What are these?

[O]

I've seen resistors before, but nothing like these. Anyone have any ideas?



I know the round, light blue ones are tantalums and there's a diode and some caps in there... but the resistors? What about the square caps? anyone have a "cross-reference" to see what the numbers mean?

[Steben]

Hmm... what's wrong with the caps? mybe you're confused with the Euro way of notation. There are some nice conversion tables on the net form Euro to US notation, but I can't remeber where. Someone will surely know around here. Guys?

Anyway: In brief:
1µ = "1.0"
1n = "0.001"
1p = "0.000001"

I don't know what to say about the resistors? Try some color decoding.

[O]

If it helps at all, this is a H&k Red Box HKII... so German resistors might be different? :?

[JHS]

R = STD. 5-band code - 6 = tolerance
C = self healing metalfilm caps - STD. coded

1uK200 = 1 uF - 5%tol  - 200V DC
1nK400 = 1 nF - 5%tol  - 400V DC

JHS

[O]

So I should read the colors "after" the red band? :?

[puretube]

the last red = 2% (metalfilm res)

edit: I stand corrected - always something left to learn....

[O]

Hmm... ok, I think I've got it...

--[|Y|V|B|O|C|R|]--

Yellow
Violet
Black
Orange
Copper <-- Self Healing
Red      <-- 2% Metalfilm

(I'm talking about the resistor between the 2 1/4 jacks). Am I close?

[bobbletrox]

what pedal is that by the way?  It looks interesting

[JHS]

5 band resister coding ?

Go to Aikenamps.com -> tech info -> resister color codes.

The fat band is the tolerance.

Caps are from the VALVO comp.

JHS

[O]

what pedal is that by the way?  It looks interesting

It's a Hughes & Kettner Red Box HKII... I've been on a quest to build one, and it seems that this one is easier to build than the RedBox Pro.

JHS, thanks for the info... you've been a lot of help.

(I just noticed a resistor hidden behind the jack on the right... anyone with guesses what value it might be? I'm thinking that I should just go out and buy one of these boxes

[RLBJR65]

Check this out, 4,5 or 6 band resistor calculator.
http://samengstrom.com/elec/resistor/6band.html

[O]

Check this out, 4,5 or 6 band resistor calculator.
http://samengstrom.com/elec/resistor/6band.html

Whoa! That is one COOL page!!!
Thanks!!!

[niftydog]

you'll eventually just get a "feel" for which end to start reading the bands from, until then it can be frustrating.

Look really closely, usually the temperature coefficient band has a larger gap between it and the rest of the bands.

4 band;
two significant figures, one multiplier and a tolerance.

5 band;
three significant figures, one multiplier and a tolerance.

6 band;
same as 5 band, but add a temperature coefficient band.

Anything with a yellow temp co and a purple tolerance is bitchingly fantastic quality! 25ppm @ 0.1%!

The caps are just as you see them. 1n = 1nF etc. the number on the end is the voltage rating.

[Gilles C]

I once wanted to make a schematic based on the pcb, and I seem to remember I read somewhere that it was supposed to be the same configuration than the Cream Machine. But I never had time to check that.

http://www.amptone.com/images/schem_cream.gif

Btw, nice info page about 6 band color codes. It helped me find the following.

I checked on my pcb and the partially hidden resistor has the same value as the one close to it: 10K 1% 50 PPM/oC, Brown, Black, Black, Red, Brown, fat Red. All resistors have the same temp coeff (fat Red bar).

The 3rd one close to them is a 470K, and the one close to the red wire is another 10K.

Good luck,

Gilles

[O]

Thanks for the additional info, Gilles. I'm trying to get it all drawn out with the pics you sent. I was actually trying to build the RedBox Pro, but the problem is locating the transformer.

I hope you're able to check back to this thread when you can; in case someone has a question about the box.

[Gilles C]

I sent you an updated pic with the resistors and some caps values added.

One thing I'm not sure is the values of the 3 small caps identified n22 and n10.

Does anyboby knows for sure if it's for 22nF and 10nF?

I will try to add more when time permits.

But being on vacation for the next 3 weeks means that I should be away from home most of the time. And I'm sure that my wife will be glad if I stay away a bit from electronics the following days.

Gilles

[niftydog]

small... as in those ceramic monolythic types? (yellow and purple ones in top right of O's photo?)

My money is on 220pF and 100pF. The 'n' acts as a decimal point.

[Gilles C]

Yes, the 2 yellow and the purple ones.

Yeah, I think you could be right.

That's the feeling I had about one of the blue caps identified u1J100 while another one is identified as 22nK250 for example. It could be a .1 uF (or a 470nF)

So the 220pF and 100pF values would be correct. I didn't see it as clearly that time.

Thanks niftydog.

We (me and my wife) decided to do a quick 1 day trip today, and come back home tonight to be able to go to Ottawa and maybe to go south to US a little bit this week.

So beeing at home tonight permitted me to work a bit on the circuit.

Having the pcb out of the box, I might as well help O with his project when I can (or when I'm home).

Gilles

Added: a cleaner scan of the layout, and what I think is the correct layout. I had to clean the flux with some solvant to be able to see some traces...

http://www.finitesite.com/gtechblues/Files/Scan.jpg

http://www.finitesite.com/gtechblues/Files/Traces.jpg

http://www.finitesite.com/gtechblues/Files/Scan1.JPG

One is upside-down

[domenico]

hey , why don't you post a picture of the trace side of the circuit ? we could make a schematics out of this ! thanks!
domenico

[domenico]

oooopsss!!! )
thanks!