band in other methods listed further below); SO, determining the value & multiplier using this Method 1 must be found backwards from the tolerance band that could have up to 3 temp bands preceeding the value / multiplier bands.

Tolerance color code: brown = +/-1%, red = +/-2%, grn = +/-5%, black = +/- 20%, white = +/- 10%.

Finding value code bands (since they can be preceeded by temp performance bands): Going backward from the tolerance band, the three bands to the left of the tolerance band denote the cap's value (2 value bands x multiplier band) in pF.

So in the case of my capacitor in question, we have 5 bands: Red, Red, Yel, Blk, Red;

Which to me translates as a red temp code, followed by 3 value bands (Red2 Yel4 x Blk0 = 24pF), followed by a Red tolerance of 2%; = 24pF with a 2% tolerance

If Method 1 is correct for this capacitor, then I don't think it would have been unusual for Nate Daniels / Danelectro to have purchased a best-price batch that just happened to have a 2% tolerance IF a 2% tolerance was even built into this type of capacitor, ...and if it would not have been then it would indicate that Method 1 is not the method to use. Best price surplus / salvage batches were common in Danelectro componant batches without unduely compromising quality of the intended use; Voila discovering that lipstick tubes worked excellent for pickup casings when the tape-wrapped-wad pickups came out from under the pickguard in 1955. Big brown square-ish blob shaped or black or green tube shaped capacitors are most common in original-vintage Danelectro guitars (in addition to the small round ceramic cap(s) that would also be present in their guitar circuits). Due to the unique nature of this discussion guitar's circuit, my old foggy memory wasn't sure that it was a capacitor until asking this forum.

METHOD 2:

Source which is congruent with other similar info & charts, this one laid out pretty good.

Basicly the same as Method 1 but ambiguous in the placement of a 5th band and whether it is voltage or temperature performance. (Seems that the 2 different temp or voltage code bands depend upon the type of capacitor?).

In any case of Method 2, my caps color bands would be Red2, Red2, x Yel10000 = 220,000 pF = .22uF, with a tolerance of +/-20% and temp figure of -80 (-800ppm / degree C adjusted for standard day 10 degrees C ?). Notice that "my" capacitor's black band would not apply to the color system that includes voltage rating.

NOTE:

I have not found any specific color code reference for the type, shape nor color code orientation of "my" capacitor we're discussing.

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Continuing:

1 mili Farad (mF) = 1/1,000th or 0.001 Farad (10^-3).

1 micro Farad (uF) = 1/1,000,000 or 0.000001 Farad (10^-6 ).

1 nano Farad (nF) = 1/1,000,000,000 or 0.000000001 Farad (10^-9 ).

1 pico Farad (pF) = 1/1,000,000,000,000 or 0.000 000 000 001 Farad (10^-12 ).

Results for previously said Method 1:
24 pF (.000000000024 F) would require moving (or removing) 6 decimal places (10^+6) to convert to uF; = .00024 F = .24uF.

Similar results for previously said Method 2 = .22uF.

Since the tolerance nor temperature performance seems critical at all, then the only important question is whether this cap is .22 or .24 uF ...and what method of determining that (and the other bands) is correct.

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Now the task remains for me to disect the scematic of it's merely-opportune solder points on componants and re-draw it into simpler 1 and 2 pickup versions to try to determine how it works; UNLESS someone here can see and explain what functions the pickup volume pots (and Master Volume pot) are controlling in their 2-sided balancing scheme; ...upon which the switching logic should become more fully apparant beyond simply ganging the pickups.

I'm also quite interested to see IF the pots have any balancing function going on between a combined series and parallel wiring scheme of the neck pickup's reverse magnet orientation (obviously for a "humbucking" effect). ~~~~~~~ In that vein, the Dano pickup leads are not color coded but a small knot tied in one of the 2 black leads as they exit the shielding sleeve in the electronics compartment; And before packing the guitar for shipment, I didn't have the foresight to wand the neck pickup with a screwdriver shaft to read the output with a meter to see whether or not the coil was reverse wound (not required but commonly thought to be required back then) or if they just flipped the taped coil/magnet wad over in the lipstick tube and reversed the leads (which is what I do to create Dano humbuckers); So I have no way to provide that info now.

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THANKS A MILLION for helping figure all this out; It's much appreciated; I look forward to learning more from you. This circuit will nag me for some time if I don't figure it out; And I'd rather it not nag me, and would rather have correct info to archive for others to use.

Aloha,
Denny T~

[This message was edited by Denny Turner on 02 September 2006 at 08:02 PM.]

Blake Hawkins · From: Florida

Denny,
The second chart you came up with does say
"military" please note that in my previous post I specified consumer.
There are many different ways to mark a cap.
However, the one you have, has a color code which I first saw in the late '50's or early 60's.
I have a code chart with your specific type of cap shown.
I will scan it in the next few days and mail it to you.
To correctly determine a component you have to not only read the code but also take into consideration the physical appearance.
Since the advent of computers we have caps that look like resistors, resistors which look like caps and diodes which look like both.
In the years when most components were made in the US and the manufacturers were all members of the RMA and later the RETMA
component id was fairly easy. Once the Far East and the Europeans started sending stuff over here that all changed.
By the way, I read your documentation on your web site and it is excellent.
Congratulations on your fine craftsmanship and the ability to present it.
Blake

Denny Turner · From: Oahu, Hawaii USA

Gentlemen,

First, ...Thank You for your input ...and to those who contributed in private emails, ...which not only helped find the right answers, but helped challenge and wake-up my old brain to a few things it had long ago forgotten.

Notice that regarding the capacitor in question, the key to deciphering it's type and value was in using the correct (consumer grade) color code system ...and noticing that there are several different color code classes / systems / schemes / etc. whose charts can be misleading and downright erroneous if we use the wrong system / code for a given componant. Much Thanks to Blake who was able to find / provide proof of the correct code for the capacitor; ...especially ones that we might not be currently familiar with.

Not wanting to leave a discussion hanging, here are the findings and finished product for the discussion / archive, ...just in case it might help someone searching for related info in the future.

Aloha,
Denny T~

[This message was edited by Denny Turner on 08 September 2006 at 11:01 PM.]

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